What is Delta 3D Printers New Hacks 2019
The most fascinating three-dimensional (3D) printer design to watch print is the delta printer. The delta design is quite different from most 3D printers and is best known for its vertical orientation and relatively small footprint (although larger units can be quite tall).
This blog explains the new hacks for the 3D printer and describes how to make a 3D printer with various best affordable 3d printers. This blog explores how delta 3D printer works.
A delta 3D printer, hence delta printer, is a type of parallel robot that uses geometric algorithms to position each of three vertical axes simultaneously to move the nozzle to any position in a cylindrical build area. Thus, when the printer is printing, all three axes move in a mesmerizing ballet of mathematical magic.
If all this sounds too fantastic, don’t worry; Before we jump into how the hardware mechanisms work, let’s take a short tour of what 3D printing is all about. A firm understanding of the concepts of 3D printing is essential to getting the most out of your 3D printer investment.
Even if you are already a 3D printing enthusiast (and especially if you have never used a delta printer), you may want to read the following sections because I present the material with delta printers in mind.
How to make a 3D Printer
The world of 3D printing is growing in popularity as more people find creative ways to use 3D printers. People buy 3D printers for creating solutions for the home, gifts, artistic expression, and of course, for rapid prototyping of components for manufacture.
I have even seen 3D printers used in architectural firms to replace the somewhat tedious art of 3D modeling—from scale models of buildings to elaborate terrain maps.
The major contributor for this expansion is that 3D printers are getting easier to find and afford. While far from the point of finding a 3D printer in your local small retailer or as a bonus for buying a new mattress, you don’t have to look very far to find a 3D printer manufacturer or reseller. Even printing supplies are getting easier to find.
In fact, some of the larger retailers such as Home Depot are starting to stock 3D printers and supplies. For some time now, MakerBot Industries has sold their products on the Microsoft online store, as well as at their own retail stores. Similarly, other 3D printer suppliers have opened retail stores.
Naturally, nearly all 3D printing retailers have an online store where you can order anything from parts to build or maintain your own, to printing supplies such as filament and other consumables. So the problem that you are most likely to encounter is not finding a 3D printer, but rather it is choosing the printer that is best for you.
Unless you have spent some time working with 3D printers and have mastered how to use them, the myriad of choices may seem daunting and confusing.
I have encountered a lot of people who, despite researching their chosen printer, have many questions about how the printer works, what filament to use, and even how to make the printer do what they want it to.
Too often I have discovered people selling their 3D printer because they cannot get decent print quality, or it doesn’t print well, or they don’t have the time or skills to complete the build, or they have had trouble getting the printer calibrated. Fortunately, most of these issues can be solved with a bit of knowledge and some known best practices.
This section will help you avoid these pitfalls by introducing you to the fundamentals of 3D printing with a specific emphasis on delta printers. You will learn that there are several forms of 3D printing and be provided with an overview of the software you can use with your printer. You will also learn about the
Consumables used in 3D printing, including the types of filament available. To round out the discussion on getting started, I present a short overview on buying a delta printer, including whether to build or buy and what to consider when buying a used printer.
What is 3D Printing?
Mastering the mysteries of 3D printing should be the goal of every 3D printing enthusiast. But where do you find the information and how do you get started?
This section presents the basics of 3D printing, beginning with the process of 3D printing and followed by a discussion on how the printer assembles or prints an object, and finally, it takes a look at the consumables involved in 3D printing.
The 3D Printing Process
The 3D printing process also called a workflow, involves taking a three-dimensional model and making it ready for print. This is a multistep process starting with a special form of the model and software to break the model into instructions the printer can use to make the object.
The following provides an overview of the process, classifying each of the steps by software type.
An object is formed using computer-aided design (CAD) software. The object is exported in a file format that contains the Standard Tessellation Language (STL) for defining a 3D object with triangulated surfaces and vertices.
The resulting .stl file is split or sliced into layers, and a machine-level instruction file is created (called a .gcode file) using computer-aided manufacturing (CAM) software.
The file contains instructions for controlling the axes, the direction of travel, the temperature of the hot end, and more. In addition, each layer is constructed as a map of traces (paths for the extruded filament) for filling in the object outline and interior.
The printer uses its own software (firmware) to read the machine-level file and print the object one layer at a time.
This software also supports operations for setting up and tuning the printer. Now that you understand how a 3D printer puts the filament together to form an object, let’s take a look at how the object is printed by the printer.
How an Object is Printed
It is important to understand the process by which objects are built. Knowing how the printer creates an object will help you understand the hardware better, as well as help you tune and maintain your printer.
That is, it will help you understand topics such as infill, shells (outer layers), and even how parts need to be oriented for strength.
The process is called additive manufacturing and is used by most 3D printers available to the consumer. Conversely, computer numeric control (CNC) machines start with a block of material and cutaway parts to form the object. This is called subtractive manufacturing.
Both forms of manufacturing use a Cartesian coordinate system (X, Y, and Z axes) to position the hardware to execute the build. Thus, the mechanical movements for 3D printing are very similar to the mechanisms used in CNC machines.
In both cases, there are three axes of movement controlled by a computer, each capable of very high-precision movement.
Additive manufacturing has several forms or types that refer to the material used and the process used to take the material and form the object. However, they all use the same basic steps (called a process or workflow, as described earlier) to create the object.
When a 3D printer creates an object, the material used to print an object comes in filament form on a large spool to make it easier for the printer to draw material.
The filament is then loaded into an extruder that has two parts: one to pull the filament off the spool and push it into a heating element, and another to heat the filament to its melting point.
The part that pulls the filament and feeds it to the heating element is called the cold end, whereas the heating element is called the hot end. Sometimes manufacturers refer to both parts as the extruder, but others distinguish the extruder from the hot end (but they sometimes don’t call it a cold end).
Delta printers typically separate the parts with the first part fixed to the frame and the second on the axis mechanism (called the effectors). Just one of the many nuances to 3D printing I hope to explain!
Delta Printer Hardware
The Delta 3D printer design, despite the radically different axes arrangement, uses the same basic hardware as a Cartesian printer.
The hardware and materials used to construct delta printers vary greatly, despite some fundamental concepts. You can find printers that are made from wood, others constructed with major components made from plastic, and some that are constructed from a sturdy metal frame, but most will be made using a combination of these materials.
Not only do the materials used in constructing the frame vary, so do the mechanisms used to move the print head and extrude filament, but not nearly as much as the frame.
A delta printer is a special type of machine called a robot. You may think of robots as anthropomorphic devices that hobble around bleeping and blinking various lights (or bashing each other to scrap in an extremely geeky contest), but not all robots have legs, wheels, or other forms of mobility.
Indeed, according to Wikipedia, a robot is “a mechanical or virtual agent, usually an electro-mechanical machine that is guided by a computer program or electronic circuitry”. As you will see, delta printers fit that description quite well.
The following sections introduce the hardware as follows: the hardware used in extruding plastic (extruder or cold end and the hot end), delta arms, axes, types of electric motors used, build platform, electronics, and finally, the frame. Each section describes some of the variants you can expect to find, and some of the trade-offs for certain options.
The extruder is the component that controls the amount of plastic used to build the object. On a delta printer, the extruder is normally mounted in a fixed position on the frame6 (also called the cold end) and connected to the hot end via a Bowden tube.
I have seen at least one delta printer that mounted the extruder on the effector, but that design is an exception because the goal is normally to reduce the weight of the effector, delts arms, and a hot end to allow for faster movement.
When the hot end is at the correct temperature for the filament used, the extruder pushes the filament through the Bowden tube, and as the effector is moved, the plastic is extruded through the nozzle.
The hot end, if you recall, is responsible for accepting the filament fed from the extruder body, and heating it to its melting point. You can see one of the latest hot-end upgrades for 3D printers.
This hot end can be used with higher heat ranges and provides a very good extrusion rate for PLA, ABS, and other filaments. Notice the fan and shroud. This hot end, like most all-metal hot ends, must have a fan blowing across the cooling fins at all times. That is, the fan is always running.
There are dozens of hot end designs available for 3D printers. This may seem like an exaggeration, but it isn’t. My research revealed several sites listing 10 or even 20 designs. The site that seems most complete is at of the more than 50 hot ends listed—and this list is a bit out of date because there are even more available.
With so many hot-end designs, how do you know which one to choose or even which one is best for your printer, filament, and object design choices? Fortunately, most hot-end designs can be loosely categorized by their construction into two types: all metal and PEEK body with PTFE (polytetrafluoroethylene) liner.
There are some exceptions, like an all-metal design with a PTFE liner; but in general, they either are made from various metals, such as brass for the nozzle, aluminum for the body (with cooling fins), and stainless steel for the heat barrier or use a liner of some sort.
The most popular PEEK variant is called a J-head hot end. Most delta printers come with either an all-metal hot end or a J-head hot end.
The earliest form of vertical delta printer axis mechanisms used a pair of smooth rails with linear roller bearings, brass bushings, or even bushings made from Nylon or PLA (and thus printed).
While this solution results in a very secure mechanism, rods can be more expensive, depending on the quality of the material.
That is, precision ground smooth rods may be too expensive and a bit of overkill for most home 3D printers. Cheaper drill rod quality items may be much more economical. In fact, you can often find lower prices for drill rods if bought in bulk.
In addition, the linear bearings can be expensive too. Even if you use printed bearings or less expensive bushings, smooth rods have an inherent problem. The longer the rod, the more likely the rod will have a slight bend or imperfection that causes the carriage to ride unevenly, which is transmitted to the effector.
While this is not a serious problem unless the bend is significant, it can result is slightly lower print quality. You can check this easily by rolling the rods on a flat, smooth surface looking for gaps between the rod and the surface.
Another disadvantage of smooth rods is that the frame formed by the rods is not stiff enough and can twist unless braced with wood or metal supporting framework. Thus to get the frame stiff enough to remove flexing, you end up with a much bulkier frame with more material.
Linear rails are much more rigid than smooth rods. Linear rails use a thick 15×10mm steel bar with grooves milled on each side. A carrier is mounted on the rail, suspended by a set of steel ball bearings (most use recirculating arrangements, but some versions use linear ball bearings).
The rail is drilled so that it can be mounted to the frame rail using a number of bolts. Linear rails are very rigid and can provide additional rigidity to the frame of a delta printer.
This is advantageous for the Kossel Pro because it uses the same 1515 extrusions as the Mini Kossel, which can flex if used in longer segments. The linear rails help stiffen the frame greatly.
Notice that there is an additional carriage that mounts to the linear rail carrier. The added complexity is the delta arm mount point positioned farther from the frame rail than the smooth rod version. This only means the offset is a bit larger, but otherwise isn’t a problem.
Linear rails are also very precise and do not require any adjustment other than periodic cleaning and a small amount of lubrication. However, linear rails are the most expensive option among the popular options for delta axis mechanisms. You can get linear rails in a variety of lengths.
An alternative to the expensive linear rods is the use of Delrin-encased bearings that ride in the center channel of an aluminum frame extrusion. Some solutions use Nylon rollers. 3D printer enthusiasts have also had success using hardware-store-quality shower and screen door rollers.
Notice that there are four rollers (two in the front, two in the rear). The pair of rollers on one side is fixed, and the pair on the other side use concentric cams to allow adjusting the tension of the rollers. Also, notice that the roller carriage is larger than the linear rail.
Indeed, the linear rail is mounted on the inside of the frame rail, leaving the sides and rear open; whereas the roller carriage requires the use of both sides, as well as the inside of the frame rail. This limits the types of attachments that you can use on the frame.
While this solution is a lot cheaper (perhaps by half), it is harder to set up because the rollers must be adjusted so that they press against the rails with enough tension to prevent the carriage from moving laterally or rotating, and yet not so much as to bind when moving along the channel.
I have found that the rollers need adjusting periodically and can be affected by environmental changes. This is made worse by carriages made from materials such as wood. Thus, while linear rails need occasional cleaning and lubrication, roller carriages require more frequent adjustment.
They may or may not need periodic lubrication but that depends on whether the roller bearings used. Since delta printer axes are vertical, cleaning the channel isn’t normally an issue but is something you should inspect from time to time.
Recall that each axis is connected to the effector via a carriage and a set of parallel arms (delta arms). The delta arms of most new delta printers are either 3D printed, injection molded or assembled from joints glued to carbon fiber tubes.
There are several types of rod ends that are used. These include ball ends (e.g., Traxxas), concave magnets with steel balls (or similar), 3D printed or injection-molded joints, and joints with captured bearings. Except for the magnet option most delta printers include one of these types of rod ends.
For example, the Mini Kossel design typically uses the Traxxas rod ends, the SeeMeCNC printers use injection molded parts (arms and joints), and the Kossel Pro uses injection molded parts with captured roller bearings.
The original Rostock and variants typically have printed arms. The Rostock Max v2 and Orion have injection-molded arms. The Kossel Pro, OpenBeam Kossel RepRap, and many Mini Kossel kits have carbon arms made with carbon fiber tubes. I have seen some examples with threaded rods, but these tend to be pretty heavy and may limit movement speed.
A stepper motor is a special type of electric motor. Unlike a typical electric motor that spins a shaft, the stepper is designed to turn in either direction a partial rotation (or step) at a time.
Think of them as having electronic gears where each time the motor is told to turn, it steps to the next tooth in the gear. Most stepper motors used in 3D printers can “step” 1.8 degrees at a time.
Another aspect of stepper motors that makes them vital to 3D printers (and CNC machines) is the ability to hold or fix the rotation. This means that it is possible to have a stepper motor turn for so many steps, and then stop and keep the shaft from turning.
Most stepper motors have a rating called holding torque that measures how much torque they can withstand and not turn. Four stepper motors are used on a typical delta printer. One each is used to move the X, Y, and Z axes, and another is used to drive the extruder (E axis).
The build platform or build plate (sometimes called print bed) can be made from glass, wood, Lexan, aluminum, and composite materials. Glass is the most common choice.
It is to this surface that the first Electronics. The component responsible for reading the G-codes and translating them into signals to control the stepper motors is a small microcontroller platform utilizing several components.
Most notably is the microprocessor for performing calculations, reading sensors (endstops, temperature), and controlling the stepper motors. Stepper motors require the use of a special board called a stepper driver. Some electronics packages have the stepper drivers integrated, and others use pluggable daughterboard’s.
Most delta printers use a commodity-grade electronics board (RAMPS, Rambo, etc.). The most common choice for smaller delta printers such as the Mini Kossel is RAMPS, which uses an Arduino Mega, a special daughterboard (called a shield) , and separate stepper driver boards.
The electronics board is where you load the firmware, which contains the programming necessary for the printer to work. This is either a variant of Marlin (Mini Kossel, Kossel Pro) or Repetier-Host (Orion, Rostock Max v2). As discussed previously, this source code is compiled and then uploaded to the electronics board.
Now that I have discussed the axes and how they are moved, as well as the electric motors that move the component, the extruder, the hot end, the build platform used to form the object, and the electronics, it is time to discuss how a frame holds all these parts together
Delta printers share a common design for the frame. While there are some differences in how the top and bottom portions are constructed and that there are several types of materials used, most designs use metal beams (sometimes called rods) or aluminum extrusions for the vertical frame components.
I have seen at least one design that used an all-wood frame, but that was a custom design and not a popular choice.
Recall that the delta printer has a base that secures the build platform, steppers for the axes, as well as a top section that holds the idler pulleys for the axes. Most designs incorporate the electronics, power supply, and other electronics in the lower section.
While the vertical axes use aluminum extrusions, the choice of frame material can vary among delta designs. The best frames are those that are rigid and do not flex when the extruder is moving or when the printer moves an axis in small increments. As you can imagine, this is very important to a high-quality print.
Some printers, such as the Mini Kossel and Kossel Pro, use the same aluminum extrusions to form the base and top of the printer. The Mini Kossel uses printed vertices bolted to the extrusions. The Kossel Pro uses aluminum vertices bolted to the extrusions. While both form very stiff components, the Kossel Pro is noticeably stiffer.
In this section, I present three popular delta variants that represent excellent examples of good delta printers. Here I present more information about each printer, including its capabilities, and a short review.
Keep in mind these are only three examples of delta printers. While there are many others available, most are some variant of a Rostock or Mini Kossel. Thus, these printers represent what I consider the best examples of delta printers available.
SeeMeCNC Rostock Max v2
The Rostock Mac v2 is an iteration of the original Rostock by Johann C. Rocholl, manufactured and sold by SeeMeCNC. The most significant aspect of this variant is the massive build volume. You can print objects up to 1300 cubic inches of build volume (an 11-inch diameter and a height of 14-3/4 inches).
Indeed, with a spool of the filament on the top-mounted spool holder, the printer itself is over 4 feet tall—presenting a very impressive profile.
I mentioned previously that the printer is constructed using laser-cut frame pieces bolted to large aluminum extrusions for the axes. However, the printer also uses injection-molded delta arms, joints, carriage mounts, and effector.
There are also Lexan panels covering the upper and lower axis towers, making the overall package clean and modern looking.
The Rostock Max v2 comes in kit form only. It is a nontrivial build given the number of parts and the moderately complicated hot-end assembly. Soldering, mechanical, and general electronics skills are required. That is, you should be familiar with using crimping tools, stripping, and soldering wires.
Although that may sound challenging, and it can be for those who have never built a 3D printer, SeeMeCNC provides a detailed, lengthy assembly manual with all the steps explained in clear language and reinforced with photos. I printed the manual so that I could make notes, and I was impressed by the size of the manual. It is very well done.
SeeMeCNC also hosts one of the best user forums I’ve seen forum.seemecnc.com/. If you get stuck or have questions, one visit, and a short query later, you will have your answers. Furthermore, the customer and technical support are also among the best in the business, easily overshadowing the larger vendors.
For example, I made a mistake assembling one of the Lexan panels and managed to break it. SeeMeCNC sent me a new one the very next day and I received it only two days later. It doesn’t get better than that.
Calibration is easy and the manual makes the steps very simple. In fact, SeeMeCNC uses macros to help set the endstops and calibrate the axes. The hot end has operated flawlessly without extrusion failures or extraneous artifacts, and mechanical noise is moderate. It just works.
This printer has everything you need for great-looking prints. The only thing I found missing is an auto bed leveling (Z-probe) feature. However, I found there was no need for this, as the print surface is very flat with no visible imperfections. Indeed, when testing the maximum build diameter, I found that the hot end tracked evenly across the entire print bed.
To understand this significance, consider that I have spent countless hours tuning and adjusting print beds on other printers, whereas the Rostock Max v2 was dead-on without any bed adjustment whatsoever!
In fact, I found the Rostock Max v2 to be a high-quality, professional-grade delta printer (despite the kit factor). If you need a delta printer with a large build volume and you can handle the assembly, the Rostock Max v2 will provide many hundreds of hours of reliable printing.
The Kossel Pro is a consumer-grade edition of the Mini Kossel made by OpenBeamUSA and sold by MatterHackers (matterhackers.com/store/printer-kits). But it is much more than that. The printer is of very high quality and in all ways is a step up from its RepRap Mini Kossel ancestor.
Interestingly, OpenBeamUSA also offers a lower-cost version called the OpenBeam Kossel RepRap, which is a smaller version of the Kossel Pro that uses more plastic parts and fewer specialized parts.
However, the OpenBeam Kossel RepRap shares many of the same parts as the Kossel Pro and it can be upgraded to the Kossel Pro with the purchase of an upgrade kit. Both printers are sold in kit form.
The most significant feature of this printer is the frame. As I mentioned previously, it uses the same OpenBeam 1515 aluminum extrusion that is popular with the Mini Kossel, as well as milled aluminum vertices and linear rails.
There are very few plastic parts, all of which are high quality and injection molded. Another impressive feature is the effector, which incorporates a Z-probe, an always-on fan for the hot end, two part-cooling fans, as well as an LED light ring.
At first glance, this printer has all the most-requested features. Indeed, the Kossel Pro has an impressive list of features, as follows. The only thing I found oddly missing is a spool holder—there is not even amount. However, due to the origins of the OpenBeamUSA components, it isn’t hard to find a spool holder that works.
Despite that this printer comes only in kit form, the build is very easy. In fact, one of the objectives of OpenBeamUSA is to make the printer easy to build quickly. This is achieved by using only bolt-on or plug-in wiring and components.
In fact, the main wiring harness for the hot end, Z-probe, and light ring use a single wiring bundle with molded connectors eliminating the need for any soldering. Furthermore, most of the tools you need are included in the kit.
The Kossel Pro and OpenBeam Kossel RepRap are very new designs and are only just now moving from Kickstarter funding to full-on production. Thus, some things are still evolving and may change slightly.
Fortunately, many of the minor issues in the first run of production kits have been solved. There is a small army of eager enthusiasts sharing the latest information about the printers.
Unlike the Rostock Max v2, there is no fine adjustability in the axis (i.e., endstops). This is partly because the assembly requires precise placement of the components during the build, and bolstered by superior- quality components and auto bed leveling (Z probing).
However, I would have liked to dial-in the tower calibration rather than relying on auto bed leveling for any minor imperfections.
In using this printer, I found the mechanical bits superb examples of what printers should strive to be, but the print quality is not at the same level as other options. More specifically, it took me several experimental prints and numerous adjustments to get good print quality, but it will require a bit more tuning to perfect print quality.
This is partly because the default settings in my software are not optimal for this printer (it’s too new) and partly because the firmware needs some tweaking.
I really like this printer. It is a sophisticated black-on-black, serious-looking delta printer that always gets a look when friends stop by. If you want a high-quality delta printer that has a moderate-sized build volume.
And you want to experience building your own from a kit without the tedious soldering and electronics work, the Kossel Pro is an excellent choice.
Given the documentation and the ever-expanding and improving user forums, I expect this printer to be a very popular choice for those who want a printer with better quality, reliability, and maintainability than the RepRap variants.
The Mini Kossel is one of the newest RepRap delta printers, also designed by Johann C. Rocholl. The Mini Kossel is a hobbyist-grade (RepRap) printer that is entirely DIY. While you can buy kits that include all the parts, most people source their own parts or buy subcomponents from various vendors.
In fact, the Mini Kossel has been copied and modified by many people. I find a new variant of the Mini Kossel almost weekly. Some have minor changes, like using a different extrusion for the frame or a different carriage mechanism (see the earlier discussion on axis movement).
But others have more extensive changes, such as alternative frame vertices and use of injection-molded parts, and a few have even increased the build volume.
Since this design is a pure RepRap, DIY endeavor, listing standard features isn’t helpful because there are so many options that you can choose.
For example, you can choose your own hot end (1.75mm or 3mm, all-metal, peek, etc.), optionally add a heated build plate, add cooling fans, and so on. Indeed, there is almost no limit to what you can do with this little printer.
About the only thing I can say that is standard on most variants of the Mini Kossel is a small size. The printer is only a little over two feet tall and takes up very little room. Although the build volume is quite small (about 5 to 6 inches in diameter and 6 to 8 inches tall), it is large enough to print most moderate-sized parts one at a time.
Building the printer is pretty easy if you have basic mechanical and electrical skills. The build time is only slightly less than what would be required for the Rostock Max v2, but because there are fewer parts, the build is a bit faster and the frame is less complicated to assemble.
While some vendors offer the Mini Kossel in kit form, few offer any form of help beyond the basic assembly. Fortunately, there are numerous articles, blogs, and independent forums that offer a lot of help. I would start with a visit to the Mini Kossel wiki and then search for topics you need help with, such as “Z-probe assembly” or “Mini Kossel calibration”.
Another helpful forum is the RepRap general forum (http://forums.reprap.org/list.php?178), but enthusiasts building all manner of delta printers use this forum, so be aware that some of the information may not apply to the Mini Kossel. You can also check out the delta bot mailing list.
Not surprisingly, given its small size and use of standard components, the Mini Kossel is the cheapest of the delta printers available today. If you opt to go without a heated print bed and use the less expensive axis components, you can find kits for under $500, and even a few around $400.
I managed to source one of my Mini Kossel printers at about $300, but I opted to use some used parts from other Cartesian printers.
If you are looking for a delta printer to start with, or want to experience building a delta printer from scratch or as a companion to a fleet of Cartesian printers, the Mini Kossel is an excellent choice. Build one for yourself or invite a friend to build one together.
Applications of 3D Printing
Every new invention is motivated by the desire to do something that was never done before or improve on currently existing ways to solve a problem. Since the 1990’s, the applications for 3-D printing have literally exploded as size limitations and costs have dropped and the list of materials that can be used with this technology has expanded dramatically.
The applications can be grouped into several broad categories:
Let’s look as a few examples in each category.
One attraction of 3D printing for commercial applications is the ability to make complex 3D prototypes or finished products that are not easily manufactured by conventional means.
At their present stage of development, 3D printers cannot crank out large quantities of identical parts at costs as low as can be achieved through mass production.
There are other features, however, which have attracted the attention of large manufacturers such as Airbus, Boeing, GE, Ford and Siemens among others.
There are other features of 3D printing that are appealing in situations where time and cost are important. Compared to conventional (subtractive) manufacturing methods there is less wasted material.
Conventionally manufactured products are often transported long distances, even across continents before reaching their final destination. With 3D printing, production and assembly can be local. When unsold products are discontinued, they often wind up in landfills. With 3D printing, they can be made as needed.
Rapid prototyping is still the main attraction of 3D printing for industrial applications. Slowly, that is changing. Today, it is estimated that about 28% of the money spent on printing things is for the final product, as opposed to a prototype.
Sciaky, Inc. has developed a metal printer using electron beam additive manufacturing technology (EBAM) for printing enormous metal prototypes.
The machine has a build volume of 19x4x4 feet and can 3d print such metals as titanium, tantalum, stainless steel and Inconel. The technology is being used by Lockheed and Boeing for the construction of jet fighter parts.
An alternate approach to a huge printer is a series of industrial size printers which can produce components of an object which can then be assembled to make the whole, something larger than the capacity of an individual printer.
RedEye, a Stratasys company, has a print facility that is fully automated, consists of 150 3D printers which can print objects on demand for its clients.
Teaming up with Lockheed Martin Space Systems, the Lockheed – RedEye team 3D printed two fuel tanks for a satellite simulation project for NASA. Using FDM printers, two weeks were required to 3D print the fuel tanks and 240 hours to complete the final assembly.
The bigger of the two tanks is 15 feet long. Ten different pieces were required for the large tank and six for the smaller one using a polycarbonate material.
Nozzles are relatively simple devices, specially shaped tubes through which hot gases flow. All jet engines use nozzles to produce thrust, conduct exhaust gases out of the nozzle, and to set the mass flow rate through the engine.
Nozzles come in various shapes and sizes depending on the mission of the aircraft. Rocket engines also use nozzles to accelerate hot exhaust to produce thrust.
GE Aviation is pulling 3D printing out of the laboratory and installing it in the world’s first factory to use this technology in the manufacture of jet engine fuel nozzles. Scheduled to open in 2015 in Auburn, AL, the plant will use 3D printing to additively manufacture the interior of fuel nozzles for the LEAP jet engine. Each LEAP engine will have nearly 20 fuel nozzles produced in this manner.
The LEAP fuel nozzles are 5 times more durable than previous models. 3D printing allowed GE Aviation engineers to design them as one part rather than the 20 individual parts required by conventional manufacturing techniques.
Employing additive manufacturing also enabled engineers to redesign the complex internal structure required for this critical part, making it both lighter and more efficient.
GE is also developing 3D-printed parts for the GE9X engine, the world’s largest jet engine which will be installed in the next generation Boeing 777X long-haul passenger jet.
Ford has employed stereolithography, laser sintering, as well as sand casting in developing rotor supports, transmission casings, damper housings and end covers for its C-Max and Fusion hybrids. This technology has also been applied to building four-cylinder EcoBoost engines, Ford Explorer brake rotors, and F-150 exhaust manifolds.
Notable is the close relationship between Ford’s research and development and its 3D manufacturing facility. CAD files are often sent back and forth between the two so that a design for a prototype can be built as a physical model, examined, tweaked as needed and then returned for fine tuning of the CAD model.
Engineers are constantly finding practical applications for the 3D print technology. An example, reported in The Economist, deals with the physical principle that “…fluids flow more efficiently through rounded channels than they do around sharp corners, but it is very difficult to make such channels inside a solid metal structure by conventional means, whereas a 3D printer can do this easily.
3T RPD, a British firm that offers additive-manufacturing services, printed a gearbox for a racing car with smooth internal pathways for hydraulic oil instead of drilled-out right-angle bends. The box not only allows faster gear changes but is some 30% lighter, says Ian Halliday, the firm's chief executive.
3D Printing in Space
The National Aeronautics and Space Administration (NASA) has statically tested a 3D printed fuel injector for rocket engines. Existing fuel injectors were made by traditional manufacturing methods.
This required making 163 individual components and assembling them. Using 3D print technology, only 2 parts needed to be made, saving time and money as well as allowing engineers to build parts that enhance rocket engine performance and are less prone to failure.
The injector performed exceedingly well. Nicholas Case, the propulsion engineer leading the testing, summed up the case for including 3D print technology as part of the manufacture of rocket components:
“Having an in-house additive manufacturing capability allows us to look at test data, modify parts or the test stand based on the data, implement changes quickly and get back to testing.
This speeds up the whole design, development and testing process and allows us to try innovative designs with less risk and cost to projects.”
In September 2014 NASA launched its first 3D printer into space. Before the launch, it had to be tested and modified to work in a low-gravity environment. Its short-term application will be for building tools for the International Space Station astronauts.
In the longer term, 3D printers may be used to supplement the rations carried on space missions by printing food. NASA is exploring ways to develop food that is safe, acceptable and nutritious for long missions.
Current food systems don’t meet the nutritional needs and 5-year shelf life required for a Mars mission. Because refrigeration and freezing require significant spacecraft resources, NASA is exploring alternatives.
So far, some progress has been made on printing pizza. The pizza dough is easy enough to make, but at this stage, you have to love it with ketchup and cream cheese!
Telescopes seem like simple devices but they are made up of many parts, are hard to build and hard to operate in space. Jason Budinoff of NASA Goddard is simplifying the process while working on the first space telescope made entirely of 3D printed parts.
Budinoff’s design for the CubeSat satellite is a fully functional 2-inch (50mm) camera. The only parts not printed are the glass mirrors and lenses. The remaining structures are printed from aluminum and titanium powders. The first prototype is strictly experimental and not yet ready for space flight. Further testing and development are in progress.
3D printing has been used for some time to build architectural models. These help clients visualize the design, reduce the hours spent on crafting models and create a library of reusable designs.
Thousands more can be found with a quick Google search. These models are not limited to a building here or a stadium there but include scale models of cities.
The question naturally arises: if one can build a model of a house, can one build a full-scale house? The short answer is – almost. There are house printers on the market.
BetAbram, a Slovenian firm, is taking orders for the smallest of their concrete house printers (13x9.8x6.5 feet or 4x3x2 meters) and is working on larger units.
The procedure is to build one level of a house at a time. Once the first level is completed, the machine can be moved upward to build the next level and so on until the desired height is reached. It can be yours for a little over $15,000 (not including the concrete).
Billed as the world’s first 3D printed house, the Canal House in the Netherlands is under construction and is expected to be completed in 2015. It is being built at ¼ scale entirely from bioplastics.
It is not expected to be an actual residence but a proof-of-concept undertaking. Each of the rooms will have furniture that illustrates the capabilities of 3D printing.
The 3D printer used to build the Canal House, called the Kamermaker, is an upscale version of the Ultimaker 3D desktop printer. The material used is a bioplastic made with 80% vegetable oil.
As a brief aside, we should mention that people are looking into alternatives to concrete for building materials.
A leading candidate is a humble soybean. Used both as food and as an ingredient in non-food products, students at Purdue University have now developed a soybean-based material which can be used for 3D printing Called Filasoy, it is a low-energy, low-temperature, renewable and recyclable filament created with a mixture of soy, tapioca root, cornstarch and sugar cane.
The aim is to provide an alternative to plastics for 3D printing as plastics are petroleum based and not derived from renewable resources.
Sofoklis Giannakoupoulous, a researcher at Barcelona’s Institute for Advanced Architecture in Catalonia, is working on a soybean-based material that could be extruded to make structures that are more solid than concrete.
Still, in the development stage, it is hoped that the material will be significantly cheaper than concrete and environmentally friendly as well.
Returning again to the real world where concrete is still the preferred material for construction, Andrey Rudenko, a Midwestern engineer, designed and built his own concrete printer and, following two years of research and development, has completed a small concrete castle.
The walls of the small fortress, as well as the tower tops, were fabricated separately and then assembled into a free-standing structure.
Ideally, 3D printing could be used to build entire full-scale houses or groups of houses. Prof. Behrockh Khoshnevis of the University of Southern California has developed a process called contour crafting which might make that possible.
Contour crafting is a fabrication process by which large-scale parts can be fabricated quickly in a layer-by-layer fashion.
It has the potential to build whole structures and substructures, complete with electrical, plumbing and air conditioning conduits embedded in the structure. Videos demonstrating the technique and its applications can be seen in.
It’s a nice, sunny day. You send the kids and the dog to the backyard to play. A few friends join them. You and the other moms have coffee while the kids play. They all come in when it’s time for the friends to leave and you discover that yours have nearly destroyed their clothes.
Your washer can deal with the grass and mud stains but the torn jeans…not so much. No problem. Their dimensions are recorded in the home computer. You call up the necessary data, input it into your 3D printer and by the time dinner is over they have new play clothes!
It’s a nice dream, but we’re not there yet. Real materials, such as silk and cotton, have an unfortunate tendency to burn during the printing process. The dream will have to wait a while. For now, 3D printing has attracted the attention of the fashion industry by way of a fashion-as-art concept.
The dresses consist of 3D printer fabricated components and the completed garment and its accessories are then finished by hand. A fascinating example of this approach is the Spire Dress designed by Alexis Walsh and Ross Leonard.
It is made up of 400+ individual pieces, some in the form of spires, using nylon plastic. Then the individual pieces are assembled by hand to form the finished product.
Two major drawbacks to printing full-size garments are the size of the printers and the ability to print natural materials. There are 2D printers which, given a t-shirt, can print virtually any imaginable design on it.
However, while there is a lot of interest, there is as yet no capability to print an entire t-shirt (or any other garment) from natural fabrics due to their unfortunate incendiary behavior. This is an area under study.
Shoe manufacturers have taken an interest in 3D printing. NIKE has used the technology for a football cleat. A prototype for a lightweight plate attached to the shoe was made with a 3D printer. The company was able to manufacture the plates using 3D technology as well.
New Balance has done customization for runners as a pilot program to test the utility of 3D printing for athletic shoes. To make the shoe, New Balance fits the runner with a pair of shoes that used sensors to record data under simulated race conditions.
Additional efforts in 3D printing shoes or shoe components are described in the article by Michael Fitzgerald.
The United States Army currently uses 2D programs to design clothing for soldiers. They are also investigating the feasibility of using 3D printing in the hope that it might eliminate or reduce the number of seams to make a garment.
Seams can cause discomfort in high heat and humidity, especially when a garment is worn with body armor. As a rule, the fewer seams, the greater the comfort.
The healthcare sector has become a major user of 3D print technology. They range from creating customized crowns and braces for teeth, shells for hearing aids, various prosthetics, and implantable devices, and models of various body organs to allow surgeons to refine their approaches and reduce the time needed for operations.
Bioprinting, still in its infancy, will eventually allow customizing the delivery of medicines to specific organs, print human tissue, and even cosmetics. Some recent articles review aspects of the medical applications of 3D printers.
There is some speculation that the dental laboratory as we know it today may be replaced by 3D printing in the future. Traditionally, crowns are made in a dental lab.
The dentist makes an imprint of the tooth (or teeth if a bridge is being designed) and sends it to a dental lab. Each lab technician, being human, has his or her unique style.
This results in a variability in the final product from person to person and day to day, In addition, the traditional materials used in dentistry expand and shrink with exposure to temperature and moisture. This is difficult to control. The result of this on the patient is more time in the chair.
A few days or a few weeks later the crown is sent to the dentist. Another visit is scheduled for the patient to fit the crown. Depending on the fit, a third visit may be required for a final adjustment.
It is now possible for a dentist to make a 3D scan of the tooth (or crown) and print it on the spot. Since it is made to measure, less time is required in the chair. As with almost all medical applications, the process is still in its infancy but shows great promise for increased patient comfort and (eventually) reduced cost.
Maxillofacial prosthetics (eyes, noses, ears, facial bones) are very laborious and expensive to produce. Ears and noses can cost up to $4,000 each. An impression is taken of the damaged area, the body part is then sculpted out of wax and that shape is cast in silicone.
Using 3D print technology, digital cameras are used to scan the injured area. A digital model is then created for the part, which incorporates the patient’s skin tone. This information is sent to a 3D color printer.
The cost of the printed part is about the same as that of a handcrafted prosthetic. The advantage lies in the fact that now a digital model exists. In the future, when replacements are needed for whatever reason, they can be made very cheaply.
3D printing has been effectively used to customize mechanical limbs. The usual goals are to add a capability missing due either to a birth defect or injury. Other reasons include improving the comfort and fit of an existing prosthetic device. As an example, consider a prosthetic hand designed for a man who, since birth, was missing a large part of his left hand.
A high-tech prosthetic which cost over $40,000 was replaced with a 3D printed hand which provided him a stronger grip and cost much less.
Due in no small measure to the fact that it was developed by e-NABLE, a global online community of humanitarian volunteers which designs, builds and disseminates inexpensive functional 3D printed prosthetics. The hand called the Cyborg Beast.
A six-week-old baby’s airways in one of his lungs collapsed causing him to stop breathing. Doctors at the C. S. Mott Children’s Hospital feared that the baby would not leave the hospital alive unless something was done immediately. As luck would have it, the University of Michigan was developing a new bioresorbable device that could help the baby.
The collaboration resulted in a custom-designed, custom-fabricated device, a splint, which was implanted in the airways to keep them open. The body will eventually absorb the device and the airway will stay open on its own.
Brain surgery requires drilling holes in skulls. Cranial plugs made on 3D printers can fill those holes. Cranial plates can replace large sections of a skull lost due to head trauma or cancer.
The Mayo Clinic and other hospitals have used 3D printed hip and knee replacements. Dr. Barry Waldman of OrthoMaryland in Baltimore, MD used CT scans to cast an implant and manufacture the plastic cutting guides that direct the surgeon’s incisions.
The replacement joints were for a former athlete who had suffered for more than ten years with bowlegged legs bent six degrees out of alignment.
The motivation for using 3D technology to create replacement joints was to minimize the amount of bone that had to be shaved off to install each implant. The article in The Baltimore Sun newspaper quotes Dr. Waldman:
“You can take an off-the-shelf implant and it may not fit. Plenty of times we’d be in the middle of a surgery and say: this is between a ‘5’ and a ‘6’ and we need a ‘5.5’. Well, there is no ‘5.5’”.
3D printed replica models of body parts and organs have proven to be valuable in medical applications. They allow analysis of complexities and alternative approaches prior to a patient’s surgery.
This has had an impact of both the cost and duration of surgeries. The patient benefits if it is found that minimally invasive surgery is possible from shorter anesthetic times and an earlier discharge.
At Houston Methodist Hospital, a stent graft made from a 3D image eliminates the need for open surgery for some patients suffering from abdominal aortic aneurysms.
An abdominal aortic aneurysm is an enlarged area in the lower part of the aorta. Since the aorta is the main supplier of blood to the rest of the body, a ruptured abdominal aortic aneurysm can be fatal. Surgery is required to treat this problem. This involves opening the belly and sometimes the chest to perform a complex operation.
In the new approach, a custom-made stent graft based on measurements from CT scans (Computerized Tomography – technique combining a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of the bones and soft tissue inside the body) and measurements is placed on the aneurysm by going through the groin.
Most patients go home after a few days with minimal pain or discomfort. The patients experience less blood loss. A shorter ICU (Intensive Care Unit) stay and a quicker return to a normal diet and regular activities than those who undergo an open procedure to fix this problem.
A number of bioprinters have appeared recently. According to, bioprinting is “using a specialized 3D printer to create human tissue. Instead of depositing liquid plastic or metal powder to build objects, the bioprinter deposits living cells layer by layer”.
The goal, still at least a decade away, is to build human tissues for surgical therapy and transplantation. Many laboratories are testing the concept by printing tissue for research and drug testing. The speculation is that patching damaged organs with strips of human tissue will occur in the near future.
Before the more than 250 3D printers now on the market became available, those interested in the subject had to build their own from scratch, known as DYI (Do It Yourself) or from kits.
The only materials available then were easy-to-melt plastics. 3D printing that was the province of hobbyists interested in learning the new technique. The items printed were small, mono-colored and the end product of a learning process.
With the greater selection of printers available today, a vastly increased selection of materials and greatly reduced costs, there now exist a very large number of
Statuettes and figurines (bunnies, birds, cats, dogs, characters from movies or video animations, game pieces, etc.)
Jewelry of every description, limited only by the artist’s imagination
Toys and action figures
Art (practical things like vases to abstract art)
Gadgets – phone cases are especially popular
Household tools – screwdrivers, wrenches, broken part replacements
Sunglasses of every description
and on and on and on.
There is constant experimentation with an expansion of the capabilities of 3D printers. The main constraints are:
The cost of the printer (fully assembled desktop units are available at prices ranging from under $400 to over $10,000)
The cost of material (plastics for printing are not cheap. Don’t be surprised if in the future the machines themselves will be available at giveaway prices because the profit will be in the materials they use)
The size of the object to be printed (this can be overcome by printing individual parts and then assembling them into a finished whole)
Constraints on printed objects by intellectual property laws. Remember, the lawyers haven’t paid much attention to the 3D printing community yet, but that is bound to change.
Food printing is being explored now that a larger selection of foods is available for that purpose . Small and large food printers are available for specialized purposes.
3D printing – it’s not just for hobbyists anymore!
Creating a Three-Dimensional Model: Scanning, Software, and Hardware
3D scanners have been around since the 1970’s. They have been used for a variety of applications, including surveying, terrain mapping, documenting construction and mining projects.
Scans have been made of historical buildings and works of art, e.g., Michelangelo’s David and the Pieta to name but a few. Scans are regularly made of ships, consumer products, coins, medical devices, and dental appliances, among many other items.
A 3D scanner creates a digital representation of a physical object. Therefore, if it exists and is accessible, it can be scanned. The data collected by the scanning process is called a point cloud.
This is an intermediate step for the creation of a mesh, also called a 3D model, a digital representation of the scanned object. The mesh can be used for:
Creating models for rapid prototyping or milling
Analysis of structures under a variety of internal or external forces using finite element or finite difference methods
Computational fluid dynamics
After some additional processing, this is the information sent to a 3D printer which creates a physical object.
A mesh is a collection of polygonal shapes which approximate, to the desired degree of computational accuracy, a real-world object. There are choices to be made in coming up with an acceptable mesh which is good enough for all practical purposes and still economically feasible.
The surface of the sphere is approximated by straight line segments. As the number of polygons in the model increases, the representation looks more and more like its physical counterpart.
This begs the question: how fine does the model need to be? That depends both on the accuracy required to represent the 3D physical model and the cost involved in printing the 3D model.
Every time the number of polygons in a model is doubled, the time required to print goes up by a factor of 8. Thus the final model used for printing represents a compromise between accuracy and cost.
For 3D printing, a solid model is a goal and the expected input for a 3D printer. The problem of mesh design and the compromises needed to get a sufficiently accurate mesh for an affordable computational price.
And fluid dynamics where a mesh is just the starting point in studying the behavior of materials and structures under various external stimuli.
If this topic interests you, consult the literature in these areas. In what follows, we touch on aspects of 3D scanning which lead to the production of a 3D model.
Methods of Data Collection
Both contact and non-contact methods are used to collect information about 3D objects. Depending on the nature of the object these can be used individually or combined.
In contact-based procedures, a probe touches various points of an object’s surface to produce a data point (x, y, z coordinates of the location). Probes can be hand-held or part of a machine referred to as a coordinate measurement machine or CMM. Such machines can be stationary or be in the form of portable arms.
Sometimes physical contact with an object is impossible, impractical or undesirable. Then it becomes necessary to resort to non-contact methods. These involve using lasers, ultrasound or CT machines.
In laser scanning, a laser (red, white or blue depending on the application) passes over the surface of an object to record 3D information. As it strikes the object’s surface, the laser illuminates the point of contact.
A camera mounted in the laser scanner records the 3D distribution of the points in space. The more points recorded, the greater the accuracy. The greater the accuracy, the more time is required to complete the scan and the greater the complexity of the 3D model created from the data. With this method, it is possible to have very accurate data without ever touching the object.
Generally, contact digitization is more accurate in defining geometric forms than organic, free-form shapes. If it has been some time since you’ve taken an art class, geometric shapes have clearly defined edges typically achieved with tools. Crystals also fall into this category even though they are created by nature.
Examples include spheres, squares, triangles, rectangles, tetrahedra, etc. Organic shapes are typically irregular and asymmetric. They have a natural look and a curving, flowing appearance. Organic shapes are associated with things from nature such as plants, animals, fruits, rivers, leaves, mountains, etc.
Laser scans produce good representations of an object’s exterior but cannot record interior or covered surfaces. As a simplistic example, consider a hollow sphere. The laser scanner will accurately describe its general shape, but if there is anything inside the sphere, this would have to be detected with an ultrasound or a CT scan.
The choice of which scanning technology to use will depend on the attributes of what you are attempting to scan, such as its shape, size, and fragility. As a general rule, laser scanning is better for organic shapes. It is also used for high-volume work – scans of cars, planes, buildings, terrain, etc.
It is the method of choice if an object cannot be touched, e.g., in documenting important artifacts. Digitizing is used in engineering projects where precise measurements of geometrically shaped objects are required.
Both methods can be combined when necessary. The end result of a scan, regardless of which method is used, is called a point cloud.
From Point Cloud to 3D Model
The nice thing about point clouds is that they can be measured and dimensioned. This makes them valuable to architects and engineers. For the former, the ability to view and measure their project directly from their computer reduces the number of trips needed to the job site and thus reduces cost.
For engineers, point clouds can be converted to surface models for visualization or animation and to 3D solid models for use in 3D printing, manufacturing and engineering analyses, including finite element analyses and computational fluid dynamics.
Now that we have hundreds of thousands if not millions of data points obtained from 3D scans, we can go on to print our object, right?
The points have disappeared and have been replaced by a reasonable facsimile of a structure. There are two considerations before creating a 3D model:
First, the point cloud data must be cleaned up a bit. A number of point clouds are generated in a scan to fully represent a 3D object. For purposes of analysis, these clouds must be merged into a single point cloud. This process is referred to as registration. Then some housekeeping must be performed on the consolidated cloud.
Inaccuracies must be removed together with overlapping data, irrelevant points, noise, outliers, sampling error, missing data, misalignment, a varying sampling density, registration errors, and other problems.
Some of this will be done by software, some will require human intervention and manual correction. Keeping in mind, though, that laser scans can result in point clouds with 100,000 to over 1 million points, help from software will definitely be needed.
Second, CAD software, which produces the 3D model suitable for various applications, doesn’t know what to do with point clouds. Since CAD software expects to receive data in the form of surface representations of geometric forms and mathematical curves, the data must be translated into a form that it can interpret.
The software packages that create 3D models from point cloud data consist of both proprietary packages and commercially available ones. Among the popular commercial packages are (in no particular order):
and many, many others. These software packages input the point cloud data, clean and organize it and produce 3D models in a wide variety of file formats, including the .STL file format popular in the 3D printing community. The final mesh can be achieved by way of a Polygonal mesh model
NURBS (Non-Uniform B-Spline) model
Before continuing, we should point out that the business of going from point cloud data to a CAD mesh is a non-trivial exercise. There is no unique path for this. It is, in fact, an area of active research.
With polygonal modeling one works primarily with faces, edges, and vertices of an object. To make desired changes to a model, vertices can be repositioned, new edges inserted to establish additional rows of vertices and branching structures created. With polygon models, the process is easier to grasp.
However, as polygons are faceted, it can take quite a few of them to create a smooth surface. The more polygons, the greater the storage requirements. Even without this consideration, polygon modeling creates much larger files than NURBS modeling because the software keeps track of points and shapes in 3D space rather than mathematical formulas.
With NURBS modeling, one obtains smoother results. A NURBS object has only four sides. These are manipulated to create surfaces. This approach requires less storage than polygonal models.
NURBS surfaces can be deformed, have shapes cut out of them, be stitched and blended together to form complex shapes. NURBS are constantly and always smooth as they are mathematically a continuous curve offering an easy way to keep smoothness within a model.
The requirements of your project – especially the time available for it - and the capability of the software package you are using – will guide your choice of the method you use to achieve the final mesh. In some cases, both will come into play. For low-resolution polygon models, NURBS smoothing can be applied to provide a nice finish, polygon control, and small file sizes.
Software for 3D Printing
The key element in that process is the software. In 3D printing, as in other fields of engineering, the hardware development tends to precede the creation of software. Almost weekly there is an announcement of a new 3D printer either being developed or being brought to market.
By contrast, some of the Computer-Aided-Design (CAD) software used to develop 3D models for those computers dates back to the 1970’s. Software packages developed later tended to be evolutionary, rather than revolutionary, so that the philosophy that guided software developments some 40 years ago is still embedded in newer software, albeit with much-improved user interfaces.
There are a number of reviews and listings of software for developing 3D models. Here we follow the approach in and categorize these as:
Freeform modeling tools
Print Preparation and Slicing software
All will produce a 3D model suitable for printing. Each category, however, is aimed at a different audience. CAD programs typically deal with hard geometries and are well suited for engineering applications.
Freeform and sculpting tools are aimed more at artists and creative modelers interested in animation, visual effects, simulation, rendering and modeling. Because 3D printers are very picky about the input they will accept.
We need another software category that checks out the model and generates the g-code used by printers (preprocessing and slicing software).
There appears to be general agreement that, for beginners, the easiest to use programs are:
They have several characteristics in common. In most cases, the basic software is free, with an option to purchase an advanced version as your capabilities and design needs increase. All are browser-based (a typically current version of Google Chrome and Firefox). Tutorials are available to help get started.
In the case of 123D and TinkerCAD, these are extensive. All come with a library of primitive shapes (cones, spheres, squares, cylinders, toruses) which can be imported to the workspace and, by addition or subtraction, combined to form almost arbitrary shapes.
SketchUp has extensive capabilities and documentation for applications to architecture and interior design in addition to civil and mechanical engineering. Most of the free versions and all of the advanced versions allow export of STL files to 3D printers, either your own or to a 3D print service.
The above is good for learning the basics of CAD software. There are several options available once you decide you need additional computing power. Some developers of 3D printers have proprietary 3D modeling software which is geared to their hardware and is not available unless you purchase their printer.
The alternative is commercially available software, except as noted. These packages come with a price tag ranging from moderate to expensive. The learning curve rises steeply because of the added capability, and therefore complexity, of these packages.
Most are intended for engineering applications. All come at a minimum with tutorials on various aspects of the software. Training and consultation services are also available, at additional cost, for some of the software packages.
A partial list of software for intermediate, advanced and professional users includes:
Free 3D CAD
PTC Creo Elements/ Direct Modeling Express
As full descriptions of these software packages are available in the cited references, only a few comments need be made here. All but Free 3D CAD are available for purchase, the cost depending on the capabilities required.
Most offer a free download of a downscale version to allow potential users to decide whether the program meets their needs.
SolidWorks and Inventor are comprehensive programs for engineering design and analysis. SolidWorks comes in three versions – Standard, Professional, and Premium. There is a wide range of books, tutorials, guides, project files and videos to assist in various aspects of its use, from setup to engineering design applications.
Training is available at an additional cost. The inventor is available in two versions – Inventor and Inventor Professional. Extensive support is available ranging from help with installation, online tutorials and a community forum through 24-5 direct contact with and assistance from support staff.
Rhino3D most likely belongs in the next section dealing with software aimed at artists yet it is frequently used to develop models for 3D printing. Rhino is a NURBS program for creation, editing, analyzing and translating NURBS surfaces.
Like other programs in this category, it supports a variety of file formats. Rhino3D runs under Windows.
CorelCAD 2015 has both 2D drafting and 3D design tools. It runs on both Mac and Windows computers. OpenSCAD is a 3D solid modeling program running under Linux/Unix, Windows and Mac OS X operating systems. Being a Unix-based system it is, in our opinion, not particularly easy to use unless one has first mastered Unix.
Free 3D CAD is an open source, modular program that is designed as a parametric modeler – it allows modification of a design by going back into the model history and changing its parameters. The program is intended primarily for mechanical design. It is still in the early stages of development.
PTC CREO Elements/Direct Modeling Express 6.0 is the free version of PTC Creo Elements/Direct Modeling 19.0. The program is aimed at engineers in search of a lightweight, flexible 3D CAD system who need to rapidly design and print one-of-a-kind objects and variations thereof. A variety of support services are available.
CAD software is not the only path to the creation of a 3D digital model. For some time, 3D computer graphics software has been available offering features which permit 3D computer animation, modeling, simulation and rendering for games, film and motion graphics artists.
The basic principles are taught at universities and the subject of many texts, among them the book by Vaughan.
Since the tools employed by graphic artists include polygons, NURBS and subdivisions, a 3D model suitable for printing is created in the process. As we haven’t mentioned it before, a subdivision surface is a method of representing a smooth surface using a piecewise linear polygonal mesh.
A mesh is piecewise linear if every edge is a straight line and every surface is a plane. The most common examples are triangles in two dimensions and tetrahedra in three dimensions, though other options are possible.
Given a mesh, it is refined by subdividing it, creating new meshes and vertices. The result is a finer mesh than the original one, containing more polygonal faces. This can be done over and over until the desired degree of surface refinement is achieved.
The software in this category includes:
Both Autodesk Maya and 3ds Max are the standards for the gaming and film industries. They used to be competing pieces of software, but are now owned by the same company.
The only difference between these two is the layout and inclusion of certain tools. 3ds Max works well with motion capture tools, while Maya allows you to import various plug-ins to create realistic effects.
Many artists have a favorite between the two and will swear up and down by it. For the purposes of 3D printing, they are identical . The full versions of both are free if you are a student. Otherwise, they are expensive.
Cinema4D is another 3D modeling, rendering, and animation tool. It has a large number of sculpting tools which let you mold the model as if it were clay to create shapes and contours.
Unlike all of the other tools mentioned in this section Cinema 4D has a tool called the PolyPen Tool which lets you draw polygons on the screen, instead of starting with a base shape and working from there.
This lets you create complex shapes very quickly and easily. For those who also work in gaming, it’s designed to import seamlessly with the Unity 3D game engine, as well as auto-update in Unity when changes to a model are made in Cinema4D. Just like Maya and 3ds Max, it is very expensive.
Blender is the free alternative to Maya/3ds Max. It’s an open source program that aims to be just as good as its Autodesk cousins. Unlike the others, it comes with its own game engine and video editor included, which is useful for anyone looking to create a game on a budget.
For 3D modeling, it’s a good option to use if you aren’t a student and want access to advanced software. If you need help getting your model from Blender to your 3D printer, Shapeways has a tutorial on how to export from Blender to a .stl file.
If you are trying to choose between the four, all of them have free trials (or in a case of Blender is just free). The best thing to do is play around with all of them and find which one works best for you.
Remember when you were young and played with modeling clay? You started with a ball of the stuff and then by pushing, pulling, pinching and squeezing you made a figure of some kind.
Well, now you can do the same thing on a computer with the help of sculpting software. Make a model, export it as an STL file, send it to a 3D printer and you can relive the glory days of youth with greater accuracy and without getting your fingers dirty. What software lets you do this? Some examples are:
Digital sculpting is a relatively new but gaining in popularity. Many of the programs available use polygons to represent an object. Others use voxel-based geometry in which the volume of the object is the basic element. Each has advantages and disadvantages for particular applications.
Almost But Not Quite
Let’s assume that you have used one of the methods described above and have designed an object for 3D printing. Naturally, you are anxious to send it to send it to your own printer or to a 3D print service. First, though, there are a few things to consider:
Your model exists in a mathematical world free of forces such as gravity. It is about to be transferred to the real world and printed with materials that have density and finite strength. Now is a good time to check the weight distribution. Otherwise, your object may wobble or not be able to stand upright.
Each printer bed has a finite size. If your object is bigger, you can always scale it down. Reality will intrude again if you do not ensure that critical dimensions such as wall thickness are of the minimum size required by the printer.
If you are working with metals you might get away with thin elements but plastics are much weaker and far less forgiving, especially when heated. Even if you succeed in printing a thin member of your object, it may break during handling or shipment.
Be careful of units. If your design is in millimeters, be sure that the printer does not expect centimeters or inches.
To overcome the limitations of the printer bed or for artistic reasons, an object can be built out of dozens or hundreds of separate pieces. Hair, buttons on a coat, different components of an object such as attire or accessories can be created as separate components in a 3D model.
This won’t work for 3D printing. Unless the individual parts are to be glued together after printing, the model received by the printer needs to be a single seamless mesh. Attaching a few parts to the object after printing is a nuisance. Attaching hundreds can be painful.
By default, your object will print as a solid model. If this is what you want, fine. A solid model, however, requires significantly more material to print than a hollow one. Most printing services charge by volume.
It is in your financial interest to print a hollow figure instead of a solid one if this is feasible. When hollowing a model, be aware of the minimum wall thickness that the printer you are using is capable of producing.
Other services (such as checking for water tightness and other geometric factors) are performed by print preparation software or printer frontends. This type of software is a collection of utilities that check your 3D model and load STL files.
The programs in this category have an integrated slicing capability to create the layers in the z-direction and send the resulting G-code to the printer. Examples include:
MakerWare (for MakerBot printers)
The slicing programs in frontend software also accept input from stand-alone slicing programs such as Slic3r and KISSlicer.
Many tutorials and articles on preparing a 3D model for printing are available and should be reviewed prior to printing.
Finally, you’ve reached the stage where you can make a printed object. But when it comes out of the printer or is returned by the print service, you see changes you’d like to make. Do you start the model creation process all over again? No. The software comes to the rescue again. Programs such as Netfabb, Autodesk Meshmixer, and Meshlab allow you to edit your STL file and try again.
We hope that you now see that software is the critical element in that process. New printers appear regularly. Software development is an evolutionary and slow process.
To paraphrase Commander Montgomery Scott (of the Starship Enterprise): Building 3D printers is easy. Designing a comprehensive, user-friendly 3D modeling software – that’s hard!
Depending on the source that you consult, there are now between 200 – 300 3D printers on the market. These range from machines for industrial applications and manufacturing through specialized printers for medical research (bioprinters) and housing (concrete printers) down to consumer-oriented desktop-sized machines or smaller.
Some of these have been developed by multi-billion dollar corporations and are focused on professional use. These market both the machines and products made with them and provide extensive support and training to their customer base.
Many of the consumer-oriented machines have been developed by small companies (20 or fewer employees) who are very good at building 3D printers but are in no position to provide extensive support and training to their customers.
A crystal ball is not required to conclude that sooner or later there will be a shakeout and it will most likely be in the consumer-oriented market. There simply is not that much demand for yet another 3D printed pink bunny or a figure of Yoda (Star Wars).
Companies with ingenious designs but operating on a shoestring budget will be bought up by the corporate giants and incorporated into the fold. Many others, with only a shoestring budget, will fall by the wayside.
Eventually, 3D printers will reach plug-and-play status just as 2D printers have, but it will not happen soon and it won’t require 300 of them. Before that happens, though, 3D modeling software needs to be drastically improved for the non-engineer, non-artist market.
There are a number of reviews and evaluations of 3D printers. Almost all are focused on the hobbyist or home user. Of necessity, this limits consideration to FFF and SLA printers since currently, these are the only ones safe for use in a home environment.
Industrial additive manufacturing machines and materials are listed in the Senvol Database. We will not repeat here material that is readily available on the internet. Instead, we point out some salient features involving the use of 3D printers.
Nice to Know
Before tackling the decision about which printer to get, if any, let’s cover a little background, starting with Expectations: There are a countable infinity of multicolored 3D printed images to be found on the internet.
Some are incredibly lifelike and look like they’ve been printed with a variety of materials. In all probability, these were made with a high-end professional printer, then post-processed for hours or days by professionals.
After looking at a number of these, it is only human to expect that when you buy your $500 home 3D printer you will be able to duplicate such results. Now is the time to remember a few facts:
(1) SLA printers print in only one color; (2) an FFF multi-nozzle printer will give you some color but not the quality or resolution you get from a machine that costs 80 times more than your desktop; (3) you need a 3D model to even think of printing.
2D printing is far more advanced technologically than 3D printing, but even in 2D printing you can’t turn on your equipment, press “PRINT” and expect a fully composed letter to come out. It won’t happen unless you first use the word processing software to compose the letter. A similar situation exists in 3D.
To get the printer to work, you first need to learn CAD. Learning any of these programs is time-consuming.
After 2 weeks of study, you will be ready to print out a simple design. After 2 or 3 years you will be able to do things that are astounding, not to mention getting a well-paying job as a software guru.
If you are not yet CAD-ready, you may download a file from the various services that provide 3D models. The number of such services grows regularly so, in theory, you should be in good shape there.
You have no guarantee, though, that these files are all print-ready. Some may have errors, others designed for a printer that is not yours. If you can edit and fix them, fine. The rule that governs such purchases is still Caveat Emptor.
Materials: Basically, FFF is the only really suitable technology for the home at this time. Unfortunately, current FFF printers produce an unappealing surface finish. If you need a nice finish, you also need chemicals to make your object look better.
Materials for 3D FFF printing are not cheap. If you are making small objects the cost is small. If you make large objects, the cost is naturally higher. If you plan to make things in bulk, the cost can be very high, so much so that it would behoove you to look into alternative methods of manufacture.
3D printers are good for awakening one’s creativity. They allow tinkering with new designs and are good for learning about technology. They are especially useful in making unique designs of objects that would be prohibitively costly and slower to make by other methods.
This last feature is particularly appealing to someone who owns an older house that was built several years before plumbing and electrical standards were put in place.
Even a small repair job, however simple and straightforward it may seem, can turn into a major hassle and involve a search of supply houses and specialty shops for parts no longer made.
After that, a call to a plumber or electrician may still be needed. Two or three of those might easily pay for a low-end 3D printer!
Are the materials you will need for your project readily available and economical? Home printers work with a single material. If you plan to use multiple materials, you may need a more expensive machine. Are the materials available locally? If not, factor in shipping costs and time delays into your project.
Home printers have nozzles that clog, moving parts that break down. Can you repair the problems that will inevitably occur? If not, can you get support for your printer, either from the manufacturer, the retailer or locally? How long will service take – a day, a week, several months? If it breaks down and you need to ship it for repairs, who pays for the shipping?
Since you are printing layer by layer in the z-direction, the bonding will be imperfect so that, in effect, you are dealing with a laminated object. Laminates are inherently weaker than an equivalent object that is machined. Will your object have the necessary strength for its intended application?
From a mechanical engineering standpoint, the greater the number of layers, the greater the degradation in its strength. If the object is to sit on a shelf, no problem. If it is to be put to some use if bending is involved, will it be strong enough for all practical purposes?
In the next blog section, we will consider factors that will help you decide whether or not to buy a printer. For now, there are two questions you must answer:
What are you going to do with your printer?
Having thought about and answered that, there is a second:
How much time and effort are you prepared to expend mastering the software that allows you to create 3D models? How much money are you willing to invest?
The two go hand in hand. Answer these, and all other considerations fall into place.
3D Printing Without a 3D Printer
So far we’ve talked about the different kinds of 3D printers, accessories, and different applications of 3D printing, now it’s time to get into more detail on 3D printing itself.
To Buy or Not to Buy
First, the big question – should you buy a 3D printer yourself or use one of the many 3D printing services that are available? For some, the choice to buy or not to buy is a bit easier.
Many companies can invest in a 3D printer (if not an entire line of 3D printers) because they have the capital to afford the printer(s) and know that they will be getting constant use out of the machine. The overhead cost is recouped in manpower savings by letting the printers run overnight.
This allows them to create prototypes and finished products quickly. They can also recoup the cost of the printer(s) and supplies by working with other companies and individuals to offer 3D printing services. On the other hand, a hobbyist looking to purchase a 3D printer without that pool of funds needs to think more carefully about such a purchase.
For both a large company and the hobbyist there are several factors to consider when making the decision to buy a 3D printer. What kind of 3D printer do you want/need? How often are you going to use it? Also, how much are you willing and/or able to spend on the machine?
Let’s start with the kind of printer. We’ve gone over the various different types of 3D printers in previous blogs, so you have an idea of what each kind of printer can do. You need to select the kind of printer you want based on what kind of things you are going to print.
Are you making mostly household décor and gifts, other highly detailed finished products ready to be shipped when printed, or are you printing out prototypes of ideas before sending it off to get printed by a commercial strength 3D printer?
These have different requirements for the kind of filament needed, the space of the print bed, and the print resolution. If you buy before you know what you want to print you might spend a lot of money to find out your printer can’t do what you need it to do.
What kinds of things you want to print will determine what kind of printer you need? After that, you need to look at how much you’re willing to spend. Speaking of money, you can judge the quality of a 3D printer by its cost.
If the price is too good to be true, it usually is. Printers under $600 often require assembly like IKEA furniture (except it’s even less intuitive), have a small print space, and/or have low-quality prints for various reasons.
If you’re trying to figure out how much a 3D printer is going to cost, assume an average of $1200 for an at home non-industrial strength printer. Add on the cost for the filament, usually $30 per roll for ABS/PLA plastics, and you have a large start-up cost.
When choosing a 3D printer you need to decide if having a smaller print space and limited color options (as smaller printers usually only have one print nozzle) is worth the saving a few hundred, or if you want to spend more for a larger machine with more options. Another financial consideration is determining what conditions your printed objects will encounter.
3D print services will have commercial strength printers that are far too expensive for most people to buy and can print in materials that can take a beating and keep on going. On the other hand, if you’re printing out something that doesn’t need to be super strong you can get by with the plastic filament that is used by less expensive printers.
Lastly, how often you intend to use the printer is important. If you will be turning out multiple prints on a regular basis, or need to be able to print on your own schedule, then the upfront cost is worth it.
The convenience of not having to wait for your print to be shipped to you, the quick turnaround of designs, and the savings of being able to print your creations (as opposed to wasting expensive material when creating designs by traditional methods), makes having your own printer a sound investment.
If, on the other hand, you’re new to 3D printing and looking to see what the buzz is about, wanting to print the perfect gift for someone, or doing any kind of work that will only occasionally use a 3D printer, then it’s better to start off with any of the large number of 3D printing services available.
There is no point in investing a few thousand dollars in machine and filament only to have it sit around collecting dust. Meanwhile, using a 3D print service will allow you to test out the quality of various machines and filaments with a much smaller upfront cost.
In summary, if you plan to use a 3D printer frequently, as either part of your work or hobbies, and have a clear idea of what you want to do with your printer then it’s worth the investment.
If you only plan to use a 3D printer occasionally and/or are still figuring out what you want to do with the technology then we highly recommend using one of the many 3D printing services available.
3D Printing Services
If you want to get a model printed but don’t have a 3D printer there are several places that will handle the printing for you. The time and cost to have your model printed will vary from place to place.
Time is usually determined by how complex and how large the print is, as well as what other projects are in the queue at the print location.
Cost is also based on the size of the print, but just as important is the material the model is being printing in. Gold, stainless steel, and other metals will be more expensive than plastics.
In determining price there is the base cost for printing, based on the material, and then an additional cost determined by the volume of the model. If you need more details on pricing, all of the services listed below allow you to upload your model and get a quick price quote.
A simple google search will give you several results for places that offer 3D printing services, with more being added all the time. Below is a list of some of the more popular 3D printing options. Some of these are designed for industrial use, while others are geared toward the hobbyist.
Shapeways is a large 3D printing service. In addition to printing, it has both a 3D model database and a service that connects you to 3D modelers you can hire to design a custom model to be printed.
Shapeways uses industrial strength 3D printers to create high-quality prints, shipped to your door. Each print goes through a checking, post-production, finishing, and quality control phase before it is packed and shipped.
There is a wide variety of materials available, including brass, bronze, gold, full-color sandstone, and of course various kinds of plastics.
They have also spent the past year and a half testing porcelain as a material and are currently working with experienced designers in a pilot program. If those tests succeed, 3D printed porcelain will be available to everyone.
Not sure what material you want? Shapeways can send you material kits so you can see and feel samples of what each material is like. There are three different kits that can be purchased and each ship in 3 business days.
The basic kit costs $30 and includes $25 in store credit. Most prints take 7 – 12 business days. Large prints, and prints using some metals can take up to 20 business days to print.
Solid Concepts focuses on printing for industrial prototypes and components. They have a wide variety of 3D printers including PolyJet, SLA, full 3D color machines, FDM, and cast urethane.
The number of materials available varies for each printer type. Their website details the best applications for models created with each type of printer. In addition, Solid Concepts offers finishing services to smooth out the final product and remove the visible layers.
The time it takes to print a model is generally 2 – 5 business days, though complex prints may take longer.
3D Hubs connects people with 3D printers to people who want something 3D printed. Upload the file you want to be printed and you can get a quote from several different places that can print the file for you, based on your location.
Each print location has reviews, just like Amazon, that rate the printer so you know what to expect. PLA and ABS filament are the most common print material; however, depending on what locations are nearby, you might be able to get a different material.
Each print location also has a Hub Profile which details what 3D printer(s) they use, the cost, the print resolution, material, and colors available for print, and the delivery time.
Once an order is placed, both 3D Hubs and the print location is notified and a 3D Hubs representative is assigned to the order to ensure that everything goes smoothly.
i. Materialize is another 3D printing service geared toward the hobbyist. There are 17 different materials you can choose from, including ceramics, alumide (a combination of aluminum and polyamide powder), various kinds of resin, ABS plastics, and a rubber-like material.
The site is simple and straightforward; simply upload your 3D model and select your material to get a quote and order.
Like Shapeways, it also offers 3D models to purchase and a forum to connect with 3D modelers for a custom design. It has a forum section to discuss ideas with the i.materiaise community and get feedback, and a blog which posts sales and exciting things the company is up to.
The time it takes to print a model is generally 8 – 15 business days, though some materials can take up to 20 business days.
If you happen to live in or near New York NY, Greenwich CT, or Boston MA then you can head over to one of the three MakerBot retail stores and have your model printed. Generally, a model will take 24 hours to print.
However, if the model is small and the store isn’t busy, turnaround time can be as quick as 2 hours. While you’re there you can step into the 3D Photo Booth and get a custom 3D model of your head and shoulders, and/or get an in-store demo from one of the staff. All of the models are printed using plastics.
The UPS Store
Everyone is jumping on the 3D printing bandwagon, and that includes UPS. After a highly successful pilot program, UPS is now offering to print in 48 stores nationwide. The stores are all using the Stratasys uPrint SE Plus printer, which is a higher grade of the 3D printer then the standard at home printers.
While the service is geared toward small businesses, you can print anything from custom cell phone cases to architectural models. The time to print will take anywhere from 4 to 24 hours, depending on how complex the object you want to print is.
3D Model Repositories
So you know where you want to print your model – now you just need the model. There are several places online that will allow you to download 3D models that can be printed.
From there you can either print the files on your own 3D printer, send the file off to be printed by someone else, or in some cases order the file to be printed from the same site that is offering it.
The major differences between the various repositories are the models they have available. If you can’t find something you like from one location, look at another. Every site gives you the .stl file for the model, .stl being the universal “this is an object that is made to be 3D printed” file type.
A .stl file can be read by all 3D printers, so once you have that there is no limitation on what kind of printer you can use.
We’ve already mentioned i.materalise and Shapeways as places that offer both 3D models and 3D printing services. Another newer site along the same lines is Pinshape.
They have a variety of highly detailed models, such as game miniatures and busts of fictional characters, so now you too can have your own bust of Severus Snape on your desk. While most of the models on Pinshape have a cost to download, there is a free section for those who are on a budget.
One of the most popular sites for finding 3D models is Thingiverse. Operated by MakerBot, Thingiverse is one of the largest repositories of 3D models designed for printing. There is a wide range of models from the very simple to the very complex. You can download models designed for gaming, household décor, fashion, and other uses.
If any of the models need to be printed in certain ways then instructions are provided. All of the models can be downloaded for free; however, you either need a 3D printer or must send the files to a printing service to get the final printed model. Other sites that also offer 3D models for download are (but not limited to):
YouMagine: Nearly identically to Thingiverse, YouMagine is run by Ultimaker.
My Mini Factory: This site has a combination of free and paid models available for download. Unlike other repositories, they have a props and costumes section. This gives you access to 3D replicas of swords, guns, and various items from popular movies and games.
Cults: This French site also contains a mix of free and paid models. While it has a smaller selection than others, many of the models are very unique (such as a necklace that looks like a window plant) and are worth checking out.
Autodesk 123D: Another large repository like Thingiverse and YouMagine. All of the models on this site were made using various Autodesk 3D modeling software, such as 123D Design and Meshmixer.
NIH 3D Print Exchange: This site focuses on models for medical uses. The different categories of models available are “Medial and Anatomical”, “Custom Labware”, “Small Molecules”, “Proteins, Macromolecules, and Viruses”, and “Bacteria, Cell, Tissues, Organism.” It also contains a small selection of video tutorials on how to use some types of 3D modeling software.
If the 3D model you select is designed correctly, downloading the .stl is all you need to do. However, you may need to clean up the model using software such as Meshmixer and Autodesk 123D. More information on how to use that kind of software will be covered in the next blog.
For now, all you need to know is that depending on how the model was designed and how large the print space of the 3D printer is, you may have to make some modifications.
For example, you may need to cut the model in half so that it fits in the print space and then glue the pieces together once it has been printed. You may also need to add a support structure to hold up pieces of the model that hang out from the rest.
3D Printing Considerations
When choosing which 3D print service to use there are several things you need to take into account; the time needed to print, the cost of printing, and the quality of the print.
First, the time needed to print. If you need your print done in a hurry that may limit what materials you can use, as some materials can be printed more quickly than others. In general, the larger the model the longer time you will need to account for. Secondly is cost. The higher the quality of the material being printed, the more expensive it will be.
A plastic model will be less expensive than one made in bronze or gold. Lastly, there is quality. Some materials are higher quality than others. Along with quality is choosing the right material.
Some materials are better for household décor then they are for constant wear and tear. You may need to use a higher quality (and possibly more expensive) material if you need your print to be able to withstand some damage.
A 3D Printing Example
To put some of the information we’ve gone over so far in perspective, let’s go over a practical example of using a 3D printing service. For this, we used a 3D model of a ratchet wrench NASA recently sent to their astronauts aboard the International Space Station.
The wrench was designed by Noah Paul-Gin, approved by NASA, and then sent up to the specifically designed 3D printer which operates in a zero-gravity environment on the space station. It’s the first object to be 3D printed in space on request from one of the astronauts. The .stl file for the wrench is available as a free download on NASA’s website.
After downloading the .stl file from the NASA website we uploaded the file to two different 3D printing services, Shapeways and i.materialise. Both sites asked if the model was created using inches or millimeters for measurements. This is done so that the website can accurately determine the dimensions of your model.
We chose millimeters and next were given the option to select the material for the wrench and the make any size adjustments we might want. Along with the list of materials was the price of printing the model in each type of material.
Shapeways also had another step in the process. Their site has a “3D Tool” menu that opens when you upload the model and can be viewed again later if you want to make another print.
This tool analyses the model and looks for possible printing problems. Some of the things it checks for are wall thickness, mesh integrity, part clearance, and detail work on the model (in this case the detail work is the engraved “3 in-lb” on the handle).
It shows a 3D view of the model that you can rotate to see where any problem areas are. All problem areas are marked in yellow and you can click on the category that the issue is in to see why there is a problem.
The tool gives you the option of having it automatically fix the problem areas for you. Once it generates the fixes it will show the new price that includes making the fixes to the model and the cost for printing in your chosen material.
In this case, the tool found three small problems with the wall thickness on one of the moving parts on the back of the model. We chose the auto-fix option and had it printed in “Blue Strong & Flexible Plastic Polished” material. The cost with shipping was roughly $27.
Three days after the order was submitted, we received an email saying the model had passed manual inspection and was being sent to the printer. A week after that came another email saying the model had been shipped, and three days later it arrived. In total, the process took two weeks.
We also tried to print the model with i.materialise. We say tried because a day after the order was submitted we were contacted by one of their Customer Support Engineers. She was worried that the moving parts didn’t have enough clearance and that the model would be printed as one solid piece.
She recommended that internal moving parts have a minimum of 0.8 mm clearance, and asked if we were willing to modify the model. We decided to cancel to order instead and see how the print from Shapeways came out.
Though the final print from Shapeways looks identical to NASA’s final printed wrench, as feared the internal parts were printed solid. This could have been a problem with the model, or with the material that was chosen.
This is a good lesson in working with 3D printing – the first print will often not be perfect. You will need to make modifications after seeing the first result in order to refine the print and get your print to come out exactly as you want. This is a problem you will encounter if you use a printing service or own your own printer.
Sometimes the internal temperate of the printer was off. Other times the model had walls that were too thin and the support structure melded together with the model.
One small model of Cinderella’s Castle in Disney World had too fine a detail for its size, and so the area around the towers looked like a mess. Whether the fault lies with the machine or the design of the model, mistakes will happen. 3D printing is an iterative process. Be prepared to have a few messes when you start out.