3D Printing & Prototypes
Just print it! That’s been a dream of engineers and inventors for ages and now 3D printing prototypes are common. But are they worth it? That depends on the purpose of the prototype. So, What do you want make?
Past And Present
At first, Rapid Prototyping Machines were a novelty, yet they captured the imagination of engineers everywhere. They were expensive, but they changed the landscape of prototyping. Fast forward, and pretty suddenly prices dropped. A simple FDM style machine, became known as a 3D Printer and though prices were great, quality was lacking.
With time, the tech is maturing. Prices are more stable and quality is up — meaning it doesn’t take as much time and fiddling and spare parts to keep them running.
Modern methods of 3D Printing prototypes coupled with unlikely service bureaus have placed new parts and capabilities within easy reach. Many schools have them. Libraries like PPLD now have them available for patrons to come in and use — just take a class then pay for material. Maker spaces are popping up all over where you can come and build whatever you want — usually with some training and membership fees.
Comparing 3D Printing Prototypes
Prototypes are a big part of Product Development. Often when prototypes are mentioned, 3D printing prototypes, FDM (Fused Deposition Modeling), are what pops in mind. However, that is not the only type available.
See this good article for some explanations on various prototyping methods.
At one point SLA (Stereolithography) was king. Then SLS (Selective Laser Sintering) came on strong, and now FDM, because of cost and availability is the most common. Choosing the right prototype process is important to getting the desired result. Different methods use different types of materials and yield very different results — both in look and in strength. Look at these photos. It’s the same part via different processes.
Differences In 3D Prototypes
Two things worth noting are: First, the part finish. Second, the strength.
- The finish that looks like fishing line laid in nicely is typical of 3D Printers. The sandpaperish look is typical of LS and MJF.
- You can’t see strength, but the LS Nylon and the MJF are much stronger and more rigid than the ABS. (MJF is the strongest.) And, the fit is more accurate with the MJF process.
My go-to prototype process is LS Nylon because it’s relatively cheap and fast, and because it’s pretty strong. MJF is not as cheap, but it’s stronger, and you can do finer details. Both of these machine pretty well if you need to drill a hole or add threads or something simple. MJF does not sand very well, however. All of them glue quite well so it’s easy to combine parts or add other materials.
Other Rapid Prototype Processes
There are a ton of other ways to get prototypes made — from the classic CNC prototypes that still can’t be beat for strength or for replicating finished metal parts — to several other ways of 3D printing.
Pros and Cons for 3D Printing and CNC Machining has more info. Then, there are prototypes that use a combination of technologies — like this example of mixed materials.
One other method of 3D printing prototypes worth noting is almost the oldest. SLA is probably the most refined process of all. The parts can come out looking awesome and with just a little surface finishing (sanding) can look perfect. Bunches of materials are available — even “water clear” that looks like glass. At one point SLA was so fragile that if you sneezed it would shatter, but now the materials are so much better — including polycarbonate. Expense is the limitation with these.
3D printing prototypes in Metals are now the cutting edge. There are several processes and lots of research currently going into this area. Things are changing and improving fast. Read the expert sites to know the latest on these methods.
With all the new technology available, we still drop back to bailing wire, duct tape and some ingenuity the most. As a first cut, the best proof of concept prototypes are the ones cobbled from scraps in the garage. Don’t ever be afraid or ashamed of doing that. Paper machete and playdough too are awesome for prototyping! They are not as “cool” perhaps as 3D printing, but don’t forget how easy and wonderful and flexible these “old time” prototyping methods really are.
The Purpose Of Writing
At Synthesis, we are not the experts in prototyping — not by a long shot. Yes, we keep up with the trends, and we do make a lot of prototypes for our customers, but we rely on the experts to guide us with new technologies for each project. Like our experiments with Prototyping Foam, we also push the boundaries to accomplish our customer goals. That’s part of who we are.
This post is simply to let you think a little deeper about potential options. Choosing the right process can make all the difference in 3D printing prototypes, but often 3D Printing is not the right answer. For more on that, you need to think about Why We Make Prototypes. Defining the real needs — questions — is the best place to start.