We eat, sleep, breath and dream 3D printers. We're also well aware that we're not the norm and some people are just starting to learn about our obsession. As the printers gain popularity and start getting talked about more and more, we've noticed that there are a few misconceptions about the technology. Rather than turning a blind eye, we're taking a page out of the MythBusters' playbook and setting the record straight.
#1: Plastic is delicate.
"Will it break?" I hear this question a lot as I meet with people and what they are really saying is, “I think that plastic parts are fragile.” There is some truth in the thought that plastic doesn’t have the strength that metal has, however, there are a lot of places that plastics shine. The strength of a printed part varies by material, orientation of the printed part, technology of the printed part but after all is said and done, the plastic parts do have a place in the engineering world.
|High-performance FDM polymers, like ULTEM 9085 and Nylon 12CF are extremely strong. This sample is metal bending tool that can take compressive forces exceeding 10,000 PSI.|
#2: You need an .STL file.
"You can't print this, can you?" My friend asked me this as he handed me a broken clip from his car. Immediately I asked, "Does an electronic 3D file already exist?" The electronic file that 3D printers need is called an .STL file. The .STL file holds the geometry of the part that is going to be printed and if you don’t have an .STL file, then you need some type of 3D CAD software to electronically create the part and then export that CAD file as an .STL file. There are exceptions to the .STL file rule, but for general purposes, you need an .STL file. Of course, he didn’t know the answer, but he expects that you just walk up to the printer and think what you would like to have printed and the printer will print you out an exact copy.
|Sketches are good for ideas - but at some point, a fully modeled 3D file like those created within SOLIDWORKS must be generated.|
#3: 3D printers can only print in a single color at a time.
"Wait, this was printed at one time together?!" The shocked expression of this realization always makes me smile because the light bulb goes on for whoever is making this realization. There are many ways that 3D printing has helped the engineering community but being able to print multiple parts as an assembly and multiple colors/textures at one time are some of the bigger advantages.
|3D printing allows for both fully printed assemblies and the ability to design parts that combine components and assemblies into a single part to reduce part counts and complexity.|
#4: You can't print in metal.
"This was printed? I thought it came from a store!" There is a general expectation that metal printing is a far off concept, and that just isn’t true. There are several forms of metal 3D printing out today and while some of them are really expensive in terms of machines, there are several technologies that are emerging that are bringing metal printing closer to the price of plastic printing. The traditional way of 3D metal printing is direct metal laser sintering, or DMLS, and it uses a high-powered laser beam to melt the powder in just the right spot. Some of the newer technologies are using a bound metal deposition process, where the metal powder and binder are mixed into a rod shape. The rod is then extruded, and the part is printed one layer at a time for a similar result as a fused metal deposition. These technologies are the beginning wave of how metal parts will be prototyped and manufactured in the near future. With that said, metal printing isn’t the same and should be treated differently, but metal printing is a good slice of the 3D printing pie.
|Metal 3D printing is a reality with systems like producing functional parts out of stainless steel alloys.|
#5: Complexity is free.
The last misconception that I would like to address is a big part of the previous misconception and that is that 3D printing, “complexity is free.” In the plastic world, there is a good bit of truth to that statement and you can certainly 3D print parts that you can’t machine or at least can’t machine easily, quickly or cheaply. However, in the metal world, there are many types of geometries that don’t lend themselves well to metal printing at this point. Depending on the size, thin wall structures, post-processing, etc. required to get a finished part are some of the discussion points when thinking about whether or not a part is printable by current metal 3D printers.
So while these aren’t all the misconceptions that I have run across, they represent some good ideas to think about. What have you run across in regards to thoughts or ideas that aren’t necessarily true in 3D printing? Leave your comments below.
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