Looking at building my first printer. A few questions

[brad91]

Hi everyone,

Im new to the whole 3d printer world and looking at building one to form a business. I am a design draftsman currently so know my way around autocad and inventor.

Im wanting to build parts for cars. Replacement parts that you can no longer buy and also new things. Anyway a few questions I have:

Has anybody ever tried to print a complete bodykit for a car? (fiberglass sucks so was hoping I could build something big enough and print entire bodykits?)

If so, what plastic would I need? It would need to have a little bit of flex to it.

What style of printer is best? From my research the only affordable and way I can see building something as big as I want is to use FDM.

What sort of finish am I going to be able to get? If im doing parts for cars to paint and finish how smooth am I going to be able to get the finish?

Is there anything else I need to know? A mate of mine has built a cnc router and is giving me his contacts for the extrusions and ballscrews I will need to build the frame easily.

Also to anyone who runs a business. Is there much of a market for 3d parts? Especially on the larger scale?

Thanks heaps guys,

Brad

[awerby]

That sounds like an ambitious project. Have you ever built any machines before? Have you got a well-equipped shop with enough space to build something like this? It really helps to have machine tools for making all the motor mounting plates and other precision components that make the difference between a machine that works and one that just jams.

While it's pretty common for people to assemble their own (small) printers from kits, it's less so for people to successfully scratch-build one. And while the FDM 3D printing process generally works okay on a small scale, there are problems with doing it on a large one. For one thing, plastic parts tend to warp severely as their size increases, especially if you use the more durable plastics like ABS. And while small parts take a matter of hours to build, if you try to print at the same fineness at a much larger scale, it might take days or even weeks. You can print faster if you sacrifice surface finish, but even the finest FDM printed surfaces aren't as good as real car body parts, and they are not nearly as strong and durable.

There have been some companies that have built car bodies using the FDM process, so it's not impossible to do. But they weren't doing it on home-built printers, and they had the support of a company to back them up. These examples might be inspirational: https://all3dp.com/3d-printed-car/ as long as you don't ask how much they cost to build...

As for the business idea, it could work, but the problem is that if you're doing custom parts, each one will be different, it will have to fit with the existing parts and function as well as the original. Often car parts are not just a piece of plastic, but have metal pieces or electrical components embedded. Just designing parts like that will be a challenge, let alone selling them at a price the owners will want to pay. A guarantee that they will continue to work is another thing customers will expect that you might not want to provide.

If you've got a friend with a CNC router, maybe you could purchase an extruder you can bolt onto it instead of the spindle and try printing some things. If that works, you could think about building something similar. If not, you'll have saved a lot of time and money. Or better yet, use it to carve some foam plugs you can lay up composite body panels on, which would likely work much better than anything you could print.

But good luck, and let us know how it goes, okay?

Andrew Werby
www.computersculpture.com