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Re: 3D printed parts
Like other posters have mentioned the parts are legal and we have been putting parts on the robot for several years. We currently have 8 3D printers in the school we work out of (6 of them were built from kits by students) plus I have 3 at home. The other day we had 7 of them all printing jobs at once.
The key is what kind of stress is the part under.
We started out printing little wrenches as hand outs.
We print a lot of covers and caps for electronics and motors.
We have designed and printed multiple encoder mounting solutions.
Camera and sensor cases are another use.
And we have printed a few more functional mechanical parts.
For Aerial Assist we 3D printed the shaft coupler for our intake. For that item we used Nylon and printed it lying flat so that the layer bonding was not subject to a lot of stress but then we had to make sure the shaft hole bridged properly.
The key is to design the part for 3D printing making note of: overhangs, bridges, wall thickness, and what axis for layer bonding vs stress. For example, vertical wall thickness should be kept as thin as possible as thick walls will often cause warping. Depending on the application, I like to make my walls all a multiple of the extrusion width. Another tip is to make sure you use fillets to strengthen joints.
Time is another issue. We are printing some gear box covers now that are 9+ hour prints. This is hard in a school as we can not have printers running when we are not there. (Hence we print stuff on my printers at my house where I have a fire suppression system installed.) Any parts you don't bag would be considered part of your withholding allowance, but thankfully they do not weigh a whole lot.
Materials are becoming more and more varied. PLA is nice but brittle. ABS is less brittle but warps. Various nylons have become some of our favorites given their high tensile strength and good layer bonding. PET-G is another good alternative to ABS. We have printed some flexible rubber items, and I am looking to test print some foam like parts for this year also.
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