by LoialOtter, published
This is a work in progress of an RC nerf tank I'm working on. It uses some advanced gear designs, printed tracks, mainly printed components overall, will look cool and should be very functional.
This was printed on Tiny, my overly large 3d printer. More info available at https://ottersoft.ca/
Oh, and the gear is supposed to run backwards to push the treads forwards. That is by design... I think it looks cooler that way.
I've got a video on it running now thanks to Marginally Clever (Dan) at Vancouver Hackspace - https://www.youtube.com/watch?v=JJc0kGrgPCs
I use a numbering system with the format so I'll be referring to everything by number.
What you will need (so far):
M4x30mm bolts - socket head x6
M5x25mm bolts - socket head x14
624ZZ bearings - 13ODx4IDx5mm x12
2 sections of treads (http://www.thingiverse.com/thing:35668)
- you'll need 84 links in total
Print (please note that some parts may need to be rotated or flipped):
8021-P02 x8 (note that these are different from my other release sprockets)
8021-G01-P04A x2 (mirror one)
8021-G01-P04B x2 (mirror one) - Updated Dec 9th
- means they can optionally be printed half mirrored but if one is mirrored, all must be (herringbone gears)
Assembly is a bit of a pain but can be done. Make sure all parts are free of stuff first.
To assemble the planetary gear:
1) screw the bearings onto the narrow (straight toothed) end of the planets
2) start with the planets loose with the sun and output ring (the one that engages the track)
3) Place the ring smooth side down and hold the sun around the center of it but up a little
4) angle the planets in so they match up with the centers of both the sun and ring
5) press down so they go flat
6) check against the planet holder, if the teeth are off adjust by twisting needle nose pliers so one point is grabbing the sun and the other the planet that's off (yes, it's a little annoying)
7) Place the bearings into the inside planet holder
8) press the planet holders in on both sides using a flat vice if necessary
9) screw planet holder together
10) Slide gear assembly onto the outside fixed ring with body
The drive may require some wear-in using a drill or other high torque motor.
Assemble the tracks, you'll need 42 links per side.