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Gearboxes,
We have had incredible luck by building our own, both the shifters and swerve boxes. I had no problems using 1/8” aluminum for the side plates as long as you aren’t using the gearbox as a structural member of the robot. If you were, I would then increase its rigidity accordingly (Thicker Aluminum or possibly a 90 degree break on each side (See Wildstang Pics). As for bearings, we used the same as the above posts, flanged pressed in from the inside of the gearbox so they are captured. The amount of press fit, we fond not to be real important, it definitely shouldn’t be so tight you end up crimping the outside of the bearing to get it into place, maybe .005 undersized hole. Now as for creating the gearbox. CNC sure helps but it is in no way required to have CNC to build the side plates. You can easily use a manual mill that has a Digital Readout as long as you have big enough cutters to cut out the bearing holes. Start by squaring up your piece, then using an edge finder locate the exact edges and zero out the display. Now drill & mill out all of the holes. The three fingers on the shifter can be done on an ordinary rotary table, again CNC not required. The most important dimensions to consider are the center to center distance between the gears to keep the meshing correct. We always add .005 to the distance to allow some clearance for the junk that gets in the box. Lastly for the CIM motor, we pressed our gear assembly onto the CIM motor instead of using a keyway. Measure the output shaft, find a drill slightly smaller, then put the gear on with some green locktite. It pretty much is never coming off now but we have found the CIM motor to be pretty robust and it never failed like the drills and FP in competition so it wasn’t a problem.
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Robonaut Next Generation Control System Development
2003 GLR Champions (302,67,226)
2003 Buckeye Semi-Finalists(902,494,226)
2002 Nationals QuarterFinalists
2001 West MI QuarterFinalists
2000 GLR Semi-Finalists
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