Quote:
Originally Posted by Ari423
The reason for the big weight difference is that all-20dp COTS gearboxes need 3 stages for the same reduction, and the extra stage adds a lot of weight. I will consider adding more plate to support the CIMs from bending. The shifting shaft is custom because the dog gear is from AndyMark while the rest of the shifting mechanism is Vex. The AM dog gear is 1/2" hex and the Vex one is 5/8" hex, so I would have to use Vex's output shaft to use Vex's dog gear.
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You can accomplish the same reduction you have in two stages of 20dp gears for a similar weight. And while an extra stage adds weight, it's definitely not a whole pound's worth. Why are you using the AM DOG gear? Just use the DOG gear and shifter shaft from the WCP DS - it's easier than making your own and the larger hex on the DOG makes spacing the bearings super simple.
Quote:
Originally Posted by Ari423
The pneumatic cylinder only has one plate, which screws into the rear plate of the gearbox. I tried to constrain the bearings on the output shaft by squeezing the flanges in between the plates. The dog gear means I can't put spacers between the gears, so the bearings could slide inward. I would use a screw and washer to constrain them, but in the front there is a shaft sticking out (i.e. it's not the end of the shaft) and in the back the shifter shaft goes through the center so I can't put a screw there. If there's something obvious I'm missing, please hit me on the side of the head with knowledge.
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Like I said earlier, using the WCP DS output shaft and DOG gear solve the issue with the bearings sliding inwards. And check out the WCP DS model and you'll see how bolt heads retain the bearing flange.