While this post is regarding using the VersaPlanetaries with a pneumatic wheel, I figured I would post it here after all the other postings about powering shooter wheels off of the VersaPlanetary.
My team's competition robot is currently running a two 8" pneumatic wheel linear shooter directly driven by CIM motors that were attached to a machined step shaft via a coupling. We found this setup to cause extreme vibrations and our small couplings would often come loose.
I believed that these vibrations (which I thought had to do with the lack of concentricity with our setup) also caused y-variability with our shooter so on our practice robot we are trying to run the 8" pneumatic wheels directly off of the 3:1 VersaPlanetary with an RS-550 on each. Looking at the motor curves, I figured that we could get close to the ~4500 r/min that we had with the CIM with this setup. Perhaps I am wrong.
When we tried powering the VersaPlanetary (with the Pneumatic wheel attached via 1/2" shaft and 1/8" keyway) using an FRC battery, the wheel would quickly get up to speed however after about 10 seconds a burning smell developed and we could see smoke coming out of the gearbox, not the motor.
We applied white-lithium grease moderately and did our best to follow the instructions for assembling the gearbox and motor.
From those more experienced than I, should I even be trying to direct drive a pneumatic wheel with the VersaPlanetary at 3:1 with the 550? Do you even think I could get the wheel up to 5000 r/min?
On to the smoke problem- should I try spacing out the motor mounting plate? It is not too hard to spin the output shaft by hand however it is pretty jerky. We inspected the gearbox afterwards and it appeared fine. Should we just try reassembling the motor onto the gearbox?
Also, it heated up quickly when powered on.
Hopefully Paul Copioli will see this and offer some advice.
Thanks!
Quote:
Originally Posted by TD78
Bob, when I set up a BB 550 (motor was purchased two years) in a 10:1 VP, I had trouble getting the gearbox to spin while powered. I could turn the shaft by hand (with a wheel on it - slightly difficult), but when I put it on a power supply, the shaft wouldn't spin at all and the current spiked rather quickly. I did not find this problem with the BAG motor installed 1:1. After much testing individual components, I eventually spaced the BB 550 motor plate from the gearbox with thin washers. This appeared to relieve some pressure between the motor (either the shaft or the face of the motor) and the gearbox. I notified VEX support and Paul sent me two things to try:
"1. As you suspect, the RS-550 shaft that you have may be a bit longer than we have tested and the end of the shaft may be pressing against the gear. To test this, please remove the input sun gear while the motor is installed to see if it sticks into the same space the gear should be.
2. The clamping hub and bolts are fighting each other. In order to get around this, try only using to bolts to mount the motor plate and tighten them after you have tightened the coupler."
I did not try either though, because my team had decided to go with a double BAG motor setup. Maybe you're seeing something similar?
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