Sanddrag,
We are using these motors and gearboxes on our arm. The gearboxes are 64:1 and there is an additional 40:1 worm gear setup being driven by the banebots gearmotor. The motor emits smoke very quickly if operated at partial load in a manner that stalls the motor. By quickly, I mean in a few seconds.
Our arm is run with the motor at full power to get it where it needs to be as quickly as possible and the motor them is then shut completely off. This can be done using feedback from a pot. You want to gear your arm so that the motor can be run at full speed and with an anti-back drive setup so that you don't need partial power to balance a load, or your motor will very quickly resemble burnt toast on the inside.
The FP motors have more power and are more robust, but will also emit their magic smoke if you abuse them. The FP motors can easily be adapted to the banebots gear box. If you do this, you can make a spacer that allows the fan in the motor to draw air through the motor as it runs. You may, or may not, need the FP motors elsewhere on your robot.
Before anyone writes anything disparaging about the banebots motors, I would like to remind everyone that all the motors that we have had in the KOP over the years have had their limitations and it has always been our job to sort out those limitations. We use the motors in a manner that keeps their limitations in mind. The banebots motors are perfectly useful, within their limitations. Running the banebots motors at stall, even at partial power, is operating them outside of their envelope. Running the banebots gearboxes with any radial or axial loading on the shaft is also operating them outside of their envelope. If you do either of these things, the motor and/or gear box won't last long.
Eugene
Quote:
Originally Posted by sanddrag
We are having a serious issue with the small bane bots motor in the 64:1 gearbox in the kit. This exact problem has also been reported by three other teams I have talked to. The scenario was lifting a rather light weight arm that was not terribly long. There was additional reduction after the gearbox, in the range from 2:1 to 9:1. Calculations show that even in the 2:1 scenario (my team), the drive should have powered the arm rapidly with more than enough torque available. The arm was unable to lift, and the motor started smoking as soon as it enountered any sort of real load. This problem was encountered the very first time the motor was tested in a load condition. This is the same problem three other teams have reported to me. The motor never once tripped a breaker (20A on my team), which, if it was stalling (spec'd) stall current about 37 amps isn't it?) it really should have. And it should trip a breaker before it ever starts smoking.
So, I don't know what's going on here. Post if it happened to you, and post if you know why.
|