Quote:
Originally Posted by Hieb
Perhaps someone can help me out here then (now that it's after the fact for us). I thought I had done the calculations correctly, but apparently not.
I had a 3.5 foot arm, total weight about 6 pounds. Using the 540 motor into the 64:1 gearbox, we then stepped down 28:10 and 70:10. The few times before shipping that we were able to test the arm it worked fine except for the backdrive. Then on ship day we fried the motor while driving it to the crate.
On Thursday we replaced the motor and swapped the 64:1 with a 125:1 gearbox. We proceded to fry 2 more motors before scrapping motors and switching to pneumatics (which were also abandoned for lack of time and a better strategy).
Also of note--we had a 20 amp breaker on the motor (stall current 42 amps) and in one practice match we completely drained a battery and the motor smoked with only 2 seconds left in the match.
Have I just messed up my calcs and completly abused these poor motors, or is there another issue here?
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Not sure if I can help, but have a question....
Are you sure that you fried the motors???? We had some problems (you can read in a previous post in this thread) with these motors, thought we had fried the motors, but ended up a transmission problem.
You might want to take the transmissions apart and check the final stage of the planetary gears, where it meets the drive shaft. Also, check the motor when it is disconnected from the transmission.