View Single Post
  #10   Spotlight this post!  
Unread 30-01-2006, 09:37
Andy A. Andy A. is offline
Getting old
FRC #0095
Team Role: Coach
 
Join Date: Jun 2001
Rookie Year: 2001
Location: New Hampshire
Posts: 1,015
Andy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond repute
Re: Andy Mark Planetary + side load

Side loads on most motors won't kill them outright, but it sure isn't healthy for them.

The rotor of a motor is supported at two places, one at each end of the motor can, usually with bushings. By placing a side load directly on a motor you drastically increase the amount of friction between the shaft and bushings with a corresponding drastic decrease in power output. Really heavy loading might wear the bushings enough to pull the rotor out of alignment in the can, upsetting the magnetic fields. The motor could probably handle that kind of abuse for a season, but you would be putting an enormous strain on it and loosing a lot of power in the process.

As for the AM planetary, I think it's clear that it's not a good idea to use it with anything more then a small spur gear. And even then, you should be very careful that that gear has a nice clean mesh with what ever it drives. If you really wanted, you could support the end of the output shaft and eliminate that load, but it might be more trouble that it's worth. As always, the final say is with Andy or Mark, but they'd probably tell you the same thing.

As a side note, the globe motor and it's planetary gear set die quickly when side loaded. Always be careful of cantilevered shafts! They spell doom for FIRST teams.

-Andy A.