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Unread 19-02-2004, 13:58
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,798
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Re: Drill Motor + Gearbox + Breaker Problems

Quote:
Originally Posted by sear_yoda
no, we're outside of detroit
Ok,
I can't run over there this afternoon, but you have a lot of teams close by that could give you some help if they were to see this in action. You have removed the locking pawl from the drill transmission, haven't you?
My advice again is remove the drill motor and transmission and the driving shaft. The remaining shaft with wheel on should turn freely. If that is OK then, put the robot on the floor and try to push it. It should just keep going by itself, in a straight line. If it doesn't keep going but goes straight then the bearing on the wheel shafts are not in alignment. If it rolls, but not straight then you do not have the wheels parallel.
If all of that works OK then put the driving shaft back in and check everything again. Remember that the driving shaft and driven shaft must be perpindicular else there is side friction on the gear faces. Check that the gears are in correct mesh alignment. This is a hard one. Visualize a line perpindicular to each shaft (as if drawn on the face of the gear.) Those lines should meet perfectly. If the tangent of the driven gear is not aligned with the center line of the driving gear, additional friction is built up. If all of that is OK, you should be able to set the wheel in motion by turning the hex coupler on the driving shaft and the wheel should continue to turn by itself for a few seconds. It make take a little trial and error to get everything to the point where it can make this test. When it is all moving freely, put it back on the floor and test again. There should be a significant improvement. Once that is OK, put the drill and transmission back in and try powering the motors again off the floor. Again the drive should free wheel after you remove the driving power if you have the speed controller set to "coast". If all of this is OK then put the robot back on the floor and try to drive. If everything was OK up until now and the breakers still trip, you may have to add a bearing to the wheel shaft. The weight of the robot may be putting too great a load on the bearing you are using. Let me know what you find. I will check in again in an hour.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.