The window motor is being mean to me...

[archiver]

Posted by Ed at 03/29/2001 7:02 PM EST


Other on team #461, West Side Boiler Invasion, from Purdue University and Purdue University.



Hi, I was hoping to obtain some help with the window motors. For some reason, when our motor turns, it rotates much faster in one direction than the other. On the side that rotates slower there also seems to be a slight delay before it starts moving. I have checked the program and it is either outputting 250 or 5, so I don't think that the problem is in the code. I have also tried calibrating the speed controller and this doesn't seem to fix the problem. The torque that is needed in both directions of the motor’s motion is nearly identical. I don't know what to do to correct this problem. Any suggestions? Thanks, Ed

[archiver]

Posted by Ed Sparks at 03/29/2001 7:22 PM EST


Engineer on team #34, The Rockets, from Bob Jones High / New Century High and DaimlerChrysler.


In Reply to: The window motor is being mean to me...
Posted by Ed on 03/29/2001 7:02 PM EST:



Have you tried a different motor ?

[archiver]

Posted by Joe Johnson at 03/29/2001 8:42 PM EST


Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.


In Reply to: The window motor is being mean to me...
Posted by Ed on 03/29/2001 7:02 PM EST:



Unlike the skepticism I have shown on the drill motors,
when it comes to the window motors I know for a fact
that there is a significant performance difference in
the CW and CCW directions of rotations.

It has to do with the relative effeciencies of the
thrust bearings on the armature.

So... that may be your problem. OR it could be wiring,
programming or even a bad Victor.

Have you tried flipping the leads of the motor and
seeing if the direction of the lag changes? If it does
then it is probably the Victor or some sort of coding
error. For one thing, I would revert to the standard
Victor Calibration (see the Victor Manual).

If flipping the wires on the motor does not change
direction of the slow rotation, then your motor or the
mechanism that it is driving is likely the problem. I
would try trading motors (RH for LH and LH for RH). If
the behavior follows the motor, you have your culprit.
If not, then I would look hard at the mechanism. Are
you SURE you are loading the motor the same in both
directions?

One final thing to try (perhaps try this even earlier)
is to hook up 12V directly to the motor leads in one
direction and then the other. If the problem goes
away, look to the Victors, the wiring or the PBASIC coding.

Good luck.

Joe J.

P.S. Track me down in the Pits at FL if you cannot
resolve this problem with the above tests. JJ