Go to Post And - I would never ever underestimate a rookie. Ever. - JaneYoung [more]
Home
Go Back   Chief Delphi > Technical > Motors
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
 
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 09-02-2017, 09:32
Garrin's Avatar
Garrin Garrin is offline
Registered User
AKA: Ranger
FRC #5720 (Jagobotics)
Team Role: Coach
 
Join Date: Feb 2017
Rookie Year: 2015
Location: Minnesota
Posts: 4
Garrin is an unknown quantity at this point
Re: Motor Speed offset

Quote:
Originally Posted by GeeTwo View Post
OK, there's definitely something fishy on that Talon or something feeding it.

Try swapping the PWM cables between that Talon and the Talon which controls the other motor on the same gearbox. If the problem moves, it's your PWM cable, RIO, or software (in decreasing likelihood). If cable or software, the fix is easy and not too expensive, and hopefully obvious. If the RIO, your best bet for now is to move the control to another DIO port, both in software and hardware.

If the problem stays with the same Talon, try swapping it to another PDP port, and (separately) to another breaker.

Edit: Try swapping the motors on the same gearbox between the talons to make sure you don't have a motor overloading the breaker.

If none of these fix the issue, sounds like a bad Talon. Fixing that is probably beyond online advice. Replace it; if it's new, try to get the replacement from the vendor.
Thanks for the advice. Using your idea we found the electrical gremlin. We had a few bad PMW cables, and one that was crossed in the wrong direction. I appreciate everyone's help in the matter.

Thank you!
Reply With Quote
  #2   Spotlight this post!  
Unread 09-02-2017, 10:12
FrankJ's Avatar
FrankJ FrankJ is offline
Robot Mentor
FRC #2974 (WALT)
Team Role: Mentor
 
Join Date: Feb 2011
Rookie Year: 2009
Location: Marietta GA
Posts: 1,954
FrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond reputeFrankJ has a reputation beyond repute
Re: Motor Speed offset

A quick dividing line in troubleshooting these kinds of issues: Mechanical issues doesn't come & go. Compare the drag of one side to the other by turning the wheels through a couple of rotations. If one side is harder to turn than the other, you have mechanical issues. Otherwise it is probably electrical.

Get in the habit of observing the status lights on the controllers. Motors pairs should be blinking at roughly the same rate and color. If you are consistent with your motor wiring, Colors on the right side & left side will be different with a non zero command. I have occasionally found CIMs to spin backwards. --With red positive it spins CW rather than the normal CCW
__________________
If you don't know what you should hook up then you should read a data sheet
Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 17:23.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi