Go to Post In Dave We Trust :) - JohnBoucher [more]
Home
Go Back   Chief Delphi > Technical > Electrical
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 16-02-2003, 20:30
Richard Wallace's Avatar
Richard Wallace Richard Wallace is offline
I live for the details.
FRC #3620 (Average Joes)
Team Role: Engineer
 
Join Date: Jan 2003
Rookie Year: 1996
Location: Southwestern Michigan
Posts: 3,667
Richard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond repute
Bad 40A Breaker

Our robot was veering to the left when climbing the ramp. The right side drive stopped working about 2/3 up, resulting an an unplanned U-turn followed by a speedy return to the carpet, after which normal control returned.

Our drivetrain uses two Bosch drill motors, pins removed, shifter ring internally locked in low gear with a spacer we made. The second reduction stage is the 2:1 helical gear set that came in the kit. Our front drive wheels are 9" pneumatics, and we use two 80mm omni-wheels as rear casters.

We spent quite a while checking and changing elements of our drivetrain, trying to isolate the problem.

We checked to be sure the friction was the same on both sides, by manually rotating the wheels and then by free-rolling the robot down the ramp with the power off. No difference observed between right and left, and the 'bot rolled straight down the ramp and continued across the carpet several feet.

We removed and replaced the right side motor controller, with no effect. Then we removed and replaced the right side motor (leaving the gearbox in place), again with no effect.

We checked and rechecked our wiring, our software, our custom electronics -- all with no effect.

Finally we tried swapping the right and left 40A breakers. That made the 'bot veer right instead of left.

Aha!

So we replaced the offending 40A breaker and have not seen the problem since.

Apparently some 40A breakers are more sensitive than others.

Has anyone else seen something like this?
__________________
Richard Wallace

Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003

I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)
  #2   Spotlight this post!  
Unread 17-02-2003, 15:49
Josh Hambright's Avatar
Josh Hambright Josh Hambright is offline
{Error Processing Custom Title}
AKA: oneangrydwarf/jtosh
no team (old school gangsta)
Team Role: Alumni
 
Join Date: Apr 2002
Rookie Year: 2000
Location: Indiana
Posts: 1,421
Josh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond reputeJosh Hambright has a reputation beyond repute
Send a message via AIM to Josh Hambright
as of yet ours are working fine. though we have been draining our batteries pretty fast.
__________________
Former 461 Student/Mentor. Former 1272 and 1018 Mentor. Team 1555 Super-Fan.
Science and Engineering Can Open New Doors. --S.E.C.O.N.D.--
=~=!=@= #=$=%=
Co-Founder IndianaFIRST

Share your FIRST photos on Flickr!
  #3   Spotlight this post!  
Unread 18-02-2003, 21:33
Richard Wallace's Avatar
Richard Wallace Richard Wallace is offline
I live for the details.
FRC #3620 (Average Joes)
Team Role: Engineer
 
Join Date: Jan 2003
Rookie Year: 1996
Location: Southwestern Michigan
Posts: 3,667
Richard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond repute
More on the Bad 40A Breaker

I got some time to test the bad breaker today. Connected it to a regulated laboratory power supply, Sorensen model DCS 20-150, in regulated current mode. Increased the current slowly and saw nothing unexpected until it reached about 30A. At that point its started switching on and off very rapidly. This is consistent with the behavior observed when the bad relay was in our robot.

Seems that we damaged it somehow, or maybe it was bad from the start.

Again, has anyone seen similar 40A breaker behavior?
__________________
Richard Wallace

Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003

I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)
  #4   Spotlight this post!  
Unread 18-02-2003, 21:42
oracle_nick oracle_nick is offline
Registered User
#1103
 
Join Date: Feb 2003
Location: Delavan, Wisconsin
Posts: 5
oracle_nick is an unknown quantity at this point
Send a message via Yahoo to oracle_nick
We (team 1103) had the same problem with a 40a breaker. Lucky enough for us we were able to get rid of it and not have any problems.
Closed Thread


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
40A Breakers popping when using CIMs galewind Electrical 9 13-02-2003 10:30
Keyang Motor Thermal breaker. archiver 2000 1 24-06-2002 00:24
Pump Problems... archiver 2001 2 23-06-2002 23:58
60 amp breaker Anne Lam Technical Discussion 10 10-01-2002 15:13
Chain and chain breaker source? kmcclary Off-Season Events 4 22-10-2001 22:51


All times are GMT -5. The time now is 15:03.

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