View Single Post
  #6   Spotlight this post!  
Unread 23-01-2002, 03:56
Jon Lawton Jon Lawton is offline
Bitter FIRST Cynic
no team
 
Join Date: Oct 2001
Location: San Jose, California
Posts: 209
Jon Lawton is an unknown quantity at this point
Send a message via ICQ to Jon Lawton Send a message via AIM to Jon Lawton
Quote:
Originally posted by Anton Abaya
how do you calculate the traction of your wheels/treads/drive train traction into in-lbs?

i'm curious to figure ours out.
Okay... well... I'm no engeneer (not even close) but this is how I wound up understanding:

Get a fish scale. Hook it to your robot parallel to the plane the center of your wheels are on. Increase power to motors until you loose traction. You can use the dashboard port to see the PWM value you were at, and I think you could then extrapolate the torque/rpm of the motor at the time. Why the scale? The force you should read should be equal to your coefficent of friction times your normal force (weight). F=uM.

Since we know a goal takes 32-35lb of force to move, you can use this little test to see if you really can move four!

Like I said, I'm not the mechanics man, so can a more authoritative source back me up on this?