View Single Post
  #8   Spotlight this post!  
Unread 31-10-2010, 18:22
lbarger's Avatar
lbarger lbarger is offline
Senior LRI NC District
AKA: Lee Barger
FRC #0587 (The Hedgehogs)
Team Role: Mentor
 
Join Date: Dec 2005
Rookie Year: 2001
Location: Hillsborough, NC
Posts: 81
lbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud oflbarger has much to be proud of
Re: Mecanum. What's Best

Quote:
Originally Posted by Ether View Post
Yeah, it's pretty tough to control the CoG precisely. But CoG should always be on your mind as the robot is being designed. The design criteria for mec wheels is equal normal force on all 4 wheels, as much as possible. This does not mandate locating the wheels at the corners of a square.
Well said. The challenge is to try to get as close as possible to the same normal force on each wheel. If your CoG is skewed to the front, move the rear wheels forward some.

From my experience, the normal force does not have to be exact. We had the CoG off by several inches (front biased) and did not have major issues. We had more of a problem with our budget built gearboxes having different amounts of internal friction. If I were to do it again, I would vote for toughbox (standard or nano) driving each wheel.