View Single Post
  #12   Spotlight this post!  
Unread 15-06-2009, 08:09
Jared Russell's Avatar
Jared Russell Jared Russell is offline
Taking a year (mostly) off
FRC #0254 (The Cheesy Poofs), FRC #0341 (Miss Daisy)
Team Role: Engineer
 
Join Date: Nov 2002
Rookie Year: 2001
Location: San Francisco, CA
Posts: 3,078
Jared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond repute
Re: Crab-drive steering modes?

Quote:
Originally Posted by Sgreco27 View Post
... the only thing is co-axial is typically much less efficient. So I'd say noncoax is a good call.
Sorry for going off topic, but I have seen this statement on Chief Delphi a number of times from a number of different posters.

Maybe I'm missing something coming from my EE/CS background, but I don't really see why a coax crab would be appreciably more inefficient than a non-coax. Well meshed bevel gears have very similar published efficiency numbers to spur gears (~95-98%). And shafts rotating within each other shouldn't be an issue if ball bearings are used. Does anyone have any actual experience to the contrary?

Sure, there are potential issues with steering (as the wheel would rotate slightly even if the drive motor was held still during turning) and without being able to independently power the wheels some steering modes aren't as efficient (i.e. ackerman or warthog), but in terms of raw power transfer I have not been convinced of this perceived "inefficiency".

I'm looking forward to being enlightened.

Last edited by Jared Russell : 15-06-2009 at 08:29.