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Subject: 
Re: Gear lash.... & casters
Newsgroups: 
lugnet.org.ca.rtltoronto
Date: 
Fri, 3 Mar 2006 19:41:34 GMT
Viewed: 
829 times
  
In lugnet.org.ca.rtltoronto, Steve Hassenplug wrote:
  
The caster Rob used here is a problem because the double-rubber-wheel design will resist changes in direction (if it’s turning, it will keep turning)

http://ffaat.pointclark.net/gallery/viewphoto.php?setalbumName=RTL20&id=IMG1164

A VERY simple change would be to remove one wheel (from each caster), and replace the #3 axle with an axle-pin. I suspect that would cut down the “drunken sailer” problem a huge amount, and make the design workable.

Thanks for the feedback, Steve.

I did try one wheel, but found that the bot would either track sideways (if the L&R were on the same side) or drag (if both to the inside/outside).

I think the problem in this case was way too much weight on the castors, due to poor planning on my part...the double wheels were an (admittedlt poor) attempt to handle the weight better.

Putting the wheel in the middle of the fork was another option, but then I couldn’t come up with a design that had the wheel axis clode anough to the pivot...

   Going with the 4-wheel a/b drive will still have some unpredicitable turning > (as some of the tires slide) and the skid-plate will slow the robot down.

I was thinking about this the other day, and playing with the idea of a 4 wheel A/B drive where the frome and back wheels are driven off a differential to get rid og the wheel skipping...Anyone try that before?

-Rob A>



Message is in Reply To:
  Re: Gear lash.... & casters
 
(...) I've been reading this, trying to figure out what you guys are complaining about. I use casters all the time. Often I'll change the caster design to adjust how the robot acts. The caster Rob used here is a problem because the (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto, FTX)

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