Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: brijesh on June 15, 2007, 08:10:37 AM

Title: Mounting wheels with small Toe-In angle.
Post by: brijesh on June 15, 2007, 08:10:37 AM
In RC cars a small toe-in angle between 0-3 degrees is used to increase straight line stability. How about using the same concept with differential steering robots, with 2 wheels and a caster?
Has anyone tried it?

Here is link which explains Toe, Camber and Caster angles of wheels.
http://www.ozebiz.com.au/racetech/theory/align.html

With a Toe-In angle there will be some scrubbing of the wheel and loss of power. Question is how much will it help in keeping the robot going straight with a diff-steering?

Brijesh
Title: Re: Mounting wheels with small Toe-In angle.
Post by: ed1380 on June 16, 2007, 02:40:48 PM
well when the robot starts going backwards it turns into toe out.
Title: Re: Mounting wheels with small Toe-In angle.
Post by: sotu on June 17, 2007, 06:16:27 AM
Most of the RC car toys i have dismounted the stearing mechanism is driven by magnets. Just magnets turning + and - by power controlling what way its going to turn, i dont know if that got anything with this to do tho.. :P
Title: Re: Mounting wheels with small Toe-In angle.
Post by: brijesh on June 17, 2007, 10:27:38 AM
ed1380,
mm...true, when it goes in reverse it becomes Toe-Out. Looks like I have to experiment a little to figure out if Toe-In has any positive effects.

sotu,
By RC cars I meant hobby grade RC cars. In hobby RC cars steering mechanism is well designed with lots of features for tuning.

Brijesh

 
Title: Re: Mounting wheels with small Toe-In angle.
Post by: maverick monk on June 17, 2007, 07:29:09 PM
Most of the RC car toys i have dismounted the stearing mechanism is driven by magnets. Just magnets turning + and - by power controlling what way its going to turn, i dont know if that got anything with this to do tho.. :P

that dosent apply to high proformance rc cars, the onroads use toe in, toe out, and camber as a tuning aid to improve the handling. they steer with a hobby servo and have bellcrank or akerman (sp) steering. very complex. great learning tool for dampning and suspension geometry.

ok, toe in is worthless on a robot unless your going at 20+ mph ( hobby rc go between 20 to about 50 or 60 on average) and are racing on a track wear hundreths of a second matter.

edit, sry didnt read the last post