Robots tilt

[Madison]

Originally Posted by B. Flaherty

I think what lrdblaster03 is talking is something on ATV's. If you notice in this pic, the front wheels are mounted on an angle. So the real question I think is do you mean lowered wheels as in a 6wd configuration, or do want angled wheels for easier turning?

This is called camber and it's present on most (if not all?) cars as well. Varying the camber can affect the over- or understeer of the car, but I can't see it having any use on a robot that skid steers.

[henryBsick]

Originally Posted by M. Krass

This is called camber and it's present on most (if not all?) cars as well. Varying the camber can affect the over- or understeer of the car, but I can't see it having any use on a robot that skid steers.

What about 116's beautiful implementation of camber (I think that would fit the definition)? They used an extreme angle for their 4 omni wheels in two axis per wheel making the point of the omni in contact with the ground closer to the corners of the physical machine thus providing a much greater footprint for their wheelbase.

I know the middle wheel drop has been established as the thread's intent. I just thought I would throw this out there.

[Dan Petrovic]

Didn't 229 have something similar to this with 8WD? The two inner-most sets of wheels were lower than the front and back set.

[Mike Schroeder]

25 Doesnt lower their middle wheels at all....

[EHaskins]

This year we lower the center wheels about a quarter inch, but also ran a lower pressure in the outer wheels.

[Donut]

60 and 254 both did this for their 2004 machines. Not sure if they still use it but their current drive systems are similar.

[Andy Baker]

Originally Posted by Big Mike

25 Doesnt lower their middle wheels at all....

That's because 25 runs their wheels along the short side of the robot. For robots who run theirs along the long side of the robot, then I suggest a 0.125" to 0.20" drop in the center wheel.

Andy B.

[henryBsick]

Originally Posted by Andy Baker

That's because 25 runs their wheels along the short side of the robot. For robots who run theirs along the long side of the robot, then I suggest a 0.125" to 0.20" drop in the center wheel.

Andy B.

Andy, I agree with you for their 2003 year, but...

03 short side
04 Long side, without full use of entire side due to step pop up mechanism.
05 long side
06 long side

Edit:
Source

[Booger]

i put a 1/4" space between the outside and inside wheels is that enough/too much?

[Andy Baker]

Originally Posted by Henry_222

Andy, I agree with you for their 2003 year, but...

03 short side
04 Long side, without full use of entire side due to step pop up mechanism.
05 long side
06 long side
Edit:
Source

Yes, I spoke too soon. Big Mike AIMed me with a correction also.

Originally Posted by Booger

i put a 1/4" space between the outside and inside wheels is that enough/too much?

In a general sense, I would suggest less. 0.2" should be fine for most cases.

This situation REALLY depends on the robot's Center of Gravity (Cg). Again, generally speaking, a robot with a higher Cg needs more "tilt" difference between the vertical location of the outside wheels and the inside wheel. Robots with a lower Cg will turn OK without a difference, but robots with higher Cg will jump and wobble as they try to turn with no difference.

AB

[Ben Piecuch]

Now that we understand what you're trying to ask, here's what you'd find if you searched for the answers...

http://www.chiefdelphi.com/forums/sh...ad.php?t=42741

BEN