Non-Colinear wheels

[ferrari77]

Wheels not in a line

Our team is using an 8WD with the two center wheels on each side dropped
Because of size constraints we are considering not putting the wheels in a line

from the top, it will end up looking like this

Front
-|----|-
|------|
|------|
--|--|--
Back

The vertical lines are our wheels and the dashes are how the spacing works

I've never seen a drivetrain like this
Does anyone know if any problems, with turning or otherwise, would arise from not having all four wheels in a line?

I can upload the CAD, or a better drawing if further clarification is needed

Thanks

[Nuttyman54]

Several teams have done this before, with no issues.

179 in 2005 (http://www.chiefdelphi.com/media/photos/21631)and 2007 (http://www.chiefdelphi.com/media/photos/27252)
1889 in 2007 (http://www.chiefdelphi.com/media/photos/26601)
234 in 2007 (http://www.chiefdelphi.com/media/photos/27405)

All of these robots performed excellently and drove very well (I think there's three regional wins, a division finalist and a world finalist in that group).

I would caution you to double check everything against the bumper rules. There's nothing inherently wrong about that type of frame, but without the specifics it's hard to say exactly.

[BJC]

The closer together the outer wheels are the more they have to be dragged sideways to turn. It will work, but how well it actually performs is dependant upon how close together the outer wheels actually are. I would say that all the robots above have wheels close enough together that performace wouldn't be affected much at all. If you were thinking along those lines then you should be good.

Further apart = less turning scrub = better
Regards, Bryan

[ferrari77]

We are creating a chassis almost identical to those robots with the chamfered corners. if those worked then ours should be fine too

Thanks!

[Al Skierkiewicz]

There should be no difference in performance between your offset design and an inline design using the same wheels and spacing. The dropped center wheels reduce turning friction and therefore minimize putting the drive motors into stall.