6WD Concept

Technical Technical Discussion
#1

Hello Chief Delphi,

Recently, I looked at this kit in AndyMark and wondered, “So, my team has all these parts already, what are this design’s pros/cons?”

This is the configuration:
Omni wheel; standard wheel; standard wheel
Omni wheel; standard wheel; standard wheel

More specific questions are:
This kit has the center wheel lowered by about 1/10 of an inch, would it be possible to eliminate the difference and still turn easily?
If the wheel axles were all in the same plane, the center of rotation would not rock/shift like a standard kitbot, right?
It would be possible to adapt a kitbot to use this concept, right?
Should I power all wheels?

Thanks in advance,
Daniel

#2

This was the format of our drivetrain in logomotion (though we did not use this kit :stuck_out_tongue: ) It was by far the best drivetrain we have made, and it was arguably better than most 6wd robots without omni’s. We DID NOT drop the center due to the fact that omnis have a slightly smaller diameter. You definitely should power all wheels in this case, even without a drop it is necessary. I do not think that It would be possible with a kit Cbase, as the center wheel is dropped. Just my 2 cents

#3

What size (4/6/8 and metal vs. plastic) were your omni’s?

#4

We used 8" omni’s in the front and 8" plactions for center and rear.

#5

You could use the Cbase, but you’d have to drill a new hole for the center axel. Just move it about an inch or so forward or backward, and keep it the same height as the outer two.

#6

We built our 06 and 07 robots like that using the kit frame with 4 kit wheels and omnis on the front. They were both very good drivetrains.

#7

^Reported

#8

Not having any of the parts handy… Would this difference happen to be able to be removed by flipping the CBase upside down? Just an idea that might help save some machining.

#9

Or because the C-Base has the holes for 8 wheels that are level.
Set the center four wheels traction and the outer wheels omins.

#10

I don’t have the omni wheels on me right now, but if their diameter is smaller than the kit wheels/other wheels we would use, then this is an very attractive idea.

Otherwise we could use a Rotozip/mill to elongate the center hole until it is even with the other two holes. All we’d have to do then is drop in the dead axle. (optional) Axle mounts would fit inside the Cbase, and could be printed in shop.

#11

If you wanted to/wouldn’t mind raising or lowering the chassis, you could bolt up a few pillow blocks and have the ability to switch between dead or live axle with the same setup.