AndyMark alert! Interesting new stuff

[Andy Baker]

Originally Posted by Jeff 801

I think it is so that teams can use an 8" wheel with the tube because at 31" the shafts are placed 27.52" apart according to the print which means when using an 8" wheel your over all length will be right about 35.52"

Also you can get 3 tubes out of a 8' piece of stock with 3" extra

Yes, this is the main reason. The center-to-center distance from the center of the front to back wheel is 27.5". This distance seems to work well with a 4wd 8" Mecanum setup. I predict that this setup will be used many times for applications outside of <em>FIRST</em> Robotics Competition setups.

If the demand is high for this type of setup, then we can vary the length of this tube.

Originally Posted by Mr.G

I agree with you. Where did you find the print? I am wondering how much the center wheel is lowered?

Originally Posted by JB987

Center is dropped .13" according to specs found below:

http://www.andymark.biz/am-0689.html

Yep, the center drop is 0.13".

Originally Posted by Billfred

They do--but going down to 31 may allow them to squeeze it into a cheaper box (or get a cheaper shipping rate). That said, I think Jeff may have the better concept.

This is along the lines of what I was thinking. You'll still make some trade-offs (especially if the current GDC direction of bumper zone rules continues), but there's nothing stopping you in theory from going down this road.

This design decision has no bearing nor any result from any shipping or GDC decisions (at least, not that I know of). As mentioned above, this setup makes a very clean drive base for people who want to make a simple drive system for their application, whatever that is.

Thank you for all of the input.

Sincerely,
Andy