Parts list for converting a tank drive to a slide drive

[Ginger Power]

The GreenHorns Ri3D team integrated a slide drive onto the AM14U2 chassis. The only added components that we used were 2 pieces of 1" 8020 Aluminum Extrusion to span the chassis, hardware to connect the 8020 to the chassis, hardware to connect a toughbox mini to the 8020, etc. The 8020 could easily be replaced by a different material like angle aluminum or 1" aluminum square tubing.

A few recommendations: The geometry worked much better for us by having a 6" slide wheel and 4" drive wheels. Don't do a 6 wheel drop center (the way the AM14U2 chassis is setup). Only use 4 wheels at each corner (the rocking from the drop center creates a bunch of problems for the strafe wheel).

We ran the wheel via pulley and it was mounted below the gearbox.

Here is a video of some of our members discussing the slide drive. I apologize for the quality, we were running on 4 hours of sleep over a 3 day period! This year we have dedicated "sideline reporters" so our video quality will be better.

Another thing to Consider: Having some sort of suspension on the strafe wheel is huge. We didn't do it because we only had 3 days, but given more time I highly recommend it. I know of some teams that have used a tennis ball as suspension, and others that mount the wheel on a pneumatic cylinder. Obviously this increases the complexity.
Sorry for the massive picture!!!

[GeeTwo]

AndyMark has a diagram of the DuraOmni fitting in the 2015 KoP chassis here.

We did a slide drive based on the KoP last year. We stripped the tread from two of the 4" AM stock wheels and used these as a spacer to keep the two timing belt pulleys in the appropriate location.

For competition, we tried hard-mounting another TB-Mini on some angle aluminum running across the chassis, but we could never get the height right; either it rocked enough to mess up normal drive, or there was not enough weight on the strafe wheel to strafe consistently. Post-season we built a pneumatic system to depress the strafe wheel. I'll take some pics this evening to post.

[DaveL]

Originally Posted by GeeTwo

Post-season we built a pneumatic system to depress the strafe wheel.

How did the pneumatically positioned strafe wheel perform?
Was there a difference in traction when moving right vs moving left?

Dave

[GeeTwo]

Originally Posted by DaveL

How did the pneumatically positioned strafe wheel perform?
Was there a difference in traction when moving right vs moving left?

Dave

I took the pics last night, but did not post them yet.

We have not yet tested the setup, but we do not anticipate a left/right difference because our design is symmetrical; the arm is located along the centerline of the robot, hinged at the front (or rear if we so decide) end, putting the strafe wheel down between the to main drive gearboxes. We do plan to add a control system and bumpers soon, to use as one of our robots to test/scrimmage against during driver practice.