2785 Drive Train- Border Hopping Capabilities

I am a new member of Chief Delphi and also a Co-Captain of Team 2785.
Being in charge of the drive train among other things, I finished the prototype today and have a video of it climbing over a modeled barrier of Rebound Rumble.


The actual Chassis is planned to be constructed out of 1" 8020, but same design with chain driven toughboxes. I just wanted to Post here and look for some feedback, comments, suggestions, and constructive criticism.

Would it be better for each toughbox to be powered by two CIM motors?

Would some sort of ski on the undercarrage help slide the robot over?

Any way to make the design more reliable?

I appreciate your time!

Team 2785

what is the diameter of a wheel you are using?

They are the standard Grey Wheels from the KOP of years past. 8" diameter.

I only see 4 wheels on that robot. Unless it’s a wide robot or you are using slick wheels, it won’t turn well. Quoted from experience. We foolishly used 4 wheels on a long chassis last year. Never again…

I’d caution you to try that again with 120lbs of weight before you build it into the final design.

Load this up to around 135 lbs and then test if it will turn on carpet. That is always a good thing to check.

Good job so far!

Definitely try it out at full weight at an estimated center of gravity as your results may change.


For information about CIM use, see this thread, which discusses the pros and cons of sacrificing CIMS for the shooter.

Regarding the barrier, this thread discusses all kinds of barrier strategy.

Also, welcome to CD. :slight_smile:

Definitely load it up like everyone else said. But more importantly make sure you test everything on carpet as well. I hate to see teams go into competition with long base four wheel drives and have to either switch one set to slick wheels or omnis because they just can’t turn. It looks like you have moved the wheels closer together. This may help some but I doubt it will be enough.

Keep up the good work otherwise.

Don’t forget about bumpers… they have to be at least 2 inches from the floor. this makes your plans a bit difficult…

Why 80/20? Our team has used the kit aluminum for the last 6 years and never had a problem with it. It’s loaded with holes for mounting, and lighter than the extruded 80/20. The only time it bent was in 2005 when we didn’t use bumpers (ahhh the good ole days).

Omni’s are a good way to go for front wheels and easy turning in 4wd. Otherwise, the kit frame is really easy to adapt a 6 wheel drive. Just make sure your center wheel is 1/8" drop.

I don’t see how this has a problem with the bumpers, the bottom of the bumpers may be mounted from 2"-5" from the floor.

I’ll mirror the above comments: load the robot with some weight, on carpet, and then try.

We did this today and it couldn’t make it over with the 8’’ 2011 wheels (with extra c-channel to provide a 1 inch lift).

What is the height of the bottom of your frame above the floor?

The Center of the frame is 7" above the ground.