Team 3607's 2013 base

[Samwaldo]

This off-season we did freshmen/ team training which involved splitting the team into 2 and challenging them to build a robot to navigate a obstacle course. One team did the same set up as you, while the other did a 6 wheel tank drive. The set up similar to yours could NOT drive straight, and every time it tried to go over even the tiniest bump (about a quarter inch at most), it would veer towards a different direction. YOU WILL GET NO CONTROL!!!

[Cody Burd]

Originally Posted by Samwaldo

This off-season we did freshmen/ team training which involved splitting the team into 2 and challenging them to build a robot to navigate a obstacle course. One team did the same set up as you, while the other did a 6 wheel tank drive. The set up similar to yours could NOT drive straight, and every time it tried to go over even the tiniest bump (about a quarter inch at most), it would veer towards a different direction. YOU WILL GET NO CONTROL!!!

yea I see what you mean.

[Cody Burd]

Yea, We just pushed it and you were right. Our drive is to have 2 wheel back powered with an independent front. Will the Omnis do ok with that

[Nuttyman54]

Omnis will be significantly better, and would be pretty easy to retrofit on to your current chassis. If you can find a way to run some chain from the back wheels to the Omnis in the front, that will also help a lot, and won't hurt your turning ability at all.

[synth3tk]

Just throwing in another "Our team made the same mistake" comment. Caster wheels are evil. Eventually we chucked that idea for a relatively "better" drive system.

You have a custom chassis, and a castor drivetrain. The former is a sign of experience, but the latter is not. Omni wheels would be *better* than castors for sure, but overall you would have been a thousand times better off with the kitbot. 6 wheel drive in general is one of the best drivetrains.

[mathking]

Everyone else has piled on with the "don't use casters" so I won't add to that. But I will say Evan is correct that if you can find a way to chain (or belt) the omniwheels you will improved performance. You will get better traction and control while keeping just as good a turning radius.

And I don't know that I would say you would necessarily be better off with the kitbot. What you seem to be trying to do is maximize your mobility, and that is a viable strategy for this game. The the ability to spin nearly in place away from obstacles/defense can be a very good strategy. Powering your omniwheels will aid in that.

[Cody Burd]

Thanks for all the help guys will discuss with my team tomorrow

[Donut]

I'll just play devil's advocate here and note that we were an alliance captain and regional Finalist the only year we ever used casters on our robot.

We did hate them though, enough that we tried replacing them with skids at Championships that year (which may be the only thing on earth worse than casters, we only won 1 match at Champs as a result of them). I'd recommend switching to omnis as others have said, they're easy to use and became 498's go to drive train starting in 2007. There are some situations when they provide an advantage over the 6 wheel drop method, namely when rocking is unacceptable to your design or you want your robot to turn about one of its ends rather than its center.