Basic Drive Train Drawings

[Sachiel7]

Yeah, those casters should work pretty good. They don't look like your typical drag casters. The further away from the pivot point the wheel is, the more likely you are to have turning problems. Those look pretty central.
My question is this though:
If you went down to 1 caster in the center of your front and made your back the front(the drive wheels), do you think It'd turn less anonymously? I personally didn't get to see sparky too much, but it did seem to be swerving around alot during the time I watched it. I'm not sure if that was intentional though.
Anyway, If it worked good, then great, there should be no problem. I also like what 422 did this year for front casters. They look two large (6x6x6"?) blocks of the HDPE material(or something like it) and lathed it down to half a sphere. They threaded through the center of the flat side and bolted them at the front corners of their bot. It worked great.
When it comes down to it, the casters function is simply to support the frame. If it's causing your bot to shift around, it's not serving it's purpose correctly, and needs fixing.
In the summer of 02 we modded up our bot for the MD state fair. When I got up there I found that they mounted 2 casters in the front with 2 rear drive wheels. It was a mess. It took me 2 days (and 4 hours of fixing programming after a new member 'tinkered' with it) to convince them to flip the bot so the back was the front and they had a center caster in the rear. All this was done on one joystick. It worked great after they finally let me try it.
What would be a really good steal is if you can get the casters where the wheel is a sphere, and the pivot point is directly over the wheel. This way, you don't need to worry about odd shifting.
Anyway, with the casters you have there I can see why you wouldn't have as much trouble, but a typical rookie team wouln't necessarily think of that. Just keep that in mind...