pic: Custom drivetrain
 

Re: pic: Custom drivetrain
 

OK, I'll bite on this one:

My first thought was "What about bumper supports?"

Re: pic: Custom drivetrain
 

How is the back wheel held in? I see axles and nuts on the front two...

Re: pic: Custom drivetrain
 

Are those stretched-out bike tires?

Re: pic: Custom drivetrain
 

We have already solved the bumper issue, but we want to see if you find any restriction on it.

Re: pic: Custom drivetrain
 

its directly connected to the motor, that is what its holding it

Re: pic: Custom drivetrain
 

yes they are.

Re: pic: Custom drivetrain
 

Might want to show your solution. What I'm seeing is an articulated frame perimeter (something about the tracks being beyond the frame, and forming the perimeter).

Re: pic: Custom drivetrain
 

Cool idea, how well does it work? What size are those wheels? For that matter, what are those wheels? What gear ratio are you running?

Re: pic: Custom drivetrain
 

My first thought upon seeing any novel tank tread solution is to wonder whether the treads are going to fall off the pulleys. In your case, I'm also wondering how much effective traction you're going to have, since you're limited by the metal-rubber coefficient of friction instead of knobby rubber-carpet.

Re: pic: Custom drivetrain
 

Is the entire system running off of just 2 CIMs (1 on each side), and are those planetary gearboxes they're driving (if so, what reduction)?

My biggest concern, in addition to the one mentioned above about getting enough traction, is whether or not you'll be able to turn at all with this. Generally the scrub on a high traction drive requires teams to use at least 4 CIMs on their drive system to avoid stalling their motors when attempting to turn.

Re: pic: Custom drivetrain
 

Have you driven it under full robot weight yet? Usually ~150lbs.

Re: pic: Custom drivetrain
 

I would expect that there is a CIM on each of the front and back "wheels/pulleys".

Re: pic: Custom drivetrain
 

If there is a CIM in the back, it would appear to be driven differently than the one in the front, as there is a threaded rod supporting the back wheel but not the front.

Re: pic: Custom drivetrain
 

It looks like your correct, so if this is the case and it is only 2CIM, then it will be interesting, that means that there is also 1/2 the friction area of the pulley against the tread, that I thought that there was. It looks like a BB 220 gearbox and while it is a rugged gearbox Banebots says " We recommend using a design that supports the end of the shaft", probably isn't a huge problem here as the wheel is close to the face, but something to be aware of