pic: Custom drivetrain

whats your opinion?

OK, I’ll bite on this one:

My first thought was “What about bumper supports?”

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

Are those stretched-out bike tires?

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

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

yes they are.

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).

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?

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.

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.

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

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

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.

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

That robot breaching defenses might land on that cantilevered wheel, so the situation might be worse than what a normal drivetrain shaft would experience. Depends on if you’re planning on going through tall defenses like the rock wall.

Excuse me for getting of the topic…
Was the orange box printed? and how?

Nope, it was definitely not printed. It was probably just a container they had lying around

I’m guessing the orange box is a printer or typewriter cover.

I’m with Kevin on the traction. I had thought at first those were 2008 KoP wheels, but I see they’re metal. You probably want to put some sort of rubbery coating like truck bed liner on those.

Unless I’m missing the scale (they look like 8" wheels) or the robot is too wide to get very far up the batter, scrub forces are going to be horrendous.

I have serious doubts that this setup can actually move. Like literally, whether it will be able to translate motor power into forward motion.

I really, really hope you’ve tested this. Your interface between tread and pulley relying solely on friction (and not even having a V-belt interface or anything) is really, really bad as far as treads go. The suggestion to coat the pulleys in something with more friction honestly probably isn’t even going to do the trick.

The moment someone T-bones you I don’t see how your treads aren’t immediately going to derail.

Not trying to be a jerk, just hoping you’ve already answered these questions so you don’t show up to competition and have a season ending “OH SH**” moment.