pic: Offseason 8W Tank Drive

[75vs1885]

Originally Posted by Knufire

Sure!

The drive channels are two pieces of 1"x3" C-channel, with the two sides connected by a single 0.090" bent sheet metal piece. You could also replace this bent sheet metal piece with the front/back rails of the 2014 VEXPro Drive in a Day or the 2015 kitbot end rails (at least as much as I can tell from the drawings).

The gearbox is mostly just a repackaged Ball Shifter. The only trick is that two of the CIMs are on a separate first stage reduction and then connected to the rest of the gearbox with a 9mm HTD belt. These then drive 8 4" Colsons on dead axles.

Here are the drive numbers:

Weight seems to be about ~40 lbs, including motors and chains.

Thanks!
I'd tend to think that the bent sheet metal would cause flexing within the frame, causing and uneven chassis. Then all the problems evolve.
Could you use 3x1 box? it would have more strength

[EricH]

Originally Posted by 75vs1885

Thanks!
I'd tend to think that the bent sheet metal would cause flexing within the frame, causing and uneven chassis. Then all the problems evolve.
Could you use 3x1 box? it would have more strength

That would depend on the bends of the sheet metal. There's a reason a lot of teams like to use sheet metal; if it's handled right, it can be as strong as channel and box. And, it's a lot lighter than box extrusion.

Some things to keep in mind for sheet metal: bends and gussets increase strength, if properly applied. This design appears to be proper application, and there's space in the outer rail for bumper supports/backing which will also increase strength.