pic: 775pro WCD



6 775pro drivetrain

2 stage reduction:
12:60
14:48
4in wheels

JVN Adjusted speed: 15.45 ft/s

I assume you plan on adding a second 2x1 cross member in front of the gearbox or closing off the front? Also, will you be welding or using gussets? I only ask because 1058 welded our frame this year in a 90 degree vice and had some minor issues with the tube heating up and deforming.

Otherwise, looks fairly simple but effective!

Yes, this is designed so that you can have a mechanism in front, with a crossbar behind it.

Using gussets. Those still need to be added in CAD.

Thank you!

By mechanism you mean harpoon, right?

He said crossbar, not crossbow. :]

Just curious, is there a reason why the front bumper mounts are in two pieces, one to either side of the main rail, rather than a single end cap?

All of our robots are Ahab-ready.

That’s just what came to mind at first. Now that I think about it, one piece is probably better than two.

Kind of a silly reason, but if you make it one piece then you can never remove a drilled out rivet from the tube.

This is true but to compensate we sometimes will drill a 3/8" hole on the underside so we can get out any shavings or drilled our rivets from a tube welded on either ends.

Good design. I’d recommend cutting your side rails an inch shorter and using one solid 2x1 for the T-piece on the end instead of the two pieces.

Just a heads up, with WCD, chain is ran internal, so you have to consider chain when placing internal crossbars. There are a number of ways to do it, but my team usually mounts internal crossbars directly on top of the 2"x1" drive train aluminum.

We had a frame similar to the one posted but with a crossbar closer to the middle of the bot. We drilled out some holes large enough for #25 chain to pass through. There was some audible rattling occasionally, but it held up without any issue through a full 4-event season. It does require 16t sprockets to work.

Wouldn’t that make the shaft collar on the end of the wheel interfere with the bumper?

I can see some benefit to cutting it about 1/2" shorter, but I would like to avoid fractions with VersaFrame.

There is also the option to run a bar above the wheels for the bumper.

Do you have a picture of one of those crossbars?