pic: More fooling around with mecanum wheels

[Tom Ore]

Originally Posted by MattC9

Have you tried shifting with mech's befor?

We did a mini-octocanum drive last year and had mecanums with fixed raised wheels for climbing the ramp in 2010. We've never done a shifting version. (The mini wheels were 2" diameter Colsons.)

[Gregor]

Originally Posted by Tom Ore

We did a mini-octocanum drive last year and had mecanums with fixed raised wheels for climbing the ramp in 2010. We've never done a shifting version. (The mini wheels were 2" diameter Colsons.)

What is mini-octocanum? Is it standard octocanum with smaller "tank" wheels?

[Tom Ore]

Originally Posted by Gregor

What is mini-octocanum? Is it standard octocanum with smaller "tank" wheels?

Yes. Since we wanted a wide robot there wasn't much room for the second set of wheels. We tucked 2" diameter Colson wheels in as close as possible to the 6" mecanum wheels.

Here is a picture of the module. It worked really well except for being rather heavy. (The frames were aluminum not Lexan.) If we did it again, we'd work on bringing the weight down.

[GRT808]

What CAD software is this?

Personally, I am interested in what you did you color the bearings. I haven't been able to make them look like the shiny metal bearings you have.

Very nice render!

[Tom Ore]

Originally Posted by GRT808

What CAD software is this?

Personally, I am interested in what you did you color the bearings. I haven't been able to make them look like the shiny metal bearings you have.

Very nice render!

We use Creo. I made the bearings chrome. The other parts are aluminum, steel, brass, plastic, etc. Creo has lots of material choices and then choices for each material. For example, under the aluminum choice you can pick brushed, anodized blue, anodized red, cast, matte, polished, satin or scratch. The room for rendering is set to glossy white plastic.

[Nemo]

Tom, you're the man. You make some really sweet models, even if you're just fooling around with some of them.

[JesseK]

If the wheels were 2.5" instead of 3", I'm not sure why this is infeasible at a first pass. I think this design would be robust enough for a FRC bot on a flat field under 2 conditions: 1.) The lexan that supports the outer edge of the dead axle were replaced with C-Channel and 2.) The robot frame only mounts to the C-Channel.

3"x1.5" C-channel with 0.2" leg thickness would work great. The added ounces of the Aluminum C-Channel would be offset by leaving the gearbox plates as polycarbonate. All robot impact forces resolve through the C-Channel, and the polycarbonate only needs to be strong enough to rigidly cantilever the CIM as shown.