pic: FRC488 - 2014 Octocanum Pod - Top



Now that the Vex 4" mecanum wheels have arrived, we were able to assemble our octocanum pods tonight. Not shown is the CIM motor that attaches to the module and drives the 72 tooth gear on the mecanum wheel shaft.

how are you actuating the unit?

These are really nice. I am assuming that you are actuating the entire pod due to the mounting holes. Cant wait to see it in action. Very nice work.

The highlighted bracket is attached to a 1.5" bore, 1.5" stroke cylinder. There is one cylinder for each pod. It pushes on a 3/8" bolt that will be located on the right side of the pod shown above.

The pivot is on the far left of the pod, behind the mecanum wheel.

This is really nice. In terms of design/simplicity, it’s the best ocotocanum I’ve ever seen.

Madison, out of curiosity what is your change in ground clearance from Mecanum to traction?

There’s about 1/2" of clearance.

That looks delightfully compact and sleek!

Curious: Why did you go with 4" mecanum wheels? Is it just a weight/compactness issue? Our octocanum switches from 6" mecanum (with a .75" sprocket) to 2" colsons (with a 1 7/8" sprocket!) to get the lowest gear reduction possible without an additional shifter.

Also, are you actuating all four cylinders from a single valve? If so, how fast is the switch?

Thanks!

It was entirely about making the modules as compact as possible. Not much additional thought went into the decision beyond that.

We haven’t decided yet if we’re going to actuate all four cylinders together through a single valve or give them each (or in pairs) a valve to increase air flow. We’ll probably try it both ways and, if there’s no really compelling reason for the added airflow, use a single valve.

Fair enough. May I ask what each pod weighs, with motors and wheels?

Solidworks says they’re 5.75 lbs. each.

Okay, so you’re about 1.5 lbs lighter than us, per pod, but (I think?) we have a greater gear reduction (7x) when switching to traction mode.

Thanks for sharing–it’s always neat to see other teams’ take on the same basic functionality.

Yeah – our low gear reduction is “only” 2.92:1 lower than the mecanum wheel and 17.52:1 overall.

Very cool design, I hope to see it in competition.

Solidworks says they’re 5.75 lbs. each.

Just curious, does that weight include the mounting bracket(s) and pneumatic cylinders?

It does not. They are integrated into the frame, so I don’t know what they weigh individually. I’ll take a look at that when I can get at Solidworks again later tonight.

I’d be quite surprised if whats pictured is that heavy, my butterfly module from last year was 2.38lbs with very little effort in regards to weight. From the looks of it there isn’t much more here.

-Aren

We really wanted to run a octonum variant of this above module but it didn’t match what we wanted to do with the game.

It would have been insanely clean. If anyone hasn’t seen Aren’s butterfly (which we ripped off), it’s hand downs the cleanest setup anyone has run by a huge margin. That’s why we stole it :wink:

I think that weight included motors (and the weight you listed is lighter than one cim so i know the weight you listed does not include a motor).

Yes – the 5.75 lbs. does include the weight of a CIM motor (which I have entered as 2.8 lbs.).

It is interesting and instructive to see the evolution of your drive from year-to-year. It is clever and well done. Good luck this year!