29-01-2014 06:44

Jimmy Nichols

Re: pic: FRC488 - 2014 Octocanum Pod - Top

how are you actuating the unit?

29-01-2014 11:40

Blackphantom91

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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.

29-01-2014 11:47

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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.

29-01-2014 15:44

magnets

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

29-01-2014 15:51

AllenGregoryIV

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

29-01-2014 16:01

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

There's about 1/2" of clearance.

30-01-2014 09:07

pfreivald

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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!

30-01-2014 12:19

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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.

30-01-2014 12:23

pfreivald

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

30-01-2014 12:29

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Solidworks says they're 5.75 lbs. each.

30-01-2014 12:37

pfreivald

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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.

30-01-2014 13:39

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Yeah -- our low gear reduction is "only" 2.92:1 lower than the mecanum wheel and 17.52:1 overall.

30-01-2014 13:45

Bryce2471

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

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

30-01-2014 13:58

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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.

30-01-2014 14:24

Aren_Hill

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

30-01-2014 14:29

AdamHeard

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

30-01-2014 14:32

Electronica1

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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).

30-01-2014 14:56

Madison

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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

30-01-2014 15:14

wireties

Re: pic: FRC488 - 2014 Octocanum Pod - Top

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!

30-01-2014 15:47

Bryce2471

Re: pic: FRC488 - 2014 Octocanum Pod - Top

I'm also curious why you decided to run your belt and gears on the same side of the mecanum wheel. It seems like if you ran the belt on the other side of the module, then your traction mode would have a wider wheel base and the cim shaft would take less side load. I'm sure you have good reasoning for why the module is made this way. I'm just curious to see what your thinking was.

30-01-2014 15:50

AllenGregoryIV

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Why such a low gear reduction, seems like 488's will be traction limited.

I would guess it is so that they don't have to cut the CIM shafts, if you run them normally the end of the shaft hits the mecanum wheel.

30-01-2014 15:50

Answer42

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Would you mind posting a pic of it? I'm curious now.

30-01-2014 15:53

AllenGregoryIV

Re: pic: FRC488 - 2014 Octocanum Pod - Top

They have a website with a really good description.
http://www.teamneutrino.org/seasons/...bot/butterfly/

Our octocanum modules this year were heavily inspired by team neutino's work.

30-01-2014 15:57

AdamHeard

Re: pic: FRC488 - 2014 Octocanum Pod - Top

This then nest in a single 2x3 (for us) or 3x3 (for them) tube which is also your frame. Real clean.

It's the lightest cleanest butterfly (that could be an octonum if hte tube was 4" wide) that anyone has done.

30-01-2014 16:10

Answer42

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Very elegant. I'll definitely remember that one.

30-01-2014 17:39

pfreivald

Re: pic: FRC488 - 2014 Octocanum Pod - Top

We're still playing with wheels to maximize our traction.

30-01-2014 23:29

Trent B

Re: pic: FRC488 - 2014 Octocanum Pod - Top

The solid 0.4lb Delrin wheel was definitely not doing it any favors with regards to weight.

31-01-2014 23:09

RobotDoktor

Re: pic: FRC488 - 2014 Octocanum Pod - Top

Nice. I really like how compact the modules are. Ours are a lot longer, but we have 6" mecanums and 4x2 Colsons.