pic: FRC488 - 2014 Octocanum Pod - Top

[Madison]

[cdm-description=photo]39405[/cdm-description]

[Jimmy Nichols]

how are you actuating the unit?

[Blackphantom91]

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.

[Madison]

http://i.imgur.com/qCSBzZZl.jpg

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.

[magnets]

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

[AllenGregoryIV]

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

[Madison]

There's about 1/2" of clearance.

[pfreivald]

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!

[Madison]

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.

[pfreivald]

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?

[Madison]

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

Solidworks says they're 5.75 lbs. each.

[pfreivald]

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.

[Madison]

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.

[Bryce2471]

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?

[Madison]

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

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.

[Aren_Hill]

Solidworks says they're 5.75 lbs. each.

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

[AdamHeard]

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 ;)

[Electronica1]

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

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).

[Madison]

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.).

[wireties]

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!

[Bryce2471]

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.

[AllenGregoryIV]

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.

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

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.

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.

[Answer42]

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 ;)

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

[AllenGregoryIV]

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

They have a website with a really good description.
http://www.teamneutrino.org/seasons/ultimate-ascent/robot/butterfly/

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

[AdamHeard]

They have a website with a really good description.
http://www.teamneutrino.org/seasons/ultimate-ascent/robot/butterfly/

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

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.

[Answer42]

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.

Very elegant. I'll definitely remember that one.

[pfreivald]

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

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

[Trent B]

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

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

[RobotDoktor]

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