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-   -   pic: FRC488 Octocanum. (http://www.chiefdelphi.com/forums/showthread.php?t=90493)

Madison 30-01-2011 00:12

pic: FRC488 Octocanum.
 

LLogan 30-01-2011 00:15

Re: pic: FRC488 Octocanum.
 
I have been waiting for somebody to create this.

Looks like you have the best of both worlds. Where are you going to place the piston? I'm having a hard time visualizing where you'll be mounting it.

What configurations are you going to have your wheels in? I.e. four traction only, four mecanum only, 4 traction + 4 mecanum, etc.

xSAWxBLADEx 30-01-2011 00:17

Re: pic: FRC488 Octocanum.
 
isnt meccum wheels designed to use counter friction...more friction the slower the wheels will go sideways if at all, i just see no advantage to this design...im not saying get rid of it at all im saying prove me wrong :)

AdamHeard 30-01-2011 00:21

Re: pic: FRC488 Octocanum.
 
I like it, what is the speed difference?

bladetech932 30-01-2011 00:21

Re: pic: FRC488 Octocanum.
 
Only one is down at a time traction for power then you switch to only mecanum for maneuverability.

xSAWxBLADEx 30-01-2011 00:22

Re: pic: FRC488 Octocanum.
 
Quote:

Originally Posted by LLogan (Post 1011507)
Looks like you have the best of both worlds. Where are you going to place the piston? I'm having a hard time visualizing where you'll be mounting it.

maybe where the ziptie is?

spiffyspleen 30-01-2011 00:22

Re: pic: FRC488 Octocanum.
 
That looks amazing,are you guys going to be at the Portland Regional this year?

xSAWxBLADEx 30-01-2011 00:23

Re: pic: FRC488 Octocanum.
 
Quote:

Originally Posted by bladetech932 (Post 1011512)
Only one is down at a time traction for power then you switch to only mecanum for maneuverability.

i see it now :)

Andrew Remmers 30-01-2011 00:38

Re: pic: FRC488 Octocanum.
 
I like it!

However a few questions

Why did you chain all the drive wheels, instead of power one of the directly and derive power off that wheel?

How much does it weigh? (without a super structure)

Where does the piston mount?

Bjenks548 30-01-2011 10:20

Re: pic: FRC488 Octocanum.
 
That is going to be a very fun drive train to watch, just like 217 and 148 last year. How much does it weigh? and Why did you put the mecanum wheels on the outside?

Nikhil Bajaj 30-01-2011 12:28

Re: pic: FRC488 Octocanum.
 
Quote:

Originally Posted by LLogan (Post 1011507)
I have been waiting for somebody to create this.

Looks like you have the best of both worlds. Where are you going to place the piston? I'm having a hard time visualizing where you'll be mounting it.

What configurations are you going to have your wheels in? I.e. four traction only, four mecanum only, 4 traction + 4 mecanum, etc.

The 488 version looks awesome. 461 prototyped this drivetrain over the last year and a half and summer, here is a link to that thread.

http://www.chiefdelphi.com/forums/sh...ad.php?t=86171

Hope that helps you see how this sort of system works.

s1900ahon 30-01-2011 13:33

Re: pic: FRC488 Octocanum.
 
Nice.

You should loop the Jaguar's PWM cable under the front tab on the Jaguar.

Katie_UPS 30-01-2011 13:36

Re: pic: FRC488 Octocanum.
 
We were joking about making that this year! I'm glad to see that someone did! :D

Madison 30-01-2011 13:41

Re: pic: FRC488 Octocanum.
 
Quote:

Originally Posted by LLogan (Post 1011507)
I have been waiting for somebody to create this.

Looks like you have the best of both worlds. Where are you going to place the piston? I'm having a hard time visualizing where you'll be mounting it.

What configurations are you going to have your wheels in? I.e. four traction only, four mecanum only, 4 traction + 4 mecanum, etc.

The wheels are going to be actuated by two pistons -- one along each side of the robot. It's hard to visualize because all of the hardware associated with that system is still missing. We'll add a vertically mounted arm to each wheel pod that the piston will push or pull upon. This creates a four-bar linkage where none of the links are grounded. The 1x1 cross piece that the pods are currently zip-tied to will act as a stop for the pod rotation and, effectively, ground one link of the four bar.

In retrospect, it would've made more sense to actuate each wheel pod individually, but the system we're implementing is a bit lighter. As a result, we can only run on all mecanums or all traction wheels.

Quote:

Originally Posted by AdamHeard (Post 1011511)
I like it, what is the speed difference?

There is an additional 22:32 reduction between mecanum and traction right now, in addition to the difference in wheel size -- 4" vs. 6". We may experiment with this some more.


Quote:

Originally Posted by spiffyspleen (Post 1011514)
That looks amazing,are you guys going to be at the Portland Regional this year?

Yep!

Quote:

Originally Posted by Joyride_67_1902 (Post 1011524)
I like it!

However a few questions

Why did you chain all the drive wheels, instead of power one of the directly and derive power off that wheel?

How much does it weigh? (without a super structure)

Where does the piston mount?


I tried to make direct drive of the mecanum wheel a reality, but AM's "long" output shafts were not quite long enough to make it plausible. It would've simplified a lot of things, certainly.

I am not certain of its weight. We'll try to weight it today, but I'd guess it's around 50/55 lbs.



Quote:

Originally Posted by Bjenks548 (Post 1011613)
That is going to be a very fun drive train to watch, just like 217 and 148 last year. How much does it weigh? and Why did you put the mecanum wheels on the outside?

Mecanum wheels are outside because they're geared faster than the traction wheels and we wanted the widest wheelbase possible to accommodate rapid changes in direction. Putting the traction wheels on the inside also makes it easier for the robot to turn while they're in place.


Here's some brief video of the first test of the mecanum wheel set. It's nothing too earth-shattering, but I understand that, by the time they left last night, our programming group has field-oriented drive running well.
http://www.youtube.com/watch?v=RA-jd48tPFM

Ether 30-01-2011 14:08

Re: pic: FRC488 Octocanum.
 
Quote:

Originally Posted by Madison (Post 1011709)
Mecanum wheels are outside because they're geared faster than the traction wheels and we wanted the widest wheelbase possible to accommodate rapid changes in direction.

Could you elaborate a bit on that please.. How does making the wheelbase longer accommodate rapid changes in direction?




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