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-   -   Omni Wheels Survey (http://www.chiefdelphi.com/forums/showthread.php?t=28168)

Ryan F. 24-04-2004 21:03

Omni Wheels
 
Hi, I'm starting this thread to get a feel of how well omni-wheels worked for the teams that actually used them. I've been looking at many possible things for out robot for next year, this being one of them. The one problem I've always wondered about is the omni wheels making the robot easily pushable. I'm wondering if they have the same effect of casters, where they allow another robot to push you around easily. If anyone out there with omni wheels could tell me about your experiances with them and especially if you got into pushing matches with other robots, that would be appreciated.

mtrawls 24-04-2004 22:10

Re: Omni Wheels Survey
 
Team 122 has used omni-wheels for a number of years (notably, we lacked them last year ... which propelled us to using them again this year!) The amount of traction they provide all depends on how you make them, and we've explored a number of methods. The "omni" part of the wheels only need to give when the 'bot experiences a lateral force -- so just because someone pushes you on the front doesn't mean it should give. Particularly 3 years ago we built our bot to be a pusher (back when we had to move goals to different zones and keep them there); we used omni-wheels, and it all worked pretty well for us. Overall, I think omni-wheels are a great thing to have.

Ben.V.293 24-04-2004 22:43

Re: Omni Wheels Survey
 
this year team 293 made the switch to omni wheels. I feel that they performed better than casters do but if someone hit us on the side by the omnis we'd spin right around. We bought them from McMaster-Carr and they were excellent but next year we'll probaly make our own. The model number was 2289T3. I recomend them to any team that does not have the time or resources to make their own.

Ben Van Selous

Kevin Sevcik 24-04-2004 22:45

Re: Omni Wheels Survey
 
I would think the issue with omni-wheels would be the simple fact that they give laterally. Thus, if you have all 4 omnis, you'd be pushed clear across the field if someone got on your side. If you have 2 omnis and 2 normal wheels, you don't have that problem, but I think you'll still have a problem of being easily turned to the side and knocked off course.

Ryan F. 24-04-2004 22:48

Re: Omni Wheels Survey
 
Yeah..that's exactly what I've been thinking. If someone hits you on the side.....you can't really do anything about it.

-casters are something I wouldn't want anywhere near our robot

UNFkrunch79 24-04-2004 22:51

Re: Omni Wheels Survey
 
Team 79 has been using omni "crab" drive for two years now. We have a very powerful robot and we can hold our own in a pushing match. One thing that we did last year to keep people from pushing us off the top of the ramp was have a lock down system. Just by pressing a button on our controls each wheel would turn in, so that they are all facing a different direction. And the wheels that we used had a lot of traction on the top platform. I think that omni drive is a very cool thing to have and work great if the game calls for it.

Ben Lauer 24-04-2004 23:31

Re: Omni Wheels Survey
 
I think it all depends on what material you use for the "omni" part, and what design you use.
For instance wheels like this and ones likethis virutally don't slip at all, even though they have a different design. The first link is one 1018's robot (my team), and we didn't climb the step, so all we needed was grip on carpet. The second did, and they need the grip on the platforms.

You should find a design, then get materials that will best suit you traction needs.

Ryan M. 25-04-2004 07:24

Re: Omni Wheels Survey
 
I'm surprised Pit Bull hasn't said anything on this thread. His Title is "Mr. Omni-wheels." (or something to that meaning)

It depends on your drive setup it you can be pushed (easily) or not. If you do something like a Killough Platform, you can never truly be hit from a "side." (If you don't know what a Killough Platform is, look it up on Google.)

Alex Cormier 25-04-2004 08:58

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Texan
I'm surprised Pit Bull hasn't said anything on this thread. His Title is "Mr. Omni-wheels." (or something to that meaning)

sorry a little late had a party here last night the people didn't leave till 2 am.

anyways...
omni wheels love em! i came up with them this year for our bot just so that we can turn in high gear and climb very easily and that was accompolished very well. if another bot did hit us on the right side all we needed to do we counteract it and drive towards that side and they couldn't push yes any more. they really work great and are wonderful. i will have a white paper up soon on my creation. check for it in a few weeks...

p.s. we had 2 omnis in front 2 pn. wheels i the back... heres a pic
pit out...

FizMan 25-04-2004 09:36

Re: Omni Wheels Survey
 
I'm trying to develop a drive system that can move freely in all directions for next year. And I rummaged through the whitepapers, and it the concept of using four omni-wheels, two in either direction, would work.


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Okay; that's a pretty bad drawing; but you get the idea. By running the two sets of wheels at different speeds, you can strafe your robot in different directions. This means you'll have a seperate gearbox/transmition/motors for each set of wheels, correct? Say you have two motors per set of wheels. Does that mean you can really only apply two motors worth of power in any one direction? So if you were up against a robot that had a tank drive with four motors of power in one direction, you'd only have two to their four? Now I'm just learning the basics of these engineering principles, so tell me if I'm way off.

And again; with that design, if a robot pushed yours, you'd really only have two wheels of traction to push back with?


Looking at a few designs of omni-wheels that use the metal spinners for the treads (rather than the plastic ones) what's the possibility of those damaging the carpet if you're in a pushing match and your wheel slips?


Also, what's the advantage of using omni-wheels if not for all-direction travel? For example in the above robot picture; you have the two omni-wheels in the front. You said it was so you could turn in high gear easier; so the omni-wheels provide half decent forward-backward traction and little lateral traction. Are there any other benefits?


Thanks for your time answering these. :D

Nathan Pell 25-04-2004 09:58

Re: Omni Wheels Survey
 
Team 1083 and 180 both used omni wheels to make a holonomic drive train. It worked very well; we rarely were pushed, as we were so much more maneuverable than anything else out there. Also, unlike casters which just "sit" there and can rotate easily, our wheels were attached directly to the motors and gear box, so pushing them was not as easy as casters.

I highly recommend holonomic drive when you want to be maneuverable.

Alex Cormier 25-04-2004 10:15

Re: Omni Wheels Survey
 
Quote:

Also, what's the advantage of using omni-wheels if not for all-direction travel? For example in the above robot picture; you have the two omni-wheels in the front. You said it was so you could turn in high gear easier; so the omni-wheels provide half decent forward-backward traction and little lateral traction. Are there any other benefits?
omni wheels = motorable casters....that can or can't be movable sideways.... like mine, they can't move sideways but they rool b/c of the rollers..

we opnly used two because of the game, we wanted to get on that ramp very qucikly in which it did b/c we had a 1/2" lip to catch the edge of the 6" platform.

anything else or i missed?

Tom Bottiglieri 25-04-2004 10:34

Re: Omni Wheels Survey
 
Quote:

Originally Posted by UNFkrunch79
Team 79 has been using omni "crab" drive for two years now. We have a very powerful robot and we can hold our own in a pushing match. One thing that we did last year to keep people from pushing us off the top of the ramp was have a lock down system. Just by pressing a button on our controls each wheel would turn in, so that they are all facing a different direction. And the wheels that we used had a lot of traction on the top platform. I think that omni drive is a very cool thing to have and work great if the game calls for it.

I think you are confusing "omni drive" with "omni wheels".

bheller 25-04-2004 12:11

Re: Omni Wheels
 
Team 931 used them for the first time this year. We wanted a robot design that was longer than it was wide, for stability with a long arm, and knew that our robot would not turn well with four standard wheels. There are two omnis on the front and two pneumatics on the back.

When we switched to the omnis, it turned too well. Think about it - omnis act as casters when the robot turns. The operator would push the stick to turn and the robot would turn, but it would keep turning when the operator moved the stick back to neutral! The polar moment of inertia kept us going. If you want to go with omnis, I recommend one of three things:
-holonomic drive
-exponential stick control for better turning sensitivity at low speeds
-(best option in my mind) a gyro to counteract the overshoot

I'm trying to get a white paper out on these wheels by midsummer.

Brandon Heller
Mentor Team 931
Alum Team 449

Quote:

Originally Posted by rforystek
Hi, I'm starting this thread to get a feel of how well omni-wheels worked for the teams that actually used them. I've been looking at many possible things for out robot for next year, this being one of them. The one problem I've always wondered about is the omni wheels making the robot easily pushable. I'm wondering if they have the same effect of casters, where they allow another robot to push you around easily. If anyone out there with omni wheels could tell me about your experiances with them and especially if you got into pushing matches with other robots, that would be appreciated.


Yan Wang 25-04-2004 13:26

Re: Omni Wheels Survey
 
Quote:

Originally Posted by FizMan
I'm trying to develop a drive system that can move freely in all directions for next year. And I rummaged through the whitepapers, and it the concept of using four omni-wheels, two in either direction, would work.


Code:

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|            |
|            |
||          ||
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Okay; that's a pretty bad drawing; but you get the idea. By running the two sets of wheels at different speeds, you can strafe your robot in different directions. This means you'll have a seperate gearbox/transmition/motors for each set of wheels, correct? Say you have two motors per set of wheels. Does that mean you can really only apply two motors worth of power in any one direction? So if you were up against a robot that had a tank drive with four motors of power in one direction, you'd only have two to their four? Now I'm just learning the basics of these engineering principles, so tell me if I'm way off.

And again; with that design, if a robot pushed yours, you'd really only have two wheels of traction to push back with?


Looking at a few designs of omni-wheels that use the metal spinners for the treads (rather than the plastic ones) what's the possibility of those damaging the carpet if you're in a pushing match and your wheel slips?


Also, what's the advantage of using omni-wheels if not for all-direction travel? For example in the above robot picture; you have the two omni-wheels in the front. You said it was so you could turn in high gear easier; so the omni-wheels provide half decent forward-backward traction and little lateral traction. Are there any other benefits?


Thanks for your time answering these. :D


Ah, you're referring to Patrick's 3DOF whitepaper right? After driving the Cornell robocup robots for a while with an XBOX controller, I have to say that such a design is just plain awesome for being mobile. If someone tries to push you, there are so many ways to move. Google Cornell Robocup and check out some of their videos for a demonstration. Patrick is also updating the Cornell team's status at the American Open in New Orleans (their first match should've been 30 min ago) in this thread: http://www.chiefdelphi.com/forums/sh...ad.php?t=28159

In addition, our team has used omniwheels in 2002 and 2003... search these forums for pics of them (and descriptions) or PM me. They've worked beautifully. We switched to tank treads this year.

Ryan F. 25-04-2004 13:38

Re: Omni Wheels
 
Quote:

Originally Posted by bheller
Team 931 used them for the first time this year. We wanted a robot design that was longer than it was wide, for stability with a long arm, and knew that our robot would not turn well with four standard wheels. There are two omnis on the front and two pneumatics on the back.

When we switched to the omnis, it turned too well. Think about it - omnis act as casters when the robot turns. The operator would push the stick to turn and the robot would turn, but it would keep turning when the operator moved the stick back to neutral! The polar moment of inertia kept us going. If you want to go with omnis, I recommend one of three things:
-holonomic drive
-exponential stick control for better turning sensitivity at low speeds
-(best option in my mind) a gyro to counteract the overshoot

I'm trying to get a white paper out on these wheels by midsummer.

Brandon Heller
Mentor Team 931
Alum Team 449

Yeah...you were one of the teams I saw that got me thinking about the omni wheels. We were in the pits right next to you at the MWR...and someone showed them to me.

MOEmaniac 25-04-2004 15:57

Re: Omni Wheels Survey
 
Omni wheels actually worked great for my team this year. But, we didnt have them on the ground the whole time. We had ours attatched to a pnumatic cylinder and when the stoke was out the wheels were down and when the stoke was in they were up. We saw early in the build season that the pnumatic wheels that were provided in the kit didn't allow for smooth turning. So our drive/chassie team came up with the idea of having a set of omni wheels stowed up under the robot and that could be deployed when ever the driver wanted them to. This turned out to be a great asset for out team this year because our driver could easliy maneuver the robot. :D

RogerR 25-04-2004 18:03

Re: Omni Wheels Survey
 
Quote:

Originally Posted by FizMan
... Say you have two motors per set of wheels. Does that mean you can really only apply two motors worth of power in any one direction? So if you were up against a robot that had a tank drive with four motors of power in one direction, you'd only have two to their four?...

this is the main reason that i (personally) don't like "traditional" holonomic setups. mecanum/ilon wheels (such as the ones on these robots) solve this problem to a degree, since it allows you to harness the power of all 4 motors whenever the bot is moving in a direction perpindicular or parrallel to that of wheel rotation. this setup is weakest when it is moving diagonally when only two of the wheels are being powered. in addition, since the rollers overlap, and are rounded, there isn't as much bumping present as there is in the traditional omni-wheel.

David Bridge 25-04-2004 18:28

Re: Omni Wheels Survey
 
For anyone considering the use of omni wheels on their robot, Andy Baker put out a great white paper on how team 45 made theirs and it has all the specs you need to make a great pair yourself. We on team 177 used a slight variation of these wheels on the back of our robot (we kept pneumatic tires on the front) and they allowed for excellent turning. Despite what people say you do not need at least 3 of these wheels by any stretch of the imagination. We recieved many comments from people attending the Philly regional and nationals that they thought we would be very easy to push out of the way with omni wheels and that they were surprised to see us do all of the pushing. If you saw any of our matches you know that defense was a big part of our game, and these magnificent wheels made that possible.
http://www.chiefdelphi.com/forums/pa...le&paperid=226

Alex Cormier 25-04-2004 18:48

Re: Omni Wheels Survey
 
Quote:

Originally Posted by David Bridge
For anyone considering the use of omni wheels on their robot, Andy Baker put out a great white paper on how team 45 made theirs and it has all the specs you need to make a great pair yourself. We on team 177 used a slight variation of these wheels on the back of our robot (we kept pneumatic tires on the front) and they allowed for excellent turning. Despite what people say you do not need at least 3 of these wheels by any stretch of the imagination. We recieved many comments from people attending the Philly regional and nationals that they thought we would be very easy to push out of the way with omni wheels and that they were surprised to see us do all of the pushing. If you saw any of our matches you know that defense was a big part of our game, and these magnificent wheels made that possible.
http://www.chiefdelphi.com/forums/pa...le&paperid=226

i am interested in your omni wheels, and why u guys choose to put them in the back.. please explain. :p

we should get all the robots that have omni wheels and make a big gallery of them, that would look cool.. :cool:

tiffany34990 25-04-2004 19:03

Re: Omni Wheels Survey
 
well it was our first year with omini wheels-- we actually have to fix them up-- only problem i saw was the rubber on the wheels-- a lot of driving just wore them down-- all well-- i'm sure S.P.A.M. won't mind sharign our design-- nobody we saw had a drive system like us-- and we plan on making them better

Rob 25-04-2004 19:06

Re: Omni Wheels Survey
 
I saw a few teams using omni wheels bought from this site:

http://www.omniwheel.com

They have an interesting selection.

Rob

tiffany34990 25-04-2004 19:09

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Rob
I saw a few teams using omni wheels bought from this site:

http://www.omniwheel.com

They have an interesting selection.

Rob


we actually did buy some from that site-- took the whole supply actually for that time period but the wheels didn't work for us--didn't hold our load and no clearance-- i had to actually take down the plastic but that didnt' help much either--so we had to fabricate our own wheels at the end of the 6th weeks-- but we did it-- many teams have seen our wheels they are really cool

David Bridge 25-04-2004 19:17

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Pit Bull 1126
i am interested in your omni wheels, and why u guys choose to put them in the back.. please explain. :p

Well, we put the omni wheels in the back for 2 main reasons... One was that we found they spun better under a larger load (which we had in the back) because we made the neoprene and delrin disks stiff so they wouldn't be free spinning unless there was significant torque from our drive train to make them and with more weight on the wheels they spun better. (Having a lighter load we found caused the robot to bounce when driving straight where as with the heavier load they rotated smoothly) Also it was important for us that the back of the robot was the part doing all the turning since we were a small ball robot and the roller was in the front. Rotating around the front wheels allowed us to stay in front of the balls.

P.J. Baker 25-04-2004 20:01

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Pit Bull 1126
i am interested in your omni wheels, and why u guys choose to put them in the back.. please explain. :p

we should get all the robots that have omni wheels and make a big gallery of them, that would look cool.. :cool:

I'm sure that Dave's answer above is the main reason that the omni wheels are on the back, but there is probably another. 177's robot was meant to have an arm for hanging and grabbing the 2X ball. If the robot had actaully ever been driven while holding a ball out in front, most of the robot's weight would have been over the front wheels. It would have been harder to control and very easy to push sideways if the front wheels had been omni-wheels. This is why our '98 and '00 robots had front wheel drive and rear casters enve though it is generally easier to control a robot with rear wheel drive and front casters (Buzz frequently builds their robots this way when they are picking up balls from the floor).

Max Lobovsky 25-04-2004 23:35

Re: Omni Wheels Survey
 
Quote:

Originally Posted by tiffany34990
well it was our first year with omini wheels-- we actually have to fix them up-- only problem i saw was the rubber on the wheels-- a lot of driving just wore them down-- all well-- i'm sure S.P.A.M. won't mind sharign our design-- nobody we saw had a drive system like us-- and we plan on making them better

i believe 1083 had your same holonomic drive system as nathan pell posted above. I wasn't priveleged enough to see SPAM in action, but i know that 1083 was excellent.

Max Lobovsky 25-04-2004 23:41

Re: Omni Wheels Survey
 
Quote:

Originally Posted by RogerR
this is the main reason that i (personally) don't like "traditional" holonomic setups. mecanum/ilon wheels (such as the ones on these robots) solve this problem to a degree, since it allows you to harness the power of all 4 motors whenever the bot is moving in a direction perpindicular or parrallel to that of wheel rotation. this setup is weakest when it is moving diagonally when only two of the wheels are being powered. in addition, since the rollers overlap, and are rounded, there isn't as much bumping present as there is in the traditional omni-wheel.

I believe you can have all your motors driving in one direction in a 4 wheeled holonomic system.

/-------\
|oooooo|
|oooooo|
|oooooo|
\-------/
for some reason the spaces arent staying between the two walls of my robot so i put o's in the middle

when that robot is moving "up" on the page, all the motors will be applying force in that direction. The one thing i can't seem to figure out is wether 100% of their force is in that direction or 1/sqrt2 of it is in that direction because the wheels are at 45deg angles to the direction we are measuring force in. Now basic physics would say that yeah, its 1/sqrt2 because the force is being applied at a 45deg angle, but the odd thing is, when you get out the other xy component vector, it doesnt seem to be applying a force when the robot drives straight assuming the omniwheels have no significant friction to lateral movement. Now im sure no one got that, but if you did, help me cause im really stumped by this.

RogerR 26-04-2004 02:13

Re: Omni Wheels Survey
 
Quote:

Originally Posted by maxlobovsky
... The one thing i can't seem to figure out is wether 100% of their force is in that direction or 1/sqrt2 of it is in that direction because the wheels are at 45deg angles to the direction we are measuring force in. Now basic physics would say that yeah, its 1/sqrt2 because the force is being applied at a 45deg angle, but the odd thing is, when you get out the other xy component vector, it doesnt seem to be applying a force when the robot drives straight assuming the omniwheels have no significant friction to lateral movement. Now im sure no one got that, but if you did, help me cause im really stumped by this...

the setup you showed is similar to team 180's and 1083's 2004 robots.
i'm pretty confident that that you're right with the second one ,[sqrt2]% of available motor power (but then again, i've been awake way too long). that is the reason i think the mecanum/ilon wheel setup is better, since it allows the motors to apply 100% of their power to full forward/back or left/right movement.

George1902 26-04-2004 02:35

Re: Omni Wheels Survey
 
Quote:

Originally Posted by tiffany34990
nobody we saw had a drive system like us

Tiffany!?

::GASP::

Not only have you guys seen one, but it was at the Florida Regional with you.

George1902 26-04-2004 02:47

Re: Omni Wheels Survey
 
Quote:

Originally Posted by RogerR
the setup you showed is similar to team 180's and 1083's 2004 robots.
i'm pretty confident that that you're right with the second one ,[sqrt2]% of available motor power (but then again, i've been awake way too long). that is the reason i think the mecanum/ilon wheel setup is better, since it allows the motors to apply 100% of their power to full forward/back or left/right movement.

You're so close, Roger. =-]

Both systems get [(sqrt2)/2]% efficiency in the x and y directions. Mecanum wheels have the rollers at 45* angles which produces the same vectors as a normal holonomic platform with its wheels at 45* angles.

Al Skierkiewicz 26-04-2004 07:10

Re: Omni Wheels Survey
 
Wildstang has used a variety of different designs for omni wheels over the years. We scratch build our own and have modified the design each time we used them. This year we used two driven omni (we call them BUPODfor Biased UniPlanar Omni Directional) and two crab drive modules for four wheel drive. In crab from side to side we had to add some software to help the robot drive straight which we called "Drive Straight". The omni wheels tend to go where they want when they are not driving.

RogerR 26-04-2004 09:11

Re: Omni Wheels Survey
 
Quote:

Originally Posted by George1083
....Mecanum wheels have the rollers at 45* angles which produces the same vectors as a normal holonomic platform with its wheels at 45* angles.

are you sure about this? when a mecanum moves 'forward' or 'backward' (relative to its wheels) the rollers don't spin, so the mecanum unit functions as a normal wheel would. i assumed that since the rollers were at 45*, when the robot "crabbed" left or right, it would exhibit the same charecteristics.

George1902 26-04-2004 13:40

Re: Omni Wheels Survey
 
If the mecanum wheels produced 100% power in the forward or reverse direction, it would be impossible to strafe. We know that this setup can strafe, so the power must be in the direction that the rollers are facing.

Another proof is to watch a video of a holonomic platform with mecanum wheels. Watch what happens when 2 wheels on a diagonal are powered. The robot moves in the direction that the rollers are facing.

Max Lobovsky 26-04-2004 13:58

Re: Omni Wheels Survey
 
George, i know 1083 wants to try to build its own omniwheels next year and i was wondering if you were planning to make them bigger than those 4.72" ones from omniwheel.com. I can't actually think of a valid reason why wheels that small are bad, but very few teams seem to use wheels that small, so there is probably a reason. Maybe a larger wheel gives you the potential for better traction. (yes, i know in theory traction is only dependent on the weight of the robot and the materials contacting each other, but in practice, it isnt that simple) Your grooved omniwheels seemed to have better traction than any others, bought or built.

RogerR 26-04-2004 19:45

Re: Omni Wheels Survey
 
sorry i took so long replying...
Quote:

Originally Posted by George1083
If the mecanum wheels produced 100% power in the forward or reverse direction, it would be impossible to strafe. We know that this setup can strafe, so the power must be in the direction that the rollers are facing....

thats the thing though; the only time that the mecanum wheels are acting like 'traditional' omni wheels are when the bot is moving at any angle between forward/back and side to side. when moving forward/back, they act like treads. when strafing, they act like propeller blades.

<hare-brained idea> on that note (prop. blades) i'd also like to throw out an idea that i got from watching the bots strafe back and forth. what if you were able to change the angle of the rollers? decreasing the angle would move you less distance per each "wheel" rotation, but would give you more pushing force.the angle of the rollers could be changed by a mechanism similar to the ones used to change the blade pitch on prop. aircraft. </hare-brained idea>

George1902 26-04-2004 23:10

Re: Omni Wheels Survey
 
Quote:

Originally Posted by maxlobovsky
George, i know 1083 wants to try to build its own omniwheels next year and i was wondering if you were planning to make them bigger than those 4.72" ones from omniwheel.com.

If we do build our own, they'll prolly be bigger. I think bigger ones are easier to make, although I'm not totally sure about that. 6" would be a good size, I think.
Quote:

Originally Posted by maxlobovsky
I can't actually think of a valid reason why wheels that small are bad, but very few teams seem to use wheels that small, so there is probably a reason.

The main problem we had with the smaller wheels was clearance. I think our robot ended up with < .5" of ground clearance. :yikes:
Quote:

Originally Posted by maxlobovsky
Your grooved omniwheels seemed to have better traction than any others, bought or built.

Thank you very much. =-]
That's probably the best argument for us using them again in the future.

Zotas 27-04-2004 07:51

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Al Skierkiewicz
Wildstang has used a variety of different designs for omni wheels over the years. We scratch build our own and have modified the design each time we used them. This year we used two driven omni (we call them BUPODfor Biased UniPlanar Omni Directional) and two crab drive modules for four wheel drive. In crab from side to side we had to add some software to help the robot drive straight which we called "Drive Straight". The omni wheels tend to go where they want when they are not driving.

I am interested in what you guys (Wildstang) used for the rollers that interacted with the carpet. I took a peek and it looked like you had neoprene disks, except they were not punched. Can you enlighten us?

Thank you,
Jake Mazotas

Raul 27-04-2004 09:54

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Jake Mazotas
I am interested in what you guys (Wildstang) used for the rollers that interacted with the carpet. I took a peek and it looked like you had neoprene disks, except they were not punched. Can you enlighten us?

Thank you,
Jake Mazotas

They were 3/4" diameter Polyurethane rods (75 durometer) bought from McMaster Carr.

tiffany34990 27-04-2004 17:21

Re: Omni Wheels Survey
 
Quote:

Originally Posted by George1083
Tiffany!?

::GASP::

Not only have you guys seen one, but it was at the Florida Regional with you.


sry george meaning that nobody made wheels like us-- design that james came up with and that i got to help make and well yeah get to fix them again :ahh: :)

Ellery 30-04-2004 10:51

Re: Omni Wheels Survey
 
1 Attachment(s)
We (X-CATS 191) used Omni wheels for the first time this year as well... They worked very well and we even made them from scrath recycling old copier parts we pulled out of some dumpster. I'll have to get some closer pictures for ya.

We made an 8 wheel drive system that walked up the platform. It worked well except for the side traction when we were halfway up a step and then we had issues sliding.. Oh well you live and learn...

Ellery

ngreen 30-04-2004 11:37

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Ellery
They worked very well and we even made them from scrath recycling old copier parts we pulled out of some dumpster.

Old copier parts work great for robots. We have pieces of an old one we keep in a box. Lot of good things. We about used a ratchet for our winch that would have came from one and use a couple other pieces to couple a motor to a shaft. If you look beside the van door motor in this picture you can see a piece of an old copier on its right between it and the pillow block. If you could see the top it has a little hole and says oil. We didn't use any though.

SpaceOsc 30-04-2004 13:04

Re: Omni Wheels Survey
 
I think everyones forgetting (or you just werent around) one of the proven bots out there with large omni wheels and they happend to use 6 of them they went in all directions they didnt get pushed around and there was no easy side to push them from they turned marvelously and speed and power to boot

MIM Metal in Motion 343 2002 bot still one of my fav robots of all time check them out and youll see there design ... i wanted to build something like that but i couldnt get the whole building omni wheels thing started any suggestions or things only expirience teaches u when building this nice lil wheels? things i should watch out for when tyring to build and use them?

Cobbimus 03-05-2004 13:22

Re: Omni Wheels Survey
 
Quote:

Originally Posted by SpaceOsc
I think everyones forgetting (or you just werent around) one of the proven bots out there with large omni wheels and they happend to use 6 of them they went in all directions they didnt get pushed around and there was no easy side to push them from they turned marvelously and speed and power to boot

MIM Metal in Motion 343 2002 bot still one of my fav robots of all time check them out and youll see there design ... i wanted to build something like that but i couldnt get the whole building omni wheels thing started any suggestions or things only expirience teaches u when building this nice lil wheels? things i should watch out for when tyring to build and use them?

I was primary operator on team 343 this season and would like to thank you for your comments on "Manuel Overdrive". One thing you might watch out for on your omni wheels is the fact that the small wheels on M.O.'s omni wheels are metal and this year metal was restricted from touching the carpet on the playing field, this may only be a temporary rule or permanent. Thats all the advice I have for now, but I will pass word along to our engineers and they might be of more help to you. Thank You and may gracious professionalism live on! :cool:

SpaceOsc 03-05-2004 13:48

Re: Omni Wheels Survey
 
Quote:

Originally Posted by Cobbimus
I was primary operator on team 343 this season and would like to thank you for your comments on "Manuel Overdrive". One thing you might watch out for on your omni wheels is the fact that the small wheels on M.O.'s omni wheels are metal and this year metal was restricted from touching the carpet on the playing field, this may only be a temporary rule or permanent. Thats all the advice I have for now, but I will pass word along to our engineers and they might be of more help to you. Thank You and may gracious professionalism live on! :cool:

Why where they metal? what did that do?

Gary Dillard 04-05-2004 13:24

Re: Omni Wheels Survey
 
Quote:

Originally Posted by SpaceOsc
I think everyones forgetting (or you just werent around) one of the proven bots out there with large omni wheels and they happend to use 6 of them they went in all directions they didnt get pushed around and there was no easy side to push them from they turned marvelously and speed and power to boot

MIM Metal in Motion 343 2002 bot still one of my fav robots of all time check them out and youll see there design ... i wanted to build something like that but i couldnt get the whole building omni wheels thing started any suggestions or things only expirience teaches u when building this nice lil wheels? things i should watch out for when tyring to build and use them?

That was definitely a sweet robot - we teamed with them to win KSC regionals (with 186 also). Kinda funny that they've switched from omni wheels to Brekoflex drive and we've switched from Brekoflex to omni wheels.


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