pic: AndyMark Mecanums

[Jonathan Norris]

So where can I buy some .

[Rohith Surampudi]

they arent on the website yet, but here

Huzah for AndyMark

[bigboi146]

I dont get them. Can you use them in an omni drive. they look awsome though.

[Qbranch]

OK here's something that has bugged me for years.

can someone verify that:

1. The wheels for holonomic drive are called "Mecanum" wheels.
2. The drive system itself is called "holonomic drive"
3. The drive system is not called "Mecanum drive"

PM me or just reply here. Thanks.

-Q

[Richard Wallace]

Originally Posted by Qbranch

OK here's something that has bugged me for years.

can someone verify that:

1. The wheels for holonomic drive are called "Mecanum" wheels.
2. The drive system itself is called "holonomic drive"
3. The drive system is not called "Mecanum drive"

PM me or just reply here. Thanks.

-Q

My understanding is that 'holonomic' means 'able to translate and rotate simultaneously'. Holonomic drive can be implemented using mecanum wheels or omniwheels.

[ahecht]

These look like a promising start if the price makes them affordable enough. However, in their current incarnation I do see a few problems. First, unless you want to thumpthumpthump down the field, I hope the final rollers are a bit rounder than that. Also, these wheels are going to take incredible side loads, so I hope those plates are steel (I would assume so, since these guys seem to know what they are doing).

[sanddrag]

I wouldn't be surpised if the production wheels remain relatively unchanged. I have a feeling those plates are quite strong due to the manner in which those tabs are bent. And for the rollers, I have a feeling those edges may have some traction enhancing properties. Just guesses though.

[Billfred]

Originally Posted by ahecht

These look like a promising start if the price makes them affordable enough. However, in their current incarnation I do see a few problems. First, unless you want to thumpthumpthump down the field, I hope the final rollers are a bit rounder than that. Also, these wheels are going to take incredible side loads, so I hope those plates are steel (I would assume so, since these guys seem to know what they are doing).

I saw them in Atlanta, and they felt pretty solid to me (at least for prototypes). I've seen a lot of things made from 1/8" aluminum, and it seems to hold up to plenty of abuse, especially once you start putting some bends in there. They were a bit heavier than, say, IFI wheels might be, but welcome to the world of mecanum wheels.

As I have yet to work with mecanum drive, I'd have to leave judgment on the rollers to The People That Know What They Are Doing(tm).

[Qbranch]

Have you all seen the vehicles that AIRTRAX is making holonomic?

I was amazed that they figured out how to do holonomic drive for forklifts and scissor lifts.

Just something that caught my interest.

-Q

[ahecht]

Originally Posted by Billfred

I saw them in Atlanta, and they felt pretty solid to me (at least for prototypes). I've seen a lot of things made from 1/8" aluminum, and it seems to hold up to plenty of abuse, especially once you start putting some bends in there.

When 190 made our mecanum wheel, we originally had our rollers supported by 1/8" aluminum tabs, but we found that lose quickly bent when supporting a 130 pound robot making rapid movements. We switched to 1/8" steel, and while those were much better, we still had the occasional bent tab.

[Alan Anderson]

Originally Posted by ahecht

...unless you want to thumpthumpthump down the field, I hope the final rollers are a bit rounder than that.

With enough weight on the wheels, the TechnoKats' prototype mecanum drive base is very smooth. The installed rollers are sufficiently "squishy" that they don't do a lot of thumping to begin with, and they also wore down a bit to a slightly rounder profile after driving on concrete for a while.

[artdutra04]

Originally Posted by Qbranch

OK here's something that has bugged me for years.

can someone verify that:

1. The wheels for holonomic drive are called "Mecanum" wheels.
2. The drive system itself is called "holonomic drive"
3. The drive system is not called "Mecanum drive"

PM me or just reply here. Thanks.

-Q

See these pictures for examples of holonomic and mecanum drive robots.

[Richard Wallace]

Wikipedia actually has a pretty good definition of holonomic as the term applies to robots:

Originally Posted by Wikipedia

In robotics holonomicity refers to the relationship between the controllable and total degrees of freedom of a given robot (or part thereof). If the controllable degrees of freedom is equal to the total degrees of freedom then the robot is said to be holonomic.

So a robot drivetrain that is truly holonomic as defined above would have three degrees of freedom; i.e., three independently controllable wheels not directed along the same axis. A robot drivetrain with four omniwheels arranged on the corners is actually redundant, but with relatively simple math can be made to function like one that is holonomic. The same statement applies to a robot drivetrain with four mecanum wheels.

[Simon Strauss]

Originally Posted by Richard

So a robot drivetrain that is truly holonomic as defined above would have three degrees of freedom; i.e., three independently controllable wheels not directed along the same axis. A robot drivetrain with four omniwheels arranged on the corners is actually redundant, but with relatively simple math can be made to function like one that is holonomic. The same statement applies to a robot drivetrain with four mecanum wheels.

Aka Kiwi drive which is usually categorized with the Holonomic drive Art had above due to their usage of the same type of wheel

[WernerNYK]

Originally Posted by Qbranch

OK here's something that has bugged me for years.

can someone verify that:

1. The wheels for holonomic drive are called "Mecanum" wheels.
2. The drive system itself is called "holonomic drive"
3. The drive system is not called "Mecanum drive"

PM me or just reply here. Thanks.

-Q

1. Mecanum refers to the name of the compnay which the original creator worked for at the time of his invention (or at least to the person whose name is on the patent of the design which is most commonly mimiced by FIRST teams). Bengt Ilon developed this design, if my memory serves me correctly in the mid-1970s.

2. A holonomic platform, most literally is defined as one which has the ability to instantaneously move in any given direction (on a given plane). It does not need to be accomplished with mecanum wheels, and may not necessarily require wheels at all (I'm thinking "bumper boats" right off the top of my head - although not as controllable, these do fit the general terms).

3. There is technically no such thing as a Mecanum drive, although within the FIRST community, a holonomic drive platform using Mecanum-style wheels has become known as a Mecanum drive platform.

I realize this is a few months down the line, but hope it clarifies some things for you -- sorry in advance if any of my "facts" or a bit off, I'm replying to this based solely on memory of research I did almost two years ago.


EDIT: His name was not Ilon Mecanum -- Mecanum was the company he worked for. Ooops.