Looking for Mecanum Wheels

[sanddrag]

Personally, I'd prefer a 1/2" bore with a 1/8" keyway to use a live axle of the type, but that's just me. Perhaps such a hub will be available?

[Kyle Love]

Originally Posted by DeepWater

Andy,

I got to see the new AndyMark Mecanum wheels in Atlanta and I love the simple elegant design. I was really bummed when I didn't win them! There was mention of a possible white paper on them to be posted on the TechnoKats website. Is this still fourth coming? How about posting a picture so that everyone that didn't get to see this much sought after COTS product can see what they have to look forward to. I predict many teams will have Mecanums this next year! Great job bringing these sort of products to the market for teams that don't have the resources to make them themselves. Kudos to you and Mark!

BTW: What sort of hub setup are you thinking of for the final design? For what it's worth I would love to see a setup compatable with IFI wheels with the same sort of 3/8" flanged bearings and sprocket hole pattern (6 on 1.875" IIRC). They would then be a drop in replacement on the KitBot chassis.

The mecanum wheels in Atlanta were not Andymark wheels, they were the TechnoKats. Some of you asked me if they would be Andymark products, now you know!

[Andy Baker]

Originally Posted by sanddrag

Personally, I'd prefer a 1/2" bore with a 1/8" keyway to use a live axle of the type, but that's just me. Perhaps such a hub will be available?

Ask and ye shall receive. Such a hub is already available.

If we go with 1.124" holes for 1/2" flanged bearings, that Universal Hub fits right in the hole and mates up with the 1.875" hole pattern.

Thanks,
AB

[Billfred]

Originally Posted by Andy Baker

We'll be coming out with an assembly print within 10 days or so (there I go making promises...).

We definitely will have the 6 holes on a 1.875" pattern, which is what our polycarbonate omni-wheels and our Traction Wheels have. We were thinking to have a 1.124" hole in each side plate, for mounting a 1/2" id flange bearing, but if most people want to use 3/8" bearings, we can do a 0.874" hole. Now is the time to give us input on this.

Personally, I prefer the 3/8" shaft. I've built two robots this way with no complaints, and the compatability with the Kitbot is handy. (Of course, YMMV.)

On the other hand, you can get bearings with the right OD and ID off of McMaster-Carr. Perhaps offering both sets of bearings would do the job?

[ChuckDickerson]

Originally Posted by Kyle Love

The mecanum wheels in Atlanta were not Andymark wheels, they were the TechnoKats.

Sorry 'bout that. My bad. Whoever designed them did a great job and I love 'em!

[Joe_Widen]

Heres a picture of the wheels the TechnoKatz had in Atlanta. I personally thought they were a bit bulky, but it was a good prototype. I hope for it to be more streamlined and a bit lighter. Those wheels must have weighted 4-6 pounds each. Well I would really like to give mad props to AndyMark for making a holonomic Drive system compatible with the KOP chassis. Now if you guys made small 14-1 gearboxes for one cim to compliment it, you'd be a FIRST God. O yeh, on a personal note, as much as I love these wheels, I'm going to try to steer my team away from it because I like having a unique design. I like the challenge of building something new, creative, innovative, beautiful, and works really good too and getting the satisfaction of building something that performs amazingly. Well I'm glad you made these mecanums and good luck to the teams who use them. Heres that picture. Sorry I made it a short monolouge there.

http://www.chiefdelphi.com/media/photos/25002

[ChuckDickerson]

Originally Posted by Andy Baker

We were thinking to have a 1.124" hole in each side plate, for mounting a 1/2" id flange bearing, but if most people want to use 3/8" bearings, we can do a 0.874" hole. Now is the time to give us input on this.

Not knowing your manufacturing process would both be an option? If not my thinking would be to go with the 3/8" setup (0.874" hole) and the user can just bore a larger hole as needed. It is always much more difficult to put metal back in the hole than it is to take it out.

[Andy Baker]

Originally Posted by DeepWater

Sorry 'bout that. My bad. Whoever designed them did a great job and I love 'em!

Designer = TechnoKat mentor Mark Koors

Originally Posted by DeepWater

Not knowing your manufacturing process would both be an option? If not my thinking would be to go with the 3/8" setup (0.874" hole) and the user can just bore a larger hole as needed. It is always much more difficult to put metal back in the hole than it is to take it out.

This is a good point. We've got some time to make this decision. I also like the 3/8" bearing hole (~0.8745") for mainly this reason.

Andy B.

[rachal]

These are the mecanums we're making for next year:
http://www.chiefdelphi.com/forums/sh...ad.php?t=46175

Blanks were cut from 3/4" plate on a CNC mill by our machinist, then everything else was done with a manual mill.

[Nuttyman54]

Originally Posted by Joe_Widen

I hope for it to be more streamlined and a bit lighter. Those wheels must have weighted 4-6 pounds each.

I'm not sure you CAN make them much lighter. With all the rubber on it, it gets heavy fast, and you need a good support structure. With how they're used, the wheels will take a good amount of sideways forces, and you need the structure to be strong enough to handle that, and then some. Now, I've got no good reference point, so 4-6 lbs may be excessive, but they will almost assuredly be heavier than any comparable standard wheel.

Andy, what material is the hub made out of, and are you using the same roller material as you have for the omnis?

[Andy Baker]

Originally Posted by Nuttyman54

I'm not sure you CAN make them much lighter. With all the rubber on it, it gets heavy fast, and you need a good support structure. With how they're used, the wheels will take a good amount of sideways forces, and you need the structure to be strong enough to handle that, and then some. Now, I've got no good reference point, so 4-6 lbs may be excessive, but they will almost assuredly be heavier than any comparable standard wheel.

Andy, what material is the hub made out of, and are you using the same roller material as you have for the omnis?

We've not made production models yet. The prototype models have 1/8" side plates and black EPDM rubber as the rollers. The rollers would be best if made out of polyurethane, but availability and cost are factors. We will shoot for a 75-80A durometer, durable, concentric, economical, non-marking material.

AB

[Greg Needel]

Originally Posted by Andy Baker

We were thinking to have a 1.124" hole in each side plate, for mounting a 1/2" id flange bearing, but if most people want to use 3/8" bearings, we can do a 0.874" hole. Now is the time to give us input on this.

I think you should bore them to 1.124 and also make pressfit bushings available to easily convert them the .874 if needed.


In actuallity though you can buy bearings from mcmaster that are 3/8 and have an OD of 1.125.


edit: although andy are the holes on the hole pattern going to be #10 (like ifi sprockets and the deka plastic hubs or are they going to be 1/4 like your molded omni wheels?

[Andy Baker]

Originally Posted by Greg Needel

edit: although andy are the holes on the hole pattern going to be #10 (like ifi sprockets and the deka plastic hubs or are they going to be 1/4 like your molded omni wheels?

Ugh... thanks for reminding me of that mistake.

These holes will be #10 clearance holes (or M5), at 0.205-0.210 diameter.

The 0.250" holes in the omni-wheels were designed to be #10 clearance holes also, but our molder turned them into 0.250".


Andy B.

[Richard Wallace]

Originally Posted by Greg Needel

I think you should bore them to 1.124 and also make pressfit bushings available to easily convert them the .874 if needed.

I'll second (or vote for) that. Let the standard wheel be a fit for the standard hub.

Originally Posted by Andy Baker

Ask and ye shall receive. Such a hub is already available.

If we go with 1.124" holes for 1/2" flanged bearings, that Universal Hub fits right in the hole and mates up with the 1.875" hole pattern.

Thanks,
AB

[Jeremiah Johnson]

I'm sure there will be some sort of display for these at IRI right? Ed showed us some video of the BattleBot, Acoholic Stepfather using mecanum wheels and our team fell in love with them. Although I knew about them far ahead of time, I had not yet made any sort of presentation about them. Ed wants to experiment with mecanum drive over the summer I think.