AndyMark Omni Wheels

Who out there have used the AM wheels?
We are thinking about using them but we can’t decide which ones to order.
Which ones have you used and what did you think of them.

  1. Omni wheel material
    A) Rubber
    B) Delrin
    C) Neoprene

  2. Wheel material
    A) Aluminum
    B) Polycarbonate

Thanks is advance :slight_smile:

I’d ask the builders of this.

We used the 6” aluminum wheels last year without much luck. On the 6” wheel, the rollers are spaced angularly too far apart. The robot bounces up and down as the wheel turns and alternately rides up onto a single roller and then down onto two adjacent rollers. The 8” wheel has more rollers, but I don’t know if it rides any more smoothly. I believe some teams put two wheels together and staggered the rollers to address this, but that doubles the weight of your wheel.

The other issue we had was with the rollers themselves. The acetal rollers rolled freely, put provided very little forward traction. The EPDM rollers had very good forward traction, but the roller would flex and wedge in its slot, which would prevent it from rolling. The neoprene rollers weren’t available when we ordered last year, so I don’t know how they will perform.

Although I’ve only seen the molded plastic wheel picture on the website, it looks to me to be much better. They have more and wider rollers, and the rounder wheel profile should turn more freely. I don’t know how freely the rollers turn, but it doesn’t look like their flexing would be a problem.

We just purchased a pair of 8" AM plastic molded Omni-wheels. They should be arriving this week, and we’ll get a chance to play with them on last years’ robot. I talked with Andy himself and asked a few questions, which is what eventually swayed me to the plastic ones. We choose the plastic omni’s for the following reasons.

  1. Only one wheel per side, no need to double up. This reduces cost, weight, and volume. (Can you get a better solution?)
  2. 1.875" bolt pattern, as opposed to the 2.25" on the AL ones. No adapter needed for the AM aluminum sprockets.
  3. Hopefully, similar traction on the carpet and the ramp. (I don’t know how the more narrow roller from the AL omni’s would fare on the ramp.)

Unfortunately, I won’t be able to do a head-to-head comparison of the AL omni’s to the plastic omni’s. But, I can certainly let you know, relatively, how they compare to the 8" skyways.

And, if my word isn’t enough, here’s one of Andy’s direct responses. (Copied without permission, though I don’t think he’ll mind…)

“I think that the plastic omni-wheels are a improvement to the aluminum-based wheels. We saw many rollers crack and break last year because they stick too far out from the aluminum body of the trick wheel. That is why we made a smaller pulley on the new plastic omni wheel. These rollers will last longer, although they are the same duromter. They won’t dig into the carpet as much as the trick wheels, but they still will have ok grab on the carpet. We need to do some tests on this… ug, I need more time for that.”

BEN
Team 228

I highly suggest the plastic omni-wheels to anyone considering between our two styles.

Simply put, the plastic omni-wheel is an upgrade of the Trick Wheel. Gary is right in his post… the Trick Wheels have too much spacing between the rollers and the rubber rollers don’t hold up as well as they should because they have a diameter that is too large.

The “Omni Wheel” is VERY robust. They are made from two halves of molded polycarbonate with a 10% fiberglass filler. All wall thicknesses of this mold is over 0.1". The rollers are molded instead of cut like the rollers on the Trick Wheels. They spin easier sideways, while still providing traction forward and backward. Each roller on the Omni-Wheel rides on a pair of brass eyelets, which are bearings for the captured dowel pin. Trick wheels don’t have these brass eyelets.

We strongly considered discontinuing the “Trick Wheels” this year, but since many people bought them last year and during the off season, we had to keep them on our product listing. We will look to discontinue them this summer, unless the demand keeps up.

It is no fluke that we priced the Omni-wheels lower than the Trick wheels. They are lower simply because we want to sell them more than the Trick wheels. Some people, I believe, are choosing Trick Wheels because they think they are paying more for a better product, but this is not true… the Omni-wheels are simply a better omni-wheel than the Trick Wheel.

I am excited to hear from people who have started to use our plastic Omni-wheels to see what their opinions are.

Sincerely,
Andy

Are the hubs for the trick wheel compatible with the new omni wheels? We already have everything based off of 1/2 drive shaft, but if we can easily change we probably will.

As of tomorrow, all of the 1/2" bore, 1/8" keyway hubs for the Trick Wheels will also fit the Omni-Wheels (and Traction Wheels). These are being finished today, and they will be sent out as hubs for either wheel.

This has not been reflected on our website yet.

Andy B.

So are you making a new hub, or is it a modifiction to the wheel?

Andy,
Unfortunally I speced out the trick wheels for my team this year as our first omni’s :eek: and after the fight with the other engineers I belive I will be looking really red if they perform as some have said, as we have not yet gotten them could I return them for the new style, or if the shipment hasent left yet is there any way to change them around?

I like them with the delrin as a omni. As I mentioned recently in another post watch your weight balence when you use them. To much over the omnis can cause the neoprene wheels to bottom out and put metal in contact with the carpet. It will also effect the handeling.
Pete

I agree with Andy, the AM Trick-Wheelsare cool…but the Omni’s give you a better looking and performing bang for your buck…and they are cheaper!

Yeah…we bought the trick wheels. 8 inch with delrin. Just came in today. havent really played with them yet…will post result when robot gets running…

Also ordered the adapter kit for “the beast motors” I will post on that also.