Re: AndyMark Mecanum Wheel tests
 

I second that.

For methodology, a drop from a fixed height with increasing weight, or a drop from an increasing height with a fixed weight. In my mind (empirically) I think your heavy bot, lifted 24 inches at one end and then dropped onto nominal playing surface would be adequate. See if it survives X drop cycles. X could be around 50-100.

Second suggestion: roller wear on macadam or smooth concrete (I am thinking parade duty here - can it go a mile?)

Don

Re: AndyMark Mecanum Wheel tests
 

I'm curious as to the possibility of using your Mecanums in a situation where accurate odometery is required. For example, on a 50 pound robot, driving forward 10 feet at 1m/s, how much "slip" is encountered on a standard linoleum floor? The application wouldn't be FIRST, but a robot designed for SLAM (Simultaneous Localization And Mapping). Mecanums may not even be feasible for the part, but having some number of slip during normal operation would help.

Re: AndyMark Mecanum Wheel tests
 

While generally happy with the 6" AM mecanum wheels this year, we did have some problems with robustness and had to replace two wheels at Championship.

As such, I am particularly interested in any tests that demonstrate how much abuse they can (and cannot) take -- the drop test is a great idea. How about stress from FIRST-speed ramming (both head-on and from the side?)

Small deformations caused the rollers to rub and effected performance (not a ton, but some) on the 6" wheels. I'm not sure if this was/is an issue with the 8" wheels.

Re: AndyMark Mecanum Wheel tests
 

We has huge issues with deformation and rubbing of the 8" wheels. We were disappointed that theses weren't a bit tougher, good to hear the new design is, but I guess it is to be expected with the large amount of shock loads this year.

Matthew Forman
Team 1515

Re: AndyMark Mecanum Wheel tests
 

To add to all the suggestions, the roughest thing on the field I saw this year was the "1/2" bump" on both sides of the ramps. I saw this bump even bend some aluminum AM omni wheels. So maybe some sideways testing on a 1/2" hard bump or something similar.

Re: AndyMark Mecanum Wheel tests
 

We has huge issues with deformation and rubbing of the 8" wheels. We were disappointed that theses weren't a bit tougher, good to hear the new design is, but I guess it is to be expected with the large amount of shock loads this year.

Matthew Forman
Team 1515[/quote]

We also had serious issues with deformation of out 8" wheels and ended up going through 2 sets of 4 (which ends up getting pretty pricey.) The problem we were having is that the wheel plates were curling over (we assume from side load) and binding the rollers.

I would like to see some tests involving side load on the wheels, the sort of stress the wheel would see when being pushed from the side.

Mike Jr.
Team 1058 Mentor

Re: AndyMark Mecanum Wheel tests
 

Our main concern was the robustness of the side plates. We used the 8" wheels and noticed the same thing as the above post. Some of our rollers would get pinched between the two side plates and prevent the rollers from freely spinning.

Re: AndyMark Mecanum Wheel tests
 

Rigolith

(just in case)

Re: AndyMark Mecanum Wheel tests
 

how about the same test while stapling some roughtop or wedgetop to the kit wheels, many teams use this, your company sells wheels with roughtop/wedgetop in mind....i think it would be a good piece of information to have

are you videotaping these tests? I think that would be good in addition to written results

Re: AndyMark Mecanum Wheel tests
 

MythcanumBusters.

Re: AndyMark Mecanum Wheel tests
 

I'd like a study performed on the correct pronunciation of mecanum. I've heard "MECK-ken-nem" and "muh-CAN-um" from very reputable sources. Which is right?

Re: AndyMark Mecanum Wheel tests
 

jester drive. :p