Mecanum: VEX VS. AndyMark

[scaryone]

Tried Vex after using AndyMark for years. Lots of broken rollers on Vex. Not sure how redesign will work. Likely sticking with AM

[T^2]

How about neither?

[Electronica1]

My team will give the 4 inch andymark wheels a try once they come in stock. Until then, we will use vex, which will work, but we want to use the andymark wheels due to the fact we have had amazing experience with their 6 inch and 8 inch wheels (they have held up for countless demos and other abuse and still are running great).

[MJ Miller]

I have no experience with Vex mechs, but for AM I recommend the 6"Heavy Duty mechs. These cost $399 per set, have thick side plates, and No 10 screws with bronze bushings - very reliable. The cheaper ones have thin side plates prone to bending, and No 6 screws prone to breaking. I had many rollers come off on the field with the cheap ones. Also, I never have used the 8"and 10" wheels sizes due to weight. Regardless of the wheel size, roller performance is critical to proper drive function (along with wheel contact and balanced robot weight).

MJ

[Jay O'Donnell]

1058 used AM for 2010 and 2011, and used VEX for 2014. I would highly suggest using the AndyMark mecanums. I believe they are slightly heavier, but they (in my experience) strafe better and last longer.

[Ether]

Originally Posted by MJ Miller

roller performance is critical to proper drive function

Quoted for truth. Minimal axial free play and roller spinning friction.

[RoboScout]

Our team has used the AndyMark Heavy Duty 6" mechanum for two of the past three seasons, without a single problem or failure. They are a bit expensive at ~400 for the set, but well worth the additional cost compared to the lighter duty AM wheels or other brands, IMO.

KenSt.

(aka RoboScout)

[Mecanum Wheel]

Originally Posted by RoboScout

Our team has used the AndyMark Heavy Duty 6" mechanum for two of the past three seasons, without a single problem or failure. They are a bit expensive at ~400 for the set, but well worth the additional cost compared to the lighter duty AM wheels or other brands, IMO.

KenSt.

(aka RoboScout)

*mecanum

[Tom Line]

We had an extremely poor experience with last year's (weaker) version of the vex wheels. In fact, after one of our sister teams ran out of replacements we wrapped their wheels with duct tape so they could complete what they needed to because so many of the rollers had broken.

Vex appears to have attempted to address that issue, but I'm always wary of being the test-monkey on an expensive product that goes into a place that is as critical as the drive train is.

On another note, the modifications they've made to the ball shifter has me drooling. I hate dog gears with a passion after this past year.

[Mike Marandola]

Originally Posted by Tom Line

We had an extremely poor experience with last year's (weaker) version of the vex wheels. In fact, after one of our sister teams ran out of replacements we wrapped their wheels with duct tape so they could complete what they needed to because so many of the rollers had broken.

Vex appears to have attempted to address that issue, but I'm always wary of being the test-monkey on an expensive product that goes into a place that is as critical as the drive train is.

On another note, the modifications they've made to the ball shifter has me drooling. I hate dog gears with a passion after this past year.

Just curious, what problems did you have with dog gears?

[mbshark]

Want to get a 4 set of 6" mecanum wheels for the robot and would like some help with:

Originally Posted by Aren_Hill

Like Mike pointed out above, a significant amount of time went into improving the roller mount. We have tested the new ones until we wore the rubber off the rollers, no more broken tabs.

If you have any concerns, please contact me at prosupport@vex.com and I'll talk you through what we did to make them better, and how they'll work awesome for your design.

-Aren

In testing the new type, have you tested this on multiple sets of robots at a full 120lbs not including battery or just bases that dont have all the weight on them. Also on the specs is the 200lbs for the set of 4 or for each wheel(trying to compare to the standard and HD on the andymark site that rate each wheel individually)? Has any team or third party heavily tested these out or played around with them yet?

Originally Posted by RoboScout

Our team has used the AndyMark Heavy Duty 6" mechanum for two of the past three seasons, without a single problem or failure. They are a bit expensive at ~400 for the set, but well worth the additional cost compared to the lighter duty AM wheels or other brands, IMO.

KenSt.

(aka RoboScout)

Would you say that there is a big difference in the regular vs HD mecanum from andymark? What are your and anyone else's teams experiences with these?

Thanks for the help and sorry for any typing errors

[CalTran]

We used AM 6" Mecanum wheels in 2010, and that robot is still driving on their original wheels, including after a few events (that I wasn't a part of) that included driving directly on concrete, so I imagine that's a plus on the AM wheels durability part.
Can't say I've ever used any of the AM mecanums that have plastic rollers, so I can't speak too much for them. The aluminum plates appear to be basically the same, so I would imagine they're pretty durable.

We used the very first batch of VEXPro mecanums back in 2013, and we liked them a lot. Personally, we never broke a wheel, but other teams have stated that they have, as well as VEX releasing a new design this year for that very problem.

Personally, I would be a little more inclined towards the VEXPro wheels, if only because they're cheaper and this year the defense is much lighter, as well as the field is fairly flat, and the rollers on the VEXPro wheels allow for a higher COF than the rollers on the AM wheels do, which may come in handy for the HDPE of the scoring platform.

[Canop3n3r]

We have been using the 6" Mecanum wheels from AndyMark every year since 2009. We usually use one set two years in a row and then buy new ones. Our old bots use the old sets still and they work wonderfully after 4-5 competitions each and many many demos. We have never broken a roller even after climbing the bridge in 2012 and falling off the pyramid in 2013. HIGHLY RECOMMENDED. Especially this year, Very heavy loads will be placed on those front wheels this year so make sure your team accounts for it.

[zinthorne]

I realize that vex has fixed the problem with their mecanum wheels, but I would still not use them. We used them last year and were not able to strafe very well. We did also get several of the bad batches and had to replace so many. I cannot recall the amount of times we had to stop drive practice to replace or repair a wheel because of a wheel breaking. We made it through 2 competitions on our competition bot and then replaced all the wheels, because they were starting to break. All the other teams I saw use Andy Mark wheels could strafe much better and they did not break.

[RonnieS]

Originally Posted by zinthorne

I realize that vex has fixed the problem with their mecanum wheels, but I would still not use them. We used them last year and were not able to strafe very well. We did also get several of the bad batches and had to replace so many. I cannot recall the amount of times we had to stop drive practice to replace or repair a wheel because of a wheel breaking. We made it through 2 competitions on our competition bot and then replaced all the wheels, because they were starting to break. All the other teams I saw use Andy Mark wheels could strafe much better and they did not break.

Are you confident your strafing problem was due to the wheels and not a flaw in the design of the system? I wouldn't just assume the wheels would make you stake way worse....maybe look into your structure a little more.

But for everyone else, we have test with the vex Mecanums and they worked very well for us.
-Ronnie