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View Full Version : 8inch Mecs or 10 inch?


Syphorce
27-01-2010, 19:08
I wanted hear your opinion on which set of wheels are better, the 8-inch Mecanums or the 10 inch Mecanums. You would think that they would be the same thing but actually the rolles are different. The 8-inch seem to have more friction than on the 10-inch Mecanums. Post your opinions here.

Chuck Glick
27-01-2010, 19:55
If you are referring to the AndyMark mecanum wheels, you may want to take a look at the weight of the 10" wheels.

7 lbs per wheel for aluminum = 28 lbs in wheels alone!
14 lbs per wheel for steel = 54 lbs in wheels alone!

When compared with the 8" model however:

2.5 lbs per wheel = 10 lbs in wheels

*This is less than 1 steel 10" or 2 aluminum 10" wheels.*


Price is also a HUGE factor:

$710 for a set of 10"
$310 for a set of 8"


Direct from the 8" page:
Tension on the roller can be adjusted by loosening or tightening the 12 Nylock rollers on the perimeter screws. Tighten the nylock nut for a more restricted roll. Loosen the nut for a more freely spinning roller.

The friction should be no problem what so ever as the wheels are completely adjustable. Many teams have had great success with the 8" version. I personally see no reason to go all the way up to the 10".

Jeffy
27-01-2010, 19:55
last i checked the 10" mechs were listed at 10lbs a piece. 40lb wheels? well i guess it would lower your CoG.

yoshibrock
27-01-2010, 20:03
We considered 10 inchers for about 10 minutes until we saw the weight and cost :rolleyes:
Of course.....there is that coolness factor, because those things just look amazing. I'd go with 8 inch though, much cheaper and lighter. And I don't see how the 10 inch could be THAT much more effective.

Stephen of REX
27-01-2010, 20:20
If you had truly ridiculous machining capabilities, you could convert bicycle wheels to mecanum. But for actually practical use, I would use the 8 inchers. They are better in most ways.

ehochstein
27-01-2010, 20:25
Could you add an option for "I want mechanum wheels"? I want Mechanum wheels, but my team doesn't! Well, I wouldn't say doesn't they just have more important matters on their mind...

dtengineering
27-01-2010, 20:30
The 10" wheels look like they would run much more smoothly, but are not, I believe, FRC legal.

8.3.3.1 G states:

If the modules are designed to assemble into a single configuration, and the assembly is functional in only that configuration, then the total cost of the complete assembly including all modules must fit within the price constraints defined in Rule <R22>.

So at $710, they would exceed the $400 limit.

But they are really cool....

Jason

EricLeifermann
27-01-2010, 20:36
We're using the 6in mecanums but you don't have them in your pole, when went based on price and the 6 in are getting us over the bump just fine.

Chuck Glick
27-01-2010, 21:53
The 10" wheels look like they would run much more smoothly, but are not, I believe, FRC legal.

8.3.3.1 G states:
If the modules are designed to assemble into a single configuration, and the assembly is functional in only that configuration, then the total cost of the complete assembly including all modules must fit within the price constraints defined in Rule <R22>.


So at $710, they would exceed the $400 limit.

But they are really cool....

Jason

However, you can buy each wheel for $180, which is allowed per COTS rule... this would have to be a Q&A question. It is possible to use 2 mecanum wheels to give a "car" like steering system.

jamie_1930
27-01-2010, 22:11
Were using 6"