15-05-2007 21:03

Lil' Lavery

Re: pic: Vex Mecanum Wheel

Are you using this for prototyping purposes for FRC, just to be cool, or intended to be used for FVC?
If being used for FVC, how much labor is involved in creating the wheels, and would the results really be worth it over the new "large omni wheels" (also 4" diameter)? Granted, if the game has large inclines (or obstacles) like "Half Pipe Hustle", a mecanum system would allow much greater ability to climb (although still requiring a fair bit of precision). Otherwise I don't see a whole lot of advantage for much greater effort put into producing the wheels.
Also, what materials are the rollers made out of?

15-05-2007 21:18

Rich Kressly

Re: pic: Vex Mecanum Wheel

Yeah, that's what I told him a year ago, but he just keeps working on it . It's a"challenge project" more than anything. If he is successful he gets to rub it in my face.

16-05-2007 00:16

Jeremiah Johnson

Re: pic: Vex Mecanum Wheel

16 collars per wheel?! Wowza... that's gonna be one heavy wheel... not to mention that those aren't cheap, either. I have yet to find a shaft collar that is exactly like the Vex ones, but cheaper... I have some that are a little bigger. Anyone got an exact size or where to find them? PM me.

16-05-2007 09:00

JesseK

Re: pic: Vex Mecanum Wheel

I'm curious as to what the actual wheel & roller supports are made out of.

It LOOKS like it's a VEX gear with machined supports(?), which could give a performance degrading flaw: Most of the mass of the wheel is on the outside and will therefore take alot of torque to overcome inertia, relative to if most of the wheel mass is around the axle. If the center is machined VEX metal, then you won't see this performance hit so much.

Looks like it would get the best traction out of all of the VEX mecanum designs I've seen though. Excellent idea for the roller hubs.

16-05-2007 11:06

Tytus Gerrish

Re: pic: Vex Mecanum Wheel

Impressive

16-05-2007 12:33

Chuck Glick

Re: pic: Vex Mecanum Wheel

Sean: The wheels are more for the cool factor, and it's something I've been trying to do for about a year now. The rollers have a solid plastic core(abs) and neoprene heat shrink for grip.

Kres: I am going to get them done, and I WILL rub it in your face...

Budda: Yea, collars aren't cheap... I've checked places like McMaster, but Vexlabs still is the best price. Any ideas for alternatives to shaft collars?

Tytus: Thanks. I was inspired mainly by your designs and wanted to bring the mecanum to vex.

16-05-2007 14:25

Rich Kressly

Re: pic: Vex Mecanum Wheel

Remember Chuck. I get to define what "successful" means

16-05-2007 17:36

Chuck Glick

Re: pic: Vex Mecanum Wheel

So...because of the large amount of weight that 16 shaft collars would add, I'm planing to change the design to use the 1" screws with nylock nuts. Much lighter and much cheaper.

16-05-2007 22:06

DB_UPS

Re: pic: Vex Mecanum Wheel

I like the idea of the heat shrink, we should try that. This frc1675 mecanum vex wheels, we are thinking about making molds and casting a couple sets and give them away for the MVL (Milwaukee Vex league).

16-05-2007 23:10

Jeremiah Johnson

Re: pic: Vex Mecanum Wheel

Would you be willing to sell a set? Those look awesome... but I probably don't need them. *Sigh* I've gotten to the point where I don't want to take my robots apart anymore and that's what I would have to do if I got mecanums, everything is perfect on my 2007 game playing robot. I just built a "poor man's rack" today... maybe I'll upload a picture.

17-05-2007 09:32

Greg Needel

Re: pic: Vex Mecanum Wheel

I would be interested to see the cad files for these wheel. From the picture I am assuming that you rapid prototyped them. I am looking as the many different ways people design mecanums for a different project I am working on.


Greg

17-05-2007 19:48

DB_UPS

Re: pic: Vex Mecanum Wheel

The wheel was base of this wheel,
Half Scale
which is base of this wheel,
. Full Scale

The vex wheel are a third scale of the big alum one. The wheel are made on a 3d prototype that one of schools owns.

17-05-2007 21:41

JesseK

Re: pic: Vex Mecanum Wheel

So the white ones aren't quite competition legal I take it?

17-05-2007 21:51

DB_UPS

Re: pic: Vex Mecanum Wheel

yep, you get it right, but they work every will.

18-05-2007 07:19

BigJ

Re: pic: Vex Mecanum Wheel

as he said, they do work well, our only problem was getting the 4 motors to run the same speed. you might have seen us playing with it in the pit in Atlanta if you were in Curie, while our robot was out at a match.

EDIT: Also, you don't want to know how many brackets were broken trying to clean them from the rapid prototyper's "build-up" stuff. They used to be pretty flimsy. >_>

19-05-2007 21:40

thefro526

Re: pic: Vex Mecanum Wheel

In my experiences with my vex mecanum wheels the labor is worth over using the 4 inch omniwheels. And with my Mecanums climbing stuff (anything less that 2") was super easy and require minimal percision. The Ideal angle of approach was less that 30 degrees but they would climb at up to 45 degree angle of approach.

21-05-2007 09:09

JesseK

Re: pic: Vex Mecanum Wheel

I agree. The first wheel I made took ~8 hours since I was trying to get it right. I created the other 3 about 3 hours, 2 of which were drilling/filing. After you figure the first one out it's pretty easy to figure out how to mass-produce them.

Very worth the effort to figure a problem out when it has substantial gain. It even took less time than a 3-D printer takes to "print" a design you give it

18-01-2013 10:31

hokagedetam

Re: pic: Vex Mecanum Wheel

Can you send me a drawing mecanum wheel?
Thank you very much

18-01-2013 10:47

Siri

Re: pic: Vex Mecanum Wheel

This is a very old thread --are you looking for FRC-level VEXpro mecanum wheels? 2D and 3D models are here: http://www.andymark.com/mobile/default.aspx#C53

Welcome to CD! Great job trying the search, but try to check the thread age.