Omni + timing belt drive =?

[sphuss]

We're a fairly new team and after attending a quick-build, we've decided to swap the standard drive for a holonomic omni wheel drive. The easiest switch we can see is to use a belt drive system together with our 8" omni wheels. We have chosen to go with belts rather than implement a chain drive mainly for ease of switch and use. For you veteran teams, I have two questions:
1)Is the belt/omni wheel combination a reasonable idea?
2) Our wheel hubs don't seem to match nicely with the belt pulleys provided in the kit... is modifying the wheel hubs ever a no-no?

Thanks much for your help

[protoserge]

I don't see any problem with belt and omni. After last year, my team has preferred belt over chain and I am quite pleased with the KoP setup for this year's game.

Do you have any specific reasons for using omni wheels? I'm curious on your design requirements that dictated their use.

Can you provide the wheel that you are using?

I'll suggest you look at supply of pulleys for the belts (look for nylon ones). Last year, we had a difficult time getting the pulleys and belts in the sizes we needed due to stock issues. You'll need to get them correctly sized for the belts you are using. Gates has a pulley calculator tool on their website as well.

[thmeans06]

You can definitely modify them as our team has several times in the past.

The trick is to learn from an experienced machinist. Everything has to be perfectly centered or your risk breaking your entire drive train. My advice, proceed with caution.

[Kevin Sevcik]

I'm trying to figure out how you're going to turn a standard 4-6 wheel drivetrain into a holonomic setup with omniwheels. Are you going to add a third gearbox with a strafe wheel perpendicular to your normal drive wheels? Otherwise you're talking about a Killough setup where you have 4 gearboxes and 4 omniwheels on diagonals at the corners of your frame. And I don't see how you're getting the standard belting to work with that.

[Lil' Lavery]

Originally Posted by Kevin Sevcik

I'm trying to figure out how you're going to turn a standard 4-6 wheel drivetrain into a holonomic setup with omniwheels. Are you going to add a third gearbox with a strafe wheel perpendicular to your normal drive wheels? Otherwise you're talking about a Killough setup where you have 4 gearboxes and 4 omniwheels on diagonals at the corners of your frame. And I don't see how you're getting the standard belting to work with that.

They could very well go with 4 wheels and 4 gearboxes, which one mounted along each external frame member. The reason why they are frequently packed into the corners is to expand your "footprint" for stability and to increase each contact points' moment arm to the center of mass. But there's no reason a holonomic drivetrain couldn't function with wheels along each edge of the frame.