Chief Delphi - Swerve: Belts or Chain?

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- - Swerve: Belts or Chain? (http://www.chiefdelphi.com/forums/showthread.php?t=128515)

Re: Swerve: Belts or Chain?

Quote:

Originally Posted by Qbot2640 (Post 1370809)

Love where this conversation has gone. Here's my design thus far.

Before everyone piles on...the prototype will use stuff we have laying around, like the Andymark wheels with the plastic pulleys, and mini cims for steering. It's just the start.

Our swerve design is somewhat similar to this. We use gears, though, and it's been working nicely.

For my team, even with one programmer (myself), the code was quite manageable with the assistance of some papers/presentations.
But I must admit, debugging errors in the code got pretty annoying.

Re: Swerve: Belts or Chain?

Thanks everyone for the great responses:

Quote:

Originally Posted by Oblarg (Post 1371897)

I would be extremely cautious about that drive belt ratcheting given the small amount of wrap on the tiny top pulley.

I am a bit worried about this.

Quote:

Originally Posted by Tyler2517 (Post 1371909)

Also 9 mm pullys may not handle the thrust at that end of the gear redction. Belts like high speed over high tourqe.

That's the kind of information I was looking for. I may make the module a bit wider and use a 15 mm belt here - at least for the prototype.

Quote:

Originally Posted by cjl2625 (Post 1371918)

Gears between the bevel and the wheel is something I had not even considered...I like that idea.

I'm heartened that the programming was manageable. It is my biggest fear.

Re: Swerve: Belts or Chain?

Quote:

Originally Posted by Qbot2640 (Post 1371966)

I am a bit worried about this.

Definitely use 15mm rather than 9mm belt, and if possible make the top pulley larger and change the ratio from the CIM to the coaxial drive shaft to account for it. Or, as mentioned, use gears; they're heavier, but have fewer failure modes. Switching to VexPro VersaWheels would make gear-mounting a breeze (in fact, they now even have gears with 9/8'' bearing holes so you can keep it dead-axle).

Re: Swerve: Belts or Chain?

We did a project in 2008-2009 and created a paper and did a presentation at the CHP. Some of the technology has changed and improved, but the basics are the same.

We use purchased modules. For our competition robot, we paired the front wheels together and the rear wheels together for rotation. Even with this "simpler" design we worked the entire fall season before deciding to use the design on a competition robot.

These documents might help.

http://www.chiefdelphi.com/media/papers/2381

http://www.chiefdelphi.com/media/papers/2378

Re: Swerve: Belts or Chain?

Quote:

Originally Posted by Qbot2640 (Post 1370809)

Love where this conversation has gone. Here's my design thus far.

Before everyone piles on...the prototype will use stuff we have laying around, like the Andymark wheels with the plastic pulleys, and mini cims for steering. It's just the start.

How are you attaching the vertical tube with the hex bearing to the U structure that holds the wheel? A cross section view might help. Also, if you are using a MiniCIM for turning you are going to need something like a 50:1 reduction, thats pretty hard to get with 1 stage of belt or chain.