Re: pic: FTC Custom Drive Train
 

I would suggest using more than two of those holes, we found that using a minimum of 3 worked best.

The gears you are using don't appear to be tetrix gears, what are you plans on mounting them to the output shaft? We've been looking for alternatives to the tetrix gears and would be interested if you found a solution! Currently, we are looking at manufacturing our own solution.

Re: pic: FTC Custom Drive Train
 

Good to know about the mounting holes. Thanks! I'm using BaneBots 1/2" hex hubs for 6mm bore to mount the VexPro gears into the motors.

Here's a link:
http://banebots.com/c/WHB-HM-HS4-M6

Re: pic: FTC Custom Drive Train
 

Do you by chance have a close up view of just the gearbox with the Banebots adapter or be willing to share your CAD file. were needing to use a 1/2" sprocket for our drive train this year and having a hard time understanding how I might be able to make one of these adapters work.

Re: pic: FTC Custom Drive Train
 

What size sprocket? AndyMark recently released this: http://www.andymark.com/product-p/am-3185.htm

Re: pic: FTC Custom Drive Train
 

I couldn't find the CAD file for them while I was designing this, and I was kinda lazy so I didn't bother making my own. So there isn't actually an adapter in the CAD, but it's designed to use them.

It's a pretty simple set-up, though. The adapter should tighten right onto the 6mm shaft. You can then slide your sprocket onto there. The adapter has a lip on one end so your sprocket doesn't slide off that way, and it has a groove to add the retaining ring for the other side. You could probably put some spacers in there to get the sprocket into the right position. You could also cut it to length and machine your own retaining ring groove if you have access to a lathe.

If you send me a picture or a better description of what you're trying to do, I can probably be of more assistance.

Re: pic: FTC Custom Drive Train
 

Here's a CAD file of the 6mm to 1/2" hex banebots adapters that I whipped up. Both in Creo and STEP flavors. Feel free to use however you want-- this is as close to the technical drawings as I think I can get.

This one is three wide, but I can make a 1 or 2 wide if you'd like. It's a real shame that it looks like BaneBots is going to stop selling these.

Re: pic: FTC Custom Drive Train
 

My brother managed to make one out of a piece of VEXPro Thunder Hex by drilling out the bore to 6mm on the drill press and drilling a hole in the side through which he tapped the threads for a set screw. It was pretty cool.

Re: pic: FTC Custom Drive Train
 

I thought about doing the same thing with the thunderhex. we did this last year with our FRC team to adapt a 10 turn pot to a shaft to track the height of our linear lift. worked out really great only instead of drilling and tapping a hole in it we cut a slit down it and used a shaft collar to lock it back together. we may have to see if we have a piece of thunderhex around and try this out.

thanks for the cad file. and the explanation of it. do you see any reason this wouldn't work with the #35 sprockets from vex pro?

-Chad

Re: pic: FTC Custom Drive Train
 

#35 chain on a FTC robot?

Re: pic: FTC Custom Drive Train
 

I don't see a reason why it wouldn't work, but I'd probably go with a couple of the #25 sprockets instead of one of the #35 doubles. I'm pretty sure buying an adapter plus two of the VexPro sprockets is cheaper than getting a single sprockets from AM or Tetrix (although I suppose those have the advantage of just dropping in).

Re: pic: FTC Custom Drive Train
 

The biggest advantage of the AM sprocket is not having to rely on a set screw to transmit torque from the motor output shaft. AM found the slit + collar clamp method that IceStorm mentioned to be more reliable, which is what that sprocket operates on.