Direct drive with CIM?

[eklaw]

Our team wants to be able to direct drive a wheel hub with a CIM with 1:1 reduction. The issue is that we dont currently have the adapter necessary to go from the CIM shaft to adapt to our 1/2" shafts and hubs. Can anybody point me to a place to buy such a coupler? Thanks!

[nathan_hui]

Take a look at McMaster and Ruland

www.mcmaster.com
www.ruland.com

If you've got a lathe and you have a full set of drill bits (letter, number, and fractional), consider making your own. A #21 drill bit should be a good fit for a 4mm shaft (4mm is .15748, #21 is .159)

You may have to settle for some misalignment in the shafts, since you may have to approximate one dimension or the other. If so, take a look at Ruland's couplings that allow shaft misalignment (last three on the front page)

EDIT: 8mm? use a O drill bit (.316). 8mm is .314961

[DarrinMunter]

AndyMark has a hub that will attach directly to a CIM motor.

http://www.andymark.com/product-p/am-0320.htm

[gibbta]

I would not recommend doing this last year we had direct drive for are shooter and when we turned it on all the control lites on the robot would fade out and c-rio would turn off. Testing it off of a test board and a real board are very diffident things. But outer then that warning we made are a custom cim to wheel hub.

[R.C.]

Originally Posted by gibbta

I would not recommend doing this last year we had direct drive for are shooter and when we turned it on all the control lites on the robot would fade out and c-rio would turn off. Testing it off of a test board and a real board are very diffident things. But outer then that warning we made are a custom cim to wheel hub.

Huh?

I'm about 100% positive you can direct drive a CIM on a competition robot. Your issue is something else sir.

-RC

[Travis Hoffman]

Originally Posted by Munter2081

AndyMark has a hub that will attach directly to a CIM motor.

http://www.andymark.com/product-p/am-0320.htm

They also offer these products:

http://www.andymark.com/product-p/am-0472.htm

http://www.andymark.com/product-p/am-0588.htm

[theprgramerdude]

Originally Posted by gibbta

I would not recommend doing this last year we had direct drive for are shooter and when we turned it on all the control lites on the robot would fade out and c-rio would turn off. Testing it off of a test board and a real board are very diffident things. But outer then that warning we made are a custom cim to wheel hub.

I'd recommend against going straight to 100%, as this would essentially cause a full short through the motor while it spins up and thus cause a huge voltage drop on the robot. A gradual ramp up in duty cycle would be better to spin up the CIM, although it would take longer than full duty cycle.

[DonRotolo]

Originally Posted by nathan_hui

EDIT: 8mm? use a O drill bit (.316). 8mm is .314961

or you can buy an 8 mm drill bit.

Seriously, unless you understand and can implement the concept of precise concentric boring (e.g. on a lathe) buy a coupler at the correct size.

[Al Skierkiewicz]

As a caveat, the CIM is a great motor but...
It only has sleeve bearings around the output shaft. If you are planning to implement a design that has significant side loading, be prepared for bearing failure. The motor shaft needs some additional support when used in this fashion.