CIM Hub

[IndySam]

You could easily buy a 250 hub from AM and drill it to 8mm and broach a key way in it. That's what we did the week before AM came out with the new hub.

[vivek16]

Our intake is a belt driven CIM drive (16 tooth drive gear and 56 driven gear). We didn't use a keyway but just put a set screw in the keyway slot and another set screw 90 degrees away on the shaft. It seems to work ok. You definitely don't want to do this for higher torques but it's not horrible for a low torque application.

-Vivek

p.s. My point is that you don't need to use a keyway as long as you're careful.

[Brandon Holley]

Originally Posted by vivek16

Our intake is a belt driven CIM drive (16 tooth drive gear and 56 driven gear). We didn't use a keyway but just put a set screw in the keyway slot and another set screw 90 degrees away on the shaft. It seems to work ok. You definitely don't want to do this for higher torques but it's not horrible for a low torque application.

-Vivek

p.s. My point is that you don't need to use a keyway as long as you're careful.

Of all the lessons I've learned in FIRST...the one I've learned the hardest is never trust a set screw...

[Andy Baker]

AndyMark now has more of the 8mm Key Hubs.

Sincerely,
Andy

[Daniel_LaFleur]

Originally Posted by Brandon Holley

Of all the lessons I've learned in FIRST...the one I've learned the hardest is never trust a set screw...

I'll only trust a set screw if I can dimple the shaft first.

[Uberbots]

Originally Posted by Brandon Holley

Of all the lessons I've learned in FIRST...the one I've learned the hardest is never trust a set screw...

QFT

our 2007 arm joint had a sprocket attached by a set screw on the motor output shaft... needless to say we had a lot of slipping that year.

[vivek16]

The set screw does fall into the keyway slot and has shaft collars on either side.

As long as we can keep it the screw tight, we should be ok. We don't have the machining capabilities to broach a hole in a timing belt pulley.

-Vivek

[Bill Beatty]

You really don't need a machine shop to broach the 2mm keyway. A broach and 8mm collar is not very expensive. We gently rap the broach with a hammer to drive it through the bore. Using a hammer seems to work better than pressing the broach, particularly in steel.

Mr. Bill