key vs set screws?

SpiderSpartan · #1 (**permalink**) 09-24-2008, 08:19 PM

I'm making a drive shaft connector for my chain drive and I couldn't find the right tools to make a keyway in it. So, I drilled holes for the set screws and just used those at 90 degrees to hold the clutch in place on the drive shaft. It seemed to work ok with no serious load on it. What do you guys think? Am I ok with the two set screws or do I need to find the tools to carve the keyway?

deacon · #2 (**permalink**) 09-24-2008, 10:05 PM

I have no idea sorry I have never done either. I always drilled all the way though and put a pin in whatever I had to attach.

**2door** · #3 (**permalink**) 10-11-2008, 05:04 PM

Spider,
You did right by installing the set screws at 90 degrees. They should hold just fine. If you want a little extra assurance look for set screws with a knurled point on them. They will "bite" into the shaft better than the flat ended ones. They make taking things apart a little harder because they leave a rough place on the shaft but they hold. Go for grade 8, not stainless.
As with anything with threads that you want to hold use a thread locking compound. Loktite makes many products for this purpose. I use it for everything that I don't want to vibrate loose and I use neverseize on things I don't want to stick, like spark plugs.
Good luck and easy ridin'
Tom

Motormaker · #4 (**permalink**) 10-11-2008, 10:34 PM

The setscrews should be ok for low power systems like bikes. I would say, if it is a 2-stroke motor, you are fine. 4-stroke motors would be borderline because of the extra torque. For a little insurance remove the clutch and grind or file a flat where the witness marks from the setscrews are visible on the shaft. That way it can't slip.

LordMaximo · #5 (**permalink**) 10-19-2008, 02:38 PM

For sure on that one.
Flats are a common deffinate on small torque engines and motors.
Broaching a key way on a shaft takes special tools and an arber press.

Maximo

SpiderSpartan · #6 (**permalink**) 10-19-2008, 07:37 PM

I actually took it one step further and drilled some holes in the drive shaft that the set screws can extend down into it for a sure grip.