Re: [CAD_CAM_EDM_DRO] Re: Keyways or set screws

The best way to, or another good way and is relatively easy to do: Drill the pulley and shaft straight thru, and insert a roll pin. I've attached several timing pulleys in this manner to large servos and it has never gave a problem. The Roll pin fits very tight and will take up some play if any ever arises. Just make sure the pulley is located properly before drilling.


Thank You, Ron Rogers
Rogers Machine
RomaxxCNC

http://www.romaxxcnc.com






________________________________
From: Frank <ftkalcevic@...>
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Wednesday, December 17, 2008 4:48:13 PM
Subject: [CAD_CAM_EDM_DRO] Re: Keyways or set screws

> A tight-fitting key is very good.

Is that hard to achieve? Will I be able to get a tight fit with a
keyway broach? Does it take experience to use one properly? I don't
have a press, can a 9x20 lathe push a broach through aluminium?

> High-torque servo motors can loosen
> any setscrew, although installing two screws, one on top of the other
> has been a time-honored trick to keep them in place. Another scheme

is

> to drill a dimple into the shaft where the screw seats. The best

scheme

> is locking collars or collet hubs on the pulleys, although these can

be

> quite expensive new.

Yes, I've seen them. Gates make the perfect set of pulleys I was
looking for, unfortuantely the local Australian distributors don't
stock the particular series - they said they would need to import some
parts from the US and the others from the UK - free shipping would take
3-4 months, or I could pay $200 for air freight :(



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