CUTTING KEYWAYS IN A PULLEY!!!

[pjf134]

Has anyone cut a keyway in a steel pulley without a broach? I was thinking about ways to do it, like using a blank cutter from a lathe and using a press taking small cuts or maybe a drill press in off position as a press taking small cuts. I have done one where the center of my tractor rear drive pulley wore out a few years ago and could not find one anywhere, odd size, so I found a piece of pipe or tubing with the right I.D. and cut a slit in it for the key and drilled out the pulley hub to the right O.D., then tact welded it in. It is still working fine. I also cut a woodruf key from a thick washer. I did not want to finish cutting grass with a push mower, lazzy I guess. Does anybody have any new or old ideas on how to do this?
Paul

 

[Tony Wells]

One old standby is to push it in the lathe. Chuck the pulley, and with a 90 deg boring bar that holds square tool steel, grind a flat nose, positive rake tool with side clearance on both flanks. Orient it horizontally on center and with minimum bar hangout (for rigidity) dial in a few thousandths at a time and push it through the bore. Lock the chuck to prevent rotation. Use cutting oil. If you take only light cuts, the stress on the carriage is acceptable. Make sure your tool width at the nose is adequate. If you have to sharpen the tool, take as little as possible, or you may lose width.

 

[Tony Wells]

Very nice, Ed. Yours? The firs time I ever did a keyway on a lathe, I only wished I had something like those. I just cranked it out!

Other method - GET A SHAPER!!! It's a very popular model maker machine. I'm a little surprised no one has talked about having on here yet. They're very versatile, and can make things so much easier and quicker than other machines, and sometimes they're just about the only practical way. I think every home shop should have a small one.

 

[Frank Ford]

Heere's my shaper:



I use it on the mill to cut keyways, and it works quickly and easily. After some time aligning it up nicely, I just plunge it through the hole, advancing the table .001" at each stroke. Very little cutting force for each stroke, and I'm done in a flash:

 

[Tony Wells]

Very good, Frank. Nice looking keyway.

 

[pjf134]

I was looking for a quick low teck way of cutting a keyway. I have a double pulley with 3/4" bore, but I need 5/8" for my lathe motor. I did put another on with a single pulley just to get it going. Maybe a press fit shim in pulley to match pulley & shaft? What would McGiver do with limited tools?
Paul

 

[Tony Wells]

Machine your sleeve to fit od and id (3/4 x 5/8")...then mill a slot through one wall the width of the key, but only halfway lengthwise. Press into pulley bore. Secure with set screws and loctite if paranoid.
That's the cheat I can come up with right quick.

 

[Highpower]

Heere's my shaper:



I use it on the mill to cut keyways, and it works quickly and easily. After some time aligning it up nicely, I just plunge it through the hole, advancing the table .001" at each stroke. Very little cutting force for each stroke, and I'm done in a flash:

Frank,

Do you make different sized cutters for different width's etc., or is it all done with table movements?

 

[pjf134]

Tony,
No mill at this time, but I do have a hacksaw. I was going to make a milling attachment for the lathe, but not right away, it's on my list. I will tack weld or locktite sleeve though, maybe 1/8" longer at each end.
Paul

 

[bollie7]

PKF134
I think what Tony meant in his first post was to use the lathe saddle to make the keyway, not a special slotting attachment as shown in mnmh's post. If you look at Franks pics using a drill press or mill, the principle is the same. The pulley is in the chuck and the tool in the tool post. Just use the saddle handwheel to push the tool through.
regards
bollie7