Reinstalling timing belt pulley

[snapman]

Hello, I need some advice/suggestoins regarding reinstalling a timing belt pulley on a Light Machines (now Intelitek) Prolight mill. I used a bearing puller to remove the pulley- wanted see if it was feesible to change the ratio by installing another size- and now I realize it isn't going back on without some persuasion. It seems the pulleys are bored out to fit that portion of the screw- and then pressed on somehow- no flats for the set screws.

Any ideas on how to get it back on there without hurting the ballscrew and ball nuts? Should I take the screws somewhere and have a flat ground and then open up the pulley a bit? Gently "tap" it back on until I can get the nut that holds it all together back on there (the nut would be able to push it on after that)? I am really paranoid about damaging the screw.

What I should have done was ditch the stock motor mounts (which limit the pulley OD to under 1.5 inches) made my own mounts, and then gone to a larger pulley on the motor- hindsight being what it is...

Any advice/suggestions will be appreciated.

Ryan

[RICHARD ZASTROW]

If there is enough "meat" in the pulley that you end up using, I would suggest a keyless connector like Spieth, Ringfeder, Zero-max etc.

[unterhaus]

they had to get it on there somehow. Maybe you can put the pulley in the oven for a while at the lowest setting. Either that, or there is a way to press it on without pushing on the bearings.

[NC Cams]

Heat the pulley in boiling hot water or perhaps on a hot plate - an old electric skillet/frying pan works like a champ at doing this (we got one for $3 from the local reuse center) .

Concurrently, chill the shaft with some ice. The pulley drops on when you do it right.

Great trick also works for installing ball bearings onto electric motor shafts.

We install distributor drive gears and/or timing sprockets onto camshafts this way all the time.

[snapman]

Thanks for the tips- heating did the trick. I figured I couldn't mess much up by heating it (and even I knew not to use the microwave ). It slid on no problem. I never would have thought something like that would work but I'm sure glad it did! Thanks again. -Ryan