Do I need a keyway?

[GEOFFREY]

in other words, john, jonathon or Jazz. rest of us need not apply

Not one of the above, but I have been running my machine for about 10 years now and the pulleys are each fitted with 2 grub screws at 90 degrees. G.

[birchy]

Not one of the above, but I have been running my machine for about 10 years now and the pulleys are each fitted with 2 grub screws at 90 degrees. G.

That's handy information! What size grub screws?

[GEOFFREY]

3mm, no shaft flats or dimples, but the grub screws are tightly screwed in. G.

[Jonathan]

3mm, no shaft flats or dimples, but the grub screws are tightly screwed in. G.

Which reminds me, if you've got no flats or dimples on your shaft, then put a small piece of brass bar under the grubscrew, such that the brass presses onto the shaft and not the screw. That way the shaft wont be marked, since brass is much softer than the steel, so if you need to remove the pulleys there wont be an annoying burr to stop them sliding off easily...

[GEOFFREY]

I agree with Jonathans comment about the bur making it a little more difficult to remove the pulley (hopefully you will not need to), but doubt if there will be room for any insert (my grub screws are about 4mm long and need as much grip in the ally pulley as possible) and I do feel that a slight burr will help to stop the pulley from slipping. G.