Aluminium Framed Router

[Davek0974]

Drilling in from the end is a good method, if at all possible, drill in and tap a thread - M3 or 4, then fit grubscrews, that way the pulley is secured both directions - axially and radially. You will only get away with it if both metals are similar hardness, my concern is the hardened end of the screw - if one is softer the drill will wander into it.

And yes, grubscrews at 90 or 120 degrees only, never opposite and only two screws, always file/grind a flat on the shaft for at least one screw, better still drill a little divot the same size as the tip of the screw.

[lucan07]

You will only get away with it if both metals are similar hardness, my concern is the hardened end of the screw - if one is softer the drill will wander into it.

The shafts will be harder than pulleys, I could Dremell a half round into shaft and use mill to match this on pulley would not be identical in all honesty but should be close enough to be able to run a M3 tap. Alternatively with opposing grub screws would I be better to drill through shaft completely and use a split pin

And yes opposing grub screws an amateurs mistake lesson learnt will remember that once is a mistake twice is stupid!

Decision made I had seriously under estimated how hard the ballscrew material was going to be.

Significant flat ground on one side and loc-tite to ensure grub screws stay put will be my plan of attack for now, just dremelled first one and grub screw replaced by an allan head A2 stainless machine screw should be sufficient to prevent rotation and lock pulley in both directions.