DIY Turntable problem

Wasted

Here seemed as good a place as any to post this. I am currently pputting together some part to build a high end turntable, I have sourced a high quality motor unit and controller, a inverted bearing and an acrylic platter need now to source a pulley to drive the platter. The pulley is critical and I need one made up to pretty tight tolerances, anyone any ideas where I might go? This is what I need

tak

What sort of size is the pulley to be ?
If of conventional size surely you can get them from motor repair shops.
So first go to some electric motor sales/repair firms and see if they have anything off the shelf to suit.

Failing that you could ask Mr Weigand of Atlas Alu
http://www.atlasalu.ie/?item=contact
Their business is pressure diecastings in Al and Zn alloys. They used to make pulleys for motors in the 1980s but now have focussed on more complex (and higher value) components.
But I'm sure that they'd remember their old customers for these parts.
And he may be able to suggest another source.

I do not know what tolerances you need. Pressure diecasting itself is about as high tolerance as any metal casting process could be at < 0.1 %.
Machining will likely be needed for your specs.

mawk

well as a general rule with pullys and sheaves you just pick the ones available and design you system to fit around them. custom belts and between-size screws and the like are pretty much just not done..

but there are plenty of common sizes so it should be simple enough to find a fitting one. and in case its still changable, a round belt is probably what you want in this case. less chance of losing fingers or burning out motors.

vaccum cleaner belts are pretty varied, no doubt one will fit

Wasted

This is for a turntable as in record player, and it uses generally silk thread to turn the platter, the motor and its controller are built but to get the platter to turn at correct speed the pulley needs to be pretty spot on. The problem is really when you switch speeds to 45rpm, the pulley to platter ratio 23:1 or a 13mm pulley, i think.

tak

Any chance of a photo of the mechanism here ?
Or a sketch otherwise ?