I just know someone here will have a source..
I am trying to make small belt drive gearboxes for model aircraft..
..there used to be a guy in the USA who sold them, but he has stopped.
Various places do some of the parts - e.g. small pulleys and belts - but I need reduction ratios around 3 or 4:1 and the larger pulleys of aluminium get very heavy. About 3 oz. Thats a bit OTT. Trying to get the whole box less than that.
So... a 10 tooth pulley and a belt - 2.5mm pitch - you can get...but a
40 tooth plastic pulley? Nah.
Power levels up to around 400W max, typically 200W, and shaft RPM 10-15K with sort of 2500-3500 being a desirable output shaft speed.
The model shops stock but one aircraft unit typically - the Olympus
2.3:1 unit..and its pretty naff. Otherwise their stocks are spares for helicopters and cars and are pretty much wrong.
surely there is a supplier of small belt drive parts SOMEWHERE in the UK.
Rapid electronics stock Como Drills who seem to stock what comes from here:-
these guys
RS components? well similar..good range and up to 6:1 reduction on 2.5mm pitch belts..but again, it looks like Al. pulleys only..