Since I acquired a Hardinge HLV with a continuously variable belt drive, I started thinking about making one for my RF30 type Drill/Mill.
A friend gave me the parts for Piaggio 125 scooter CVT. They looked like they might fit so I thought I'd give it a go...
I looked at various ways to fit the two pulleys in place of the originals before settling on this design. See attached pictures.
I had to make a new shaft to hold the Piaggio variator (front pulley) to the motor. I used the spring from the Piaggio's clutch pulley to close the variator (the scooter uses centrifugal weights to control the speed)
The Piaggio's spring loaded clutch pulley now becomes my variator and is mounted on top of the RF30's intermediate pulley.
ATM for testing, I am varying the drive with a simple threaded wheel screwing down from the top. I will have to make another shaft for the intermediate pulley than will support the bearings in the CVT pulley (ATM the CV pulley is simply screwed to the IP)
The new IP shaft will be drilled through, so a pull rod operated from a hand-wheel under the casing will alter the speed.
I was pleasantly surprised that it all fitted neatly in to the existing belt case