Hello all. Am in the process of building an autogyro, like this one http://www.rotorflightdynamicsinc.com/pictures/ea81dom001.jpg The main rotor is not driven, unlike a helicopter. it freespins. The propulsion is from the rear prop. To takeoff, there is a system called a pre-rotator which is engaged and which then spins the rotor head up to about 250+ rpm. It is then disengaged, and the machine runs down the runway like a plane until the rotor rpm is high enough to take off. I want to build a mechanical pre-rotator system. essentially there is a cog just behind the rear (driven) prop onto which a belt is tensioned. It spins a shaft, and the shaft then transfers this power to the main rotor via some universal joints and another set of cogs (which also engage and disengage). My reasoning for putting a CVT in the line. Initially it will give a soft start, allow for a smooth transfer of power to the rotor head, and will hopefully allow for a maximum transfer of power at the higher end. My query is this. The engine is a rotax 582. Engine specs are http://www.rotaxservice.com/documents/582perf.pdf The gearbox reduction is 2.58:1 I would like to engage the pre rotator from idle up to 5000 rpm, so the shaft from the engine (to apply to CVT) would be running at approx 390 rpm to 1950 rpm. This could be geared up or down dependant on cog size I choose, so I can choose what rpm to send to the CVT primary input drive. The output can also be geared, depending on the cog ratio I apply to the rotor head. My query is this. Would a CVT be suitable for this task. I only need to apply perhaps 5 hp to the rotor head to get it to spin to speed, I am aiming for 300 rpm. Given that the engine output is approximately 45 hp at 5000 rpm, if this was applied (gently, to spin the rotor up slowly) to a small CVT capable of transferring 5+ hp, would the CVT be capable of handling the power without damage. If suitable, what CVT would be best. I am looking for the lightest most compact unit that would do the job.