A sprag clutch is something completely different, often called a free-wheeling-unit. It's like the FWU on a bicycle, so you don't have to pedal all the time...
My gyrocopter has a very similar system for engaging the pre-rotator except that the tension is provided by a pneumatic cylinder. We engage it when we want to start the rotor spinning and disengage it immediately before we begin the takeoff roll. It is common to hear the belt squealing until the speeds synch up. To reduce the squealing (and minimise the damage that can be done by this vibration), we use something as a mild lubricant to allow the belt to slip without squealing. Some people use talcum powder, although something called "bumper shine" is also quite commonly used (it's what I apply during my pre-flight). Do you guys use anything to reduce belt squeal? Is belt squeal an issue on the R22 or is it just that the R22 is so loud that you cannot hear it?? ;)
1:27 why do you need to immediately engage the clutch after starting the engine? Isn't it better to warm up the engine without loading it up with weight of rotors?
You start the engine and immediately emgage the clutch..this is when its idling.then u wait till its fully engaged,look at cyl.head temp and raise the rpm.
@@allex9524- okay, but the question was, "why?" I must admit, I would have thought that warming the engine prior to loading it would be sensible, so I am interested as to why the clutch is engaged so soon after start-up.
My gyrocopter has a similar assembly for its pre-rotator. When loose, the belt will not squeal. Squeal only happens on a tensioned belt (when the tension is not quite sufficient to prevent slip). Gyrocopters will often squeal during the initial stages of pre-rotation (before the pre-rotator pulley has come up to speed) and we use a lubricant to prevent the squeal (and hence, minimise the damage from the friction and the vibration). I am curious as to whether R22 pilots use anything to minimise squeal as the belt tensions and the rotors come up to speed.
Nope. In a turbo-shaft engine a so called free turbine is used - it means it's not connected to the main spool of the gas generator. The main spool = gas generator spools up using the startergenerator, then the fule ignites and a self sustaining combustion and rotation begins. You let go of the starter button. Only after sufficient pressure builds up in the gas generator - the free turbine which is permanentyl connected to the rotor start to slowly rotate as well. No need for clutch, belts or any other crazy shenanigans xD
@@adrianrubi5012 It's smooth and pleasent indeed. I've never flown a Robinson but I have 100+ hours on MD500 and Bell 206. Both with turboshaft engines.
