brsseb

Ok, getting ready to fire up the new Raptor any day now (just waiting for better weather). Got most of it sorted out, and learned ALOT about how the chopper works while assembling it (like what the paddles do, and why the rotordisk dont actually tilt, etc).

But one thing I havent quite grasped yet..how does the clutch actually work? I know how the clutch on a car works, but on a heli there is to my supprise no disengage mechanism to disconnect the engine and the rotor shaft. I really though this was controlled by a servo and the radio. So my million dollar question is, if the rotor is connected to the engine, why wont I be cut in half while starting the engine for the first time..? I know you are to hold the rotor head while starting it..is the clutch designed so that when the engine is running at low rpm, it wont generate enough torque to force the rotor out of my hands, so to speak? Or do the clutch bell got some way to release that energy (when the rotor is held back when the engine is running), perhaps by having a gear to spinn around with the clutch not spinning at all..?

Hope someone can explain this the proper way so I have no doubt on how it works. HATE stuff i dont understand...[&:]

Just need to sort these things out so I dont have to be scared to death when starting this think for the first time (if not ill just send my little brother to start it as the guenipig . If he is cut in half, then i still got a spare littlebrother around somewhere as a backup).

FLYBOY

My Feedback: (11)

The little clutch disc you put inside the bell has 2 slots in it. At the end of the slots, there is a hole, as the engine spins faster, the metal expands and grabs the clutch bell, spinning it, as it is slow, the metal contracts and the engine spins but the clutch doesn't.

Thats the quick and dirty expl, hope it works for you.

flyerdarren

what you have on a heli is a cetrifugal clutch. Basically when the engine is at idle, there is enough clearence between the clutch shoes and the bell for the shoe to spin freely within the bell. As you increase the engine RPM the the clutch shoes are forced out to the bell by centrifugal force, transferring power to the drive belt. that's why you can spool down the heli with the engine running. The only reason to hold the rotor head while starting the engine is in case you have a hot start. I.E. you start the heli at full throttle. You always want to hold the head when starting , but it's got nothing to do with the clutch. Hope this helps

brsseb

Ah, the metal expands, and therefore there is no need for mechanical operation of the clutch. Brilliant. Thankz

-pkh-

My Feedback: (2)

Well, just to clarify... the metal itself doesn't really expand... the clutch shoes are pulled away from the center of the clutch (as RPMs increase) and engage on the clutch lining inside the bell, as flyerdarren explained. That may have been what you meant though ...

FLYBOY

My Feedback: (11)

Yup, but I was in the middle of three things. Yea, the metal doesn't grow, but the cuts allow the clutch to expand so they contact the inside of the bell and drive it. Like a merry go round, the faster it spinns, the more it throws you to the outside. The clutch works on the same principle and the centrifical force causes the circular disc to expand because it has the cuts in it.

brsseb

Ok. Thankz. Now i wont have nightmares anymore of me being cut in half when starting it up for the first time

-pkh-

My Feedback: (2)

The worst I've had happen was the blade bolt (protruding from the bottom of the blade grip) dug into my hand when I accidently hit the throttle stick while carrying the "idling" heli by the blade grip... just a small cut and a bruise! It is pretty scary when that happens for the first time... just hang on tight and kill the engine via the TX or pinch the fuel line to kill it!

Radd

It also has a one way bearing that allows it to spin freely in the oppisite direction....just to complicate your confusion...

But remember...er ...huh....We arent talking about a Cummings Diesel here either.....You wont even get the first WAAAck...out before the tail comes around a hits your brother in the forehead anyway....

Just kidding....hold onto the head...you'll be fine.....

-pkh-

My Feedback: (2)

The oneway bearing in the clutch is there to allow the starter shaft to turn the engine over, and then remain stationary while the engine runs. This means the starter shaft can spin freely in the clockwise direction, and it will turn the engine over in the counter-clockwise direction... it doesn't really have anything to do with the direction that the clutch spins, as it's bolted directly to the engine's drive shaft...

Radd

....yeah.....but....just tell your little brother to keep his eyes open.....without the bearing the starter poll can do the hoolla dance......boink!.....

Nothing to be afraid of I tell ya.......Just a lot of spinning.flinging,whipping things to watch out for.....LOL

Sorry....I'm in a good mood and thats rare......usually I want to kill people.....