clutch failure Hawk 30

[LameHK]

clutch fails after every flight .is there any other kind of better clutch lining out there

[Chris DeSain]

Somthing is not right there.
The lining should last many seasons. I know I am flying the stock hawk clutch with an OS 50 and have over a year on it.

I take it the clutch itself is in tact ? It is just the lining ?

Can you provide more details to your failure

[RAV50]

I agree with Chris.

There are a number of Hawks in our club. All have hundreds of flights on the original clutch linings. I have one with over 240 flights!! The only time anyone has ever replaced the clutch or lining is after a bad hot start or a crash that resulted in a motor run-away. This would be the same result in these situations with any heli. So I suspect there is something re: the installations that is wrong and causing this. Please give us more information.

When you receive the clutches, you may find the linings are just tack glued to the inside for shipping. They must be removed and gued properly with epoxy, thick cyano or JB weld.

Where do you live in B.C.

[teamitk]

My Hawk Pro has had clutch problems right from the first flight; was dragging so bad after the first flight that spinning the head by hand would drive the engine! So I took her apart, expecting to find that I either assembled something wrong or something came loose. Everything turned out just fine. The only problem I found was that the clutch was dragging against the lining, so I cleaned and "machined" (read: sanded) the clutch liner down a little to free up the clutch. After the next flight, it was noticeably dragging again. Flew it until I felt like messing with it again; this time I actually squeezed the clutch feet together with a rag and some channel locks. *Disclaimer: I am not recommending this be performed by anyone, as I don't know if it will weaken the clutch. This post is for informational purposes only. If there is something wrong with your clutch replace it or contact the fine folks at Century for support!

After reassembling, the head rotated smooth as silk with no resistance from the clutch. On the first start, I found that the head was much easier to hold still while at idle. 5 flights later and it is still performing beautifully. Needless to say, I have a new clutch and clutch bell an the way, but I may just keep running the old one for a while to see if it holds up.

Don

[JMasula]

I am having almost the same issue with my kinetic 50. I had 6 flights with no incidents and then this happened. I installed a new clutch and only got one flight before the linning destroyed the cooling fan again. Any suggestions. I have the os 50hyper installed and am running it at 1.5 turns on the needle.

[RAV50]

LameHK

What do you mean by "failing"? What are the symptoms?

I have found this clutch system one of thee longest lasting of any heli I have ever owned.

JMasula

Your pictures show clearly what your problem is.

1) The clutch liner was not properly glued to the bell, or came loose during a "hot" start.

or

2) Your clutch is unscrewing from the crankshaft. This will make it move up as it come loose, This in turn will allow the clutch bell to also move up and come into contact with the bottom of the fan and gouge it out as you see in the picture.

You may not securing the clutch properly when you thread it onto the engine's crankshaft. You must use locktite on the crankshaft threads AND use something to keep the crank from turning while you screw the clutch onto it (using the fan, keyed intop the top of the clutch, as the wrench). To lock down the crankshaft during this operation you can remove the carb, and insert a plastic toothbrush handle (must be something softer then aluminum) down the opening, when the intake hole of the crankshaft is lined up. Or use a crank locking tool from the back after removing the backplate, or a piston locking tool through the glow plug hole.

If you do not do so the clutch will always come loose on ANY heli.

I suspect something similar may be happening with some of the others.