Fury Extreme: Clutch Broken

[Knud Pedersen DENMARK]

Fury Extreme

Last flight, my Clutch wouldn’t engage correctly.
When spinning up the engine, a lifting up the heli into 1/2meter, you could see the rotor rpm decrease (with revlock on).

The clutch become so hot, that I could touch the clutch bell…..

Then I tried an hold the rotor by the bladegrip, as spinning up the rpm – the force felt not as high as normally.

I took out the clutch, and noticed a tiny bit off “Steel foil” look-alike piece between the clutchbell and one off “clutch weight”…….
The Clutch look a bit blue/black on the tip of the shoes, the Clutchliner look black.

The Clutchbell measured Ø37,85mm and the clutch measured Ø37,4mm (on the Clutch shoes).
In my logbook I can see that the cluchtbell messured Ø37,75 mm when it was new……

- is it normally that the Clutch weights get blue/black?
(Fligts about +180)

- If the Shoes on the Clutch is slight blue/black – should I then replace the Clutch? And the liner?

- I have 0,225 mm gab between liner and clutch….to much?

:( :?:

[DavidH]

Is the clutch bell liner loose from the clutch bell? This sounds to me like that is the problem. Your clearance, if that is total is within acceptable specs. That is 0.008 total clearance in inches.

David

[Knud Pedersen DENMARK]

Hi DavidH


Have change the clutch linier (glued the new with JP weld), drill out the dia. to Ø37,60 – (clutch is Ø37,4mm) that means 0,10 mm gab between the clutch and the liner.

The Old liner was not loose……

I will start to the old blue clutch to see if it still works – if not I will mount the new one.

But I hope the old I OK – then I can use the money one the HD clutch

Is 0,10mm gab to small....????

.

[Knud Pedersen DENMARK]

I´ve been flying with the “new” Clutch liner for some time now – seem to work fine( I´m now Heavy 3d’er)
BUT Next time a have Clutch slip, I want to change it to a Heavy Duty Clutch.
And now I would buy the part, so I have them in “storage”
But I have some “loose ends”,,,,,:
-------------------------------------------------------------------------------------------
1.
Buy the Heavy Duty Clutch (Only), part number MA121-22
http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=MA121-22

Heat up the old clutch, with a Heat gun,
Turn it off – Counter clockwise / Left rotation
Fit the new Heavy Duty Clutch, add loctitie (278 heavy srewlock or ballbearinglock 648)

-------------------------------------------------------------
2.
Buy the Heavy Duty Clutch Bell With Bearing and Liner, Part number MA121-20
http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=MA121-20

How do I remove the Bell?
On the picture of the MA864-13 Pinion http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=MA0864-13
I can see that there is thread on it – is it left or right handed thread?
--------------------------------------------------------

3.
I guess I can keep my old #Clutch Drive Bearing Block MA120-23?
-------------------------------------------------------------------------------------------
4.
If I do Heavy Duty change my self – will it then a as “straight”/ good as if a buy a complete Heavy duty Clutch and Bell
BTW: What would be the “Complete Heavy duty” replacement for the MA864-10(Assembly Clutch Bell) and MA128-20 (assembly Clutch)??
-------------------------------------------------------------------------------------------

:( :( :?:

[DavidH]

To change the clutch and clutch bell is a simple operation.

For the clutch you need a tool to attach in the holes in the clutch so you can grip it to screw it off. You can hold the pins on the driver with some pliers.
Looking at the clutch from the top ( start shaft), the clutch will screw off by turning it to the left. I have not had to heat the area around the threads to get it to release.

The clutch bell screws on the pinion also. Hold the bearing block and looking down at the clutch bell, it will screw off towards the right ( clockwise). Take something and heat the area of the clutch bell all the way around where the pinion is threaded into the bell. Hold the pinion with something that will not damage it. Screw the clutch bell off by hand. I hold the pinion lightly with some pliers and screw the clutch bell off.
I then use some loctite and screw the new bell back on the pinion.


David

[Knud Pedersen DENMARK]

Thanks DavidH.
BTW: just saw the manual for the Stratus - it´s shows how to change the clutch.......

ChopperKnud
Denmark

[Knud Pedersen DENMARK]

DavidH

Is the thread on the bell left or right handed ?

ChopperKnud

[DavidH]

Lefty = Loosen
Righty= Tighten

Both the clutch and the clutch bell are threaded the same direction.

David

[Data]

I wonder if I'm the first one this happened to.
I just had to remove my clutch in order to replace the bearing to the tempest one (for the stratus conversion)
I thought I did everything right.
driver between vice, heated up the clutch close to shaft and gave it a little kick to brake it open.
after the first turn I felt that something wasn't right.
to say it short, the clutch was still on the shaft as tied as ever, but the driver started to unscrew from the shaft and due to the two set screw in the driver, it completely messed up the threats on the shaft.
I ended up grinding a big flat spot into the shaft and put it into the vice with all force possible to get the clutch of that shaft.
$50.00 later I wonder how you get the clutch off the shaft if it refuses to come off before the driver does and do you always loosen up the two set screw inside the driver, so that in case the driver loosens up first it won't at least brake the thread?
and how do you get the clutch off without grinding a flat spot into the shaft if that happens?

[DavidH]

I have not had that happen and I have had several clutches off the driver assembly. I guess you could heat the area of the clutch where it screws on the driver before you try to unscrew it. I have not had to do that in the past, but it would probably be a good idea.
MA uses loctite when they screw the clutch onto the driver assembly.
I have tools that I have made to remove the clutch from the driver. These tools are simple to make. All that is needed is two fan wrenches that come in the MA kits. One of them needs some grinding done to it so it will fit over the delrin ball and drive pins on the driver. The other one just needs two 4 mm allen head bolts and nuts installed in it so it will fit down in the holes in the clutch. This is the same tools MA uses to assemble the the clutch and driver.

David

[WillJames]

I have tools that I have made to remove the clutch from the driver. These tools are simple to make. All that is needed is two fan wrenches that come in the MA kits. One of them needs some grinding done to it so it will fit over the delrin ball and drive pins on the driver. The other one just needs two 4 mm allen head bolts and nuts installed in it so it will fit down in the holes in the clutch. This is the same tools MA uses to assemble the the clutch and driver.


EXCELLENT tip David! Chris Cooker could have used this tip at Chatti!! There is no substitute for experience, thanks for sharing yours!! :noteworthy