Spectra Clutch ?

[NUZA]

My Spectra is slipping the clutch any one else having clutch problems? :arggg:

[Peter]

Only after i hot started it ; wrong model memory ; :oops: :oops: :oops: cooked the liner and , because I was too lazy to replace it , I destroyed the bell housing and clutch shoe assy as well a few flights later .......... :( :( :( :( :(

[WillJames]

If you Spectra Clutch is slipping there is definitely something wrong.

[NUZA]

It only has one gallon through it. You can hear it on a hard acceleration. I was thinking of putting the blue 3-D liner in it? Any ideas
:?:

[WillJames]

After you fly is the clutch bell hot?

[NUZA]

Not sure I if it's getting hot. I was doing some setting up with Bill this weekend and he noticed it.
What if it was getting hot?

[LVeillon]

Not sure I if it's getting hot. I was doing some setting up with Bill this weekend and he noticed it.
What if it was getting hot?

I would guess that it would be dragging or staying slightly engaged if it is running hot at the end of the flight?

Does anyone know the exact material or where to get a sheet of the material that works best for the SpectraG or is it a one-piece solid liner? At $18-$20 a pop that's a little high for clutch liner.

[cbergen]

What exactly were the symptoms? Or was it Bill just telling you it was slipping?

[Billme]

Chris,
You could make a normal approach to hover..As you add pitch to transition, the engine would rev up, even with the gov on(gov slow to catch it)... We cleaned the auto hub too....
Bill

[carey shurley]

Hey Nuza

any way to check the clearance gap between the clutch shoes and the clutch liner material? If I remember correctly, the correct clearance is about .022" when its new. If its significantly more than this, the clutch won't deflect enough to engage properly.

[NUZA]

Chris,
I could here it rev like Bill said.
Cary, I have not taking it apart yet no matter what I find I will be replacing the liner just to be sure. So is there something better then the stock one?What else should I look at?

[carey shurley]

Hey Nuza

to be honest, I've never seen a setup where there was actually something wrong with the material itself. There could be an installation problem or it could be cut to the wrong dimension, I don't know yet.

The same bell is used for the zenoah and the .90 sized models, but the final cutting dimension for the material is different. When used in a .90 more material is removed because at hover and above a glow motor is turning much faster. When used in a gas model, less material is removed since the engine is turning slower, it needs to have a closer tolerance to the clutch to engage properly.

first, make sure the clutch is actually slipping. The bell should be pretty hot when you land. If its not, check the fan to see if its slipping on the crankshaft.

Next pull the clutch assembly and measure the outside diameter of the clutch and the inside diameter of the liner with something accurate. If the difference is more than about .024", send it back to the shop and have them put a new liner in it and in the note tell them what model its for.

Under normal conditions, you shouldn't see any clutch slippage in this model.

[DavidH]

If your going to replace the liner. Your going to need access to a lathe. All the MA clutche liners are sized to the clutch on a lathe once the liner is installed in the bell.
The liner material MA uses is durable. I have MA clutch bells with the original liners that have been in use for years. The liners will usually last a long time unless there is a hot start or a crash and the motor runs while the clutch bell is stopped.

Here is the liner for the Spectra Clutch

http://www.miniatureaircraftusa.com/Store/proddetail.asp?prod=105%2D62

David

[NUZA]

Thanks for the input guys I will get it removed and update you of my findings. :?

[rbort]

Three things to check:

a) is the clutch bell hot?
b) is the fan is not tightened all the way down?
c) is there any grease inside the clutch bell?

And one thing to ponder:

a) is it possible the engine is just revving due to incorrect throttle curve or incorrect gv-1 settings?

As others said, under normal use this clutch will not slip. Unless you had a hot start and smoked the thing, I highly doubt your liner is worn.

Another statement that is a good fact:

If your liner is worn, the clutch would enguage initially at a higher rpm. In other words, you have to go to almost 1/2 throttle on the TX stick (say 25% throttle on the gasser engine throttle curve) before you get the clutch to enguage enough to spin the blades.

So, that being said, if you are NOT seeing this issue as stated above, then your clutch liner is fine. Look for grease in the clutch or a loose fan instead.

And as far as the grease symptoms:

You can hover OK but when you power up to climb out its like auto transmission the engine revs first before the blades catch up. Also another tell tale is that the clutch bell will be hot when you land.

-=>Raja.

[LVeillon]

I thought there was something special to those liners...I just couldn't remember. I could also hear the revving.

I figured if it was the liner that it would just be harder to engage initially, but get better when hot or at a higher throttle position.

I'm sure the throttle positioin and curve are fine since it was Bill tuning on it.

Phil...Maybe you should try swapping those since you have two identical machines before you order a new clutch. It may also be worth while to retighten/check the fan.

It looked like it was engaging pretty good to me, but I'm not the expert by far.

[brunobl]

Hey Lane,

I Am Sofa King We Todd Did...
Ha!

Did you hear about the anunciator catch that teens were doing at airports a few years back? They'd go to those PA desks and request a call for a list of presumably foreign passengers with very odd names.

So odd in fact, that the PA operator would broacast *very* strange things without realizing what he was saying, for the whole airport to hear!

[wjvail]

The liner isn't loose in the clutch bell is it? I've had few come loose (not the heavy duty clutch). The only time I've actually had a clutch slip is when I got some oil on the liner material. K2R pulls the oil out nicely.

Bill Vail