Vibe 50- Clutch Bell / Clutch Shoe / Fan Hub Alignment

[StreetDragster]

Hi All,

In numourous threads across the internet i have read about how the Vibe 50 is sensitive to miss-alignment in the clutch/fan hub.
How do i check and adjust this?

What i have done so far is built up the fan assembly on the engine, mounted the clutch shoes, which can go on the fan hub in two positions, and i then DTI'd the clutch shoes to make sure the shoes measured the same run out. I don't think this is correct as the shoes are not round, with the highest points being obviously the bits that expand to meet the clutch bell.

The manual states the following-

I do not understand the "reposition the clutch at 90 degree intervals through the use of the four holes in the fan hub"

From what i can see, theres only two holes on the cooling fan hub for the clutch assembly, so that can only be fitted in 2 positions, one 180 degrees out from the other. There is another two holes in the cooling fan hub for the clutch (which isn't shown in the diagram) , but if they are used, the relief for the clutch shoes to move (you can see the lines in the picture) do not line up, so the clutch shoes could drag on the cooling fan hub.

If they mean rotating the cooling fan hub on the crank shaft by 90 degrees, surely you can put it at whatever angle you want, as its mounted to the crank by the taper collets?

Also, how's the best way to position the engine so that the clutch assembly is centred in the clutch bell? People over on the otheRR forum talk about dummy clutch bells with the one way bearing pressed out and replaced with bushes, just for alignment. I don't really understand that

Thanks for any and all help in advance

Matt

[spike5150]

Dial indicate the fan hub, not the clutch. You can check runout on the solid parts of the clutch, but the fan hub is a better bet.

Also watch this video by Pinecone on dial indicating:

http://video.helifreak.com/?subpath=...vibefanhub.wmv

[Pinecone]

The clutch it not round. The shoes move, so the outer edges are not on the actual circle.

What they really mean, is instead of tapping the hub to align, just rotate the fan and hub 90 degrees on the shaft. This will change the orientation slightly to change the runout.

So to do it, mount the fan on the hub, balance and they mount the hub to the motor, with minimal torque. Remove the backplate and have your crank lock handy.

Check runout, if not acceptable, using crank lock to hold eninge steady, rotate the fan/hub 90 degrees and check again. Check runout, repeat as needed. Once you get the runout low, tighten the hub nut moderately and check runout again. Turn 90 degrees is needed.

I think I videoed this, need to find it and get it uploaded.

[Mystic3D]

Step 1 is Dial Indicate the Fan Hub to ensure it is within .002 runout. Don't worry about the clutch.
Step 2 is to ensure the alignment between the Engine, Clutch Hub, and Main Gear is all correct. There are a few ways to accomplish this.. I have tried most of them.
a. Losen the blots that hold the Engine to Engine Mount, Engine Mount to frame, Clutch Hub Bearing Block by about 1 turn from tight so all assemblies can move.
b. Piece of paper between main gear and pinion gear for proper mesh, leave it there.
c. Now the objective is to ensure the CLUTCH ONE WAY BEARING is in perfect alignment with the START SHAFT.
1. You can Eye Ball it, then try and adjust till spinning the fan does not move the start shaft(very hard to get it not to). Then tighten all bolts.
2. You can use a micrometer to measure from bottom of clutch to top of clutch to get side to side same diatance, then eyeball front to back.
3. My favorite is to use a spare clutch and press out the one way and press in two bearings 6 X 10 X 3. Put the spare clutch in and tighten all up. Then mark the Engine Block sides with sharpe so you can tell where it goes. Then remove the Engine from the Engine block. Put the regular clutch back in and you are done.

[StreetDragster]

Thanks all, extremely helpful

Matt

[Mystic3D]

That's what is so great about the culture here on Helifreak. Everyone is very helpful, very cool, and just try to solve problems.

[Punkin71]

Old thread, My vibe 50 will at idle will engage the clutch causing the blades to spin at all but the absolute lowest possible idle setting, almost to the point of stalling the engine. My measured runout is .001 and gear mesh was set with a piece of printer paper. Only a very small amount of backlash is noticed in the gear mesh.

Since I bought this heli used and dont have printed manual the manual says to set mesh "with paper the same thickness as this manual" should I try a thicker piece of paper? Being this heli was bought used I am almost led to believe that maybe the clutch is sprung. This is my only peeve with this heli, otherwise it flies beautifully!

[Punkin71]

Surely someone has some insight on this?

[JesusFreak]

Does anyone know if this setup process has improved with the Vibe 50 NEX?