VIBE RATIONS !!! OS 55 PROBLEM ???? THE VIBE HUM ? HELP Please !

[Mslater]

[QUOTE=Steve;640256]Doesn't the piston have a curved cutout along the bottom edge that clears the inside of the backplate? If it does then it wouldn't turn if it was in backwards.[/QUOTE]

Yes you would smack the piston to bits. The only way to get it in backwards is if you change the piston then refit the rod the wrong way around. It will go over this way but it's really hard to do. Even worse to get it back off when you realise what a numpty you've been. (and that could have been me)

[derrick]

[QUOTE=rachel;640217]

I have allways had a small vibe from new that was just a tail fin shake and a noise in flight that is hard to describe but sounded like a police siren an out of balance type of thing.



X Rachel[/QUOTE]
I had this on the 90 when i first built it, went away after a dozen or so flights, two weeks ago i fitted new front tt gears and the noise is back, but i will just run it for a bit and let the gears bed in.

[rachel]

Well , Can you believe it !!! I started up my DX8 and,.......... oops wrong thread,:biggrinjester::rofl:


Back with the Vibe, engine removed and stripped , crank bearings as new because they are ,;)
Hub / fan runout checked and less than one thou ,so thats ok . remove clutch and balance seperatly and , humm slightly out , not much but a little bit so rather than try and balance it I turned it through 180 degrees . I will give that a go over the weekend and let you know what I find.
If it's still vibrating I will video it.
Laterzzzz Rachel

[Steve Roberts]

Rachel

Sorry just found this thread.

Not read all of it so sorry if this has already been suggested.

I think that your problem may be the alignment of the engine/fan/clutch vs the clutch bell.

I had a vibe on my vibe (!) after a crash and then stripped the model down and re-built it and noticed that the engine stack was slightly out of alignment, completely fixed it....

Easy thing to do is to look at how much of the clutch shoe is sticking out of the bottom of the clutch bell, should be a constant amount all the way around.

Steve

[rachel]

[QUOTE=Steve Roberts;640973]Rachel

Sorry just found this thread.

Not read all of it so sorry if this has already been suggested.

I think that your problem may be the alignment of the engine/fan/clutch vs the clutch bell.

I had a vibe on my vibe (!) after a crash and then stripped the model down and re-built it and noticed that the engine stack was slightly out of alignment, completely fixed it....

Easy thing to do is to look at how much of the clutch shoe is sticking out of the bottom of the clutch bell, should be a constant amount all the way around.

Steve[/QUOTE]


Hi Thanks Steve ( and everyone else) Your reply has me thinking as my clutch shoe actually is recessed in to the bell about 1 MM ish and not flush, My Vibe is before the clutch engages so I am thinking hub , fan or engine !?

Back to the post should I remove the shim from below the tapered collar and run that against the front bearing , as that will drop the clutch ?

I should add the clutch works perfectly and is as inline as I can get it .

Thanks again x Rachel

[Steve Roberts]

[QUOTE=rachel;640979]Hi Thanks Steve ( and everyone else) Your reply has me thinking as my clutch shoe actually is recessed in to the bell about 1 MM ish and not flush, My Vibe is before the clutch engages so I am thinking hub , fan or engine !?

Back to the post should I remove the shim from below the tapered collar and run that against the front bearing , as that will drop the clutch ?

I should add the clutch works perfectly and is as inline as I can get it .

Thanks again x Rachel[/QUOTE]

Rachel

You shouldn't need to remove the washer, I'm 100% sure that my one has it and the manual says to use it!

May be something else thats causing the clutch bell to be too low or the engine too high but check it out. Does sound like the cause though.

Steve

[dav20043]

check or change the clutch

[rachel]

[QUOTE=dav20043;641029]check or change the clutch[/QUOTE]

Thanks but they are £50 :ack2::ack2::ack2: so I am going to try swapping it round first.

[Steve]

The clutch doesn't want to be pushed too far into the clutch bell - it should be even all the way around like Steve says and poking out by about 0.5mm ish. Push it in too far and you'll get vibes - I've had this in the past with the Vibe 90 and Airskipper 50. Try backing the engine off out of the clutch bell a tad. I can post a pic of mine this evening if it helps.

[rachel]

[QUOTE=Steve;641314]The clutch doesn't want to be pushed too far into the clutch bell - it should be even all the way around like Steve says and poking out by about 0.5mm ish. Push it in too far and you'll get vibes - I've had this in the past with the Vibe 90 and Airskipper 50. Try backing the engine off out of the clutch bell a tad. I can post a pic of mine this evening if it helps.[/QUOTE]

Hummm this has me thinking what have I built wrongly :( from memory there is no adjustment to move the engine up or down :confused:

Could I have built the clutch stack wrongly ????
or
should I remove the shin from under the hub collets, I am using an OS 55 HZ ???

Thanks x Rachel

[Steve]

This is a difficult thing to catch on camera, but here's my best shot.

The pic is trying to show how much of the clutch is poking out under the clutch bell on mine - about 0.5 - 1mm all round. The engine mount is rigidly fixed to the side frames and the bottom plate so cannot be vertically adjusted, but there is a small amount of vertical adjustment on the engine mounting bolts.

[ATTACH=CONFIG]25043[/ATTACH]

[lee mister]

i had the vibe hum today on my os 50, i richened it out about 3 or 4 clicks and the hum had gone and i had a lot more power back, are you running a bit lean ?, im no expert on engine tuning but you cant do any harm trying a few clicks out.

[Leo77]

Hi Rachel. Have you checked the con rod for any play in the big and little end bearings,

[rachel]

[QUOTE=Leo77;641619]Hi Rachel. Have you checked the con rod for any play in the big and little end bearings,[/QUOTE]

Hi and thanks for the reply , yes I have even checked to see if the connecting rod was bent.
I will be out flying the Vibe to morrow and I will see how it goes, keep you posted.
:-) Rachel

[rachel]

[QUOTE=lee mister;641598]i had the vibe hum today on my os 50, i richened it out about 3 or 4 clicks and the hum had gone and i had a lot more power back, are you running a bit lean ?, im no expert on engine tuning but you cant do any harm trying a few clicks out.[/QUOTE]

Strange you should mention this as I have just removed the pump from my OS91 in Dave and wow the vibes at Idle were huge , Definatly lean so I will play with mixtures to, thanks for the info
X Rachel