Vibration Issues
 

Hello-

I have some vibration issues with my Great Planes Escapade and I am not sure how to correct the problem. The vibration has even caused a glued joint to separate just behind my firewall (I used epoxy for reinforcement). I have already balanced my prop. Any suggestions on what may be causing the excessive vibration?

Thanks!
Bjfrankl

RE: Vibration Issues
 

Read this thread, where you will find some recommendations to solve your problem:

http://www.rcuniverse.com/forum/m_18...tm.htm#9705733

Don't run the engine in those conditions, or you will cause further damage to the model structure.

Best luck!

RE: Vibration Issues
 

Shouldn't happen with a balanced prop. But I wonder if you might have a loose engine mount or the engine isn't tight in the mount?

RE: Vibration Issues
 

has that motor youre using been involved in a wreck,,,,it nay have a bent shaft

RE: Vibration Issues
 

Maybe the prop wasn't correctly reamed. The hole might be off center slightly. Try another prop. Trial and error, just start with the easiest thing. I think that is the prop in this case.

What kind of engine ? Some 4 strokes kick like mules.

RE: Vibration Issues
 

A little moire info would be helpful. What engine are you using? What prop?

I used a Saito 72 on mine and it vibrated the firewall off of the plane, eventually. It was a powerful but rough running engine.

I now use a Magnum 52 2 Stroke and it's a screamer with no big time vibe issues.

RE: Vibration Issues
 

I would also like to know what engine you are using.

RE: Vibration Issues
 

Grab the prop firmly and check the crankshaft for axial play.

RE: Vibration Issues
 

Hi bjfrankl
Do others, with more experience, agree with you? Our planes and engines actually vibrate a tremendous amount. A certain level is considered "normal". That "normal" amount is difficult to describe. Compared to an electric motor, our engines are terrible! I have been in RC planes for about 38 years and I don't even bother to balance my APC props anymore. Occasionally I will see one vibrating above "normal" and I will check the balance. Any of this help you?

RE: Vibration Issues
 

I assume you're using a 4-stroke engine ?
Possibilities:-
Unbalanced prop. balance it.
Out-of centre hole in prop: Try a new prop
Unbalanced spinner: try model without spinner
Bent prop shaft: Observe the arc of the prop. If the edge of the prop disc is "wide", then the shaft is bent.
Detonation: Too "hot" a plug and/or too high a nitro content. Too lean a needle setting. Too big a prop for the engine.
Engine loose in bed or mount is loose on firewall.
Violent flick manoeuvres.
Engine too big for model.

RE: Vibration Issues
 

Worn or faulty crankshaft bearings.

RE: Vibration Issues
 

A fellow addict bought a new engine. Vibs were so bad that the back bit of the muffler keep on falling off, even after double-nut locking it. The hobby shop - "we tested it and found nothing wrong". BAAAAHHHH !! What uttermost extremely humongous superior oversized BS this is.

I personally think that the crankshaft of the motor is out of balance. Yes, 2-strokes do vibrate but in this case it is excessive.

RE: Vibration Issues
 

I am using a Tower 46 with an 11x5 Master Airscrew prop. On of our local club members with many years of RC experience thought that there was too much vibration, more than normal. I expect a little vibration, but I am a bit concerned that the wood tab that sticks out from the fuselage (to the left of the motor) keeps rattling and loosening. The rattling actually gets very loud (you can hear it rattle/vibrate in the air at a certain RPM). I used epoxy 30 to reinforce the glue joint on my first Escapade, and I suspect that I may need to do the same on my second Escapade.

I still fly both of my Escapades, and they fly very well despite the vibration. Neither engines have ever been involved in a crash.

Bjfrankl

RE: Vibration Issues
 

loose the master paint stirrer prop

RE: Vibration Issues
 

I agree with everyone so far. I would first check the prop balance, then the crankshaft for axial play. I did have a prop that was so whacked out of balance that in time my firewall started cracking at the joints and things started loosening up. But it wasn't right away, it started happening about the 3rd or 4th flight in and I started not liking the way my airplane was vibrating on the ground at idle. Not to mention, that God Awful vibrating sound it made in flight.

I re-Epoxied the joints, re-fuel proofed the firewall and re-balanced the prop and it solved my problem. ( Thank God )

I hope your problem is as easy to fix like mine was.


Best of luck,

Pete

RE: Vibration Issues
 

Axial play is in the direction that the propeller moves the air. Play means in and out. This play will cause no vibration since the prop will keep it all in one direction.

RE: Vibration Issues
 

This will fix it for sure:

1. remove fuel lines
2. remove throttle linkage
3. remove 4 engine mount fasteners.
4. remove engine from aircraft and place on ebay
5. Install OS 46ax in reverse order.

No offence but I am just not a fan of the Chinese engines I have 1 in my fleet and am not that impressed with it.