Varad

I am putting together a Funtana X100. Can I seal my aileron and elevator hinge lines with Hangar 9 ultratrim?

krayzc-RCU

My Feedback: (31)

yes

Zippi

My Feedback: (10)

Varad,

I normally seal my control surfaces with clear Monokote.

LDM

My Feedback: (15)

either way , its a great step to make your plane fly better

garydogwood

agree with the others. i always seal my control surfaces with either monocote or ultracote. not only for strength but to also reduce any flutter.

gw

opjose

Sealing your hinges is a minor aid in reducing flutter. There are more important things that you should pay attention to first...

e.g.

The Funtana is really a SLOW FLYING 3D acrobatic airplane. It should be flown with a wider but lower pitch prop to maximize thrust wjile reducing speed.

Flutter is introduced because of harmonic vibrations caused and exacerbated when the plane is flying over its design speeds.

If you intend to fly it faster than intended, then look to strengthening the linkages and the holding power of your servos and connectors.
The more grip they have, that prevents movement, the less prone the surfaces will be to flutter. This may be more important than sealing a hinge gap.

One of the positive effects of sealing the hinge gaps is the effective dampening of any induced vibrations... so it does not hurt to do it, though often the air passing through the hinge gap is overstated as being a big cause of flutter.


Your primary recourse however should be to keep the plane within it's design envelope.

On my Funtana s90 I have a 16x4W APC prop which gives the plane plenty of torque and pull, but it becomes impossible to overspeed the plane... This was the recommended combo for this plane with very good reason.

captinjohn

Zippi, Do you just attach the clear monocote to the front part of the gap...or seal both edges? Thanks Capt,n

Zippi

My Feedback: (10)

captinjohn,

I normally deflect the control surface as far as I need and measure the crack down one side and up the other and add about an 1/8" extra on each side. In other words, once I cut my piece of Monokote I'll fold it in the middle to make a "V" shape and shove it down in the crack of the control surface and seal it down. I like it to come out of the crack and seal the added 1/8" on the the control surface itself. It's better to work with short pieces and overlap as you go. I't just to hard to seal a piece as long as an Aileron and get it all sealed down and looking good. This is not a very good drawing but I think you'll get the idea. Of coarse you would seal it on the bottom of the control surface.

Varad

thanks for all the help. I was just worried because ultracote is stick on and I had a roll of orange so it should come out okay.

Opjose, the plane is almost done and I have a pumped OS 120 FS on it. I just went into my basement to check what prop I bought and it is an APC 16x4W.

This leads me to another question I forgot about. I have a great planes aluminum 2 3/4" spinner and it wont come close to fitting over this prop. Should I just dremel the cutouts more until it works? Won't the balance get messed up?

Zippi

My Feedback: (10)

Dremel away. That is what I do all the time and don't see any problem with balance. It's to close to the center of rotation of the crank to make any noticable difference.

Bozarth

My Feedback: (15)

Clear or colored monokote - I use matching colors.

Try blenderm tape sold by Dubro as hinge tape for electrics (don't use it as a hinge in this case, but rather to seal the hinge!)

Kurt

ram3500-RCU

My Feedback: (221)

I use clear Ultracote because it is easier to use (I have tried both). It has a different type of glue on it that does not produce gas when heated like Monocote does (less trouble with trapped air), and can handle more heat. I cut it in strips 1/2" wide or so, crease it down the center, lay it in the joint with the surface at full deflection, and seal it with a small trim iron, then trim the excess.

opjose

I would not recommend Blemderm, covering material may be better.

Blemderm resists glow fuel more than other tapes, but it does deteriorate when exposed to glow fuel over time... much more so than covering...

Ask me how I know!

Varad:

That should be a great combination!

Flutter will NOT be an issue, and you could forgo sealing the hinges.

Varad

oh alright so I shouldn't even have to seal the hinges now as long as I fly the plane for how it was built.

Zippi, thanks for the help I will start shaping that spinner tomorrow.

Since you guys are so helpful I might as well ask the last question that is keeping this plane from getting done. I am using a Futaba 7CHP radio and have already used the flaperon mix for the dual aileron servos. Is it possible to create a mix for dual elevator servos with this radio? I thought I figured it out but if I trim elevators, the elevator halves go in opposite directions and that would be bad in the air.

Rocketman_

I agree with your post.
The belief that flutter is prevented by sealing the control surface hinge gaps persists in the forums no matter how many times someone attempts to explain how flutter occurs.

ZebraOne

My Feedback: (8)

That's funny! When I was in the Navy and worked on various A/C the control surface had sealed alerons and elevators!
Zee AMA19570

Rocketman_

And?

opjose

That is funny!

I didn't know the Navy was using RC covering material!