Hello everyone,

Now my engine is coming @, but now I have an other huge problem.
The Hole stab is fluttering, very baldly. It seam’s like a bird wing when flapping.
Don’t know why…
Everything is looking ok.
There is only a minor play, but everything else is fine.
I’ve even trim-seal the gaps.
When I’ve look at it at the ground, it seems very stiff.
The only thing I could ( We, some other friend’s at my flying field ) think of is that
the elevator push-rod is vibrating and is the cause of this problem.

Anyone else have this problem.[sm=confused.gif]


This is my set-up :
Plane: Focus II
Engine: Webra 160 XP with MC-Carb.
Fuel: Morgan’s Cool-power 10%
Prop: APC 17X12 Pattern
Servo: on the elevator JR 8411 SA

I’m thinking of putting a piece off styro Foam to help reduce the vibration.
Could this be the answer.[sm=confused.gif]


Thanks a lot in advance for the help, Suggestions. It will be greatly appreciated
Danny Koolman,

Have you fitted a support in the middle of the pushrod as per the instructrions?

The pushrod is a meter long and needs to have some support to stop it flexing.

Hello Eric.Henderson ,

I haven’t done that.
Could this be the solution …. ???



Thanks in advance for the help suggestions. It will be greatly appreciated
Danny Koolman

Erics right put the foam in, it will fix it. Heard of another guy with the same problem, foam fixed it.

Will do that.

Hopefully next Sunday I could fly wit out any more problems.



Thanks a lot for al the great suggestion’s, Help
Danny Koolman

Danny, if nothing works out, I'll see what I can do with it when I come down there for the pattern contest next month. HOPEFULLY you'll have it fixed long before then, but I'm just ofering to help.

-Mike

My DB soft mount OS 1.40 powered Focus 1 shakes like crazy. All the other similar equipped seem to do the same.
I've tried different rubber, no good at all. Hard mounting it make it even worse! You the softest you have.
Theres some thing about the engine box design and the fuselage length,,, you just seem to hit some type of harmonic resonance at certain setting... making it shake... violently!
There's been several posts about this. It has nothing to do with the push rod, even though with all that shaking, you need several supports to make if safe.
It's a design problem... I've even seen the Focus copy (Onyx) showing exactly the same behavior.
You need a Hyde mount to reduce the vibration down to a visually acceptable level!

I agree with Eric that it is the push rod. My Focus II with O.S. 140RX in Hyde ARIAS mount had the flutter as well.

Option 1. Toss the central hobbies push rod in favor of a Dave Brown push rod (make sure you get the long one). Install per instructions but add foam blocks in at least two places down the fuselage for the rod to pass through. If you use the Dave Brown rod you will have to enlarge the hole in the rear fuselage to the size of the push rod - I found some long brass tubing in a hobby store and sharpened one end, took some time but it cut through.

Option 2. Install JR DS368 digital ultra-torque micro servos - one in each stab and use a JR match box to get them moving in synch and the same direction. You will also need an JR 36" extension. (I'm thinking about doing this but don't want to weaken the stab structure in the process)

Eric Henderson has alot of experience with the Focus both I and II, his advice is good - although I never saw any mention of neccessary support of the rod in my instructions, and I just set them down.

Alot of airplanes have their own "quirks", this one belongs to the Focus II.

Hello Mike Hester,

Looking forward to see you over here.
Thanks for the offering to help me out advance, but I will love to compete against you instead of you helping me with my plane.

Hopefully this will solve my problem.
This Sunday we will find out.

I’m really forward to have you here, I’ll love to measure my skills against you.

Will sea you soon.

Danny koolman

Hello everyone,

I’ve begin with the fixing.
I have cut a peace of a foam. The dimensions are W 2 ½ , H 2 ½ .
Hope this works.
I’m planning to push it till the fist former that you could see where
the Elevator servo is mounted inside the fuse, at the pipe tunnel.


Hi Bla Bla,

I have a Hyde A type Soft Mount for the Webra 1.60 Xp.
So I don’t think that is the problem.
The Fuse. it self doesn’t seems to vibrate that much.


Thanks a lot for the help, suggestion. I appreciate it.

Danny Koolman

Well, you'll definitely have home field advantage

I'll be there for sure, I'm discussing details with Luis about how to get my plane down there. Do you fly intermediate? I was going to fly advanced, (and get beaten BAD), but I hear the action will be in intermediate, so I'll fly there! (ONE last time).

I'll be interested to see how I fly in that much wind with so many distractions. (Like an ocean in the background). Talk about pressure! But, that's what I love the most, competition, clallenges, but most of all, just flying pattern and being around great people.

BTW that brace will more than likely solve your problem, I've seen quite a few do that. Installed brace, fixed.

Cya in about 4 weeks,
-Mike

Hi Mike,

I could fly both. No problem there, but currently I’m flying Advance.
I’ve just made the decision.
But Hearing that 2 People from Curacao is coming to fly Intermediate
and that you also fly intermediate, we (Me and John Salas) decide to go
back to Intermediate so we could get some really interested competition going.
I also like a good challenge.

Well you’ll have an advance over me, because the FOCUS II is the only Plane
I got at the moment.

Hope you will come with you’re plane.
Love to see it to, very nice. In my opinion.

See you soon, And damn I have to get the plane going. The day is getting closer and closer

Danny Koolman

Well, if both of you fly advanced, I might too! I just started practicing it, and have NO idea if I could handle it under those conditions. But I do love a challenge. I already said I was done with intermediate, so why not? (Although I only flew 2 contests in intermediate, and only have 14 AMA points). But Luis said there may not be anyone flying advanced, that's why I was thinking intermediate.

OR....well, we'll see. I could fly either one I suppose, I guess I'll know for sure when it gets closer. It really doesn't matter to me, I just want to have fun and have some competition, and one hell of a vacation too.

Get that plane fixed and burn some fuel! I'm marking the days off the calendar!

-Mike

Hello everyone,

Well here is how I did it.
The reinforcement with foam.
Hopefully this is the solution for my problem.

Here follows the Pic’s, form inside and the former made out of foam it self.



Regard’s,

Danny Koolman

Here are the pic’s from inside the plane.


Regard’s
Danny koolman

Well, did it cure you're stab fluttering problem ?

Here is another way to stiffen up your elevator connection :-)

Hello Everyone,

Didn't test it yet, probably this Sunday.
I'll let you all know how it went, the result off the reinforcement.


Regard's
Danny Koolman

And guess who the test pilot is ?????

C Lim

I Wonder who .. indeed.



Danny Koolman

Hey Danny & Chee Chong,
Are you sure it isn't just your nerves flapping
See you on Sunday!
Jock

So did it fix it??? We all want to know. (All I really wanted to do was fix the title....) (VBG)

Hi everyone,

I’ll let you all know when I test it (the result), but most probably it’s going to be this Sunday.


Regard’s
Danny koolman

Hello Everyone,

There is some good news, the fluttering problem is solved.
Thank you all for the (tip) advice, I’m very grateful.

Still have some minor set back, but soon en off I’ll get there.
Engine seems to be getting there to.
Hopefully everything will come a long for the upcoming Sunday.



Again thanks for all the help, I’m very great full.
Danny Koolman

Hold on a second here...you said that supporting the pushrod with foam has cured "The Hole stab is fluttering, very baldly. It seam’s like a bird wing when flapping. "
Mine is supported (with light ply formers) in three places along the body yet my stab shakes so bad it looks like it's about to break free! Is foam the answer here? Help, I'm not the only one.