Heads_Up

I have had small flutters on planes in the past but last weekend was jaw-dropping. Was cutting a hole in the sky with the TopCap ARF .... snaps, blenders, flat spins up and down, back to back knife edge loops, harriers upright and inverted, prop hangs, torque rolls, walls, z-bends ... you know, my normal 10 minute TopCap flight

Well, I came out of a knife edge spin in a nose down attitude and was really hauling arse ... pulled level at about 20 feet and ... and ... and GOD GAWD ... the whole plane from the wing back fluttered H.A.R.D.! It was so loud you could hardly hear my OS50SX ... or maybe I was over-concentrating on the flutter noise

As I was spewing forth every obscenity known to mankind, I instantly chopped the throttle to idle and the plane-quake stopped .... I called emergency landing and brought it in ... ugly landing but not bad considering my thumbs where shaking so bad

Upon inspection, we found the fuse was cracked up high from behind the "cowling" section all the way back and down to the bottom of the fuse and behind the main wing where one set of pull-pull cables enters the fuse.

Only thing holding the fuse together was the covering ... thank gawd it was the good stuff and not cheap shelf paper.

Also, the main wing is now a tad loose and sloppy in the fuse. No wing damage but she IS loose.

Need ideas on beefing up the TopCap from you guys. I fly it hard and the fact there is only balsa in the fuse worries me. Also, suggestions on beefing up the main wing-into-fuse area and maybe some thoughts on tail section strengthening.

I'm just glad it is not a pile of toothpicks

Any ideas or comments are welcome.

Rick

BotleRocketWar

Sounds like you just need to slow it down...These things are not made to fly fast!!

Same thing happened to me with my Sledge when I was testing it's limits (ya know, like touching wet paint)...The whole dang tail started to flutter. Instantly I cut the throttle and it stopped and there was no damage...I was lucky and stupid at the same time.

Heads_Up

Story of my life I wasn't trying to go fast, just came out of the knife edge spin in an awkward attitude low to the deck. It all happened so fast. Also, had just broken a major no-no rule ... told everyone I was going up for "one more flight" .... that bites me every time!

Like the new Avitar btw ... nice trim scheme.

Need to update mine ... the 29% Aeroworks Edge 540 is no longer a part of my fleet.

Rick

BotleRocketWar

Thanks...

I've actually had that pic there for a couple weeks now, but it seems like it's just now getting noticed... I stole the scheme from http://www.*************.com I posted some videos and pictures somewhere around here...

Anyway, another possibility is that your TC was damaged before you left the ground. Maybe the KE spin did it? Who knows?

I just use epoxy for my wing to fuselage joint. I tape up one side and shove it in the opposite side and just fill up all the little gaps and holes. As far as tail section strength, I'm more than happy with the Sledge. Sheeted 3/8 inch sticks is very strong.

Carbon fiber? Iron on carbon fiber? Fiberglass cloth? Some extra sticks?

My last profile was built with 1/4 inch sticks and was plenty strong...

jsonin

My Feedback: (4)

My TopCap is a wonderful performer but at high speed (in a dive with an OS 50SX), the tail has a bit of waggle. Thin zapping the parts of the middle/rear of the fuse will help, just don't get any CA on the pull pull lines.

I didn't have any tail waggle until my 100th or so flight... after a few hard landings and lots of hard snaps, etc. Once I thin CA'ed the fuse, the plane was fine for a while... and then I just CA'ed the back again.

Eventually, I just wanted to test how much rudder flutter the airplane could take... so I put the TopCap in a power dive and managed to have the rudder flutter itself completely off. Now I use the plane in combat sans rudder.

See video of the TopCap in action at the link below.

Yours,
Juhan

Billy Hell

My Feedback: (2)

Your talking about he "Fish Dance". I would CA it all back and maybe put in some CF strips.
BottleRocket
I want to know about that site that you listed and was censored out. Please PM it to me.

ChuckAuger

My Feedback: (12)

www. d-o-w-n-o-n-t-h-e-d-e-c-k-.com

RSands

Looked like a fish? Been there. Broke the fuse aft of the main wing, top to bottom. I said the hell with it, if I can't fix it without taking the covering off, it's time to get a Sledge. Mixed up 4 oz of 2 hour epoxy and injected it into the fuse with a big syringe in a couple places, clamped the fuse flat, and put tape over the split covering. Haven't got to buy that Sledge yet (happened last summer). You're mileage may vary!

BotleRocketWar

Why aren't we allowed to mention that website on here?

Texas 3D

My Feedback: (16)

I think the owner of this website was banned from RCU. That's what I heard.

JNohsey

My Feedback: (28)

Hey is this the ARF topcap? I had one and it flutter bad, ended up scrapping the fude. The wood in the fuse was pretty soft. I had an scratch building one and didn't have any problems with futter.

Billy Hell

My Feedback: (2)

I'm actually putting mine back together. We will see.

Heads_Up

Yep ... TopCap ARF ... I am thinking of taking the covering off the fuse, CA the crack, and putting a piece of thin plywood down both sides in the same profile to harden and stiffen it. The fuse will be a tad thicker but stronger.

Rick

Heads_Up

Billy

Yep ... looked like a shark going after a tuna.

Gonna pull all the radio and engine gear out and transplant it to another plane. After that, I think I will strip the covering, CA the damage, profile both sides of the soft ARF fuse with thin plywood, sand it and do another color scheme. Wanna do something really out of this world and ProBro worthy.

Or ... do you think that is too much work? I HATE BUILDING AND REPAIRING! Do yo think just using thin CA on the crack and putting CF strips down both sides of the fuse would be enough?

Rick

Heads_Up

WELL GUYS ... TopCap is toast ...

The flutter was a killer ... I just got done with my inspection. I removed the covering from half of the TopCap fuse. Damage is a lot worse than I thought. The plane actually fell apart in my hands as I was stripping it. The fuse is cracked clear through all the way back and RIGHT between the rudder cable guides.

I have to say I am very disappointed in the soft wood Morris used for the fuse. I can understand the weight advantage, but gimme a break.

As it stands right now, the wing and other remains will go in my closet for maybe a winter project. Will probably use the wing to make a new, self designed fun fly.

In the mean time, its time to try my first SPAD.

Any suggestions on a good 40 sized SPAD for 3D that will take a 46FX or 50SX? I have flown a fellow pilot's 30 sized QHOR and it was fun, but it needed more vertical lift. Had to go full throttle to harrier it and prop hanging was not possible. He was way underpowered for my flying style.

I still brought it down to about two feet altitude and did solid harries all up and down the runway. IT WAS A BLAST. He then told me he had about $12.00 invested in the airframe and I made up my mind to build one when I found the time.

The reason I asked about engine size is the 46FX is the smallest engine I own and I have 4~5 50SXs. I am leaning towards the 40 sized QHOR, but dont want to over power it.

Anybody out there flying the 40 QHOR with a 46FX or 50SX Ringed?

Suggestions and comments welcome.

Rick

Ed_Moorman

My Feedback: (1)

Is anyone flying a 40 QHOR with a .46! Go to the SPAD forun and check the PQHOR or SPA3D threads. They are flying them with Saito .72's and .75 2-strokes. A .46 is the nominal size engine, not the overpower one.