Wall of Fame/Shame - Heaviest model

[Frank Egyed]

This is the baby I'm flying in the Queensland State Championships tomorrow.

This recently refurbished IC Impact (Thank You Paul Walker - I LOVE this design...) was donated to me as it was just gathering dust. So I cut the nose off, glued and screwed a firewall on, mounted electrickery, and glued the nose back on. 80oz ready to fly. Is this the heaviest Impact ever?

[Gerald Arana]

Is it made of pine??

No! Mahogany.......................but it has lightening holes! 

Jerry

[Tim Wescott]

They're not supposed to be called an Impact because of what happens after the wings snap off in a maneuver, but...

[Avaiojet]

This is the baby I'm flying in the Queensland State Championships tomorrow.

This recently refurbished IC Impact (Thank You Paul Walker - I LOVE this design...) was donated to me as it was just gathering dust. So I cut the nose off, glued and screwed a firewall on, mounted electrickery, and glued the nose back on. 80oz ready to fly. Is this the heaviest Impact ever?

Frank,

What are you using for a motor, etc.?

I have a heavy model happening.

Charles

[Brett Buck]

This is the baby I'm flying in the Queensland State Championships tomorrow.

This recently refurbished IC Impact (Thank You Paul Walker - I LOVE this design...) was donated to me as it was just gathering dust. So I cut the nose off, glued and screwed a firewall on, mounted electrickery, and glued the nose back on. 80oz ready to fly. Is this the heaviest Impact ever?

   Maybe the heaviest Impact, but as far as wing loading on a modern stunt design goes, not even close. I know of an SV-11 derivative that was *84* ounces, I have sworn a pledge of secrecy as to whose it was, unless he wants to out himself.

    The interesting feature of this example is that, with a GMA-Jett 51 on a tuned pipe, it flew/flies respectably well! We flew a lot of airplanes back in the old days at 690 square inches and larger with ST46s - but at 84 ounces, you might only get a fast taxi. In fact I had one about half that weight.

   Get a BIG battery, as little pitch as you can safely run with the capacity you have, and you have a chance, even as is.

     Brett

[Brett Buck]

Frank,

What are you using for a motor, etc.?

I have a heavy model happening.

Charles

   I am stunned.

    Brett

[Avaiojet]

   I am stunned.

    Brett

Show some respect for Frank.

You shouldn't be trolling me in his Thread.

But you know this and don't care.

If you want to pick a fight with me do it at CFC Graphics.

I'll go one on one with you.

And any of my other trolls also.

STAY OUT OF OTHER MODELER'S THREADS IF YOU CAN'T KEEP FROM TROLLING!

Promote the hobby? You wouldn't know where to start.

[Brett Buck]

STAY OUT OF OTHER MODELER'S THREADS IF YOU CAN'T KEEP FROM TROLLING!

Promote the hobby? You wouldn't know where to start.

   I answered his question and gave him sound technical advice, you pinged about yourself and added nothing but a narcissistic mini-rant.

   Who was trolling again?

    Brett

[Randy Cuberly]

I had an Impact that weighed 72oz and it was IC powered by a PA65 on a pipe!  That weight of course since it was IC was without fuel.  It actually flew very well but was a handful in high wind because it tried to pull me across the field when down wind, but then that was my "short coming" not the airplanes...

I also had a Trivial Pursuit that weighed 74 oz and flew very well with a PA51 and later a ROJett65.  It flew very well but also need a strong arm in the wind!

Before you think I can't build anything but "bricks" I'll also tell you I had a Geo XL (710 sq in) that weighed 54 oz with a puny little Belko 56 in it and was a dream to fly in the wind!

Point is; a "good" Heavy airplane design can fly very well but...they are more difficult to fly!  At least that's been my experience!  Being MEAN and working with weights a lot helps too!   


Hey Brett...Stop poking the BEAR...it just makes him roar and nobody understands his noise anyway! 

Randy Cuberly

[Dan McEntee]

    I have had a SIG Magnum that the weight got away from me when finishing it, and it weighed in at 72 ounces powered with a stock ST.51. Too many large sticky vinyl decals on it plus the clear. I entered the world of expert class with that airplane and did OK with it. I got my first 500 point score with it and won my first expert class contest with it. I have vowed to do another and have the weight come in at 60 ounces next time or less and have some fun with it.
    I also had a big red Cardinal that I bought ready to fly from another guy in our area with a T&L ST.60 in it and it weighed 73 or 74 ounces. I bought it mainly for the engine and to learn the ways of the might ST.60 with it. Finding props that would work on it at that time was the big problem, but when I tried the VESS 13-6 on it things began to happen. I never really did finish trimming the airplane and the lines where probably too long, but it would fly a respectable pattern.
   If a model is big enough, straight enough and trimmed well enough, it can be made to be acceptable.You have to REALLY fly the model very carefully, and after some time at the handle on one you begin to under stand what smooth control is all about. I think every one should learn to fly a heavy model,it will make a better over all pilot out of them.
   What did Windy's Sweepers weigh, 100 ounces plus??
   get some practice on it and good luck to you Frank.

    Type at you later,
    Dan McEntee

[Trostle]

Since we are talking about heavy stunt models, maybe it is worthwhile to visit a design from American Aircraft Modeler, Oct 1971 called the Marut by Ron Adams.  72" span, 850 sq in.  Trike gear, sort of a semi-scale jet thing.  Veco 45.  Adams goes at length about his rational for a big, heavy airplane.  Says this was competitive, missing qualification at a Nats (1970?) by one point and was second once to Jerry Worth by a "couple of points".  Weight of the thing was 98 oz.  He wrote that "everyone seems to agree [that] a heavier plane flies better in the wind".

Keith

[Noel Corney]

O/K , I'll put my hand up, I built the Impact for a Saito 72 when they were popular , It flew very well as I recall , I never weighed it as it had a foam wing and the finish started to build up , If I knew it was that heavy I probably wouldn't have flown it . Not flying now ,Too old and arthritis is getting really bad along with vertigo . Get on with it . Noel. I still love Stunthanger tho'.

[Frank Egyed]

“Is it made of pine??” Not pine, or mahogany, this is Australia mate – ironbark

“They're not supposed to be called an Impact because of what happens after the wings snap off in a maneuver, but... “ Hehehe - I was worried there for a bit but the foam-core’s holding up:)

“What are you using for a motor, etc.?” E-Max BL2832/05 (for 2-4kg aircraft 13x8/14x7 according to manufacturer), Phoenix Ice Lite 50 in Set RPM, Hubin FM-2SR, Zippy Compact 4S 3700, APC 12x6EP at 9400rpm for 5.5 second laps on 70’ lines.

“If a model is big enough, straight enough and trimmed well enough…”  Well, one outta’ three’s a start… The flaps and elevators all have a lovely gentle French-curve which I’m still trying to straighten but at least they’re curved the same both sides. And when the flaps are level, the elevators are slightly down which makes level flight quite interesting, especially inverted.

“get some practice on it and good luck to you Frank” Thanks Dan , got four full patterns in practice yesterday for the first time since converting the model, as I’d only been doing short trim flights until then. And another four today (1 practise, 2 scoring, and 1 for my 8yo daughter who arrived late) and the other competitors said it was “pretty to watch” although I’m pretty sure I never got closer to the deck than 10’, my verticals were definitely not in the same places, I was way over 45, lost line tension twice and had to bail mid maneuvers, and I missed my 5 second warning and the motor cut traversing to the start of loop four of the clover. I think they were being kind and encouraging… (bless their cotton socks )

"If I knew it was that heavy I probably wouldn't have flown it" Bahaha! Ignorance IS bliss 

I have to admit though that after sharing a few ‘moments’ over the weekend I think me and the Impact are starting to come to a bit of an understanding. Once I got used to it, I quite enjoyed the flying medicine-ball trying to pull me out of the circle, it's somehow reassuring... (mental note - speak to therapist re this)

Now for some surgery to at least level the elevators… I would like to be able to fly level at some stage…

[Eric Viglione]

IIRC the Impact is designed intentionally with quite a bit of elevator droop to offset the high stab placement. Before you cut into it, you might want to do some other checking for the source of your hunt, just to be safe. Free controls, and making your your retrofitted power plant doesnt have any wierd up thrust angles would be where I would start.
Just my .02 US (but hey, that's about .03 AUS!)
EricV

[frank williams]

Hello .... My name is Frank .... and I'm a heavy airplane builder.

It is possible to qualify at the Nats with an 80+ oz airplane. 

It's a lot easier to qualify at the Nats with a 60+ oz airplane.

A 72oz Impact is quite flyable.

[Ken Culbertson]

"And when the flaps are level, the elevators are slightly down which makes level flight quite interesting, especially inverted."

Frank - Step away from the aircraft and put down that X-Acto knife.  You should have a bit of down in the elevator.  I typically end up with about 1/8"

As for weight?  If it flies well and the lines don't snap, who cares what it weighs.  However, if they ever drop the line size requirement in favor of a more robust pull test I may retract that statement!

Ken

[Frank Egyed]

IIRC the Impact is designed intentionally with quite a bit of elevator droop to offset the high stab placement. Before you cut into it, you might want to do some other checking for the source of your hunt, just to be safe. Free controls, and making your your retrofitted power plant doesnt have any wierd up thrust angles would be where I would start.
Just my .02 US (but hey, that's about .03 AUS!)
EricV

I'll take that conversion rate
Thanks heaps Eric, a couple washers behind the backplate sure is easier than surgery...

[Larry Fernandez]

   Maybe the heaviest Impact, but as far as wing loading on a modern stunt design goes, not even close. I know of an SV-11 derivative that was *84* ounces, I have sworn a pledge of secrecy as to whose it was, unless he wants to out himself.

    The interesting feature of this example is that, with a GMA-Jett 51 on a tuned pipe, it flew/flies respectably well!

     Brett

Gee Brett, thanks for not mentioning my name

Larry, Buttafucco Stunt Team

[BYU]

I know of an SV-11 derivative that was *84* ounces, I have sworn a pledge of secrecy as to whose it was, unless he wants to out himself.
The interesting feature of this example is that, with a GMA-Jett 51 on a tuned pipe, it flew/flies respectably well!

It's why this person's (Evil Larry's) plane was nicknamed "Heavy Equipment" by Uncle Jimby

I have the pleasure of refinishing this plane and I can tell you once you remove the engine, the pipe, the landing gear, the cowl and other small unimportant parts like the wing it comes in at a very respectable 45 oz of paint.

[Air Ministry .]

It should have No Problems with Line Tension , as long as it keeps moving .

Dont Think Id be game to go over 5.0 / Lap .

If the controls are no deflection under load. Otherwise wear a crash helmet . 

[Mike Greb]

One year I was going home from the DAMAA june contest and due to traffic I had to do emergency breaking  and damaged my model when everything shifted in the back of my car. That was the year that had a 78? oz weight limit for .018 lines.  I had a Strega arc model that I slammed together for the nats.  It was apparent that it was going to be well over the weight limit for .018 lines.  Out came the dremel and after serious whittling down of the ribs and wingtips, and a monocote finish it was a fraction of an ounce under the weight limit.
Was furiously finishing up on the model the day I was leaving for the NATS.  Got to the NATS and the model was absolutely horrible. Warped wing, no outside turn,springy flaps.  Had taken the old model to the nats and hastily repaired the model in the hotel room and flew the old model in the NATS. After the NATS the flaps were replaced, wing straightened, down thrust engine shims,lots of down elevator trim,lighter engine and big chunk of lead bolted to the tail the model now flew reasonably well. Have no idea what the weight ended up at.

[Russell Bond]

Go to a normal rotation prop and most of the hunting should go away. (Unless there are alignment problems.)
How much battery are you landing with?
3700mah on a heavy plane may not be enough, you may have to go up to 4000mah. That will push the weight up even higher!!! 

[Frank Egyed]

"retrofitted (electric) power plant doesn't have any weird up thrust angles would be where I would start. " Two washers one each under the two top mounts improved stability. Thought some's good more's better (if it's worse take'em out) improved things some more! Still not solid though


"Go to a normal rotation prop and most of the hunting should go away. (Unless there are alignment problems.)" - Thanks, sadly made hunting worse with a tractor prop same pitch
"How much battery are you landing with?" - A tad under 15V. 13.4 is 80% so if I'm reading it right it's not draining the battery excessively?

"Hello .... My name is Frank .... and I'm a heavy airplane builder."

Bahahaha!! Surely there's an F2B twelve-step group near you

[Eric Viglione]

Well, glad it's working better with the washers.... if still not totally stable, try this. Since you say its a heavy plane, and if its been flown a lot, there may be excessive wear on the flap horn bushings.  Pinch the leadouts in your fingers tight against the tip to lock the controls at nuetral. With your other hand grab the flap and see how much play you have there. If the flap TE moves a hair, like a 64th or so its prolly not the source, if it moves the TE of the flap more than a 16th or so, thats prolly the next fix, rebushing the horn. Bellcrank wobbles can be an issue also. I've fixed that through a small access in the pipe tunnel... not fun, but doable.
Keep at it, because it is an essential learning experience to help learn why stunt planes do what they do. If you get a chance to have a local guru look at it when you run out of idea's, take it! A lot of these things are much easier to diag in person.
EricV

[Russell Bond]

You need to get a Hyperion Sentry battery checker or similar to see how much battery % you really end up with.
80% measures approx 3.85 volts on the checker. APPROX!!
If you go down to 13.4v that is 3.35/cell. WAY too low. You will kill the battery as that would measure about 4% or so. Been there/done that! 

[Frank Egyed]

You need to get a Hyperion Sentry battery checker or similar to see how much battery % you really end up with.
80% measures approx 3.85 volts on the checker. APPROX!!
If you go down to 13.4v that is 3.35/cell. WAY too low. You will kill the battery as that would measure about 4% or so. Been there/done that! 

My Accucell 6 tells me the batteries have 15V when I first start charging.

Do I really need another tool when I'm already trusting my battery safety to to an existing tool (Accucell 6) which one would hope is reasonably accurate enough to not overheat/blow a battery up?

And I'm confused (just for a change...) I thought 'not below 80%' was ok, but you're saying 80% IS way too low? You've killed batteries with 80%?

Cheers,
Frank

[Russell Bond]

No, that's not what I said. In fact I regularly go down to 15% with no problems.
What I'm saying is you cannot calculate 20% remaining in the battery by that method. (80% usage works out to about 3.85v left in each cell.)
4.2v x 80% = 3.36v. That is not 20% left.
If you use the Hyperion meter it will show about 4% left. This is way too low.

So to answer your question; Yes you need another tool.

[Russell Bond]

No, that's not what I said, in fact I regularly go down to 15% with no problems.
What I'm saying is you cannot calculate 20% remaining in the battery by that method. (80% usage works out to about 3.85v left in each cell.)
NOT........ 4.2v x 80% = 3.36v. That is not 20% left. (You can't work it out this way.)
If you use the Hyperion meter it will show about 4% left. This is way too low.

So to answer your question; Yes you need another tool.

BTW; Peter Pine in Sydney sells them. (flyelectric.com)