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Keil Kraft Falcon 96" Build from Plans


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I recently purchased a complete set of Bellair laser cut formers/rib parts for this classic model plus the plans.

 Strip and sheet wood is required to finish the model. Are there any modellers out there who may have constructed this particular model before and may have a list of the additional materials that are needed?

Kind regards

SW

 

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Hi           I have constructed two Falcons over the past two years, both built from plans.

               Never had any issues with the builds, just follow the plans and you will be rewarded

               with a fantastic model.

 

               How do you intend to power the Falcon, mine are both Laser powered. Keep the rear end light.

               
 

               

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Thanks for the comments folks. I'm intending to fly this one electric! Our Field has to be kept 'neighbour friendly'.

The Falcon will be my Winter build project so I'm not intending to fly until 2022. Seems a bit like winter round here just recently- rain and wind for days!!

Cheers for now

Chris (SW)

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Right, I’m oldish. And a monthly drool, at the back of aeromodeller, in the KK advert, was the Falcon. And I will build one. Thanks, Rodney, I have an ancient early 75, in a very geriatric airframe, ie, not far from falling to pieces. 
It will do nicely.

 

But I’m tempted to go electric, and lose weight.

Lose weight in the covering. Doculam and tissue. Not much paint.
All the fusalage frames and ribs in foam. Bit of Carbon in the spars. Small, high tech servos. As far forward as possible. Closed loop to the back, in HT cord, adjusters at the front. 
And an electric setup.

Battery as necessary to balance it, having done what I can to reduce tail weight.

Then, deckchair, and relax.

Not exactly retro, but light flies better.

 

Skippers Walker, if you have a short kit, why not just go to the plan, and look, bit of LE edge sheet, strip by the meter, big wheels, and some hardwood to give stiffening to where the engine used to be. And some wire. Go over each sheet, order 20% extra. Order 50% extra, it will get used, at little cost.

Take note of Rodney’s comment re tail heavy. The originals flew with heavy engines. We are blessed with powerful and light power plants.
 

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Thanks for the reply Don. I'm nearing 77 and having spent most of my modelling 'life' flying slope soarers and thermal gliders, the power scene is relatively new to me. I picked up the modelling hobby again about 3 years ago following a lengthy break from building and flying. Fortunately I have become pally with with a small local group of mainly power fliers and it's good not to feel under any pressure to 'perform' on the flying field. I've recently built and flown a standard Junior 60 a have a Vic Smeed Madcap that's awaiting a maiden flight. I first flew this model design as  F/F in the 50's.

 I have a selection of electric gliders that fly well. Almost all of the flying at our field is electric. I'm amazed both by the modern kit and by it's efficiency, you never stop learning.

The Falcon is a short kit and will no doubt take me many hours of workshop time to complete with the hope of flying it next year!

Best wishes

Chris

(SW)

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  • 4 months later...
  • 11 months later...

The KK Falcon build continues very slowly, I'm way behind my onetime expectation that it would fly this year! The fuselage is almost 85% finished with the u/c silver soldered and ready to bolt in. The tail feathers   are also almost done with the intention of fitting the rudder servo in the fin area and the elevator servo to the rear of the fuselage- both powerful Micro units. The mammoth wings should be started in the next week or so. I'm really glad that I purchased most of the wood before the huge price rises of late 21-22. As for covering material I sourced 5yds x 5ft of SIG Koverall from the US for about £25 + PP much cheaper that the now expensive Oratex type materials. Koverall dopes on to the airframe and is then heat shrunk before finishing...only comes in white unfortunately.  

I'll keep chipping away through the winter months and hope to fly in 2023?A5E1F1F4-C19D-42DB-8B05-8C7829F02AAA_4_5005_c.jpeg.573fbe959b846e8a581ddde42c88569b.jpeg575E5270-B0EC-45F1-B261-1D6C3749E059_4_5005_c.jpeg.e62c67beb81be4412d2f110457bd8991.jpeg

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1 hour ago, Skippers Walker said:

the intention of fitting the rudder servo in the fin area and the elevator servo to the rear of the fuselage

Please do not do this.

 

While the intention is probably good, you really must not add unnecessary weight to the tail of models like this.

 

Look at the lovely side view on the photo Chris has posted. There is approximately 1/3 of the fuselage in front of the CoG (I have guessed) and about 2/3 behind.

Allowing for the fact the motor will be at the very front end the proportions may even be 1/4 & 3/4.

 

Let us say you fit a 15g servo at the back for the rudder.

At a 1:4 proportion, 15g at the back will need 60g at the front to balance the plane.

This is not a good idea when you are likely to struggle to get the CoG anywhere close to where it should be when it is finished.

 

Fit your servos either under the CoG or in front if you can. I know you can add weight but planes fly much nicer the lighter they are especially vintage ones.

 

Cracking building, by the looks of it it should fly well.

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Offering a different view...

 

My KK Falcon maidened just a year ago, and has had a lot of flying since.

The elevator and rudder servos are in the tail, the battery is at the trailing edge of the wing, and there is no ballast at all. Powered by an OS56 four stroke originally on a 14x4 prop, now on a 15x4 prop, takes off at half throttle, flies around just above idle, and only sees full throttle for the occasional loop or roll. It was modified slightly to allow access to the undercarriage in case of bent legs, but not needed so far. Touch and goes are interesting!

 

https://forums.modelflying.co.uk/index.php?/topic/49098-ben-buckle-kk-falcon/&tab=comments#comment-905197

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Thanks for the comments guys. I take your point about servo positioning relative to the CG. I admit to discovering the idea of rear mounting servos after following a series of Build Blogs featured on the RC Groups website. Some of the builders appeared to be fitting electric power units instead of the original petrol or glow engines.

I'll certainly consider the CG carefully, the actual position is not clearly shown on my KK plans so any information about this would be welcome please?

Cheers for now

SW 

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5 hours ago, Don Fry said:

Fit servos as far forward as you can. Use Dacron fishing line to run closed loops to the rear. No weight behind the CG.

Plenty of these things have a pound or so of weight up front.

look up the original weight of the 10 cc spark engines those things were designed for.

 

10cc engines of the era were much lighter than modern engines (e.g. Brown Junior weighed 7.5 oz). Although they did need ignition coils & batteries these were often mounted under the wing & of course the engines never had silencers.

The cg was often not shown on the plan, as is the case with the Falcon (& the Shereshaw Cloud Cruiser that it's a copy of) because builders were expected to arrive at what suited them after a few short trim flights. Generally the cg came out a long way behind what is common today mainly because the models were free flight, have a generous tailplane/wing area ratio with decent distance between the two. Unlike some models of the time the nose of the Falcon isn't particularly short either . 

That said I'd still keep the tail end light as possible & mount the servos in the wing area connected to intermediate fulcrums then fishing trace wire pull/pull to the elevators & rudder. 

 

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The pictures and comments  are all very inspiring as I prepare to pin the wing plans to the building board.

First class carpentry Chris, your weight saving tail ribs are particularly impressive. I started my build during June of this year and I spend a few hours each week working on the construction......it's certainly going to be a long job for me. I've shown my idea for accommodating the 4s battery that will slide in above and behind the ESC.  A detachable cowl will allow easy access for changing the Lipo.

E4445C91-B677-4785-9A08-0C6DF32BBF0D.jpeg.4bf79bb021b8459170a677a4fec5d757.jpeg

 

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Cheers David, but my plans have firmed up to a depron and balsa airframe, doculam and tissue covering, no paint to speak of, and electric.

Given the very interesting responses from others regarding CG of this thing, I think I will built in a set of rails in the avionics bay, to take the servos, RX, it’s battery,  ditto tube for the motor battery, so all the lumpy weight can be shifted at will, to set and alter CG, after build. 

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