Keil Kraft Caprice gets electrified!

[Stuart Eggerton]

I built a Keil Kraft Caprice free flight glider when I was 12 years old as my first free flight model. I remember the model flew well with a flat glide and the sink rate was incredibly low. The span of the Caprice is 51 inches and in it's day (1950's) was a contest free flight glider.

A couple of years ago I bought the short kit from Replikit, and built her up. I decided to instal a simple 2 channel radio control system in the model and power it using the ever more efficient small electric motors.

The result is a very light weight model that has an excellent glide performance. The Caprice is not a big model by any means but a pleasant one to convert to radio control. The video below shows the model in it's glide mode, with the folding prop folded back to reduce drag. The penetration of the model into the wind is very good considering its light weight construction of balsa and doped tissue

[Tom Wright 2]

Excellent Stuart ! Takes me back nearly 60 years .Back then we had to be good at cross country running or rely on a DT fuse .

To.

[Tony Bennett]

my very first own build was a caprice.

lost it in the local pond.

[fly boy3]

Nice one Stuart, just love that di hedral tipped wing shape. I know you are a busy builder Stuart, but any info on the power train, and AUW. Cheers

[Mike Etheridge 1]

Stuart

I can remember when the Caprice was introduced!----my nephew Nigel had/s a Caprice which we flew during a free flight session at the Nationals a few years ago. It was tow-line launched and had the recommended dethermaliser. I have had a kit for a few years I got from a morning market in Chagford Devon so I would be very interested in the details of the motor/radio control kit you have introduced.

Mike

[Tom Wright 2]

Mike

If I remember correctly I did the electrics conversion for Stuart . A small bell motor with the circular mount small enough not to over lap the nose block bulkhead . A two cell lipo should be ok keeping the weight down, and fitting into the narrow fus . Best to check motor power on a fixed prop then fit a folder that draws around 80 W .

Can give the exact spec if Stuart calls round with the model ....as he often does .

Tom.

[Alan Randall]

My Caprice was the only model I have had fly away on its first day of flying. No DT fitted because none of the other gliders I had built up until then had needed one. It took a thermal and off it went into the wide blue yonder. It was a bitter-sweet feeling. That was about 45 years ago but is still imprinted on my memory.

[Stuart Eggerton]

Glad to see that people have fond memories of the Caprice too, it did seem much bigger though when I was twelve years old! would be nice to scale her up to say 3 metres wingspan, now that would float!

For those who want info on the power train and model set up:

The weight of the model including a 2 cell 800 mah, 25c battery is 317g

As Tom says the motor is a bell motor, not sure on the exact size, but the photo below might help identify it? The bell is about 26 mm in diameter.

The model has an aeronaut carbon 7x4 folding prop, this was probably a bit OTT for a model this small, i.e. going to carbon one of the cheaper props should be adequate.

The esc is a Hi Model fly-33A

The model uses 2 x 5 g servos, one for rudder and one for elevator as shown in the photo's below. You will need a small receiver as well my Hobbyking V2 receiver fits fine. (Sorry it looks a bit messy) and the battery goes in the second compartment just behind the blue esc. Wings are banded on as per the original and tow hook was omitted.

I have just charged a 2 cell, 800mah ,25c lipo and tested the power. The model produces 46 watts at W.O.T. on the wattmeter. Holding the fuselage in hand and applying full power the model wants to support it's own weight (minus wing). The model climbs well on this power setup but could have a better / more powerful motor keeping in mind as well the weight penalty.

The tailplane of the Caprice is a "lifting" tailplane, i.e. it is shaped like a wing with an airfoil. I cut out a notch to make an elevator and extended both the elevator and the rudder areas by glueing some clear plastic to them. This was to maintain the original "look" of the model.

The model is controllable but will not do aerobatics, you can gently steer it around but it is not that responsive. I suppose it want's to fly free! like it was designed to do.

[Stuart Eggerton]

Hi Alan, yes I know what you mean. I used to fly my Caprice without a de-thermaliser, but was always thinking of getting one of those clockwork ones from the model shop.

One day  I launched the model and noticed that the air was filled with dust/flies/ birds etc knew the Caprice was on the way up!..she ascended higher and higher and I gave chase at least 1/4 mile down the road, the road was a steep one downhill so the model looked even higher, eventually I could just make out a speck and then it disappeared! and I was elated it had managed to go so high and sad it was lost, that's when i decided to go to RC! so I should get them back again.

Incidentally I used to fly my Caprice on a school playing field (Top Valley School's) in Rise Park, you can't get access to the field now but it was great, a large grass palying field but housing around every side. I managed to land on the same bungalow roof 3 times in a row and owner of the bungalow threatened to burn my model if it landed on his roof again lol!

Edited By Stuart Eggerton on 17/11/2012 21:19:07

[Alan Randall]

Hi Stuart,

It's a small world. I lost my Caprice from the Holgate schools fields at Hucknall. The close proximity of the Salterford and Ruffs estates gave plenty of rising hot air for the thermals. All morning the flights had each been getting longer than the last, then approaching mid-day away it went.

I seem to recall one being flow with radio at Old Warden earlier this year.

I used to fly a KK Invader and a Mercury Swan down there too. Also a Mercury Marvin control line.

My mate had a KK Chief go flyaway when we flew it on the Misk Hills. We found it cantilevered out on one wing from the gutter of a bungalow on Beauvale estate

Edited By Alan Randall on 19/11/2012 20:43:01

Edited By Alan Randall on 19/11/2012 20:47:40

[Steve Colman]

Thanks for posting this Stuart.

Brings back such great memories. The Caprice was my first "proper" model; an Xmas pressie from my parents circa 1971 when I was just a kid of 12. I built it on the living room table while the rest of the family did more mundane things. I can smell the PVA, tissue paste and dope as I write.

I flew mine in the local park. After a few hand launches for trimming I climbed the steps to the top of the big park slide and launched it from up there before finally using a towline.

After a few successful flights it finally flew into a copse of pine trees next to the park. Sadly, even my most skilled tree climbing friends couldn't manage to climb high enough to rescue it so there it remained.

The following May ( Birthday pressie this time) it was replaced by a KK Chief. A friends dad built a home made simple 1 channel non proportional Tx/Rx which we installed controlling the rudder. Together we flew the model most of that summer until it flew away never to be seen again.

Oh such simple happy days !

Steve.

Edited By Steve Colman on 19/11/2012 21:56:28

[Mike Etheridge 1]

I assume all the fly-away planes had no addresses or phone numbers attached to them.

As I have reported before my only 'fly-away' from Epsom Downs racecourse was a Southern Junior Models 'Southern Dragon' never to be forgotten even though it was September 1962. I had covered the plane in black Modelspan tissue and had painted Humbrol black white and green decoration on the wing and tail leading edges and the fuselage all carefully Sellotape masked. Although the plan showed a Mills 1.3, mine was powered y a DC Super Merlin and with only 1/2 of integral tank it flew away on it's first flight. It also as described before got so high it became a speck in the sky and then disappeared. ---All that building effort wasted in a few minutes!

Mike

[Stuart Eggerton]

Hi Mike, yes I did not put my name and address in the glider as when one is that young there is no belief that one could possibly lose a model until it happens lol!

Nice stories Steve and Alan, it's amazing because the next model from the Caprice for me was the KK Chief, it seemed to be a natural progression and also rubber powered stuff like the Gypsy, I remember having difficulty carving the prop by hand from the instructions on the plan!.

Alan my Caprice could have landed in Hucknall, Bulwell is just west of Hucknall lol, small world indeed. I remember floating upstairs for bed after a long session using the cellulose dope! and my mum said I looked 'spaced out' it must have been a new craze called 'unintentional glue sniffing'

Edited By Stuart Eggerton on 20/11/2012 22:29:13

[Stuart Eggerton]

Yes Mike I know when a model disappears it can be disheartening, but that's what we did back then just built and flew (real model building) and enjoyed the process of building and the challenge of flying!

[Richard Harris]

Stuart,

Very nice brings back fond memories, I bought mine back in the 80's with saved up paper round money and bought the kit from Penn models when it was in Penn. I put 27 MHZ radio in it out of my Tamia Rough Rider using a ne servo on the rudder,me and my mate used to rush home in the summer to fly it. We took it in turns to tow it up on the school field and used to have a bit of a wager on who could land it on the cricket strip! I altered mine so its fin was on top.

I believe it is still in the loft at my parents house.

Rich

[Stuart Eggerton]

Hi Richard, yes I remember using a 27mhz "car" radio, used to speck out my Flair sunrise, which was amazing and never had a glitch!. Yes sometimes the greatest fun can be had with a favourite model, it need not be pristine but a beat up old model that for some reason just asks to be flown and enjoyed!

[Rob_P]

Stuart,

It was great to see your notes. I too am building an electrified Caprice and have been documenting on RC Groups. I still have a little more work to do but it will probably be at least a couple of months or more before we have any decent flying weather.

Would love to hear your input

**LINK**

Rob

[Charles Smitheman]

Ahh Memories.

My Caprice was the best by far of my free flight gliders. My pal Derek and I took turns towing and launching it one evening on Rondebosch Common, Cape Town SA. We ran out of DT fuse. It was my turn to tow, the model headed off down wind with Derek giving chase on his bike. I packed up and went home. About three hours later a slightly dishevelled Derek arrived with the model, all OK apart from a slightly dented nose; apparently it had flown into a block of flats after about 20 minutes, and ended up on an adjoining rooftop.

I later made a marvellous automatic hand launcher from an American mag, for the Capiche, which used a screen door hinge, it was hilarious, and it usually worked, if set up properly.

The mouldering fuselage still resides in a box in CT.

I must make a leccy one some day.

Charles

Edited By Charles Smitheman on 24/02/2013 16:41:32

Edited By Charles Smitheman on 24/02/2013 16:42:34

[John Farley]

[IMG]http://img.photobucket.com/albums/v145/johnfarley/Caprice2_zpsbf2aa7f9.jpg[/IMG]

I cheated and treated my very old Caprice to a small pylon on top of the wing and a tiny direct drive motor and prop with some 70gm of thrust. Plenty to make such an efficient glider self launching. It is free flight with a timer for the motor run.

[John Farley]

Sorry I hoped it would put the pic up. But the link works.

J

[Stephen Jones]

Hi ,

Caprice

Could you not get the battery in side ?

How well does it fly ?

[John Farley]

The batery is outside (and not in the nose) because I did not want to butcher the model until I knew the electrics would do the job. Then once I flew it I couldn't be bothered to change it!

It self launches ever so well in gentle climbing turns for as long as you want to set the timer.

It has only about 70gms of thrust but when planning the mod I decided that would be sufficient based on the aircraft weight and the likely lift/drag of the glider. I took a conservative L/D of 6 so the drag was 1/6 of the weight and the thrust needed to be a bit more than that to get a climb. Pretty childish calcs but they worked.

The power 'egg' was made by taking a piece of very thin ply and holding it onto the wing with the normal attachment rubber bands and cutting and gluing a pylon base to fit. So the wing did not need any mods.

I would recomend that approach to developing/making a power egg for any glider. It is so easy.

 

 

Edited By Pete B - Moderator on 08/04/2013 19:56:49

[John Farley]

Craked it

[John Farley]

Thank you Pete B - sorry if I let the side down.

JF

[Pete B]

No problem John, it's a great pleasure to see you here - although you might have set me up for a stoning if any Ppruners are lurking.........

Pete