La Coupe Des Barons 2023.

[David Davis]

Good Day Gentlemen.

 

My entry has been accepted for La Coupe Des Barons on 10th June down at Jonage near Lyon. For those unfamiliar with the event it's a competition for a three-channel French trainer the "Baron 1914," which looks vaguely like a WW1 monoplane fighter. The model was made under licence by Svensonand sold as the "Vicomte 1915," plan available here: https://outerzone.co.uk/plan_details.asp?ID=5077 There are five aspects to the competition: concours d'elegance; caisse baguettes, in which you have to knock over 1 metre high balsa sticks; a pylon race; chasse renard in which a trainer pulls a streamer round the sky and you have to cut it with your proplerr or at least touch it with your model and finally the dreaded limbo. Have a look at the 2017 video and you'll see what I mean: https://www.youtube.com/watch?v=vYlLvJC-MuE

 

I have flown in this event for about five years. I started with an electric powered model but have become well-known not only as the only Englishman at the event but also as a competitor with a four-stroke engine. You don't stand much chance of winning with a model fitted with a four-stroke engine but I won the four-stroke class in 2021 finishing in 30 something position from an entry of 75 on the day but last year I crashed out in the first round! This year they've changed the rules to allow four strokes of up to 0.56 cu.ins to compete, the size of the smallest OS four-stroke currently available. This will allow me to use my Thunder Tiger 54. They've also limited electric powered Barons to 825 Watts, a 13" propeller, and a 4S 6000mAh LiPo. 

 

There are still nine places left plus ten on the waiting list so if you want a holiday in La Belle France why not build a Baron?  😉

[Paul De Tourtoulon]

So they accept 'Le Vicomte" now ?.

[David Davis]

Le Vicomte was a Baron made under licence by Svenson. It was exactly the same as a Baron 1914 in every respect, besides, the regulations allow you to make changes to the overall shape and structure of a Baron provided that its wing area for example is within 10% of the original and the aerofoil section is Clark Y.

 

 

Edited January 21, 2023 by David Davis

[Paul De Tourtoulon]

There is what most men want in the Vicomte, that's the extra inch,,,,

[Nigel Grant 1]

The link in David's post above to the outerzone plan also includes a review by Peter Miller on the kit. Its a fun read and includes an inspirational colour scheme! The review takes you back to when the pictures were captured on a roll of film. The one Peter built went OK on a K&B 20 sportster. The more contemporary builds using an OS 35AX or 56 -4ST must be pretty hot. All the best for this years event David, will look forward to the report - go well!

[David Davis]

Thank you Nigel.

 

I actually have two Barons. I built a second one just in case I crashed the other one while practising for La Coupe. The first one was originally finished in Great War Russian markings, the other in RNAS markings because it's flown by a teddy bear I picked up at Yeovilton!  After the invasion of Ukraine I stripped the Russian cockades from the Russian Baron and substituted Ukrainian roundels, not that many people know what WW1 Russian markings look like!

 

The first one flew well but I tried to be too clever with the second one by reducing the dihedral to make the model more manouvrable. This resulted in a model which was quite unstable and had to be "flown" all the time. You couldn't relax for a second. Nevertheless, this was the model with which I won the four-stroke class in 2021. Last night I was examining both wings and I noticed that the RNAS wing not only sported less dihedral it was also three inches shorter! No wonder it was such a pig to fly! 

 

I'm going to build another wing for it with the correct dihedral, maybe even make it slightly bigger, you are allowed 10% tolerance and I will probably convert the current wing to ailerons. It will not be eligible for La Coupe with ailerons but I could use the model in that form as an advanced trainer for beginners.

[David Davis 2]

The throttle servo failed in my Baron. Impressed by their power and reputation, I bought a Savox SH-0255MG servo to replace it. When it arrived I discovered that it was not supplied with any rubber mounts.

 

Three questions:

1. Is this servo intended for electric powered models and gliders only?
2. If I were to screw it to the Baron, would the vibrations of the Thunder Tiger 54 FS soon destroy?
3. if this servo is unsuitable for this purpose, which similar size servo would you recommend?

PS. I'm still the same David Davis as above but I'm David Davis 2 when I use my laptop and my PC Keeps switching itself off!

[Paul De Tourtoulon]

I just saw it's specifications, I wouldn't use it in a 4 stroke powered plane, ok saving 20 grams from a Futaba std servo is it really worth it

in an overpowered plane ?.

 

 And yes, Grommets for any internal combustion powered plane.

Edited April 25, 2023 by Paul De Tourtoulon

[J D 8]

   As above, grommet mounted servos for IC aircraft.

[David Davis 2]

Thank you gentlemen, I'll fit an old Futaba 3003 and accept the extra 20 grammes.

[Ron Gray]

You can always get spare grommets or use O rings which admittedly won’t prevent vibration between fixing screws and lugs but will still stop a lot of the vibration.

[Paul De Tourtoulon]

And use a bit of silicone fuel tube as grommets on your  3003.

[David Davis 2]

I have found an old Acoms servo amongst mu souvenirs. I'll press that into service and pass the Savoxes onto to my mate. He's exclusively electric!

[David Davis 2]

I connected the Acoms servo to the throttle channel and switched on the receiver to see whether it would work, it did. Fortunately I had not fitted it into the airframe, I was holding it in my hand. Then I noticed that it was warming up, then it became hot! I disconnected it from the receiver and threw it into the electronic recycling box. I replaced it with a trusty old Futaba S148.

 

On a different tack, we've had a few calm days here recently and I took my Big Guff vintage model and my Baron to the flying field in order to get in some practice. I have several OS four-strokes from a 40 to a 70, three Thunder Tiger four-strokes, and single examples from ASP and Magnum. I have always run these engines on 10% nitro because that was the conventional wisdom. 5% nitro fuel I've reserved for my Laser engines and what two-strokes I still use. The Big Guff is powered by a Laser 62 but when I got to the field, I discovered that I had left the 10% fuel at home. I filled the Thunder Tiger 54's tank with some of the 5% fuel and after a little needle fiddling, the engine ran very well. OK I wasn't able to do to carry out an accurate comparison but the engine certainly went well enough. You learn something new every day!

 

Jonathan Harper of Laser has insisted that 5% nitro is perfectly adequate for Japanese four-strokes for some time now. I've just looked at the Thunder Tiger's manual and they recommend a fuel containing 10-30% nitro. I wonder why?

 

I've decided to put the Savoxes into an electric powered Sharkface.

 

 

 

 

 

 

 

[Chris Walby]

Probably wrong, but I thought higher nitro allowed a wider state of tune (more tolerant of miss tune) and produces more power (in the right conditions!). I was told when purchasing a model with a Super tigre G30 to use no nitro as they don't like it (model came with 2 gallons!).

 

I now look like an fuel depot as I have an ASP that runs 10% nitro, fuel with no nitro, and both Laser normal and low oil....TBH I'll be glad to ditch the non Laser engines and just move to the low oil....

 

PS - I bought a model with one of those pesky petrol engines, TBH I'll never run it and just stick a Laser in it, so that makes an empty can that will not get filled!

[Paul De Tourtoulon]

Yes Chris, Nitro gives the engine more oxygen, power and also makes it easier to tune, but it also needs the right compression ratio to run properly and give you all that, for instance my OS .50 Hyper in a Raptor is useless under 10% nitro and really only runs how it should with over 15% nitro.

 

 I have a Saito 100 that threw props when throttling up for take off that I had to shim to drop the compression ratio on my 10% nitro mix.

[David Davis 2]

Took my Baron flying yesterday afternoon. I had added some nitro to a gallon of straight last week. The engine, a Thunder Tiger 54, started up straight away and ran well. I practised low level passes until one of my clubmates joined me in the air. When he called a landing I parked my model fairly high and downwind until he'd retrieved his model. Suddenly my motor stopped. Being that sudden I assumed that it had either thrown a prop or siezed! There are fields each side of our flying field which are both sown to wheat this year. I thought I'd overshoot the runway so I put the model into a 360 turn but over-estimated a Baron's gliding ability and I landed in the crop downwind of the runway. The model had disappeared in the wheat which was over a metre tall. It took us three quarters of an hour to find the model and by the time my mate Frans had found it my trousers were soaking wet because it had rained earlier in the day and the wheat was still wet. My faithful doggie joined us,charging and barging through the wheat. Actually she was more of a hindrance than a help because she made such a noise barrelling her way through the wheat that I was unable to hear the servos moving when I operated the transmitter! I had indeed lost the propeller, nut, spinner and washer but there was no damage to the model.

Frans had brought his own Baron to the field. He had repaired a Baron which had been damaged in a previous coupe. He is very enthusiastic but not very experienced or competent and his repaired wing was badly warped. We will have to strip off all of the covering, soak the wood and pin it down flat to remove the warps

[David Davis 2]

Behold, 75% of "Équipe Étrangere!" British pilot, Ukrainian Baron, and Swiss Shepherd! Only my Belgian mechanic is missing. He's in Belgium for a music concert.

 

I had a couple of satisfactory flights yesterday practising low level flight. The engine runs very well on the home made fuel. It runs for nearly ten minutes on 90ccs of fuel flying mostly at low throttle settings. As each flying round in La Coupe lasts for five minutes I think that the tank will be big enough. I made the cowling from very light sheet metal supplied by a club colleague who works as a printer. It's supposed to look like the cowlings fitted to SE5as!

 

The second round in the competition is the pylon race. At full chat I have to hold in considerable down elevator. The model was never intended to be powered by an engine as large and powerful as the TT54 of course and I ought to see whether the tank is big enough to allow five minute continuous flat out flying as this will be required in the pylon race. If it cuts out before five minutes I'll fit a SLEC blue tank which is 120cc or 4 fluid ounces.

 

Otherwise, I'm ready for La Coupe Des Barons on 10th June.

 

 

[J D 8]

                It is likely it is possible to program your radio to feed in some down elevator in as the throttle is opened. I have done this on an over powered aircraft, stops that ballooning effect as you power up and saves having to hold in down stick all the time when flying at full power.

    

[David Davis 2]

Thank you JD8. I have a Spektrum DX9. I haven't a clue how to program the computer to achieve this result but I'll look into it.

[J D 8]

               Futaba myself David, but have you any lets say [likely] younger computer savvy club members who could help? I can see that having to hold down stick while concentrating on the race. Cheers, John.

[David Davis]

1 hour ago, J D 8 said:

               Futaba myself David, but have you any lets say [likely] younger computer savvy club members who could help? I can see that having to hold down stick while concentrating on the race. Cheers, John.

 

Yes there's a seventy year old Belgian in the club who is prettty good with the programming of Spektrum computers. I'll be going flying this afternoon if the rain holds off. If it rains I'll go round to his house and he can programme it there.

[Paul De Tourtoulon]

If it climbs under power, put some more down thrust on the engine.

[David Davis 2]

I flew both of my Barons yesterday.

 

I put a piece of 3mm ply between the firewall and the engine mount to get even more down thrust; there were already two pieces of metal sheet behind the mount but even that did not stop the climbing under full power. With the help of my clubmate Gerard we tried to dial in some down elevator at full throttle and then assign a switch. Gerard is much more comfortable with computers than I am but he was not successful so he scrubbed all of the alterations and we went back to square one. I suppose we could try again.

 

Then I tried my British Baron, "Bertie." The engine, a Magnum 52, fired up straight away and with a little needle twiddling it flew well. It did not climb under full power,  on the contrary, I needed to add up trim on the elevator. I had deliberately built this model's wing with less dihedral than standard to make it more manouevrable. I remember finding the model difficult to fly and unstable when I'd first built it but yesterday i did not find it intimidating at all. It was this model which  won the four-stroke class in 2021.

 

I will try the effect of putting some 1 mm ply under the trailing edge of the Ukrainian Baron to see what effect that has. I had always regarded the British Baron as a reserve model in case I crashed the other one in practice but after yesterday's experience maybe I'll fly Bertie in the competition. Picture of Bertie in the 2019 Coupe Des Barons below and in my avatar. I have subsequently changed the colour of the fin to red and fitted a Hispano Suiza inline engine!

[J D 8]

Adjusting the wing incidence a bit at a time is another answer to the ballooning under power.

 Tad at a time or one may have switched the issue into wanting to dive.