La Coupe Des Barons 2024.

[David Davis]

La Coupe Des Barons 2024 takes place on 15th June next year at Ste Marie d'Alloix between Chambery and Grenoble. 

 

I will be campaigning my British Baron featuring a new wing based on the structure of a Keil Kraft Super 60 but with wing ribs made from depron. I also plan to increase the wingspan by 10% to lighten the wing loading. The Ukrainian Baron will be my reserve aircraft in case I damage "Bertie" shortly before the event.

 

Two more compatriots are building Barons so there may be three British pilots at this year's event. I have attached a video of the 2017 event for those unfamiliar with La Coupe Des Barons.

 

 

 

https://www.google.com/search?client=firefox-b-e&q=La+Coupedes+Barons+2017#fpstate=ive&vld=cid:97830b33,vid:vYlLvJC-MuE,st:0

[Wilco Wingco]

Pity the BMFA can't organise a similar event to replace the NATS. 1500 mile round trip is a bit far from southern England. Even further from the north I'm sure most flyers have a WOT4 electric or I/C tucked away in the loft and there is already a site ready and waiting at BMFA HQ. 

[David Davis]

Perhaps I should have explained that the other two Englishmen are both French residents so not so far for them to go.

[Paul De Tourtoulon]

Still 3h drive for me, maybe not this year either,,,,

[David Davis]

That's nothing! It's a five hour drive for me and one of the other blokes lives in the Somme department.

[Paul De Tourtoulon]

Getting too old  David,,,

[David Davis]

I know what you mean. I hate driving long distances myself these days. Just need to steel myself for this one!

[leccyflyer]

It's clearly a highlight of your modelling year, for which driving for 3-5 hours needs to be weighed up against the enjoyment derived. Maybe you could break it down into shorter segments, but it sounds like you would still be coming down on the positive side of the decision, even if were a much longer journey.

[Ron Gray]

2 hours ago, Wilco Wingco said:

Pity the BMFA can't organise a similar event to replace the NATS. 1500 mile round trip is a bit far from southern England. Even further from the north I'm sure most flyers have a WOT4 electric or I/C tucked away in the loft and there is already a site ready and waiting at BMFA HQ. 

Laser and Best of British weekend at Buckminster, 27th - 29th September.

[David Davis]

57 minutes ago, leccyflyer said:

It's clearly a highlight of your modelling year, for which driving for 3-5 hours needs to be weighed up against the enjoyment derived. Maybe you could break it down into shorter segments, but it sounds like you would still be coming down on the positive side of the decision, even if were a much longer journey.

 

 

Quite so. I won the four stroke class in 2021 and finished second to last this year so I've got a reputation to defend. It would be nice if the other two expat Englishmen were to enter as well. I plan to build a new wing for my model increasing the wing area by 10% to allow for the extra weight of the four stroke engine.

[David Davis]

I've cut out the wing ribs for the new wing out of depron. I am going to make up a D section wing with a third spar halfway between the main spars and the tailing edge. I will be using a film covering so will fit cap-strips to the wing ribs to protect them from the heat. I am thinking of using carbon fibre tube for the leading edge. I have bought some UHU POR glue for the balsa-depron interface but which glue should I use to fit the carbon fibre tube to the wing ribs and the balsa leading edge sheeting to the carbon fibre tube?

[Geoff S]

I bet the UHU Por would work there, too.  Try a little test piece.  Having discovered that with Por left to dry for 15 minutes or so, contact means what it implies - ie no wiggle time.  I usually use it when it'still fluid.

[David Davis]

A question for the cognoscenti of aerodynamics.

 

The wing are of a standard Baron is 3720 sq cms. The tailplane area of the standard Baron is 25.64% of the wing area. If I increase the wingspan by 10% to allow for the extra weight of a four-stroke engine which is permitted under the rules of the competition, the wing area increases to 4080 sq cms, so the tail area is now only 23.2%  of the wing area.

 

Will increasing the wingspan by 10% make that much difference to the model's flying characteristics?

 

Will the proportional reduction in tailplane area (2.2%) make any difference to the model's flying characteristics?

 

Or should I stick to the tried and trusted wing and tail?

[Chris Walby]

Might not be possible due to the rules, but based on your last few comments about 4 stroke weight and wing loading could you not move the engine back (shorten the nose on the fuselage) assuming you are using tail weights. If not move the engine back and make the tail lighter, but he idea would be to lose weight while retaining a 4 stroke engine.

 

I know nothing, but making it heavier and longer wingspan seems to be the opposite to how you want it to perform (as in agile) and the lighter it is the better the power to weight ratio. Colin Chapman quote "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere."

 

Is there a minimum weight for the class?

[David Davis]

Thanks for your reply Chris.

 

I have two Barons. The one in the Ukrainian colours is stock. The one in the RNAS colours has a shorter nose but it's only about 1 cm shorter than stock. It also has a wing with a lower dihedral. This makes it less pleasant to fly hence the idea of making a new wing. The new wing will have the standard dihedral but I haven't yet decided whether to make the 10% longer because the tailplane will be proportionately 2.2% smaller and that might make the model less stable.

 

At the moment the Ukrainian one has a broken wing but with a bit of hacksawing, some glue and some covering film it'll soon be back to flying condition.

 

The fuselages on both models are sound and I'm reluctant to start hacking them about to move the engines back because I want to get on with finishing off my Galaxy Models Mystic and my DB Sport and Scale Auster.

 

There is no minimum weight rule in La Coupe. Some people even fit wheels intended for indoor models.

[Robin Colbourne]

The Coupe Des Barons certainly looks a fun event.  I'm fascinated how in this type of competition the builder is allowed to modify the design.  I've tried looking for the rules, and this is my translation of them from this site La Coupe Des Barons 2024.  Clearly there is more to it, as David has mentioned that he is flying a much larger engine than the 3.5cc one mentioned, plus the increase in span is permitted, but none of that is mentioned here.

La Coupe Des Barons (The Barons' Cup)

The Free Flight Club of Ste Marie d'Alloix has been organizing the Barons' Cup since 2005. This famous competition, initiated in 1976, is one of the most famous model making competitions and has always been open to all competitors, from beginners to experienced.

Many European clubs have copied this competition at national level, thus putting the spotlight on the competition which celebrates the famous "Le Baron"; a semi-scale model of an aircraft from the 1914 era, halfway between the Fokker DRIII (sic, maybe they mean EIII Eindecker?) and the Blériot XXIV artillery observation aeroplane.

The Free Flight Club

With nearly 60 members from all professional backgrounds (traders, business leaders, technicians, workers, lawyers, private or professional pilots, glider pilots, high school students, students, retirees, schoolchildren, etc...) In short, several generations of aviation enthusiasts under the aegis of of its founder Gérard Ferroud and its entire administrative team, the club has decided this year to pay tribute to these famous Knights of the Sky of 1914/18 by organizing the Barons' Cup. All these modellers will compete at the controls of a model identical to the one invented by M.C. Chauzit in various ruthless and terribly nerve-wracking ordeals, but also for templates (awards?).

The Model

A monoplane created in 1972 by Mr. Christian Chauzit, it is rather intended to be an early aircraft resembling a machine that once existed and with the incomparable charm of these "trapanelles" (flying jalopies?) that left their mark at the start of our fabulous aeronautical history.

With a wingspan of 1550mm (61”) and a weight of less than 2kg (4.84lb), it will be powered by a modest 3.5cc engine and will reveal incomparable flying qualities as well as manoeuvrability possibilities phenomenal, despite only having two axes controls; thus making it the model of choice for almost all beginners in model flying and by the same token an aircraft worthy of being included in a one-design competition.

The Tasks

Aesthetic Test (Static Judging)
Each model is scored according to specific criteria (realism of the bonnet (Engine cowling?), machine gun, wheels, etc.).

The Baron had to get as close as possible to the real aircraft of the time.

Over the years, flyers have indulged in more and more fanciful decorations (for their pilots), e.g. a cow, a "Barbie" doll...

Broken Sticks

Metre-tall balsa sticks are stuck in the ground. The same number and position of sticks for each competitor.
The goal of the event is to break them in mid-flight or "Touch and go".

The Pylon Race
Two 6 metre tall masts are erected 100 metres apart from each other. the other.
The Barons have to pass through as many pylons as possible.

Fox Hunting

A strip of crepe paper hangs on the back of a Baron.
The purpose of the test for the other Barons is to come and cut this band with their propeller.

The Limbo

A rope is stretched between two masts at a height of 4.5 meters. The Barons must go to flights under this rope the greatest number of times. Some dare to cross in a loop...

All participants are divided into six groups of seven or eight Barons. The tasks take place by heats each of 5 minutes. Each heat is made up of 7 or 8 Barons who fly at the same time, the start is made also simultaneously.

[Robin Colbourne]

I've just realised there is another page of rules here:  La Coupe Des Barons 2024 regulations

[Chris Walby]

Hi David,

 

The point I was trying to make (badly) is that adding weight and drag for some beneficial lift might just diminish the overall performance.

 

I have owned two FMS kingfishers, the first bought off a clubmate as I wanted a model my wife could fly (on buddy lead) and although it had been crashed and well repaired it flew well. I then stupidly lost it so bought a new one and WOW what a difference in flight characteristics. It can't all be due to just the re-glued bits as some of it must be due to the minor increase in weight.  

 

Another example is we fly (Sunday morning crew) FT Versa's (foamboard delta) of which one of the chaps cuts the commercially white board and the rest of us just assemble. While I was ordering another FT kit and the P&P cost I added a FT Versa. Now the FT foam board is only slightly lighter and the overall weight of the model is low again the additional weight of the commercially available foam board makes a noticeable difference in agility and stall characteristic.

 

I think if you can lose weight then you don't need to add drag and mass, I appreciate it might not be that easy now they are build, but worth considering for the next one  

[J D 8]

  Agree with Chris, there can come a point where just that bit more weight/distortion from repairs turns what was a nice flyer into a flying pig. Always reluctant to give up on a model it has happened to me a few times. 

[David Davis]

Well I've certainly experienced enough repaired models to realise that the weight of the repairs can adversely affect the performance of the model but I've looked into the question of wing to tail area ratios and the consensus seems to be that a tailplane with 20% of the wing area is adequate so I'm going to go ahead and make my new wing 10% longer in the hope of gaining a bit more lift. It only amounts to adding an extra bay to each wing. I will also use more dihedral on this new wing than I did on my first wing in order to make the model more stable, something like one inch for every foot of half-span plus an inch, so about 9cms (3.5 inches) under each wing tip.

 

PS. They are accepting ninety entrants this year, nine groups of ten pilots and yes, a four stroke engine of up to 0.56 cubic inches is eligible. Two strokes are limited to a 35. It's a pity they don't allow 36s to compete as there are some strong engines in that category.

Edited January 4 by David Davis

[Graham Davies 3]

Hi David,

There's various things likely to be affected:

• Wing loading decreases, which lowers your stall speed
• Weight/ drag will increase (I think only slightly though, drag more than weight). Increased drag = reduced speed. Increase weight = increased stalls speed, lower rate of climb etc
• Increased span will reduce your roll rate
• Increasing span will increase the aspect ratio. This may improve aileron efficiency, if they were fitted!
• Increased wing area does (as you rightly point out) reduce the relative tailplane area. This will affect the longitudinal stability and may affect ideal CG position (may move it forward IIRC). However, I think the amount you are proposing to increase the wing would not make a big difference.

Would I increase the wing area? Only if I could do it for zero net weight gain. I agree with Chris; the disciplines of the Coup really favour light weight over a slow stall. You're going to need what speed you can get, so you don't really want additional drag. If you were to get really clever, use a thinner wing section AND increased area! 

 

I think for me though, I'd spend my time reducing the wight and retain the dimensions. I think you risk unwanted consequences (such as you found by reducing the dihedral; you probably lost a lot of roll authority, which is the last thing you needed).

 

I hope that helps!

 

G

[David Davis]

Thank you for all of the advice gentlemen. There's no easy way to reduce weight as both models are already built and despite all that I've written above, I've decided to repair the wing of the Ukrainian Baron first. Apart from basswood main spars it is absolutely stock then I'll decide what to do with the other wing.

[Robin Colbourne]

On 05/01/2024 at 18:28, David Davis said:

Thank you for all of the advice gentlemen. There's no easy way to reduce weight as both models are already built and despite all that I've written above, I've decided to repair the wing of the Ukrainian Baron first. Apart from basswood main spars it is absolutely stock then I'll decide what to do with the other wing.

David, with a rudder/elevator model, manouverability comes from reducing the inertia in the extremities.  If you are going for heavier spars, may I suggest you consider tapering them?  A friend built a new wing for the Bowman's Simpleton glider on which I had broken the original wing.  He used spruce spars and the thing became an absolute pig to turn.

[David Davis]

Thank you Robin.

 

The Ukrainian Baron, Boris, has a stock dihedral which makes it easier to fly than the British one. It also has the standard Baron wing construction consisting of five spars and two turbulator spars. Of these five spars, only two, those at the wing rib's widest point, are made from basswood. The starboard wing had snapped off at the  junction of the centre section in a crash. To repair it simply involves repairing one of the balsa spars and the trailing edge and cutting two new wing ribs before joining the wing back onto the centre section. I'll post a few pictures of the job later. I must drive over to La Chatre to buy a gas stove to heat the workshop.

 

I intend to build a complete new wing for the British Baron, Bertie, with the stock dihedral or a little more. The model is currently in flying condition but as I have said above, it is not very pleasant to fly with its reduced dihedral. However, I intend to change the construction of the wing quite radically. Three balsa spars arranged a la Super 60, ribs at 3" centres as opposed to the standard Baron spacing of 2" centres, fully sheeted D section at the front of the wing, depron ribs with cap strips and a fullt built-up trailing edge. I'm hoping that this form of construction will produce a lighter wing and with the increase in dihedral, it will be a more pleasant model to fly. I may even make the leading edge out of carbon fibre tube. I know that this will increase the weight but it may help in a collision. Thesae are not unknown in La Coupe!

 

[Martin Dance 1]

1 hour ago, David Davis said:

I intend to build a complete new wing for the British Baron, Bertie, with the stock dihedral or a little more. The model is currently in flying condition but as I have said above, it is not very pleasant to fly with its reduced dihedral. However, I intend to change the construction of the wing quite radically. Three balsa spars arranged a la Super 60, ribs at 3" centres as opposed to the standard Baron spacing of 2" centres, fully sheeted D section at the front of the wing, depron ribs with cap strips and a fullt built-up trailing edge. I'm hoping that this form of construction will produce a lighter wing and with the increase in dihedral, it will be a more pleasant model to fly. I may even make the leading edge out of carbon fibre tube. I know that this will increase the weight but it may help in a collision. Thesae are not unknown in La Coupe!

With all of the design and construction mods you are planning  La coupe de Barons, a fun fly competition is taking on a seriously competitive  edge. Next it'll become an international  competition. Oh it is already, unles you've taken French citizenship.😀