Robin Colbourne

The move to ARTF models has bought a lot of people into the hobby without the skills and facilities to repair used models. I tend to buy a lot from auctions and bring and buys, yet it is very rare to get one that I would feel comfortable flying without any repairs or modifications beforehand. Fine, if you have years of experience and can see the best way and have the tools to tackle the repair, but for someone with only an electric trainer under their belt, it is a daunting prospect. They would probably rather buy a new known design mail order with a much greater chance of satisfaction. The other thing is space to store these secondhand airframes. Not everyone has a workshop or shed and mothers, girlfriends and wives may tolerate a new ARTF in the house, whereas a dusty, oily and smelly artifact may get the hackles up.

Extra Slim, you mentioned that the tank is right on the bottom of the fuselage. If this means that it has no foam between it and the airframe then there is a possibility that the fuel is frothing with the vibration being transmitted to it.

NigelR, it was probably empirical data from testing a number of different aerofoils until Chris found one giving the qualities he desired. Anyway, Sukhoi used something along the same lines for the Sukhoi Su-26, and they seemed to know what they were doing. (image from RC Groups)

In the late 1980s the Sailplanes International 'Secret Weapon' aerobatic slope soarer was very popular. The box stated that the tip aerofoil was a NACA symmetrical section, however the root was the 'LBMD001'. After searching all sorts of aerofoil databases to find info on the root aerofoil, I finally discovered that LB and MD were the initials of the two designers.

I don;t know about the Wots Wot, but at a talk Chris Foss gave to our club many years ago, when it came to questions, he was asked which aerofoil the Wot 4 used. "Size 9 left foot" was Chris's answer, i.e. he drew it around his shoe. He then went on to elaborate a bit, adding that it had a slightly of concave section between the spar and aileron to make the aileron more effective.

You could equally argue that the 'foamie' is a model and as a person is flying it, that must make them an aeromodeller. If you read Flight magazine from 1909/1910, the letters pages were full of debates whether an 'aerodrome' was a thing that was intended to fly, as in Samuel Langley's 'Aerodrome' or the place from which one took off and landed as in Farnborough or Brooklands. Ultimately it doesn't really matter, provided the listener knows to which type the conversation refers. When I taught an adult education couse for people wanting to learn how to build and fly R/C models, I had the full spectrum of interests amongst those on the course. Some were happy to buy a secondhand model, charge it up, put fuel in it and fly; others built and flew; whilst one chap who built a very nice 'Pilot Kits' Tiger Moth, once the model was up in the air and trimmed out, when I offered him the buddy box, replied, "Oh no, I'm happy to just watch you fly it". We get from the hobby what we want, and as time and money pressures vary through life, what we build and/or fly varies too.

Wood screws into wooden bearers don't stay secure for long. The engine vibrates, which vibrates the screws, which opens out the holes and before you know it the engine is flapping all over the place. If you can easily get at the underside of the bearers, then machine screws, washers and nyloc nuts are an option. My prefrerred method is captive 'T' nuts epoxied into the underside of the wooden bearers and machine screws, passing through washers on top of the engine's mounting lugs going into the T nuts with a drop of nut lock on the screw thread. If you use non-high tensile screws there is the possibility of shearing the screws and not the engine's lugs in the event of an 'arrival'. With regard to a separate engine mounting plate, Using fairly widely spaced mounting lugs gives you the option to change to a different make or size of engine without making a mess of the wooden bearers, as it seems no two engines have exactly the same mounting hole spacing. Use either a 1/8" aluminium or 3/16" or 1/4" tufnol or paxolin if you can get it. They are fabric or paper reinforced phenolic resin.

The issue with a lot of kit and plan models is that they are designed to be simple to construct, thus giving the builder maximum liklihood of getting them finished and flying. Ideally material should be where it is needed to give strength and taper away to nothing where it isn't. As an example, an Airbus A340 has wing skins over an inch thick at the wing root, tapering away to about 1/8" thick or less at the tip. Full-size gliders often only have a root rib, tip rib and a hefty mainspar at the deepest part of the wing chord. Wing skins are a sandwich of glass fibre cloth laters either side of a upper and lower skin foam cores. These cloth layers are at 45° to the spar and at right angles to each other. The primary objective is to resist torsional,wing twisting loads. The WW1 Albatros DVa did something similar for its fuselage but without the core, and the WW2 De Havilland Mosquito for its whole airframe, with balsa instead of the foam core. The main reason modellers don't copy this construction is that it needs complex jigs to construct the curved surfaces and that lengthens the build process unless several of the same design are to be built.

Hi Skippers, Laurie Barr and Sams Models used to be the go to places for indoor models. Mike Woodhouse at Freeflight Supplies would be a good place to start these days. He may not do any kits for microfilm models, but is more likely to stock appropriate materials than a normal model supplier. He may also know of more specialist suppliers. Mike Woodhouse - Free Flight Supplies - Indoor Accessories This is an Outerzone search for any plans with the word 'Microfilm' in the title, although a few clearly aren't what you are after: Microfilm plans

Different makes of film have different requirements. As I recall, Oracover (Polyester film) sticks from about 90°C but only shrinks from around 140°C. It melts at approx 250°C. You really need to find the instructions for the film you have, or failing that, do some experiments with scraps. Solarfilm (Polyproylene film) is far more sensitive and easier to burn holes through. This Solarfilm covering tutorial should answer most questions for it.

Does this page help? NACA0018 Polars

Another vote for the Lidl Digital Hot Air Gun. I bought one for work and liked it so much I bought another for home use. I have one of the cream coloured Weller ones that I use for small jobs, but if its for use on covering film the Digital one is the bee's knees. You can pick the Lidl one up from Ebay if you're not prepared to wait for the shop to get them in: Lidl Parkside Digital Hot Air Gun and this one in an auction: Parkside Digital Hot Air Gun Auction

If a drone was fitted with a 35MHz receiver, would it be unaffected by the jammers? (Asking for a friend 😈)

Having googled the well known model engine designers such as Lawrence H Sparey and Edgar T Westbury, it doesn't appear to be one of theirs. The general style of the engine to me puts it somewhere in the late 60's to 1990s, although that is just a gut feeling. An enquiry on the Model Engineer Forum may get a result, or an enquiry to Adrian at https://www.adriansmodelaeroengines.com/catalog/ may help, although he has been hospitalized lately.

Frank, you could try posting on this Polish Facebook groupwhich translates to "RC planes are our passion"

This is a Cat 500 designed by Harry Gilkes (RM450 from Sarik). I bought it probaby 25 years ago or more and flew it regularly for a few years. Firstly with an OS25FSR and later with an MDS38. A heavy arrival resulted in a broken silencer, broken wing dowel and elevator horn, plus some damage on the wing leading edge, which projects forward from the spar along the side of the fuselage and a twisted undercarriage. It then got put aside whilst I flew other models then full-size gliders for a number of years. The recent wet and wind weather gave me a good excuse to get her sorted. The broken elevator horn crubled to dust as I removed it. A salutory reminder to check all the other nylon fittings. Here is the broken horn next to a complete one.

Its worth noting that the early Futaba Challenger was the FPT-6NL and didn't have a buddy box socket, whilst the later one was the FPT-6NFK (or FPT-6NPK) I believe the early ones (6NL) had electronic components with legs through the boards, whilst the later ones 6NFK & 8NPK) were surface mounted.

My apologies Frank. I didn't update the link when I edited the text. This is the right one for the model III. The text mentions a special cylinder head for the R/C version, maybe the R/C one doesn't have the offset plug? September 1960 Model Aircraft - Test Report - OS Max-III 35

That looks like the OS Max-III 35 from 1960. The odd thing is that the photographed engine in this test report doesn't have the slight bellmouth on the venturi casting that Frank's engine has, althoug hthe drawing shows it. Generally non-RC glow motors of this size are of more interest to collectors (and vintage control line fliers than the equivalent R/C (throttled) versions. February 1958 Model Aircraft Test Report - OS Max-II 35 Frank's box looks newer than the engine to me.

What you are asking represents many hours of work. A lot of it is already available on the net and in books. If you do your research first, so you learn the terminology, then you can speak to some experienced modellers who can then guide you further. Steps to take are: Get a good book such as David Boddington's Radio Control Primer This will cover a lot of the basic information on aspects such as mounting your engine, fuel tank tank height etc. Download the instruction sheet for the engine you have or as close to it as possible, e.g. OS46AX instruction manual Watch some Youtube videos This is the two I found, I'm sure there are better ones Basics of glow motors Starting and Tuning a 2 cycle Nitro RC Airplane Engine Go to a club and speak to a few people who have glow models. Ther may be someone who has a test stand on which they would be willing to run your engine.

How about the two channel conversion of the KeilKraft Invader as championed by John Woodfield? John used wing twist and pitch rather than try to make a linkage to the twin fins. John quotes a total weight for the model including R/C of 130 grammes (4.6oz). As most of these gliders needed some lead inthe nose in free flight form, the radio replaces much of this, so their is very little overall increase. John Woodfield's KeilKraft Invader converted to R/C R/C KeilKraft Invader in flight The KeilKraft Invader can be bought as a kit or downloaded from Outerzone

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.

A good many modellers have had a relationship with a tree. Its usually a bit like a divorce; the tree finds out what you treasure most and grabs it from you.

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

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.