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David Davis

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Everything posted by David Davis

  1. I have decided to put myself in the position of a modeller returning to the hobby after a break of twenty or thirty years who is unsure as to whether to build a Skyrider or to buy a Speed Air for £263. I'm assuming that he's kept his modelling tools but has no wood, glue, hardware or covering. The engine/electric motor, speed controller, propeller, fuel and radio are not supplied with the Speed Air so those items will need to be added to the cost of building and covering the model.
  2. I suppose that I could keep an account of both options. When I thought, " I could build this for £50!" I was naturally thinking that I have considerable stocks of wood, glue, and covering material. The radio, motor and wheels were also in stock.
  3. Thank you for the information Graham, very interesting. I think I'll go for the smaller prop and the largest battery. If I could get five minutes out of a 2200 mAh LiPo, I should be able to get ten minutes from a 4400 mAh LiPo. So that decides it, a plywood F2 former with a hole in the bottom to allow for the LiPo!
  4. I forgot to add that one of our forty somethings is the father of three sons. He doesn't believe in spending much on the hobby. He flies time-expired patternships and his middle son who is twelve years old, flies a battered old ARTF trainer as well as a half-size Bird of Time glider which he built with his dad. A few weeks ago I noticed that his engine, a Webra 40, kept cutting out in flight. When I asked why this was the case I was told that the engine was worn out. I happened to have the identical engine fitted with an Enya carburetter and MDS Q silencer sitting in my cupboard amongst all of the other unemployed bargains. I gave it to the lad. After removing one of the baffles from the silencer the engine ran faultlessly and the lad proceeded to fly inverted circuits with his trainer! He's a better pilot than I am and I've lost count of the number of times the lad thanked me for the engine.
  5. ...and welcome back from me in the middle of La Belle France Dan!
  6. The fuselage sides are complete. I reckon it's taken me about two hours to get to this stage. According to the build notes which came with the short-kit, the prototype weighed 5lbs but weights of up to 6lbs are acceptable. If it were my model I would fit a two stroke glow but as it's intended for Trish I will fit an electric motor. Electric flight is not my thing but I have two electric motors sculling about: a Pro-Tronik DM 2830 and an Axi 2820/10. Specs here: https://www.absolu-modelisme.com/moteur-dm2830-kv660.html and here: https://www.modelmotors.cz/product/detail/221/ I will probably go for the Pro-Tronik. I have a number of LiPos which would fit in the aircraft ranging from 2200 3S LiPos to 4400 3S Lipos. The 2200s will fit without modification but will they provide sufficient flight time if I were to prop the motor to provide 100 Watts per lb? If I need to fit a bigger battery I will mount it diagonally in a tray as per Chris Foss's modification for the WOT 4. This will involve cutting a hole in the F2 former to accomodate the tray. What is the view of the electric bretheren? Another modification I intend to make is to make the F2 former out of 6mm ply and to extend the height of the former by 5mm to allow me to fit a dowel to the wing's leading edge and to use plastic bolts in captive nuts at the trailing edge rather than use elastic bands.
  7. In my first post of May 20th, I expressed surprise at the alleged cost of building a simple sports model being £150-£200. Indeed I said, "I reckon I could knock up something similar for £50!" I don't think that I will have spend much on the Skyrider simply because I already have stocks of most of the materials. I've had to pay £37 for the purple and pink covering material because that's the colour scheme she wanted but I could have saved that if I'd used film from existing stocks. I am keeping an account of expenditure to see whether £263 is a fair price for a Speed Air. So far this model has cost me over £100 and that includes the cost of replacing the wood.
  8. I started work on the Skyrider today. What you get for your £53.40 in a little cardboard box is a set of laser cut wing ribs, a dural u/c, a set of profiles for the formers and a plan which is not shown in the picture. The profiles are printed onto paper which has adhesive on the other side, so you cut them all out, stick them to the balsa and cut round them. The fuselage is thirty-six inches long and nearly five inches wide. I didn't have any sheet wider than four inches so I was forced to cut a little more from a third sheet and to glue it edge to edge. I'll leave it to dry overnight. Cost of balsa so far: £10.44.
  9. 911, the best advice I have ever received regarding landing was to establish the model's Minimum Flying Speed (MSF) when all of the forces acting upon the aircraft are in balance. Having established MSF so that the model is neither climbing nor diving, throttle back a click or two. The model will start to descend. At this stage hold in a little up elevator. This will lower the tail and present the wing at a higher angle of attack enabling the model to fly more slowly than MSF. Don't use too much up elevator or the model will stall. Try practising circuits at a safe altitude at this slower speed. I have only an amateur's knowedge of aeronautics but I'm going to call this speed Landing Speed. Fly a rectangular circuit starting into wind at Landing Speed, i.e, holding in a little up elevator to give a higher angle of attack to the mainplane. There are five elements to a landing circuit: into wind; cross wind; down wind; base leg and finals. I try to get my trainee pilots to level the wings after every turn, indeed my nickname in my club is "Aile Plat!" This means "Level your wings." On finals, level the wings and keep a few revs on give better control response over the tail surfaces. As others have said, use your throttle to control height and your elevator to control speed on finals.
  10. Three quick points. 1. At risk of repeating information with which you are already conversant, when you enter La Coupe you are given a competition number which you keep for life. In the very first Coupe Des Barons there were only eighteen entrants so all of those entrants with a competition number ranging from 1-18, were founder members. The No 5 Baron is flown by Leo Brunori, an artist by profession, who regularly flies in the competition but he will admit that he's not the greatest pilot in the event. Trish and were sitting down behind the safety barrier watching the early groups trying to break the one metre-high balsawood sticks. Behind us several people had erected gazebos. Suddenly a Baron came shuddering down the sky and passed over our heads to crash in one of the gazebos behind us. It was Leo's No 5 Baron but how it had become so out of control I can't imagine. There was a man inside the gazebo at the time too but no-one was hurt. 2. There were several entries from the the RMCC club based in Province. They all wore orange tee shirts with RMCC printed on them. One elderly pilot presented a lovely Baron finished all over orange with black detailing but in the air the model was dangerous. Either the cg was too far to the rear or the pilot was completely incompetent and he shouldn't have been in the competition. In either case his clubmates should have put him right. While the other entries were aiming for the balsawood sticks, this model was performing all sorts of uncontrolled evolutions while the drifting down wind. The model's performance attracted the attention of the principal organisers but mercifully it crsah-landed gently in the wheat! 3. The pilot of Baron 224 turned up with his face painted to simulate some kind of monster in order to frighten us all. His wife was dressed as a pirate! He was not a bad pilot and went on to finish in 30th position. Photos to follow.
  11. I'm afraid I don't have much to report. After a six hour drive south and having booked an apartment at a nearby town, Trish and I arrived on site on Saturday morning long before the start of proceedings and even before the French had got the coffee and croisants ready. I have been practising low level flying for much of the year and consider myself to be moderately competent at it, though most of my practising has been with my No1 Baron which lost its wing in practice about a fortnight ago. I'm no longer scared to fly just above the ground. I finished equal fouteenth in the concours delegance. I was in the sixth group of ten pilots, I watched the others fly and decided that most of them were flying too high and too fast to be successful. When my turn came I flew in low and slow, hit a balsa stick, then my propeller hit the ground breaking off the tip and stopping the engine. Teach me to use a 13" prop, I may have got away with it if I'd fittede a 12 incher. I was credited ten points for hitting the stick and another ten for a landing. Competitive flying was curtailed until my model was recovered then I went back to the pits to change the propeller. I changed the prop but the impact must have weakened the glue joint between the firewall and the fuselage causing the joint to fail. I had not brought any epoxy or clamps with me so I was out of the competition. Later on Trish started to feel unwell in the 38C heat (100F) so I made my apologies to the organisers and we went back to the apartment. I finished fourth from last. My worst performance ever! I could not even be there to give out the fourstroke prize which was won by my chief rival, Christophe Pierre who prefers a tortoise-like approach to the event compared with my faster flying style. Nil desperandum, there's always next year! Talking of next year, the event will be held at Jonnage next year which is seventy miles closer to my home but the site is less spectacularly pretty. We will hire an air-conditioned motor caravan and buy a pair of folding chairs and a gazebo too! Pictures to follow.
  12. Off to La Coupe Des Barons tomorrow with Miss Blue Eyes. Not looking forward to the six hour drive and I will be flying my Reserve Baron in the British colours which is not so stable as the other one because I reduced the dihedral in an effort to make it more responsive! I should have known better! You cannot relax for a second when flying it. When the wing parted from the Ukrainian Baron owing to an overstressed glue joint, the subsequent crash after the fuselage had described a perfect parabola to land 100 metres away, damaged the fuselage, the landing gear, the elevator, the fin and rudder, the servo output arms and even the engine! That part of the casing which secures the carburetter to the inlet pipe had broken but I was able to epoxy it in place. Trish gave me permission to repair the model and I've done quite a bit of it but yesterday lunchtime I gave up. Too much to do in a limited time, besides I felt that I was neglecting Trish, so Bertie Baron it is for the competition! While making a few last minute adjustments, I detected a dodgy elevator servo. This was replaced by a larger Hitec digital metal geared servo which required some open heart surgery. All is well. No time for a test flight with the new servo but I'll give you a full report on the event when I return.
  13. I have always tuned my engines by ear but I have read that best practise is to use a "rev counter," if that's what they're called, especially on four-strokes. Given that this is the case, which rev counter would you recommend?
  14. Some engines require a bit of running in Danny.
  15. Wot Ron said! Danny, your Saito is a high quality engine with a reputation for reliability. Ok, the exhaust is non-standard but that is not usually an issue with four-strokes in my experience. With two-strokes on the other hand, they are so simple that everything needs to be pretty well spot on before they'll go. I have seen two-stroke engiines fail to start because the glow plug was the wrong heat range or because the fuel was old or otherwise unsuitable. A change of plug and fuel and away they went.
  16. Unsurprisingly Danny, I am the comlete polar opposite to you, I never take pictures of my models until they have had their maiden flight! Taking the picture before the model has flown will surely bring bad luck!
  17. Outstanding work Danny, mine will be nothing like so well-built and finished as yours. I admire your skill, dedication and persistance, three qualities which I do not possess in sufficient quantity to produce a model to this standard. If I were capable of building to this standard, I would be scared to fly it!
  18. At least my dog seems to be interested in helping me to repair it!
  19. Unfortunately while practising for La Coupe's Pylon Race, a forward glue joint failed forcing the wing upwards and ripping out the glue joint where the nylon bolts hold the trailing edge to the fuselage. The wing fluttered down with the wind and the fuselage described a perfect parabola to land 100 metres away from the wing in another wheat field! The model was four years old, a veteran of the 2018 Coupe Des Barons and it had had lots of flights. I will be going back to England for a week on Friday to visit my sister who has pancreatic cancer. It's her birthday on 2nd June so I will not be entering La Coupe Des Baron with the Ukrainian model this year. There isn't the time to repair it. Fortunately my Reserve Baron, piloted by Pilot Officer Bertie Bear RNAS, is seviceable. It's not as easy to fly as the No. 1 Baron because I've reduced the dihedral but I won the four-stroke class with it last year so should be able to do so again! Pictures below.
  20. I plan to power my DSM Aerostar with an OS 61SF. I usually use Hitec HS11s in sports models. Will they be adequate for this model or would you recommend something stronger?
  21. They were excellent trainers weren't they Steve? I wish they were still making them.
  22. We had a smaller version powered by an old Laser at our fly-in which was held yesterday.
  23. I had a DSM Smart Move and a Super Delotel in the past and an Aerostar awaits it's turn to be renovated in the cellar. They were wonderful flyers. I hope that someone starts to produce them again.
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