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Philip Barrett 2

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Everything posted by Philip Barrett 2

  1. When I converted my Ben Buckle Junior 60 plan to electric I lengthened the nose to reduce the amount of lead in the front to achieve the necessary c of g. The nose is now six inches in front of the wing leading edge. Hope this helps.
  2. Finally flew the Hunter this morning, launched using a doubled 4mm bungee of around 20 feet long. Having been used to flying the Jet Provost, the Hunter is in a different league. It is seriously quick, and looks fantastic. The only change for the next flight will be a reduction of the aileron throws, as it was just a bit too twitchy especially on full power. Full credit to Tony, this is a marvellous model.
  3. I flew my Jet Provost successfully for the first time yesterday. I had previously tried hand launches, but with no success. For the record the model weighed 760 g and I was getting 440g of thrust on 3 cells. The game changer was the use of a Graupner bungee cord doubled up, with a static length of around 20 feet. I screwed a tow hook on the C of G position to the hand hold block in front of the cheat hole. This had been enlarged as previously discussed. With a good pull before release and full power the JP climbed out strongly, pitching up slightly before the tow line disengaged. It then continued to climb out, and looked fantastic. So the message is don’t give up, a good bungee will sort it !
  4. Build the inner panel flat to the board, and as you suggest pack the trailing edge of the outer panel by the half inch at the tip. The best way to do this is to cut a wedge from balsa strip the length of the outer panel trailing edge, half an inch thick at the tip tapering to zero at the root of the outer panel. Pin this under the outer panel trailing edge as you assemble the outer panel, with its leading edge pinned flat to the board. Hope this helps !
  5. I built the Playboy Senior a couple of years ago. I changed the wing to allow flat inner sections which then allowed the wing to be split in two halves, using brass tubes araldited in the first couple of bays and carbon fibre rods to make the join. I modified the wing fixing to allow wing bolts rather than rubber bands. Mine was also electric. I lengthened the nose and used an EFlite 25 motor with a 2700 mah battery on 3 cells. I still needed a fair amount of lead to get the correct centre of gravity, so in retrospect I could have increased the nose length even more. I can confirm the Ben Buckle kit was excellent,with good quality materials and clear plans. The finished model flew really well, with a great presence given its size. I used Solartex (alas no more!) for a vintage look. In summary, an excellent kit leading to a great build with an impressive end product.
  6. I finished the Phoenix Models Chipmunk last year and managed a few flights before the rains came and our strip became unusable. I added a few more details including fairing the undercarriage legs and including a landing light on one of the legs. It was a great build which I fully enjoyed. More importantly it flew really well on the recommended Overland motor and 3 cell 2200 mah pack. On a maiden flight I would normally take this gently, but this time I felt confident to explore the aerobatic potential. Like the full size it performed really well. Fully recommended !
  7. I can understand why an EDF unit installed gives significantly less thrust than on the bench, given it has to breathe through nacelles and cheat holes. However, I can’t understand why running a parallel thrust tube gives such a better thrust than the slight taper used by Tony in the Jet Provost. Can any contributor out there explain this???
  8. Adrian, before taking any drastic measures have you tried increasing the size of the cheat hole on the underneath. I got around a 100g of extra thrust by increasing the size of the cheat hole to around 25 sq cm. It now is 4.5cm deep and 5.5 cm wide. Worth a try!
  9. This may be due to the throws being reversed. Try moving the stick to the right and see if the cursor goes to the left.
  10. Apologies if you have already seen this but I put it on the wrong thread initially ! Two pictures of my Junior 18 indoor model. This is a 30% scaled down Ben Buckle Junior 60, largely 2mm depron but with a wing from 4mm depron. This gave me the opportunity to carve an wing section section using a Permagrit block. The power train, receiver and servos came out of an old ParkZone T28 that had received one too many mid air collisions ! Hope you like it.
  11. Two pictures of my Junior 18 indoor model. This is a 30% scaled down Ben Buckle Junior 60, largely 2mm depron but with a wing from 4mm depron. This gave me the opportunity to carve an wing section section using a Permagrit block. The power train, receiver and servos came out of an old ParkZone T28 that had received one too many mid air collisions ! Hope you like it.
  12. Just thinking again about Martin’s comment about the feature on Tony’s Concorde in front of the fan unit, the original Concorde had an elaborate system of movable intake ramps in front of the Olympus engines to slow the incoming air to subsonic speed so the engines could handle the air flow. I suspect Tony was partly replicating this for scale effect.
  13. I have built the Jet Provost and the flap does not feature on that design. I was able to locate the battery partly under the wing so achieved the specified balance point without the need for any ballast.
  14. I think the pictures show the hatch generated by cutting the cheat hole before it is extracted and discarded. As you say nothing on the plan, and as shown would obstruct the cheat hole.
  15. I have checked the build photos posted by Tony and can’t see anything near the fan I haven’t built into the model .
  16. Yes that is the correct site. Given how long the business has ceased manufacture I was surprised how much Solarfilm was available in terms of colours. Unfortunately this is not true of Solartex, my favourite for scale models.
  17. I should have mentioned that the covering material is light yellow Solarfilm sourced from the website where the old stock is still being sold. The cockpit canopy is trimmed with Solartrim, an exact match to the Solarfilm. This removed the risk of melting the canopy as no heat iron was needed.
  18. I thought I would share my experience in building the Hawker Hunter by Tony Nijhuis. I have just completed it, having got off to an early start before Christmas by ordering the plan, CNC wood pack and canopy from Tony before the publication date in RCM&E. I would really recommend the wood pack. Some of the fuselage formers, particularly the one securing the tail pipe, are both complex and delicate and would not be easy to cut from 3mm liteply. I have finished it in the same yellow scheme Tony used, hoping to get the same benefit in terms of visibility in flight. The only change I made from the plan was to fit a battery hatch on the underneath to facilitate access for the battery. Using an Overlander 3S 2200 pack it slides happily under the wing, allowing it to be located to give the correct balance point without the need for any ballast. I made a floor to the battery compartment from hard 3mm balsa, gluing it at the junction of the vertical fuselage sides and the sloping sides. The battery is secured with Velcro, and is restrained from moving forward by a balsa wedge from triangular stock. I was very impressed with Tony`s design. It is easy to build and gives a very representative finished shape. My version has come out at 21 ounces with battery, which is a testament to both the design and the wood selection in the pack. If our patch ever dries out I will let you know how it flies! T
  19. I would recommend Overlander Batteries available on line. This is a UK company that assembles its own packs. They may not be the very cheapest but the quality is consistently good and the service is excellent. All my batteries ( around 15) are all Overlader. They also offer different C ratings, depending on whether you need them for general sports flying or all out power.
  20. I have had the same problem trying to get my Jet Provost away with a hand launch. This puzzled me, as the weight was around 26 ounces only. Admittedly on all occasions the breeze was very gentle. I decided to take the fan unit, a FMS 50, out of the model and test it. I was only getting around 330 g of thrust installed, against the 600 promised. Out of the model and in a test rig I got 620g, so what was happening in the model? I decided it had to be a breathing problem. I increased the size of the cheat hole on the underneath to a maximum by taking it to the wing trailing edge, then tried it with the top hatch off. Amazingly, was now getting around 480g of thrust. As it spoiled the look of the model I drilled 12 holes in the top hatch and opened them up top 12mm diameter with a Dremel coned grinding stone. Checked the thrust again, now got around 430g. It feels totally different now, and I am sure it will get away whenever our patch dries out. Worth a try if you are struggling!
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