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Mike Chantler

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Everything posted by Mike Chantler

  1. We have a couple in the club, great light wind flyers, need a bit of ballast for anything more, i found the pin to keep the tailplane aligned needs a bit of reinforcement, enjoy your build 👍
  2. I second that! - Fusion is extremely powerful but rather confusing and frustrating to start with. I think it took me about a 18 months off and on to really get to grips with. Given time, I can now generate quite complex fuselage shapes for a 3D printer, but I suspect that the next time I use it I will have forgotten how I exactly did these! The key I think is not to be too ambitious at the beginning. Small things made out of simple rectangular blocks and cylinders such as servo trays etc are a good place to start. The other is to keep really good notes of all the tutorials that you visit and the tips that you pick up along the way! I've found it very useful and like the others would not go back 🙂
  3. Took it up the Sunday before last - and it was a bit like a bucking bronco, suspected CoG, had rough landing, broke front bolt and snapped rear fus. so could not experiment that day. Measured CoG when home, and some how or other it was 3mm further back than intended (duh 🤔 ) Thought I'd been pretty careful with setting it up as well 😮 Anyway, adjusted CG and up hill last Sunday and it seemed to fly very well, PW51 seems a lot more slippery, faster and tracks well. Well pleased 🙂 Somehow or other I managed to get the control horn holes too far forward (again, thought I'd been quite careful here!!) but I seem to have almost twice the amount of up as down!! Rolls are currently very non-axial, which I'm putting down to the tons of +ve differential, and I have a feeling that planks require a little -ve differential? Anyway - will get some programmable aileron and elevator differential added for next trip. Looking forward to getting that sorted and adding ballast 🙂
  4. Ready to go and with nose weight it's 1120g That's about 250g heavier than the laminating film version. That said, I normally fly the lam version with half ballast to give reasonable loops and rolls, so given that it's a lot cleaner it will be interesting to see how it flies 🙂 Hopefully we'll have wind on Sunday 🙂
  5. Impressive looking kit of parts 🙂 Will follow with interest 🙂
  6. Thank you for your interest 🙂 Programmed radio yesterday, so all I have to do is nose weight. Was going to do that today - but the Pentlands seem to be in the doldrums so will have to wait (hopefully) until next week. Interested to see how much heavier it will be than the version covered in laminating film.
  7. Soldered up cables and started putting it together 🙂
  8. Made up some linkages, had to replace the 105HV servos with 125WVs, as one of the 105s failed (eek) Drinking straws for servo runs worked well as the normally awkward twisted wiring just pushed through 🙂
  9. Had a bit of a disaster with the Montana Gold. Paint looks as if it dried before hitting the wing - result is a finish rough as 90 grit, and I'm not joking 😬 Didn't hep that I didn't have my reading specs on so didn't realise until I'd finnish - was just way over-confident given success on a previous model. Decided just to go with it as it's just a 'quick' slope model, hay ho ... 🙄 And a bit of a storey behind the wing bolts: used test part print of fus to align tap at correct angle, it's balsa so threads need toughened up with CA a 2,3 times, impatience got the better of me and I managed to retap before the hot CA had completely cured ... Wrecked tapped hole and tap 🙄 An insert nut saved the day, remembered to coat bolt with wax and epoxied inset in and it worked fine, phew! (and one side seems to be enough)
  10. Did 2 coats of light filler tinned to double cream with a bit of talc but no water Went on quickly, was a bit worried about all the bits in the mix - but sanded away quickly, sprayed with deep fill primer and sanded to what I thought was a nice finish 🙂 This went much faster than a PSS I did before, think it was applying the glass early in the process as this gives plenty of warning of potentially wrecking the surface by sanding through to the foam.
  11. There's a good description of using tissue over mylar here, and Mike Woodhouse wrote a very nice article in Silent Flight Jan/Feb 1997 🙂 George Stringwell also had an article published in Electic Flight International March/April 1996 that includes a section on mylar/tissue covering. As folk say above - it does produce a good tough and taught covering over open structures, probably lighter than anything else 🙂 (Materials from https://www.freeflightsupplies.net/index.php/products) He also sells 1oz/yd2 kevlar cloth which is great for hinges and light weight repairs 🙂
  12. Boob! I meant to note that some of the deep fill primer must have got through the 25g glass/WBP combo and started dissolving the foam EEK! Not so bad, and only in one place, so coverup was quick. BUT could of been a bit of a disaster, blush 😞 I think it was where I sprayed too much primer on an area with little filler - silly really, as I just wanted it to show high/low spots after sanding, and probably no need for the heavier deep fill at this stage 🤔
  13. Gave quick sand with 120 grit mesh - surprised at the coarseness of sandpaper that I could use. Sprayed with high-build primmer to find bumps and lows - there are lots!! Saned with 120 and coated in Feddy B's sauce filler mix: Hmmm... lots of specs of talc I think - must siv 50yr old talc first next time 🤔
  14. Added 50g/m2 glass to forward 4"-5" of wing, top and bottom with brushed over ultra-low viscosity epoxy: This may seem a little crazy to put 50g/m2 on top of 25g/m2, but my idea was that light glass + wbp would 'seal' the EPS voids, while not adding too much weight, while the heavier glass + resin would add a reasonable ding resistance (I just didn't fancy the idea of all that very fluid epoxy going into all the voids 😞 ) Rollered off excess with foam roller on toweling - this combo worked really well so will definitely do this next time 🙂 But had afterthought that I should of coated top of sevo boxes and esp. the screw heads in wax before covering in the glass 🤔
  15. Quick weight check: Weight of mk3 seems to have grown from original 860g to 927g. Only difference is I reprinted the fuselage in yellow - so suspect I forgot to set the fill to 0% for some of the components. Mk4 at 874g not bad, but I'm going to add more glass to improve ding resistance and may paint top of wing - this will likely move the CoG aft a bit so will need increased nose weight.
  16. Gave 2 quick coats of filler mix in places with big dings, covered top, bottom, elevons with 25g glass + one coat WBP. The very fragile glass cloth went on surprisingly easy - but not to be attempted late at night after a couple of pints (!) Now wish I had used the filler mix all over - as very easy and fast to put on smooth coating, and stops WBP soaking into EPS voids 😕
  17. Added elevons with 25g/m2 aramid hinges, circa 10mm top, and 18mm bottom. May be a bit ott, but I hate sellotape hinges gradually coming apart 😬 Aramid was from offcut of old material that I had sprayed with 77spray glue a couple of years ago + cheap transfer tape- made it much easier to handle. I'd been dreading it a bit but went on quite easily with just the right gap.
  18. Balsa template for dremeling out servo holes did not work well 😧 🤥. Just prepping with scapple much quicker and more accurate. Under and over servo linkages went in surprisingly easy 🙂as just dremmelled the channels and will cover with glass. Servos in with (yellow) drinking straws for leads 🙂
  19. Made up some servo boxes and did small mockup to see how an under/over linkage would work a while back - but including here to remind me as they worked ok but next time I'd be very tempted to 3D print the sevo housings (but keep the carbon tops and bottoms).
  20. Spent a while testing old servos. The cheaper wing servos seemed to have quite a lot of slop 😞 but I baulked at using the KSTs at £33 a pop for what is supposed to be a cheap model. The MKS are also quite pricy so went with the old bluebird 105s from a previous model (and am now feeling like scrooge!!)
  21. Thinnest aileron stock i could find was about 2mm too thick, microplaned it down which was a bit hairy as width of stock wider than micro-plane and it kept on skimming over the wood or digging in too much. And that was with a fresh blade. Then sanded to final shape. LE of aileron and TE of Elevon LE and wing sub-TE took an age with sanding bar. Next time I think I'll bag the whole wing and then cut the ailerons out!!
  22. Yes - if you have the stuff I'd keep it simple and go for analogue 🙂. I always have a tendency to overcomplicate and regret it! I found that the PU foam that they use for house insulation now (yellow stuff silvered on both sides) does not cut easily with a hot wire - it needed a lot more force when I tried it. I seem to remember that it has lots of little fibres in it which I think caused the problem so I stick to XPS and EPS. I find EPS a pain to carve or sand into new shapes - it's great for hot-wired shapes and it's nice and light. After a bit of experimentation with the swing arm setup, I found the easiest way for me was to cut separate top and bottom surface templates. This means that you don't need to turn the wing upside down for the lower cut. You do need to make sure they register well - and hence the 3 aligned registration holes and common bottom surfaces.
  23. I've experimented with a variety of foam building techniques for slope soarers, had some success and some disasters! You can build some really light, very stiff, veneered foam wings that can be the basis for floaty to quite fast slope machines and pss. Not as fast as carbon mouldies of course, but mouldies make me nervous most of the time(!) My first attempts were with a handheld hotwire bow but I got horrible ridges 😩, I think you need one person at each end of the bow for this to work. Then used the bow in swing arm system driven by a weight. If you use fishing line to pull each end of the hot wire then you can just use little screw hooks instead of little pulleys and t-track - works just as well. The main pain is cutting the templates. I use some thin electrical insulation sheet that you can cut with scissors and then file to final shape. Then I built a stepper motor system (plans and very good instructions from rcKeith). You really only want to do this if you like these sort of building/electronics projects - as the swing arm stem works fine, it's just a bit slower to setup. I've only been able to veneer wings using a vacuum bag, but other folk seem to manage with just weights - the problem with vac. bags is getting them to seal! I have used XPS but it's a bit more difficult to source and is heavier, however, for wing tips and things you want to carve and sand to shape it's great. (and don't use the PU insulation if you want to hot-wire it) I've experimented with 75 micron laminating film directly on top of hot-wired EPS and this works surprisingly well, but you need wood TEs and LEs. If you have a 3d printer then you can print the fuselage and produce a surprisingly light (and cheap!) slope machine (1.5m/800g) with the EPS/laminating film wing. (I have a build log on this in the Slope Soaring forum) Good luck 🙂
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