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John Minchell

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Everything posted by John Minchell

  1. E.D. - I was trying to renovate one of the first ever foam models - a late 70's/80's Byron 1/3 scale Pitts S1. Sadly it has defeated me so far - you can't sand off the adhesive and colour left on the surface because the stringers and "sag" of the covering between ribs and stringers is replicated in the moulds and hence detail on the finished model. You can't use a hairdryer or heat gun to ease the removal of the solarfilm 'cause it melts the polystyrene. Parcel tape trick pull of lumps of the foam too. So only option left is fill the holes with lightweight filler and then skin it with glass cloth and then paint it - but that is a lot more weight. John M
  2. All the above pre-supposes that the underlying structure is wood (balsa or ply). How do you get the glue and colour residue off if the model is a foam one? Because you can't use heat or thinners? John M
  3. GPS satellite sensor generated data used to be used for speed telemetry in GPS Triangle glider racing. That is not accurate enough in competitions, so now a pitot tube / head is used for more accuracy. The GPS trace is used to plot the track on Google Maps. Correct me if I am wrong, but FlyinFlynn - if you are at 230m to 240 metres above your house, are you not breaking the 400ft rule (122m) for drone with camera? John M
  4. What a superb flying site you have there. Where is it please? John M
  5. I will endorse Dick's recommendation of the Kingmax servos. In all my larger (and faster) models than your Fly Fly DG and they are faultless so far (a few years). John M
  6. Well I always have discharged any cells I use or ones that are still fully charged and didn't use back to storage charge. Including the 150mAh 1s indoor cells. I have not had to throw away any battery for over a year now. However, since this cost of living crisis, I have been using the larger batteries 3,4,5 & 6 cells to charge up my phone, or tablet or laptop. Since I have already paid the utility company to charge the battery anyway why waste it on storage charging the battery back to 40% and still paying to top up the phone/etc from the mains. Works for me.
  7. OK all, Paul Bardoe bought up the rights to all the PFM kits a couple of years ago. I borrowed the NOS kit of the Zlin from Colin Leighfield (above) and Paul copied everything to re- start making the Zlin & some of the PFM kit range. The Zlin is now available from PB Models and he should have the plans and patterns for the Cranfield too. Get in touch and ask if you are still looking for plans.
  8. Sorry, but as an engineer and user of 3D printer, I would never make such a flight critical part as the elevator bell-crank out of anything which could be suspect. A local club's existence is potentially in the balance due to an elevator failure and crash into the farmer's garden. So personally I wouldn't make a bell-crank out of anything less than a sheet of G10 glass or carbon sheet - to ensure its mechanical strength and longevity. Also all the Micro Mold plastic bell-cranks I have in the spares box will remain in there now, as most of them are 20 to 40 years old and God (if there is one) only knows what the material degradation has been. Just my 2 pence worth. John M
  9. Peter, here is one option for B&B right next to the Sherlowe airfield ready for the next one in August. https://www.ercallmill.co.uk/ Regards John M
  10. Thanks Andy I'll keep an eye out next week.
  11. So when do we find out if last years record was exceeded or not? There's nothing on the BMFA website.
  12. As I have this engine in mind for a large scale powered glider project, are there any feathering props commercially available that are suitable and safe for IC engines on the market? Since the cowl shape precludes a folding prop and the obvious electric power option.
  13. I have a Saito 36cc petrol engine and considering the installation in a model by looking at the plan. Unfortunately in the inverted installation there is not enough space for the magnet pick up inside the cowling (now on the top of crankcase). Is it possible to substitute a different Hall sensor pick up for the magnet in the prop driver (much smaller & lower profile like the Rexcel one) and for it to work OK with the Saito ignition box? Saito is 18mm tall and wide and Rexcel is 7mm x 7mm and a DLE one is 8mm x 8mm. I'm not sure about compatibility. Anyone done it? Thanks in advance for any help.
  14. I just use Adblock Plus on all the browsers I use (Firefox, MSN and Chrome) and it stops 99% of all ads on forums etc. If I click on a post from FB or whatever and it asks me to disable the Ad blocker software, I just move onto another post or google the subject directly if its a news item I want to read. But works well for all the motorcycling, classic car and many modelling forums I am on.
  15. Hi Martyn you say there are 5 events in 2023 but there are only 4 listed under events on the UKCAA website
  16. Anybody know if the Brian Gaskin softbore hole punch tools are still available and if so where to get them from? Thanks John M
  17. I've done it in the past by putting the motor shaft in the chuck of a pillar drill (where I know the revs from the manufacturers info plate and gear ratio). Hold the motor body on its mounting in a machine vice (not the body of the motor though). Then measure across two of the wires the voltage, then repeat for the other 2 combinations of the 3 wires to get 3 readings. Average them out and do the maths to check on the Kv figure. You could also do this using a lathe. John M
  18. Thanks for all the comments chaps. Looked at continuous rotation servos and also just modifying a standard one. They rotate too slowly and winding in 30m of line would take a few minutes. We want to avoid all specially written software or extra electronics - so a low Kv outrunner controlled with a standard ESC and some time and amp spike sensors and limit switches should do the job. Still looking for a commercially available small cheap low Kv motor though. Don't want the extra complexity of gearboxes.
  19. Nope - an on board glider tug tow line winch drum to stop hooking the tow line on fences and hedges when landing. Wind the line in after the glider unhooks. Pay it out again after landing, when taxiing forwards to hook up the next glider.
  20. I've been donated an AXI 2217/20, 840 Kv motor to try out. So I'll make a test rig and do the measurements. Thanks for your suggestions. John M
  21. Pat not difficult for you maybe, but too much hassle for me. An easy off the shelf motor is what I am after. Also that makes it repeatable if anyone else wants a kit of parts to build one.
  22. Frank Skilbeck and I are collaborating on a little project. Anyone know of a small lightweight out-runner motor with a KV lower than 1000? We found the 4Max one at 1000 KV (https://www.4-max.co.uk/A2212-13T-1000kv.htm ) but ideally want about half that - 500KV. Low KV motors are available but the weight and size and cost go rapidly north. So about a 28mm dia can and around £20 would be ideal. TIA John M
  23. Ah never thought of gripping the bar in a vice and working the pipe in my hands. Will try it at the weekend. Thanks Mike.
  24. Mike, the crease is 165 mm along the taper from the open (inlet) end and dia from the exhaust header is 21mm. The dent at the exit end of the pipe is 46mm in from the rear end and its only 14mm dia. So can't get a curved mandrel in big enough or strong enough to do the job.
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