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David P Williams

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David P Williams last won the day on August 17 2021

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  1. I’m building a Wots Wot from the Chris Foss kit, not the ARTF. The top wing is designed to be held by rubber bands, which I would rather not do. The kit also contains an addendum to the instruction manual showing an optional bolted top wing arrangement, but I think it looks a bit crude and I would rather not have bolt heads protruding from the top surface of the wing. Has anyone devised a more elegant attachment method that they could share? Thanks, David
  2. My Saitos run fine on MT Laser5 - 5% nitro 15% oil. I’m sure they’ll run fine on the Optifuel equivalent when I need to buy some.
  3. When I worked at Spanhoe airfield we had a Gemini based there. It had been obtained in a part exchange deal and was on the Belgian register (OO-RLD I think). Lovely old aircraft, flew in it quite a few times. When I was 15, well against the run of form, I won the form prize at school, and the guest speaker at Speech Day who presented the prizes was Douglas Bader, so I got to shake the great man’s hand. Like many very successful men he was quite brusque and arrogant, not quite as portrayed by Kenneth More.
  4. Paul - grease will pick up dust and grit from your field and turn into grinding paste.
  5. Yes Dick, me too. Electronickery baffles me, I thought 555 were cigarettes years ago. Thanks for the input everyone. I’m as sure as I can be that there is no binding, they are wire legs and the wheels are not too heavy. The battery is buried under the fuel tank and if I change it to a four cell I’ll need to go upon the church roof again. So - I think I’ll stick with the five cell and either a second smaller 4.8v pack for the retracts (lose some lead!) or a diode in the retract feed. It’s a VQ ARTF and heavy and a bit naff generally, but I picked it up cheaply to use the 91fs I had lying around, so if I get a few flights out of it I’ll be happy.
  6. The servo is now out of the model, I’ve taken the bottom of the case off and had a good look around the wiring and circuit board and there’s no sign of burning anywhere. It is now totally unresponsive using a servo tester and regulated supply, both 5v and 6V. The replacement servo works fine with the tester.
  7. I've just put together an ARTF model using Savox 0351 servos with a Hitec HS75BB retract servo for the mechanical retracts. All of these are rated for 4.8V or 6V operation. I usually power model radio gear with a 2 cell LiFe with no problems but I needed a fair bit of weight up front so I decided to use a '6V' 5 cell sub-C NiMh pack. I did the bench setup with the pack as delivered which showed about 6.25V on my battery tester. All worked fine, the mechanical retracts worked perfectly with no binding at all. I charged the pack, noted it topped off at about 7.25V, and set off to the field for first flights. The model was transported wheels up, so when assembled I powered up and selected gear down - all OK. Range checks, engine setup, etc then first flight. A few circuits, trims sorted, so selected gear up. Flew by and saw the gear was still down. tried cycling to no effect so left selected down. When I came in to land the gear just collapsed, obviously not locked down. The retract servo was totally unresponsive. Back on the bench, checked all connections, still dead. Tried it on a 5V regulated supply, still dead. So - I guess I've cooked it. I have another HS75BB but I obviously need to do something about powering it differently before I fry that too. I know I can use a separate battery for the retracts (and I know it's good practice to do so) but would the trick of adding a diode in the retract power supply drop the 5 cell NiMh voltage enough to keep the servo happy? Maybe two diodes in series?
  8. But that’s not Weston though is it, tarmac and a control tower. Weston’s just a big park.
  9. Thanks for the prompt Chris - I remembered that I had found, years ago, somewhere in the depths of the internet, a copy of the DeHavilland Care and Service Manual for the DH89a. A quick rummage in my old desktop computer and I found the control movements for the full size aircraft. This may help, but of course full size doesn't always translate directly to model size.
  10. Hi James, I have the Jerry Bates plan and also the Martin Tuck plan at the same scale but no clues on either. Have you tried contacting Jerry himself via his website? Click here
  11. The article to which the OP refers (and I have just read) is about the possibility of mobile phones corrupting TX (and RX) software by electromagnetic swamping, and the OP was questioning how this relates, if at all, to WiFi updating of the TX.
  12. You would also be surprised how small the wing attachment bolts are on the full size -a couple of 1/4” diameter bolts for each wing half and the same for the struts IIRC.
  13. No pawls or ratchets, these are used a lot in model helicopters for autorotation freewheels.
  14. SLEC sell balsa in 48”, 1220mm lengths, I buy that. Four blades easy.
  15. I have the same two-stage flap settings as the full size - 15deg and 30deg - and they work just fine. No elevator compensation needed as Tim says. Good luck with the maiden, they do fly nicely.
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