A.A. Barry Posted May 3, 2015 Author Share Posted May 3, 2015 So the with the tail feathers "nail down", it is time to start and add the acorn to them, polyurathane foam used, the tiny end bits will be balsa. The lot will then be covered with some thin weave F/G and filled with epoxy, ( West Systems) Cheers Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 7, 2015 Author Share Posted May 7, 2015 So the acorn has been built, and in the first stage of finish. My orginonal idea was to vac mould the nacelles in 2 parts ( L and R/H sides) after applying the moulds with Wests epoxy and cloth, I got to thinking that the moulds are exactly what is required, without the internal structure, my thoughts now is to continue with the cloth and epoxy, because I have 1/8" outside form to make up for the planking, on the rest of the nacelle, love for anyone to have a comment on my idea??? The only drawback will be to build a second set of moulds....uummmm I suppose I could use the exsisting ones, if the first 1/2 works out Barry Edited By A.A. Barry on 07/05/2015 04:46:01 Edited By A.A. Barry on 07/05/2015 04:48:00 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 7, 2015 Share Posted May 7, 2015 Barry, why not? I appreciate that if it goes wrong you need to start again, but why should it? You'll most likely be successful and the finished result will be tougher than the vac moulded options. They'll be slightly heavier, but most of the extra weight will be forward of the cg, so no harm in that, is there? Referring back to earlier postings about the flaps, looking at your photos shows the way that the method of hinging connected to the nacelle means that do they slide back as they open, so they actually do increase the wing area, making them even more effective. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 7, 2015 Author Share Posted May 7, 2015 Thx Colin, I'mm still in 2 minds about it, I was almost going to give the idea away, until I read your comments, I like the idea of "vac forming" them, cleaner and quicker and all my work building one seems a shame not to use it. On the other side of the coin ( is the Queen),is the Vac forming might not be as a good fitting as a made up cowl,....might just sleep on it In the mean time pics of the tail wheel doors being built, the foam sits on 1/16 + 1/4" side rails, these are glued appox. 3/32" in from the outline, firstly to accept hinges and a slightly thicker edge to work with, at the moment waiting for the poly glue to set Barry Edited By A.A. Barry on 07/05/2015 11:06:05 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 7, 2015 Share Posted May 7, 2015 You will arrive at the best decision Barry. Tailwheel doors have been beyond me so far. Maybe I'll get there eventually. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 7, 2015 Author Share Posted May 7, 2015 Hopefully, this how it will work:- the tail wheel is a mechanical one driven by a Gold-n- rod and a servo, which will be "Y" connected to the electric U/C, the doors will be open and closed via 9g servos, this also connected via a seperate ch.(slave) and linked to the u/c ch 9 (master)the servos will go through a little device ( H/K ) delaying the operation....that's the A plan plan B will be just using a "paddle plate" to do the opening and closing Plan C is to use piano wire toque set to open, when the wheel retracts., it contacts a lever to pull the doors shut Barry Edited By A.A. Barry on 07/05/2015 11:51:14 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 7, 2015 Share Posted May 7, 2015 Wow. I bought a Robart retractable tailwheel unit years ago, never used it but still got it. I keep thinking I'll use it one day. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 7, 2015 Author Share Posted May 7, 2015 Yes Colin, that's the same one in my Fuz Barry Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 9, 2015 Author Share Posted May 9, 2015 So a vac box was built and all sealed to extract the most vacuum as possible, using the correct type plastic 2 mm sheet it was time to "give it a go". a gas torch was liberally heated the sheet, until it sagged, placed over the mould and ....here is the result So not to waste any more time and $$'s, the vac box will be made redundant the tail wheel retrieved and glass cloth added The nacelle 1/2 s where joined and another coat of F/G and epoxy laid, the nacelle looks OK Barry Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 10, 2015 Author Share Posted May 10, 2015 So So more epoxy added and the nacelle stripped of unwanted framing,mainly to fabricate a 2nd nacelle cowl, because the flap servo sits high, the firewall has to have a "roof" Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 10, 2015 Share Posted May 10, 2015 Getting there, looking good. I've dug the Welkin drawings out. I'll get them copied this week and hopefully posted by next weekend. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 10, 2015 Author Share Posted May 10, 2015 Thx Colin Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 14, 2015 Share Posted May 14, 2015 All being well Barry, these will be in the post to you today. The deviations from scale are:- the fuselage is slightly flattened at the sides to simplify the build and although the wing is scale thickness, I used a flat bottom section. That is because this is designed for hand launching and I wanted the low speed characteristics to be good. Also the full-size wasn't wildly aerobatic, so I didn't see this as a problem. However, altering the drawing to show a semi-symmetrical section wouldn't be too difficult and if I introduced retracts, I'd do that. There are 3 degrees of wash-out included. Scale is 1/12, 70" wing-span. Thinking was after proving this one, scale up to 1/8, 105" wing-span. The alteration I plan to make to mine is to use two Lipos and put one in each nacelle instead of the one in the fuselage, to get the cg right without adding ballast. For your interest. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 14, 2015 Author Share Posted May 14, 2015 They look super, thanks Colin, most graitfull Barry Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 14, 2015 Author Share Posted May 14, 2015 Colin what motors did you have in mind for it??? B Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 14, 2015 Share Posted May 14, 2015 Barry, I'm a way from the house until this evening. They are Axis, but I can't remember each one. When I get home I will check, also the ESCs and send you the details. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 14, 2015 Author Share Posted May 14, 2015 Cheers Colin, it was just for a reference to compare with this build, I'm putting ( at this stage) Aeolian 3648 790kv in it, rated at 780w each, might not be big enough, as ya can see there is stacks of room for changes if required Barry Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 14, 2015 Share Posted May 14, 2015 No problem, I'll let you know later. Your Whirlwind is bigger than this Welkin and will have more wing area, so you'll certainly need more go than that will. I've posted the drawings by the way, should be with you in a few days. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 14, 2015 Share Posted May 14, 2015 Barry, motors are Axi 2808/24 Goldline, 1190 Kv, maximum loading 22A, ESCs Castle Creations 35A. With hindsight, I might swap these for something more potent, a bit more weight up front would be useful anyway. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 17, 2015 Author Share Posted May 17, 2015 Ok now for the U/C doors, the same proceedure as the other mouldings, false nacelle framework, foam and epoxy resin, after the epoxy was spread over the cloth, I used some "cling wrap" to get an even surface...well sort off. Left to dry in front of the open fire place, not too close, mind ya Edited By A.A. Barry on 17/05/2015 11:24:53 Edited By A.A. Barry on 17/05/2015 11:25:47 Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 22, 2015 Author Share Posted May 22, 2015 Well after much laying of F/G and epoxy all the nacelles,U/C and tailwheel doors they are done, albiet sanding and painting ( later), so onto mounting the motors and Esc's, the firewall (F5) is a long way back, so a ply box was built and mm 15mm "stand-offs" where added to bring the prop out to the right place. The Esc's and motor will get freash air via a 40mm fan and duct's through the exhaust outlet covers. The 40mm fa will be mounted on the inside of the cowl, Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 22, 2015 Share Posted May 22, 2015 All very clever stuff Barry. Looks good. Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 23, 2015 Author Share Posted May 23, 2015 Just a quick one to show the outcome of the nacelle setup, the spinner backplate is only a guide for a built-up one Quote Link to comment Share on other sites More sharing options...
A.A. Barry Posted May 28, 2015 Author Share Posted May 28, 2015 I've been at it again.....epoxy...this time the 4 exhaust shrouds, fished result ...not too bad sorry the last pic should have been first Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 28, 2015 Share Posted May 28, 2015 That all looks excellent. How do you plan to build up the spinner? Quote Link to comment Share on other sites More sharing options...
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