David Gilder Posted March 10, 2013 Share Posted March 10, 2013 I have to ask Phil.. On the above picture, Do you know what the purpose of the 4 grilled parts under the wing tip? Not seen them on any other aircraft.. Well, not in the wing tips anyway!! Cheers. Looking good. Dave Quote Link to comment Share on other sites More sharing options...
A10FLYR Posted March 10, 2013 Share Posted March 10, 2013 Some type of counter measures like chaff I believe. I'll have a look at my publications later today to confirm. Quote Link to comment Share on other sites More sharing options...
Fly_Boy_Rez Posted March 10, 2013 Share Posted March 10, 2013 ALE-40 Chaff and Flare Dispensers I think... Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 10, 2013 Author Share Posted March 10, 2013 Hi Dave yes they are ALE-40 chaff and flare dispenser units, they have them fitted under each wingtip and on other parts of the airframe underside too, including the rear fairing of the wheel pod... I may model them simply - but no flares on my PSS model - Im not sure the warden on the Great Orme would like that!! Quote Link to comment Share on other sites More sharing options...
David Gilder Posted March 10, 2013 Share Posted March 10, 2013 Makes sense now!! I agree that flares may be frowned upon, but what about foil paper chaff being released !! It would make for amazing pics!! Dave Chaff dept!! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 10, 2013 Share Posted March 10, 2013 Posted by Phil Cooke on 10/03/2013 16:46:14: Hi Dave yes they are ALE-40 chaff and flare dispenser units, they have them fitted under each wingtip and on other parts of the airframe underside too, including the rear fairing of the wheel pod... I may model them simply - but no flares on my PSS model - Im not sure the warden on the Great Orme would like that!! I know she wouldnt ! Great stuff as ever Phil. Quote Link to comment Share on other sites More sharing options...
Fly_Boy_Rez Posted March 10, 2013 Share Posted March 10, 2013 Found your Maiden flight schedule for you Phil! Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted March 10, 2013 Share Posted March 10, 2013 Quality, and proper, building as always Phil. I look forward to a masterclass when you start those tips, some things can't be put off any longer.... Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 11, 2013 Author Share Posted March 11, 2013 Matt is right, some things can't be put off any longer... So the challenge is to make these tips from balsa with a ply trailing edge for robustness where it gets thin and curvy at the back - these downturned tips wont last the first landing without a bit of thought there... They also need to house the 2 wingtip lights and enable cable runout into the main wing panel. Edited By Phil Cooke on 11/03/2013 22:34:37 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 17, 2013 Author Share Posted March 17, 2013 It's the round, thin Trailing Edges of the tips that's had me thinking this week which has resulted in a few nights of sketching ideas and performing assembly trials in the garage as opposed to actual building... The front 2/3rds of the tips have been constructed fairly conventionally with 1/2" hard balsa templates spaced at key positions with a soft balsa infill. The last 1/3rd Im planning to roll 1/32nd ply around 3 curved formers, the rearmost of which is more like a fish bone than a former(!) as such I've made this from 1/4" ply cutting carefully on the scrollsaw. First, a kit of parts. The formers are bench mounted square onto a 1/4" sub tip as I thought this would be easier to work up away from the wing for now... The hole in the sub tip and former 3 is for the wingtip strobe wiring. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 17, 2013 Author Share Posted March 17, 2013 The 4 1/2" hard balsa formers are glued square to the sub-tip... ...you get the idea... ..back on the bench, the gaps between the 1/2" formers are filled with soft balsa, using aliphatic resin to aid profile sanding later. Edited By Phil Cooke on 17/03/2013 18:45:26 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 24, 2013 Author Share Posted March 24, 2013 The 2 wingtips were built up using soft balsa sheet from the L/E to a point on the wing section where the suction surface curvature ends and the straight lines top and bottom converge towards the T/E. Once the balsa was rough sanded to shape, 3 further guide formers were glued to the sub tip and reinforced to allow 1/32" ply to be attached and rolled to form the final shape at the back. The sheeting was positioned and tacked to the formers with thin cyano, the joints were reinforced with PVA once it was held in position. A similar piece of 1/32" ply was rolled 'into' the concave section of the tip on the underside, at the extreme T/E the 2 mating pieces of 1/32" ply were bonded with a thick epoxy fillet giving me something robust to sand back into without making a hole (as the T/E is still to be trimmed to the wing plan profile and I wasnt sure at this stage of the exact angle) Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 24, 2013 Author Share Posted March 24, 2013 The finished wing tip ready to be fitted to the wing for final sanding... Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 24, 2013 Author Share Posted March 24, 2013 dry fitted to the wing. Once this tip assembly is epoxied back onto the wing it can be final sanded and blended smoothly and the final shape can be refined. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted March 24, 2013 Share Posted March 24, 2013 Impressive work there Phil! This must mean most of the big jobs on the wings are done? Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 24, 2013 Author Share Posted March 24, 2013 yeah - we are nearly there - the only bit of 'proper building' left to do on the wings is the installation of a tube in each root for the incidence bar, then its just hinging, servo installation and fitting the lighting, but all of those tasks will be done after the glassing of course... Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 31, 2013 Author Share Posted March 31, 2013 Decided to give myself a break from the final sanding of the wingtips and instead focus on completing all the flying surfaces. I'd decided quite recently to cover all the flying surfaces in Solartex as opposed to glassing them like the main structure - laziness more than anything as it will save me hours of sanding/filling/sanding/priming of the ailerons, elevators, flaps and rudders where the strength of glass cloth isn't needed. Anyway before the veneered foam surfaces could be covered I needed to consider the hardpoints for servo horns, and this saw me this afternoon spending an enjoyable hour or so assembling some carbon horns for the primary controls - the elevators and ailerons. The size of these surfaces has led me to the top end spec horns, using a ball connector and 3mm threaded rods. The flaps and rudders will use smaller horns which I'll cut from glass board. Twin horn arrangment for robustness - I'm taking no risk with the primary control connections on this one... these will now be let into plywood blocks fitted flush in the flying surface. A handed pair for the elevators and ailerons... Quote Link to comment Share on other sites More sharing options...
A10FLYR Posted March 31, 2013 Share Posted March 31, 2013 Very nice indeed! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 1, 2013 Author Share Posted April 1, 2013 1/4" plywood hardpoint/loadspreader cut with a slot to accept the carbon horn... Flush mounted in cavities cut in the veneered foam flying surfaces... The horn dry fitted - ready for some epoxy! Thats the Ailerons and Elevators now ready for covering! Quote Link to comment Share on other sites More sharing options...
chris basson Posted April 1, 2013 Share Posted April 1, 2013 Even the control horns on this beast are a work of art!.. This thread has kept me entertained at work since it started, I just have to get to one of the PSSA meets later in the year to see this in the flesh!! Nice one Phil! CB Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 2, 2013 Author Share Posted April 2, 2013 Thanks for that Chris, glad you are enjoying the thread... I look forward to seeing you at one of the PSSA events this year, although there is no guarantee the A-10 will be finished in time for a 2013 event appearance - its more likely to make its debut at the first event in 2014 I think having been test flown next Winter. Although the main components are now nearly all complete (only the rear fus left to contruct) there’s still loads of finishing and fitting out to do, and once the flying season is underway my build rate will inevitably suffer! Edited By Phil Cooke on 02/04/2013 09:52:55 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 3, 2013 Author Share Posted April 3, 2013 Last day off today having enjoyed an extended Easter break from work - finally the snow here in Derbyshire has all gone and the sun was shining(!) - there was even a breeze blowing up the street - that's PERFECT sanding weather!! I set the wings up on the joiner and clamped it firm to my workmate - in fact it was a bit too gusty, on more than one occasion I thought the A-10 wings might be getting their first flight - thankfully it all stayed on the ground and I was able to final sand the wingtips with the space outdoors to walk around them and view from all angles, ensuring we had a matching pair. Sanding the underside of the tips is a bit tricky as its all concave whilst still compliant with the aerofoil section - anyway these are done now and the wing is all but complete ready for glassing and finishing, only the incidence tube is yet to be set in the wing roots. I want to build the rear fuselage before that is put in, so I can best fit the tube axially. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted April 3, 2013 Share Posted April 3, 2013 That's a nice looking set of wings, it's gonna be big for sure p.s. car needs a wash Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 3, 2013 Author Share Posted April 3, 2013 Back to the ailerons as I realised they weren't quite ready for the covering as I'd written! Both are now pre-drilled and dry fitted with 4 x Robart knuckle hinges, the actuation horns are in and the characteristic Trailing Edge Trim Tab has been modelled (fixed in my case) in the 'aileron neutral' upper position. This serves no real purpose on the model - its merely a scale feature I wanted to capture as it's quite distinct on the full-size. A final sand and these are ready for covering now. Quote Link to comment Share on other sites More sharing options...
A10FLYR Posted April 3, 2013 Share Posted April 3, 2013 Phil, it does make a difference with the large surfaces. We had to do that on ours because we didn't have powerfull enough servos. Full scale has the inner, moveable one, (the one you show), as 35º up and the outer one fixed at 15º up when the aileron is in the neutral position. But then, we have much more powerfull servos now! Quote Link to comment Share on other sites More sharing options...
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