Engine Doctor Posted May 5, 2022 Share Posted May 5, 2022 14 hours ago, MikeQ said: Hi yes, Balsa is unbelievable. I have a decent stash but am loathed to use it. I could eat the price but it’s getting hold of decent quality stuff for whatever you do pay. I’ve asked this question before and it’s kind of gone round the doors but, where would you get 8’x4’ x4” sheets (or as close to that size) of foam for cutting wings these days. Used to be able to get single sheets from the LocalModelShop but that was 20 years ago. I like built up wings but foam can be useful. Used my last little piece a year or two ago to cut a 1980s Obelix slope soarer flying wing if any of you remember that far back. Hi try contacting Saimaxx building supplies they list 8 x4 sheets 100 thick at £29.50 each . They should be able to give you local stockist . They list it as EPS70. Quote Link to comment Share on other sites More sharing options...
kc Posted May 5, 2022 Share Posted May 5, 2022 (edited) Veneer has become expensive so check the price locally before you buy the foam! Normally one needs 1 pound per cu foot weight foam and obeche veneer for model plane wings. Other veneers may well suit as the weight is not much different but the cost and size available may be the deciding factor. Some foam wings were only partially veneered - LE and TE, centre section plus capstrips - rather like a built up wing. Saves cost and weight. Found on Avicraft kits of the past, like Moronic etc. Edited May 5, 2022 by kc Quote Link to comment Share on other sites More sharing options...
kc Posted May 5, 2022 Share Posted May 5, 2022 (edited) There is a more economical way of cutting balsa wing ribs which is applicable to larger models really but might be worth considering - Mini Waste wings and further details are here. Edited May 5, 2022 by kc Quote Link to comment Share on other sites More sharing options...
Nigel R Posted May 5, 2022 Share Posted May 5, 2022 kc, that's impressively minimal use of material, but way too much effort for me! As stated above, I'm mostly sold on hobbycraft foamboard for ribs, wherever possible, it costs peanuts and is easy to cut to shape. One drawback, it is quite thick at 5mm, so tapered wings need a light touch with a long sanding block to get things fitting nicely. Can be easily reinforced with liteply riblets for e.g. UC mounts or wing dowels or whatever. The biggest material cost in wings is the sheeting, anyway. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted May 5, 2022 Share Posted May 5, 2022 I notice obeche veneer is either unobtainable in large sheets or is expensive. For covering foam wings I have used 1000 grade lining type wall paper and pound shop PVA. The only wood required is a trailing edge to mount ailerons. An advantage of doing it this way as opposed to using a latex contact cement is that there is "slip" between the core and the covering before the glue sets so it doesn't accidentally become twisted. Quote Link to comment Share on other sites More sharing options...
kc Posted May 5, 2022 Share Posted May 5, 2022 Do you use a balsa LE Andy? And do you paper right over the TE? Presumably glassfibre on the centre section as normal? Anyone planning to collect a big sheet of foam - it would be best to plan in advance how it should be cut to maximise it's use. Unless you have huge estate car or van that can take an 8 by 4 ft sheet! Take a handsaw and ruler. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted May 5, 2022 Share Posted May 5, 2022 KC, All the ones I have done so far have had the leading foam edge wrapped around. I have tried various methods for the centre section from glass to epoxy with more lining paper. Lining paper method does pull tight on to the foam as it shrinks when it dries out so it can leave a pattern of the foam granules on the outside this shouldn't be problem with pink or blue foam. Quote Link to comment Share on other sites More sharing options...
MikeQ Posted May 5, 2022 Author Share Posted May 5, 2022 Hi Used to use Obechii but the swapped to balsa for veneering cores. I’ve had success with light/medium 3/32 straight grained balsa applied with PVA. Especially if glassing. On the subject of glassing. Try Peel Ply. It really takes the pain out of it. I’ll be going built up wing on this build but will check out the foam supplier mentioned. cheers mike Quote Link to comment Share on other sites More sharing options...
Tom Flynn 1 Posted May 5, 2022 Share Posted May 5, 2022 Thank you Steve, I’m building an old Cat 25 by Henry Wilks at the moment. So I know what’s next. just need to arrange the 2nd mortgage so I can buy the wood. thanks again. Tom Quote Link to comment Share on other sites More sharing options...
kc Posted May 5, 2022 Share Posted May 5, 2022 I think you mean Harry Gilkes Cat25. Quote Link to comment Share on other sites More sharing options...
Tom Flynn 1 Posted May 5, 2022 Share Posted May 5, 2022 Yes that’s the guy. I have built all of his Cat series. Some several times, like this one. This time I’m making it from my large box of odds and sods left over from other projects. so far I have only bought 4 x 1/16 sheets to do the wings. I have joined a few half sheets together, but I’m getting there. Only the rudder to make. Quote Link to comment Share on other sites More sharing options...
MikeQ Posted June 20, 2023 Author Share Posted June 20, 2023 Hello thought I’d knock this Chilli Breeze out just before getting really started on two glider projects. I’m attempting to speed build it 🤣. The pipe is 50g heavier than the silencer but I figure that can be compensated for by its weight being closer to the CG, stretching the fuse 1” at rear, using micro/mini servos as opposed to S148s like back in the day. Separate servos in each foam wing and fixed UC. Should still come out lighter than the first one I had which had an Irvine 40 squeezed up front and that was a heavy motor. Tail feathers 90% sorted. I like to cut sheet sides out slightly (say 1/8 to 3/16”) bigger all round and leave for a couple of days to settle as they sometimes ‘move’ once the stresses are released, then cut out final shape. i went lazy and had the wings cut as a father’s day present. Will use closed loop rudder with elevator servo mounted at rear of fuse. Was thinking Savox 255MG all round but might not be robust even though they have the performance. 2 Quote Link to comment Share on other sites More sharing options...
MikeQ Posted June 25, 2023 Author Share Posted June 25, 2023 Hello bit more progress. Going with HS85MGs in wings and Hs225MGs on rudder and elevators as other have recently. made the fuse a tad wider just to get the engine mount in there with a little more clearance. mike 3 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted June 25, 2023 Share Posted June 25, 2023 Nice - I like your servo choice. 😎👍 Quote Link to comment Share on other sites More sharing options...
MikeQ Posted June 30, 2023 Author Share Posted June 30, 2023 One for the electric flight experts. I have a new 2S 500mAh Lipo and a new 3A UBEC lying around doing nothing. The servos above aren’t rated for 2S 7.4v. Gut feeling on whether the 3A UBEC would have the juice to power the HS85MG/HS225MG above? cheers mike Quote Link to comment Share on other sites More sharing options...
MikeQ Posted June 30, 2023 Author Share Posted June 30, 2023 (edited) As per usual, as soon as you ask something you find more details yourself. https://www.4-max.co.uk/servo-hitec-HS-225MG.html https://www.4-max.co.uk/servo-hitec-HS-85MG.html i’m thinking with the stall current listed, even if servos weren’t stressed anywhere near that far the 3A UBEC might be a bit low rated? mike PS Now I’m thinking I’m being a tightwad for the sake of a 800mAH NimH 😂 Edited June 30, 2023 by MikeQ Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 1, 2023 Author Share Posted July 1, 2023 (edited) Hello Decided to go with servos above, except will have a Spektrum A5040 servo mounted in rear fuselage on elevator with an 800mAh 6v Nimh which isn’t much heavier than the 2S 500mAh/UBEC I was thinking of. will use a Ripmax plastic or JP Ali spinner depending how it balances out. If anyone has a black 2” Goldberg spinner (I had same same on my original Chillis and I like the shape) they want to sell I might be interested 😀 Edited July 1, 2023 by MikeQ 1 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 2, 2023 Share Posted July 2, 2023 I think you'll be ok. If the servos are anywhere near stalled then you must likely have bigger problems. Make sure everything moves freely etc. Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 4, 2023 Author Share Posted July 4, 2023 It more progress. used 5mm depron as a crutch. Only an extra 3g but adds some stiffness for not a lot of weight. Going to need the weight at the rear end. The elevator servo is a bit clunky at the backend but again, will help with weight. Used a couple of 1/64 ply doublers on top of existing ones in tail area. Will add a small ‘ballast’ box too under the tail. 1 Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted July 4, 2023 Share Posted July 4, 2023 Work of art! Love it 😀 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 4, 2023 Share Posted July 4, 2023 Progressing nicely. Also, a nice neat building area! Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 7, 2023 Author Share Posted July 7, 2023 Hopefully finish the fuse apart from cowl today. Off work so might go flying too 😀 side thrust looks too much but is bang on 2.5degrees with a shim. mike 1 Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 7, 2023 Author Share Posted July 7, 2023 (edited) Getting there Edited July 7, 2023 by MikeQ 2 Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 11, 2023 Author Share Posted July 11, 2023 Hello bit more work to do on cowl/motor and tail end and should be ready to cover. Unimaginatively going for the exact eye burning scheme I used on my previous two Chillis. fluro and sunglasses all round. mike 2 Quote Link to comment Share on other sites More sharing options...
MikeQ Posted July 22, 2023 Author Share Posted July 22, 2023 The great cover up under way, mike 1 Quote Link to comment Share on other sites More sharing options...
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