David Hardaker Posted May 12, 2015 Share Posted May 12, 2015 A pair of Hitec HS82's would do nicely. Good resolution and small enough to hide in the wing. That's my 10 penn'orth ! Keep going.... Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted May 12, 2015 Author Share Posted May 12, 2015 The response on this thread is fantastic, thank you very much! This is becoming the model flying forum designed aeroplane, which is great! It will be a better aeroplane thanks to your help which I am grateful for. I use Hitec servos and until recently they have never gone wrong. Oddly one got really hot and burnt out when ground testing the radio which I assume was just a unique manufacturing defect. I still trust the servos, 99% of them work perfectly. It's worth noting that cost is also a factor. The wood that I am using is the lightest stuff I can find in the shed! That's partially why I chose a foam wing. I will have enough servos from unused aeroplanes to build this one if I use one aileron servo. I also have a spare set of aileron torque rods. When I cut the wing I will look into both options. With two servos I would do what Simon recommends (thanks!). Even if I did need to replace them it would be easy to put a brown paper patch on afterwards. I would use HS82's, nice and light, thanks David. I'll try and get a bit more done tomorrow when I am back from school, perhaps the fin frame. CS Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 13, 2015 Share Posted May 13, 2015 Just as an interesting fact about the wing shape. The Cosmic Wind air racers used the straight leading edge as per the Edge wing. The late, great Neil Williams flew Cosmic Wind G-ARUL in aerobatic competitions very successfully. Cosmic Wind has an even more pronounced taper and uses what are in effect strip ailerons/ Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted May 13, 2015 Share Posted May 13, 2015 CS, If you are worried about weakening the wing with the holes for the servos (I would) then why not make a cut along the top of the wing along the span to a depth of, say 8mm and push an 8mm x .5mm strip of carbon fibre into the slot you created. Then run some (foam Friendly) thin cyano along the top to wick into the slot/carbon strip. If you do this top and bottom of the wing to create some carbon spars you will be amazed how stiff the wing will become. It is quick to do too and much stronger than just relying on the brown paper. Just my 2p worth, Piers Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted May 13, 2015 Author Share Posted May 13, 2015 Peter, I didn't realise that about the Cosmic Wind, thank you. Piers, thanks for the input. A central servo is still my favoured option. Been a bit ill today so I cheered myself by constructing the fin frame! The vertical pieces are over-cut; to be trimmed down afterwards. I really like these framed structures, but they will soon be sheeted over! The elevator and rudder are open structure (with diagonals of course) which will look nice when the sun shines through the covering. I will cut the holes for the hinges before sheeting so they go into the blocks I have put in. I designed those bits! How satisfying. CS Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 14, 2015 Share Posted May 14, 2015 Just a suggestion for the future. If you take the cross members right to the uprights you can then use the hinge blocks as gussets to reinforce the joints in the corners AS you did on the outermost hinge block on the tail plane. Not important here because you are sheeting the parts Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted May 23, 2015 Author Share Posted May 23, 2015 I found some time and sheeted the fin and tailplane (after cutting slots for the hinges). Now they are very rigid and light, which is what we want! They have not been sanded down yet so that is why you can see some overhang with the sheeting. This next picture shows the thickness. They are considerably thicker than normal sheet surfaces which I like, a bit of drag is useful for slowing down and it is not designed for speed. Need some wood now! CS Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted May 24, 2015 Share Posted May 24, 2015 CS Looking good. "they are very rigid and light" However it does rather depend on what you are comparing them too! Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted June 27, 2015 Author Share Posted June 27, 2015 Good evening! Exams are now finished so I have a lot of spare time till September! I will make progress on the Spitfire, but to get myself back into it I have done some more on this still un-named aeroplane. I have cut out the engine bulkhead and I built some of the formers. The fuselage is quite wide like the Edge/Extras of the full size world, which I think is to accommodate the horizontally opposed cylinder engines. For me it means lots of space for servos and all the other internals. Undercarriage, torque rods for ailerons, and a Galaxy P51 Mustang canopy. Why the P51 canopy? Well the back half will make an excellent canopy for this aeroplane. I bought the foam for the wings. I got quite a lot... That will allow for mistakes anyway! I need some wood of correct thickness before major construction of the fuselage can start, but I might do the wings first anyway. CS Quote Link to comment Share on other sites More sharing options...
cymaz Posted June 28, 2015 Share Posted June 28, 2015 Watching with interest..good so far. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted July 21, 2015 Share Posted July 21, 2015 I'm a bit late to this thread but most 1/12 scale combat models were (are?) built with blue or pink foam wings covered with a single layer of brown paper, doubled on the centre third and applied with diluted PVA. There was no spar or wing joiner whatsoever. This method has proved to be immensely strong - flat out flying and maximum rate turns (I set mine to just not flick out at a full throttle 90 degree bank / full elevator) never caused one to fail in my experience. The wings on the ones I designed were almost as thin as the regulations allowed (I aimed at 11% to give me a slight margin) and outboard servo cutouts didn't affect the wing integrity during "normal" flight - although some wings did crack there after mid-airs or other crashes! So I wouldn't be too concerned with the construction method you've suggested other than the use of the fibreglass bandage which (although tapered) might concentrate stresses a bit close to the centre... Edited By Martin Harris on 21/07/2015 01:16:29 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.