Radge Posted September 10, 2012 Share Posted September 10, 2012 After the succesful maiden flights of my high wing cabin jobber and mini stick yesterday. I decided to crack on with my low winger today. The drawings Sizing up the electrics, my target weight is 3lbs (ish) so I'm going to try it with my 3548 kv900 driving a 13 x 8 E prop through a 60amp ESC using a 3s 2235 25c battery. This combination has produced 445 watts constant on my test rig so I have do a bit to play with. I built the basic wings a while back, just got to join and sheet them now. I intend using 15g servo's. Fuselage sides and all formers cut. I had photo copied my former drawings and pritt stuck them to the 1/8" ply and balsa, I don't have a scroll saw so I mount my jig saw upside down in my workmate and feed the wood in to it. This is me playing with the formers to size them up for the doubler panels. I normally use PVA and CA for building but I've bought in Delux Materials Aliphatic glue for this one. Is this a good choice and can I use it for the ply formers or shoulg I use epoxy? Quote Link to comment Share on other sites More sharing options...
bouncebounce crunch Posted September 10, 2012 Share Posted September 10, 2012 Looks interesting Radge hope she is a good flyer, well I only use epoxy on critical joints(wing spars,engine bulkheads,fin/rudder posts,) pva and balsa cement( my favourite -must be the smell and dries quickly.) are used mostly and I have cut back on the Ca glue. You've done a good job cutting out the parts and the plans don't look to shabby either. good luck. bbc. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 10, 2012 Share Posted September 10, 2012 Deluxe Aliphatic resin is just about the best you can get. Some time ago I did some tests on various glues, gluing hardwood togther and balsa to hard wood. In every case the wood broke, not the glue so there is not much point in using epoxy unless you want to. The aliphatic resin is stronger than the plywood so you could use the strongest glue in the world and the wood will STILL be the part that breaks. Quote Link to comment Share on other sites More sharing options...
Radge Posted September 10, 2012 Author Share Posted September 10, 2012 Thank you so very much, that certainly justifies the expence of the aliphatic resin(Scottish you see, "You'll no be having a sale?" I'd use wall paper paste if I thought I could get away with it). G'day BBC, the plans ARE shabby, can't you see the coffee stains mate? Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted September 10, 2012 Share Posted September 10, 2012 What's the wingspan by the way? Looks like it'll be a nice one! I am currently in the process of drawing up plans for a low winger, about 40-45" span for a 30 four stroke. Fuselage drawn, need to get on! CS Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted September 10, 2012 Share Posted September 10, 2012 Nice one Radge, I like it. Another positive for Aliphatic is that you can sand it much easier, and it will not leave any rubbery type strands as other glues tend to do. Cheers Quote Link to comment Share on other sites More sharing options...
Radge Posted September 10, 2012 Author Share Posted September 10, 2012 Thank you Fly boy3 thats great. Thanks CS, it's wingspan is 52" and assuming an AUW(all up weight) of 3lbs the wing loading will be 20 oz per sq ft with cubic loading of 13 oz per cu ft and a rough stalling speed of about 20mph which to be fair is the same stall speed of my high winger which has 17 oz per sq ft with a larger wing area of 416 sq ins. Very happy with that!(however it's like going to fat fighters, "And how much do you weigh this week?" Quote Link to comment Share on other sites More sharing options...
Radge Posted September 11, 2012 Author Share Posted September 11, 2012 Perpendicular formers and doublers glued in. I had intended to plank the upper front cowl with 1/8", would wet & bend be a better idea? Any feedback would be gratefully appreciated. Thank you. Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted September 11, 2012 Share Posted September 11, 2012 Nice! Just out of interest, why is the 3rd former bck angled forwards? Instrument panel perhaps? CS Quote Link to comment Share on other sites More sharing options...
Radge Posted September 11, 2012 Author Share Posted September 11, 2012 That's right CS, I'm going to mount the low voltage alarm and digital cell voltage read out there so I can check it at a glance. Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted September 11, 2012 Share Posted September 11, 2012 Don't know what they are, assume something to do with battery capacity! Looking nice! CS Quote Link to comment Share on other sites More sharing options...
Radge Posted September 12, 2012 Author Share Posted September 12, 2012 That's right CS, just in case I forget to start my timer and drain the lipo's too low. Can't do any more to the fuselage until I line up the wings and cut out and make up the captive nut mounting plate which is attached to the rear of wing former. So the dihedral brace is in and the wings are joined. Former with captive nut plate and servo tray. It's around about this time when I wish I'd bought an ARTF or a CNC kit so that when things don't line up it's someone elses fault! Edited By Radge on 12/09/2012 23:05:56 Quote Link to comment Share on other sites More sharing options...
Radge Posted September 13, 2012 Author Share Posted September 13, 2012 Fuselage and wings lined up and all relevant measurements taken. Another little job done, the landing gear. Note all my copper wire comes from this old motor. If I need more I'll have to buy another washing machine Quote Link to comment Share on other sites More sharing options...
kc Posted September 13, 2012 Share Posted September 13, 2012 Have you joined bits onto the end of the u/c? Why? Is it soldered or glued? Surely you need to remove the lacquer from the copper wire to solder it? Even good soldering is hardly likely to stop the end part rotating in a slightly heavy landing (in my opinion.) Quote Link to comment Share on other sites More sharing options...
Radge Posted September 13, 2012 Author Share Posted September 13, 2012 The garden staples I used weren't quite long enough for prop clearance so I added the extensions with copper wire and epoxy. This is done on a recommedation from a recent build article if you don't have decent soldering kit. Do you think this will not do KC? If not I'll invest in some wire. Radge Edited By Radge on 13/09/2012 19:03:17 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 13, 2012 Share Posted September 13, 2012 I am sorry but that is never going to hold. You only have to look at what a relatively gentle landing will do to 8SW piano wire. The landing bends it back but it takes all ones strength to haul it back to its previous shape. Invest is some piano wire and bend it all in one. Quote Link to comment Share on other sites More sharing options...
kc Posted September 13, 2012 Share Posted September 13, 2012 I agree with Peter - even a 3 pound model can bend 8SWG piano wire in a slightly poor landing. Bending 8SWG needs a proper bender for that many bends.( you need both sides the same ) As shown your u/c looks rather like a Peter Miller style u/c to be sewn to the former and cannot be removed . Personally I prefer the Boddington style seperate u/c leg for each side this crosses the fus outside which forms the torsion bar and then goes up vertical into ply plates on fus side.. This is slightly easier to make and can be removed for maintainence. I did once bend 10SWG piano using just a vice and hammer but never again! Try asking other club members if you dont want to buy a bender. ( don't even think about using heat to bend piano wire! ) Edited By kc on 13/09/2012 19:49:04 Quote Link to comment Share on other sites More sharing options...
Radge Posted September 13, 2012 Author Share Posted September 13, 2012 Thank you Peter and KC Great stuff! I've found some 11swg piano wire and bent it as a one piece and shaped a plug for the 'pants'. I'll now put that to one side and cut and bend another as a 2 piece Boddington style. Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted September 13, 2012 Share Posted September 13, 2012 Radge, An excellent build thread - well done! Look eminently publishable to me....... tim Quote Link to comment Share on other sites More sharing options...
Radge Posted September 13, 2012 Author Share Posted September 13, 2012 Thank you Tim Shucks. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 14, 2012 Share Posted September 14, 2012 Posted by kc on 13/09/2012 19:47:08: I agree with Peter - even a 3 pound model can bend 8SWG piano wire in a slightly poor landing. Bending 8SWG needs a proper bender for that many bends.( you need both sides the same ) As shown your u/c looks rather like a Peter Miller style u/c to be sewn to the former and cannot be removed . Personally I prefer the Boddington style seperate u/c leg for each side this crosses the fus outside which forms the torsion bar and then goes up vertical into ply plates on fus side.. This is slightly easier to make and can be removed for maintainence. I did once bend 10SWG piano using just a vice and hammer but never again! Try asking other club members if you dont want to buy a bender. ( don't even think about using heat to bend piano wire! ) Edited By kc on 13/09/2012 19:49:04 The only U/C that I have sewn on like this one is in Sandow or on scale subjects that do not allow the prong type. Most of mine are of the Boddington set up. Quote Link to comment Share on other sites More sharing options...
kc Posted September 14, 2012 Share Posted September 14, 2012 Sorry Peter, there is some misunderstanding! I was referring to the u/c shown on your plans for Lil Mustang, Miss Lizzy, Trivial Pursuit, etc as the 'Miller' style sewn on u/c because they are all sewn on to the former. While your Harmony, Harlequin, Swizzle Stick, Sonerai etc use what I referred to as Boddington style because he often used it too. Personally I prefer not to use the sewn on type because the u/c is in the way during construction and covering. Also it cannot be removed for long term model storage or reuse on another model. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted September 14, 2012 Share Posted September 14, 2012 Yes, you are right and know my designs better than I do. Trivial Pursuit is a pretty old and pretty small design, Miss Lizzy is Trivial Pursuit but bigger. Not sure why I used it on Lil Mustang. I do prefer the Boddington system as it allow the U/C to be added after covering and to remove it for straightening. The Boddington system is rather heavier for small models. Quote Link to comment Share on other sites More sharing options...
Radge Posted September 19, 2012 Author Share Posted September 19, 2012 I've been mulling over the undercarriage question on this model and have decided to go down another route entirely, I'm building moulds and will be laying down bidirectional carbon cloth and glass fibre to produce unique carbon landing gear for this model. I'll post photo's when I start the process. Thnak you for your wise input Peter and KC, much appreciated. Quote Link to comment Share on other sites More sharing options...
Radge Posted September 19, 2012 Author Share Posted September 19, 2012 Thank. Quote Link to comment Share on other sites More sharing options...
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