Simon Chaddock Posted January 18, 2009 Share Posted January 18, 2009 It seems to me that the powered version of the Hamilcar transport glider would make a good electric scale aircraft. 1. A pretty simple shape with plenty of wing area. 2. Relative to the size of the airframe the engines and scale props (2 bladers) are small and well clear of the ground. 3. Simple robust U/C with big wheels and skids as well under the fuselage. 4. Big flaps (two each side!) 5. Lots of space inside. The ultimate show stopper of course would be to carry a scale RC Tetrarch tank which would drive out of the front on landing. Amazingly this is exactly what the full size did. Once at rest the pilot activated a release valve which caused the oleo struts to collapse so the glider rested on its skids, the driver pulled a cord that released the tank tie downs and its initial movement both unlocked and swung open the nose door. Technically of course when carrying a Tetrarch you should have a Halifax towing it as well! Quote Link to comment Share on other sites More sharing options...
winchweight Posted January 18, 2009 Share Posted January 18, 2009 Very nice idea! I'd love to see it disgorge a tetrarch as well! As for the Halifax, if Tony N. designs it as the 2009 free plan, then we're laughing! Quote Link to comment Share on other sites More sharing options...
Chris C Posted January 19, 2009 Share Posted January 19, 2009 can't wait to see it :D Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 19, 2009 Author Share Posted January 19, 2009 I have begun drawing out the Hamilcar. I intend to use a 3 piece wing of just about 6 foot span. This means the centre section (and engines) can be permanently attached to the fuselage. I have found some interesting detail cutaways. Here is an example. I am not sure I will copy this construction exactly! It seems mind boggling that they went to all that trouble for what was likely to be a "one use" airframe! The wing centre section is certainly massive. With a chord of 12" and the scale RAF 34 section it is 1.5 inches deep at the main spar, allowing the possibility that everything (including the batteries) could go in the wing. My one concern is that with the scale 8" props it might end up with a real "scale" performance - the originals could only take off at minimum weight. It will have to be built light. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 20, 2009 Share Posted January 20, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 27, 2009 Author Share Posted January 27, 2009 Still musing over just how best to build the Hamilcar. I have the batteries (2x2200 3s LiPo) with 2x30amp ESC & 2xOutrunners on order with the servos still to get, but what to make it out of? The original was largely built out of commercial (not aircraft) quality timber so it could be said that foam is the model equivalent. So a 6ft Hamilcar built out of foam with the minimum of wood in it? Interesting! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 29, 2009 Author Share Posted January 29, 2009 During my research I found this film (with sound) of a couple of Hamilcar flypasts (towed by a Halifax), then landing and unloading a Bren carrier. You can tell it was all arranged because the glider pilot neatly turned the Hamilcar to face the camera! Note the oleos being deflated and the Bren carrier engine exhaust being ducted out of the bottom of the glider. Fascinating. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 29, 2009 Share Posted January 29, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Phil Claridge Posted January 29, 2009 Share Posted January 29, 2009 looks like they were the lock down fittings eric Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 30, 2009 Author Share Posted January 30, 2009 Yes, the first guy knocked his pin out with one blow but the second seemed to be hitting all over the place. Notice the break in the film because suddenly it is all released and the carrier is driving out! Quote Link to comment Share on other sites More sharing options...
Mowerman Posted January 30, 2009 Share Posted January 30, 2009 Fascinating film. The powered version should make a good model. Full size at Museum of Army flying, Middle Wallop, Near andover. Good luck. Quote Link to comment Share on other sites More sharing options...
Ernie Posted January 30, 2009 Share Posted January 30, 2009 GREAT STUFF Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 1, 2009 Author Share Posted February 1, 2009 Just a little further with the Hamilcar It looks like it will need no less than eight servos. 6 in the wings (4 for the flaps, 2 for the ailerons) and 2 in the fuselage for elevator and rudder. If I can keep it to 2 lbs all up (that's right - 2lbs!) it will have about 60 watts per lb, which should be adequate, but it will fly pretty slowly - a sort of big park flyer! Quote Link to comment Share on other sites More sharing options...
Malcolm Fisher Posted February 1, 2009 Share Posted February 1, 2009 Good piece of film. I wish ALL my landings were as gentle as that of the Hamilcar appeared to be Keep us posted with your progress Simon if you go ahead with it. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 2, 2009 Author Share Posted February 2, 2009 Malcolm I will go ahead with it - I have most of the hardware bits already but I am first going to convert my Wing Dragon to a 6 channel brushless twin with flaps and Hamilcar type u/c to get an idea of what's involved. Quote Link to comment Share on other sites More sharing options...
Malcolm Fisher Posted February 2, 2009 Share Posted February 2, 2009 Simon, Is that the Art Tech Wing Dragon? If so is it the 3 or 4 channel version and what do you think of it? I was looking at it as a possible aerial camera mount but can't decide if it would have the necessary power and lifting ability. I've also been told that the R/C gear which comes with it has a fairly limited range. E-mail me direct if you don't want to use this thread to "chat". Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 3, 2009 Author Share Posted February 3, 2009 Hi Malcom It is the Art Tech Wing Dragon 4 channel. I don't know what sort of camera you are considering but it can certainly lift a FlyCamOne see here. Note the cold got to the FlyCam battery after 3 mins in the air. I found the Wing Dragon excellent value for money, incredibly tough and quite aerobatic for a simple trainer. Flying from rough grass I removed the U/C and hand launch. I have now considerably modified it with a built up Depron wing and V tail (see Build Blog "Depron Wing") and a 3S 1500mAh LiPo instead of the original 1000mAh NiMH. The new wing has differential ailerons so the rudder servo became redundant. Still with a brushed 480 it is now 15% lighter, climbs at 45 degrees and can potter about for a good 20 mins. With two wing mounted out runners for the same total weight as the brushed 480 and even with 2 servos for the flaps I expect it will go nearly vertical although that is not really a capability required in a test bed for the Hamilcar layout! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 6, 2009 Author Share Posted February 6, 2009 Its all going rather slowly but I want to make sure the layout works before I commit to a large scale model so first flaps on the "depron" Wing Dragon. The first one simply cut out of the wing. Both flaps complete and re-fixed bottom hinged. Using 2x5g servos they will be set to go from 0 to 80 degrees to give a steep descent. If it works OK then put in a new ESC and add two wing mounted out runners. When that's all going work will start on the Hamilcar. Quote Link to comment Share on other sites More sharing options...
Chris C Posted February 9, 2009 Share Posted February 9, 2009 looks really good :D are you going to use one engine or two? iam pretty sure i saw a plan for a powered hamilcar somewhere in the traplet plan book Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 9, 2009 Author Share Posted February 9, 2009 Chris The object of converting the Wing Dragon is to get some experience building and flying a twin brush-less set up with flaps, as will be required on the Hamilcar, although on the Wing Dragon they will be pushers. For its size the original Hamilcar X was somewhat underpowered as the engines only were intended to fly it when empty. As my model will in effect always be flying loaded (with a heavy battery) it will rather unusually use slightly over scale props! Scale would be 8" diam, I will use 9x5 (I would like to use 10x3.8 but they are to big!) each driven by an Emax CF2822 that will be completely hidden inside the scale cowling. In fact if my calculations and building skills are OK it should end up with a most un-Hamilcar like take off performance! We shall see, but first I need to complete my "twin" Wing Dragon. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 15, 2009 Author Share Posted February 15, 2009 Just a bit further making flaps. The Wing Dragon is light and the flaps relatively small compared to the Hamilcar so each has just a 5g servo. The Hamilcar will use 4x9g. This shows the kink in the push rod required for maximum flap. A test flight or two to check it works OK then conversion to a twin. Quote Link to comment Share on other sites More sharing options...
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