Peter Jenkins Posted September 25, 2021 Share Posted September 25, 2021 I started at top wing rear bolts. It's perfectly safe therr but too far forward. I will be gradually moving the CG aft until I find a good compromise between stability and manoeuvrability. Quote Link to comment Share on other sites More sharing options...
cymaz Posted September 25, 2021 Author Share Posted September 25, 2021 Page 30 I mention that the cg is in the wrong place. I went by the plan but this turn out to be tail heavy. Very nearly brought it home in a bag. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 25, 2021 Share Posted September 25, 2021 Thanks, looks like the rear bolt is the place to be for the first flight and see where we go from there. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted September 25, 2021 Share Posted September 25, 2021 I said earlier that it is 1" forward of the upper wing TE. Never needed to change it. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted September 26, 2021 Share Posted September 26, 2021 Thanks Martin. I'll aim for that. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 26, 2021 Share Posted September 26, 2021 All assembled and balance checked tonight, on the rear top wing bolts it looks slightly nose down to me, these bolts are 2" from the trailing edge in the centre cut out, following Martin`s advice of 1" from the trailing edge it tilts nicely down at that point so unless anyone else wants to give their thoughts i think it is good to go with no lead added. I will be checking all the control rods as one of the aileron link rod ends is not secure, they are made up of carbon rod with metal pushed down the middle, what is the best way of gluing this in, epoxy or cyano? Many thanks for all your help guys, just waiting on the larger prop to be delivered and the wind to be favorable. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted September 26, 2021 Share Posted September 26, 2021 I use carbon tube, mainly on an elevator linkage, 2 or 3mm i/d depending on the rod but I do die a thread on first even if it is a bit shallow. JB Weld may be the best bet or maybe epoxy but do ensure that the carbon is roughened up a bit inside and out. I also use ca in conjunction with 3M 05917 polyolefin primer which allows you to ca almost anything to anything else, even polythene to itself. CA by itself does not adhere to carbon so don`t try it. A short length of brass tube over the carbon and filled with glue is belt and braces. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 27, 2021 Share Posted September 27, 2021 Forgot to mention, flying weight is 16.4 lbs, is that about average for one of these? Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted September 27, 2021 Share Posted September 27, 2021 Mine's just under 15.4 lb (7 kg) with tanks full - 14 oz tank. I think you should be fine with your weight albeit it's a dry weight. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 27, 2021 Share Posted September 27, 2021 That is the flying weight Peter with 2 x 3700mah lipo packs in parallel, no lead needed to balance it. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted September 27, 2021 Share Posted September 27, 2021 Ah, I'd forgotten it was electric. Well, that's only 1 lb more than mine and that floated quite a bit on landing. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 29, 2021 Share Posted September 29, 2021 (edited) Ran the motor up this morning on with the Watt meter on it and the larger 20x12 Turnigy wood prop, got the desired results, it is now putting out 1360 watts at 59 amps, that is 83 watts per lbs which is a good bit more than it needs but gives plenty in hand for a get out of jail card! Motor is a Turnigy Aerodrive 5065 280kv and a Turnigy 70A ESC, Batteries are 2x 3700mah 6s Zippy compacts in parallel. No lead needed to balance it on the upper wing rear bolts. Just waiting on the weather to test fly now. This Stampe has a castoring tail wheel, never been a fan of those myself, what have others got, i was thinking of trying to link it to the rudder is some way to give it better steering. Here are some pictures of the motor mount\battery compartment i made up, notice the re purposed door slide bolt for keeping the hatch shut, the velcro flap then goes over it to make sure the bolt can`t turn and slide out. It shouldn`t do as it is a nice tight fit into the hole in the fuselage but it gives me peace of mind! Edited September 29, 2021 by martin collins 1 Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted September 29, 2021 Share Posted September 29, 2021 Martin, the Stampe I bought also had a fully castoring tailwheel. I used some 20 g wire to form a "tiller arm" and soldered it to the the vertical part of tailwheel wire (having bound it with fuse wire). I then bent the wire to the shape of the fin and drilled an appropriate size hole into the TE and glued the end of the wire into place. It has survived 3 flights so far all with cross wind take offs. It makes taxying it a darn sight easier than having a castoring tail wheel. I fly off tarmac so that doesn't help with a fully castoring tail wheel. Most pictures of full size Stampes appear to show tail wheel steering. Interestingly, I used that motor in a 2 mtr Loaded Dice FS airframe with a 10S pack and in that form it dragged the LD around in fine form. The max power is quoted at 2 kW so plenty of room to grow if you feel you need more power for larger vertical manoeuvres. Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 29, 2021 Share Posted September 29, 2021 Thanks Peter, yes i am at the lower end of the motors capabilities, plenty of room in the battery box if i decided to go to 8 or 10s, gone with the 6 paralleled as i think it will have enough for this plane as is but give me extended flight times or two shorter flights from the one `pack`. Once i have the maiden flight out of the way i will remove the tail wheel and modify it as you suggest. Quote Link to comment Share on other sites More sharing options...
William Macleod Posted October 1, 2021 Share Posted October 1, 2021 Anyone flying with a ngh 38 four stroke petrol? Thanks Bill Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 1, 2021 Share Posted October 1, 2021 Unless things have changed recently on these then do not touch one with a barge pole. The cams on the one I had wore away after less than two tanks of fuel and I got a no quibble refund. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 1, 2021 Share Posted October 1, 2021 My experience of the breed is that they are noisy, messy and underpowered but I have heard of others who tell different stories. Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 1, 2021 Share Posted October 1, 2021 I had a look at Martin's engine and discovered the nuked cam. I recently had a crack at tuning a clubmates example and found it rather lacking in refinement. It was like driving a 1980's ford escort vs a modern ford focus. They both do sort of the same job but one is much more comfortable than the other! It wasnt super powerful, shook like crazy and was pretty sharp on the exhaust. Certainly any 180 4 stroke glow would thrash it performance wise. I was not really that impressed by it. I think the 30cc version is better but i have never seen one turning and burning. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 1, 2021 Share Posted October 1, 2021 Mine was 2000 rpm down on the quoted figure on the smallest suggested prop, and that was with no silencer, so draw your own conclusions. All NGH motors I have seen at my club inexplicably seem to stop at take off. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 1, 2021 Share Posted October 1, 2021 Seen a couple, bit noisy, less power than others, longevity, who knows. NGH 2 strokes, numerous at ours, all no bother, not as powerful as some but do the job and reliable so far, and no surprise....a bit noisy on stock exhaust. Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 2, 2021 Author Share Posted October 2, 2021 Wouldn’t touch one based on feedback. Whatever happened to Mintor Engines, reliability issues and seizures. If you want a four stroke petrol I should spend the extra dosh Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 2, 2021 Share Posted October 2, 2021 I would still stick to 4 stroke glow to be honest. The cost is much lower than equivalent petrol, and this will subsidise your fuel cost for about 8 years. The fuel consumption and oil splatter is not a major problem with 4 strokes if they are tuned correctly and run on the right fuel. They are also easier to install, lighter, cool better...Admittedly 180 4 strokes are in short supply these days but still, there are plenty available 2nd hand. Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 2, 2021 Author Share Posted October 2, 2021 Jon would see you right for a four stroke ? Quote Link to comment Share on other sites More sharing options...
William Macleod Posted October 2, 2021 Share Posted October 2, 2021 Thanks for the feedback. Was looking for another petrol 4 stroke so I could finally give up glow and just run on aspen petrol. Any ideas ( sensible) welcome. Ideally 20 to 30cc Bill Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 2, 2021 Author Share Posted October 2, 2021 This might suit https://www.morrisminimotors.com/saito-fg-30b-gas-petrol-single-cylinder-4-stroke-engine.html Quote Link to comment Share on other sites More sharing options...
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