Dad_flyer Posted February 20, 2021 Share Posted February 20, 2021 I started this as a quick build in Jan. It was prompted by something on the forum but I now don't remember what. It is a bit of a mash of a couple of designs from the FliteTest forums, and the various versions on Outerzone. Overall size is the 62" Jensen version, but with the squared tail of the Ultra Stick. All in Hobbycraft foamboard, 4s electric, about 3lb 12. I made a symmetrical wing with no dihedral. Because of the way I made it the leading edge is quite sharp. In general a sharp leading edge is not a good idea, but what bad things do I need to watch out for in flight? Similarly I am now doubting my decision to have no dihedral. How are Stiks with flat wings? I need to just fly it, but obviously just now... Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 20, 2021 Share Posted February 20, 2021 (edited) Hi @Dad_flyer A flat wing stik flies fine. I built the Jensen 62" with a flat wing no problem. I have a HK Crusader stik again a flat wing and again no problem. When I was researching the Stik I went right back to Phil Kraft's, design and build article, and I believe his original was a flat wing. I think Jensen introduced the dihedral probably to appeal to those wanting a trainer. I have an old 1990? 50" stik with veneered foam wings with dihedral weighs 6.5 pounds and also flies like it is on rails. I am a fan of the stik to the point I bought a VQ Giant Stick and Saito FG21 to go in it just before the first lockdown so it has not flown but yes it has a flat wing, Now thinking about it the only stik with a dihedral was the Jensen which is why I thought hmm he is trying to appeal to the trainer market, for which it was ideal. My 62" weight 5.5 pounds and power is a 3548 900kv on 4000mAh 4S with a 12x6 prop. What power set up are you using? Edited February 20, 2021 by EarlyBird spelling 1 Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 20, 2021 Author Share Posted February 20, 2021 Thank you Earlybird. All the 3548s I was looking at were out of stock. I have fitted a 4-Max 4240 890kv, which is rated at relatively low current. Probably on 11x6, but I have not tested on a full battery yet. Everything is at storage charge. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 20, 2021 Share Posted February 20, 2021 When you say tested do you mean with a watt meter? Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 20, 2021 Author Share Posted February 20, 2021 Yes, with a wattmeter, not in flight ☹️ Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 20, 2021 Share Posted February 20, 2021 Sorry I was not suggesting you would be flying. I was wondering what ground testing you would be doing and assumed it would be with a watt meter. That motor is rated at 540 watts and I was wondering what watts you measured purely as a comparison. Just out of interest... anyway you made me laugh ? 1 Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 20, 2021 Author Share Posted February 20, 2021 At storage 4s (15V) For 10x6 I had 414W at 9000rpm from wooden MAS and 346W at 9900rpm for a composite JXF. For 11x6 JXF it was 409W at 9200rpm. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted February 20, 2021 Share Posted February 20, 2021 2 hours ago, Dad_flyer said: I started this as a quick build in Jan. It was prompted by something on the forum but I now don't remember what. It is a bit of a mash of a couple of designs from the FliteTest forums, and the various versions on Outerzone. Overall size is the 62" Jensen version, but with the squared tail of the Ultra Stick. All in Hobbycraft foamboard, 4s electric, about 3lb 12. I made a symmetrical wing with no dihedral. Because of the way I made it the leading edge is quite sharp. In general a sharp leading edge is not a good idea, but what bad things do I need to watch out for in flight? Similarly I am now doubting my decision to have no dihedral. How are Stiks with flat wings? I need to just fly it, but obviously just now... That is quite sharp. It'll be ok right up the the point where it stalls, at which point it very suddenly will fall out the air. Be prepared. 1 1 Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 The worst time for that to happen is when you flare as you come in to land. ? Thanks @Nigel Rthat could explain why I keep ripping the undercarriage out of the Jensen Stik, the leading edge is quite sharp as the design uses 1/4" at 45 degrees. I must check this out before we get flying again. Interesting. Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 21, 2021 Author Share Posted February 21, 2021 Hmm, I don't like the sound of that. Keep it fast then. If Toolstation open before we are let out to fly I shall build another wing. I need more spray paint and masking tape. For the leading edge I prepared it in the same way as for a flat-bottomed wing which does need an edge. It should be quick and easy to make it rounder. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 Yes keep the speed up on landing, fly it in. When I built it I had not learned that, as my trainer was a Riot, now I know better. What is interesting is that I could not understand why it fell out of the sky when a couple of feet above ground, so I parked it up. Now I have renewed enthusiasm for flying it. Sometimes answers come from unexpected directions. ? Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 21, 2021 Share Posted February 21, 2021 14 hours ago, Dad_flyer said: I started this as a quick build in Jan. It was prompted by something on the forum but I now don't remember what. It is a bit of a mash of a couple of designs from the FliteTest forums, and the various versions on Outerzone. Overall size is the 62" Jensen version, but with the squared tail of the Ultra Stick. All in Hobbycraft foamboard, 4s electric, about 3lb 12. I made a symmetrical wing with no dihedral. Because of the way I made it the leading edge is quite sharp. In general a sharp leading edge is not a good idea, but what bad things do I need to watch out for in flight? Similarly I am now doubting my decision to have no dihedral. How are Stiks with flat wings? I need to just fly it, but obviously just now... I built a Liddle Stik from a free plan I downloaded in the first lockdown with no dihedral and it flies well. Mines a bit smaller (1.2metre? - can't remember offhand) on 3S. It does have a more conventional l/e with a built-up wing so I don't have that sharp l/e like yours. I'd be inclined to try and blunt it somehow. Perhaps insert another length of foam board just behind the l/e and trim it back with balsa or foam to get a more conventional shape? Just a thought. Geoff Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 14 hours ago, EarlyBird said: Hi @Dad_flyer A flat wing stik flies fine. I built the Jensen 62" with a flat wing no problem. I have a HK Crusader stik again a flat wing and again no problem. When I was researching the Stik I went right back to Phil Kraft's, design and build article, and I believe his original was a flat wing. I think Jensen introduced the dihedral probably to appeal to those wanting a trainer. I have an old 1990? 50" stik with veneered foam wings with dihedral weighs 6.5 pounds and also flies like it is on rails. I am a fan of the stik to the point I bought a VQ Giant Stick and Saito FG21 to go in it just before the first lockdown so it has not flown but yes it has a flat wing, Now thinking about it the only stik with a dihedral was the Jensen which is why I thought hmm he is trying to appeal to the trainer market, for which it was ideal. My 62" weight 5.5 pounds and power is a 3548 900kv on 4000mAh 4S with a 12x6 prop. What power set up are you using? I thought I had missed one from my list. How could I forget that one ... it's an age thing! ? Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 21, 2021 Author Share Posted February 21, 2021 (edited) @Geoff S I might be able to blunt the existing one, the trouble would be fixing something all the way down the 62" l.e. With foamboard building a new one is very quick, but painting it takes a while longer. Edited February 21, 2021 by Dad_flyer Quote Link to comment Share on other sites More sharing options...
kc Posted February 21, 2021 Share Posted February 21, 2021 (edited) The leading edge determines how the model flies, blunt LE gives a gentle stall and doesn't allow the model to pick up speed in a dive. The RCM Ugly Stik plan from 1985 clearly shows the 3/8 balsa LE well rounded off, while the Jensen plan also has 3/8 and is slightly rounded off in the drawing. Both on Outerzone if you want to see. The model won't fly like an Ugly Stik with that pointed LE and might be vicious. I suggest slicing off the LE and gluing a balsa one that can be rounded. Or on a new wing try kerfing the inside edge of the foam board so that it can be formed right around in one piece. ( kerfing = multiple cut through the inside surface but not the outer surface. Sometimes the cuts are filled with epoxy after bending ) Edited February 21, 2021 by kc link Quote Link to comment Share on other sites More sharing options...
kc Posted February 21, 2021 Share Posted February 21, 2021 As an alternative to kerfing you could consider making a Kline Fogelman airfoil from several layers of foamboard to approximate the Ugly Stik shape. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 21, 2021 Share Posted February 21, 2021 (edited) Just had a look at my Liddle Stik ribs and they have a fairly sharp edge because the l/e is a length of 6mm (1/4") square. However, I'm almost sure I rounded it off before covering. I also adjusted the bottom main spar to be parallel with the upper so that the spar web sheeting fitted better. You can just about see the l/e profile in this view: Flies great and was just a bit of a quick build fun. I really must try building with foam board. I also have a Paper Aviation Ezee Pezee which I bought part built at a Nats swap meet and that's mostly foam board, but the wings are an open structure with foam board ribs and covered with film like a balsa one. Geoff Edited February 21, 2021 by Geoff S 2 Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 21, 2021 Author Share Posted February 21, 2021 Ok, I actually think I can cut the existing leading edge to a much better shape. Will it be good enough, what do we mean by rounded or not sharp? This wing is about 13" chord and 1.5" thick. Is 1/4" round at the front of a pointy shape rounded, or is it still 'sharp'? Or 3/8" to 1/2"? Does it make it even better to be close to a 1.5" semicircle? Is it something that scales with wing thickness, or is it more an absolute? Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 21, 2021 Share Posted February 21, 2021 Looking at my l/e above, it's not very rounded and works OK so perhaps a minor rounding is all you need? Geoff Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 From the Jensen Plan The L/E is 3/8 square and not very rounded. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 21, 2021 Share Posted February 21, 2021 In fact very like my smaller one. Hardly surprising, I suppose. Geoff Quote Link to comment Share on other sites More sharing options...
kc Posted February 21, 2021 Share Posted February 21, 2021 That's really just a cross section to show construction, there may be something in the instructions about rounding. I would round any square LE anyway. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 21, 2021 Share Posted February 21, 2021 It does show a little rounding but, I agree, rounding the l/e is preferable, even essential. Geoff Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted February 25, 2021 Author Share Posted February 25, 2021 Looking at the different plans then judging by the size of the square leading edge, I need about 3/8" rounding on the 62" version. (The little one would be 1/4" and the giant 1/2"). I can do that without rebuilding the wing. It will need the leading edge repainted, so I got out in the sun today for a couple of pictures before I ruin it. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 25, 2021 Share Posted February 25, 2021 (edited) Nice ? looks neat. Edited February 25, 2021 by EarlyBird spelling Quote Link to comment Share on other sites More sharing options...
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