Ben-Erik Ness Posted November 11, 2020 Author Share Posted November 11, 2020 After quite a fee hours in the production hangar, another milestone has been reached, the airframe is now glassed. To allign up the tail, and to construct a solution to make it detachable took some time but now it's all in place. The fuse and tail is now glassed, ready for some sanding, and construction of 4 detacghable engine pods... Some photos of the process and result so far: It has a good size... Glassing... Quote Link to comment Share on other sites More sharing options...
Martian Posted November 11, 2020 Share Posted November 11, 2020 That's a really unusual want to build but wow it looks great Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted November 11, 2020 Author Share Posted November 11, 2020 Posted by Martian on 11/11/2020 20:28:50: That's a really unusual want to build but wow it looks great I'd like to disagree - hotwire cutting foam and covering it with balsa or other wood is a method as old as the hills... But it works and has done so for along time! Quote Link to comment Share on other sites More sharing options...
Mike Chantler Posted November 11, 2020 Share Posted November 11, 2020 Lovely build, fuselage and wing saddle look great. Simple carbon reinforcement really appealing. But how did you get the white foam carved so well? When I've tried it, the white EPS beads go everywhere and ruin the surface. Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted November 12, 2020 Author Share Posted November 12, 2020 Posted by Mike Chantler on 11/11/2020 23:27:14: Lovely build, fuselage and wing saddle look great. Simple carbon reinforcement really appealing. But how did you get the white foam carved so well? When I've tried it, the white EPS beads go everywhere and ruin the surface. Thanks! I use a very very sharp fishknife, with a long blade that gives me the ability to "shave" off small thin peices at the time... https://www.marttiini.fi/Condor-Filleting-Knife23 Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted January 29, 2021 Author Share Posted January 29, 2021 Hello there! Christmas and a hectic december is over and we are still in "stay home mode" The project is now slowly movinf forward. Before X-mas I used way too many hours figuring out how to make the 4 engine pods. I did find a solution that can be incorporated with the huge flaps, but I have decided to put them aside and focus on the plane itself. To put the pressure on mysel I had this caps specially made! Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted January 29, 2021 Author Share Posted January 29, 2021 So this is the status post: Fuselage and wings etc has been primed and given a light sand I have now cut loose the big flap, and the ailerons and midle flap has been cut and are moving on the built in mylar hinge The elevator is also cut so it moves on the mylar hinge line built into the wing Next... Well, I would like to continue with radio and servo installation. Hope to get the garrage heated to a level that allows me to start spraying the fuselage. Some photos! Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted January 30, 2021 Share Posted January 30, 2021 There are a number of things that we come across in our hobby that stand out for me Ben, and your project includes quite a few of those. Big beautiful aircraft, big beautiful propellers Long nacelles And spraying. I will spray anything from 1/76 scale to 1/5th. You realise that temperature is important and I can t wait for the weather to warm up again. For me, I never spray below 10°C but prefer 15° and above. Indoors, I work on 1/76 to keep my interest, but in summer anything goes, as I can work outdoors. Keep up the good work Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted February 3, 2021 Author Share Posted February 3, 2021 I'm in my Hangar working, mounting flaps, mounting servos, programming my radio etc... Slowly getting there! So while I do a lot of the time consuming nitty gritty, you guys can enjoy this old video of a Dash-8 from New Zeeland in 2010 PSS Fest - Dave's Dash 8 from MawhrinSkell on Vimeo. Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted February 4, 2021 Author Share Posted February 4, 2021 Milestone! I have a wing with all surfaces moving in the right directions, at the same time. There is still many adjustments to be made, but you get the principle! I hope that these big flaps will slow it down in order to land it slowly in tight spaces... Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted February 10, 2021 Author Share Posted February 10, 2021 (edited) Another milestone! Everything hooked up, all servos and flying surfaces. And it works like I intended Video! However I'm debating with myself if the outer flaps should move with the ailerons like they do now, would it contribute to adverse yaw? Any comments? Edited February 10, 2021 by Ben-Erik Ness Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted February 20, 2021 Author Share Posted February 20, 2021 Rattle can time... Now it's time for all the imperfections to stand out! But I don't think you'll see them on the maiden video, so I'll just live fine with them and carry on making progress ? 2 Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 18, 2021 Author Share Posted March 18, 2021 Out of the paint shop! I hate rattle cans, I have never got the hang of it. So, it's far form perfect - but good enough! Before having my decals made by a mate (who runs a signshop) I usually test them fist, printed on paper, and attach them to the model. Pretty happy how it turned out. Next now is to get the decals cut, and in the meantimehook up all servos and connections again. The slope where I intend to maiden the Dash is still coverd in snow, so I got a few weeks before it can fly... Pretty happy with how it presents is self ? 4 Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 24, 2021 Author Share Posted March 24, 2021 Next challenge! Where do I place CG for maien flight? Any qualified answers will be appreciated. (In the end the decission is mine alone, and I'm the one to blame if everything goes down the drain on the maiden....) Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted March 25, 2021 Share Posted March 25, 2021 That is a great looking model Ben and I think it will look fabulous in the air. Regarding your comments about your flaperons and adverse yaw, differential aileron usually takes care of adverse yaw (I take it the wings have some wash-out built in). I don't think landing your model slowly in tight spaces will be a problem, with it's big wing and huge flaps. What I would say is drooping the ailerons with the flaps may provoke a tip stall which would be most unwelcome, especially close to the ground when landing, so personally I would not bother. In fact reflexing the ailerons, 'crow-braking' fashion, might help with accurate hilltop landings as well as giving you a measure of protection against a tip stall. The only downside being that it might not be very scale. Just my view. Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 25, 2021 Author Share Posted March 25, 2021 2 hours ago, Piers Bowlan said: That is a great looking model Ben and I think it will look fabulous in the air. Regarding your comments about your flaperons and adverse yaw, differential aileron usually takes care of adverse yaw (I take it the wings have some wash-out built in). I don't think landing your model slowly in tight spaces will be a problem, with it's big wing and huge flaps. What I would say is drooping the ailerons with the flaps may provoke a tip stall which would be most unwelcome, especially close to the ground when landing, so personally I would not bother. In fact reflexing the ailerons, 'crow-braking' fashion, might help with accurate hilltop landings as well as giving you a measure of protection against a tip stall. The only downside being that it might not be very scale. Just my view. Thanks for your input! There is some washout built into the wing yes, and I will mix ailerons up when landing, like a traditional butterfly setting we use on the 3m F3F gliders. I don't care too much about scale, that's why I don't have any undercarrage ? 1 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted March 26, 2021 Share Posted March 26, 2021 Not sure if this will help you with C of G thoughts - eCalc 1 Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 26, 2021 Share Posted March 26, 2021 (edited) Hi Ben-Erik, can you check the dimensions of your wing again please? It looks to have symmetrical taper but 70 mm (sweepback) 165 mm (tip chord) and 70 mm (sweep forward of the trailing edge) only adds up to 305 mm (should be the same as the root chord, 420 mm). I estimated the sweepback of the tailplane at 55 mm. Using the drawing as it is the calculated CG with stability margin is 171 mm aft of datum (AoD, wing root at leading edge). Assuming an untapered plank wing (420 mm chord at root and tip) the CG is 128 mm which I would expect to be the same for a symetrically tapered wing. Eppler 205 works very well at 38% (for optimum sailplane performance which might not be stable enough for a slope model). 38% of 420 (root chord) is 160 mm. Cheers Gary Edited March 26, 2021 by Gary Binnie Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 26, 2021 Author Share Posted March 26, 2021 20 minutes ago, Gary Binnie said: Hi Ben-Erik, can you check the dimensions of your wing again please? It looks to have symmetrical taper but 70 mm (sweepback) 165 mm (tip chord) and 70 mm (sweep forward of the trailing edge) only adds up to 305 mm (should be the same as the root chord, 420 mm). Very well observed, I think I have to go back and meassure on the wing and not the drawings. I have so many versions of drawings, and I think I might have used the wrong edition here... Back later this afternoon with updated and dependable meassurements.... Ben-Erik Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 26, 2021 Share Posted March 26, 2021 Cool. I use a mixture of drawings and actual measurements, if you have laminate flooring in your house you can use the join lines as datums and measure sweepback etc from them. Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 26, 2021 Author Share Posted March 26, 2021 (edited) 21 minutes ago, Gary Binnie said: Cool. I use a mixture of drawings and actual measurements, if you have laminate flooring in your house you can use the join lines as datums and measure sweepback etc from them. I think you read my mind.... ? The "distance to the tip leaning edge is 15cm and the equivalent distace from the tailing edge is 10cm. The corde at the tip is approx 17cm (rounded curve) Again, very well observed! The floor is nice too... Ben-Erik Edited March 26, 2021 by Ben-Erik Ness Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 26, 2021 Share Posted March 26, 2021 There will be a rush on buying laminate flooring now! Some plans only show one wing, I tape them to our big front window and draw the second wing on the back as the Sun shines through and shows the lines. I wave to the neighbours as they walk past. Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 26, 2021 Share Posted March 26, 2021 (edited) Sorry, I didn't see the numbers at the bottom of the last post. So the taper of the wing is more swept back than swept forward? CG with static margin would be 193 mm, 41% MAC (Mean Aerodynamic Chord). Neutral point 203 mm (no stability). I would test fly around 180 mm where it should be safely nose heavy and remove nose weight in stages if required. I was given a guided tour of a Dash 7 of Tyrolean Airways at Innsbruck, by pulling a handle in the cockpit each pilot had independent control of the aileron on their side in case of a control jam. The pilots were very skilled in maximum crosswind take-offs and landings, Innsbruck is usually calm until lunchtime then the Foehn wind starts, blowing about 25 knots straight across the runway. Edited March 26, 2021 by Gary Binnie 1 Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 26, 2021 Author Share Posted March 26, 2021 Okay, here goes again, and now the map is in sync with the terrain! Thanks to the trained eye of Gary Binnie who spotted my errors! Ben-Erik Quote Link to comment Share on other sites More sharing options...
Ben-Erik Ness Posted March 26, 2021 Author Share Posted March 26, 2021 Calculations.... Maybe I shouldn't have started this discussion with myself ?... eCalc says: between 19,7 - 20,6 cm from leaning edge Aircraft Center of Gravity Calculator: 18.8 cm from leaning edge When measuring the root at the wing and listening to my gut feeling i'm more at 16 ish centimeters from the LE at the root. I'm considering various options: Make a chuck glider and see how it flies, maybe find a gentle slope and try the plane somewhere else than the grand big slope... Any input will be appreciated! Quote Link to comment Share on other sites More sharing options...
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