Tom Wright 2 Posted April 29, 2011 Share Posted April 29, 2011 I designed this twin boom a couple of years ago and it has been reliable ,versatile and very easy to fly .The .landing speed is very low,and the inverted performance is surprisingly good ,just thought it might be of interest for budding designers ,improver's looking for something different,or the old hands who may want some relaxed but interesting flying without much build effort or expense. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 29, 2011 Author Share Posted April 29, 2011 Span 60in chord 16in Length 49in Wing section optional flat or low angle jeljelsky . Wing loading 15 oz per sq ft with 3A 3cell. Power Turnigy SK 42-40 .Prop 12x6. UC trike (indestructible). Single bolt retains each boom ,for easy transport. Magnetic canopy,gives simple access to battery and gear.Construction from 1in thick foam and balsa sheet .Three servos (rudder servo optional) AUW 3.5 LBS .no hot wire used in the building,adhesives epoxy and UHU por or 3m 77.Observe heath and safety with foam don't breathe in sanding dust. Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted April 30, 2011 Share Posted April 30, 2011 Looks great! Get it drawn up properly, and then submit the plans for possible publication. The world needs off-beat models like this! tim Quote Link to comment Share on other sites More sharing options...
birdy Posted April 30, 2011 Share Posted April 30, 2011 Does look nice... I would consider building it if I had the space - it would go on to the "to build one day.." list. Is that what you do with your models Tim? Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 30, 2011 Author Share Posted April 30, 2011 Posted by Tim Hooper on 30/04/2011 17:12:24: Looks great! Get it drawn up properly, and then submit the plans for possible publication. The world needs off-beat models like this! tim Thanks Birdy ,and Tim i would need a professional to do the plan ,don't mind giving away the design rights,any offers ? PS Tim how do you spell jelskey ? Tom.Edited By tom wright 2 on 30/04/2011 23:48:43 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted April 30, 2011 Share Posted April 30, 2011 jedelski? jedelsky? Google seems split on it. I haven't seen that structure used for a while Tom, and then it was simple single channel or freeflight jobs. Is it aerobatic at all? Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 1, 2011 Author Share Posted May 1, 2011 Thanks for that BOB I think he was polish so will settle for Jedelski it sounds a bit more appropriate. Yes the twin boom will do most sports aeros ,with either wing section but the flat section version ,which is very simple to build,can be be quite precise, the stall and landing speed is a bit higher ,but if the weight is kept under 4lbs ,it is still STOL,and yet handles a stiff breeze no problems. Tom. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 1, 2011 Author Share Posted May 1, 2011 Posted by Tim Hooper on 30/04/2011 17:12:24: Looks great! Get it drawn up properly, and then submit the plans for possible publication. The world needs off-beat models like this! tim Tim " Off beat " i will have you know i was a proffessionl dance DJ back in the 90s . Tom. Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted May 1, 2011 Share Posted May 1, 2011 Posted by tom wright 2 on 01/05/2011 00:34:02:Tim " Off beat " i will have you know i was a proffessionl dance DJ back in the 90s . Tom. Tom, Then you're eminently qualified to enter the rough and tumble world of aeromodelling publishing! You don't need to be a draughtsman or CAD expert to get a plan accepted for publication. All mine are 'old school', in that they're drawn with non-Techno pencil and paper..... tim Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 1, 2011 Share Posted May 1, 2011 I also like it. Off beat, and small enough to put in the car complete. Also the term "slow landing speed "always interests me. Trouble is I an an ic freak. Cheers Quote Link to comment Share on other sites More sharing options...
Rob Lewis Posted May 1, 2011 Share Posted May 1, 2011 Looks like a fun little thing. Shame i'm an ic freak as well, but i'm sure with a little mod it could easily be done. Definately would be on my build list if plans became available. Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 1, 2011 Share Posted May 1, 2011 I'm with you Rob, I did wonder if there was a way to fit a fire wall ,or engine bearers to a foam model. I'll have to do some on line research. Cheers. it may give Tom nightmares LoL Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted May 1, 2011 Share Posted May 1, 2011 The prop doesn't care what turns it. There's nothing to say that an EP model has to stay that way.......tim Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 2, 2011 Author Share Posted May 2, 2011 Thanks for the encouragement Tim, i suppose it would be a good one to start with as it is very simple ,maybe a smaller version would be popular but the overall dimensions have been worked out to optimise the strength to weight ratio of the material.My problem is that in the early days i had a professional draughtsman on staff so i have few skills in that department. I have also started on a own design 7ft span Cessna 152 (trad build) as the current offerings all seem to have draw backs that i would like to illiminate. FB3.and Rob. Fitting I/C would be a "piece of cake"the shear and compression load capability of blue foam is excelent , this is well proven by the the way the U/C attachment soaks up any thing you can throw at it. The Blue Foam Monster has 1.5 hp up front ,bolted to a 4mm ply fire wall epoxied to the foam nose ,i have cartwheeled it in a cross wind landing with no damage and that one weighs 12lbs . Tom. Edited By tom wright 2 on 02/05/2011 01:16:32Edited By tom wright 2 on 02/05/2011 01:22:24 Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 2, 2011 Share Posted May 2, 2011 Thanks for the info Tom I will be looking forward to a plan. The 60 inch would be fine. Also on second thoughts, we epoxy hard wood u/c blocks into traditional foam wings, and as you said, if done correctly, all will be well. How does the blue foam compare with trad. white foam used in obechi covered wings.? Cheers Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 3, 2011 Author Share Posted May 3, 2011 FB3. The blue foam is much stronger,the twin boom does not have a main spar ,and the 10ft span blue foam monster flew without a main spar or struts ,as per the original video,although it did have 1in x 1.5 mm carbon on the l/e and t/e ,but just on the centre wing panel. Its all a matter of getting to used the material to achieve best strength to weight ratio. Tom.Edited By tom wright 2 on 03/05/2011 01:07:05 Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 3, 2011 Share Posted May 3, 2011 Thanks Tom,very interesting stuff indeed. Cheers FB3 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted May 3, 2011 Share Posted May 3, 2011 If it's any help, all my combat models(.15s up to .25s) have used 1/8" birch ply firewalls butt jointed to the blue foam (wall thickness no more than 1/2 an inch) with epoxy and the joints have never failed. I'm with Tom on its strength - the combat models are very highly stressed in flight but with a skin of PVA soaked brown paper don't need spars. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 3, 2011 Author Share Posted May 3, 2011 I would post some new photos but Joanne has taken the camera on holiday to Italy . Martin has not yet revealed details of his brown paper and PVA covering method,unless is been covered (excuse the pun) on a previous thread. One thing i am not sure of is the effect of glow fuel on bare blue foam ,it is a closed cell material but for IC, Martins covering method, or cap strip and a conventional covering would help to keep things tidy. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted May 3, 2011 Share Posted May 3, 2011 Tom, I can't claim any ownership of the blue foam/brown paper construction method but you simply paint the matt side of the paper with 50:50 watered down PVA, let it soak for a couple of minutes and lay it on to the foam with more PVA brushed on top. It's best to cover both sides of a component to avoid warping - as it dries out it should taughten up to give the appearance of a solid wood-like structure. An overlapof the brown paper to 1/3 of the span of the other wing gives loads of strength for 1/12 scale WW2 fighters. I use B&Q emulsion testers (they can mix any colour for you) and fuel proof with a coat of water based polyurethane floor varnish (Skincrylic, Poly-C etc.) Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 4, 2011 Author Share Posted May 4, 2011 Thanks for that Martin , for the people that have been asking ,that should be helpful. Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 4, 2011 Share Posted May 4, 2011 You are quite right Tom. That was the next question (fuel proofing) for us ic boys. Cheers Martin. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 4, 2011 Author Share Posted May 4, 2011 If the bulk of the fuel spray can be directed downward you could get good service without covering ,after all half the fun with this simple quick to build model is getting good performance and economy and not adding weight or extra build time ,or..... just pop it on EP........... Flew mine to day ,nice leisurely aerobatics, landing / take offs took less than 6ft into the moderate breeze. Rolls loops and maintaining inverted flight surprisingly precise,and the glide is way better than the average power model so dead sticks are no problem.With sensible use of the throttle 15 to 20 Min's flight time from a 3A three cell can be achieved Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 5, 2011 Share Posted May 5, 2011 Hi Tom, on second thoughts, one small, foam, unusual looking electric model in my shed, would not ruin my street credibility as an ic nut. As it would be a "first" could you recommend a budget power supply. Cheers FB3 ps Its the twin boom model. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted May 5, 2011 Author Share Posted May 5, 2011 Hi FB3. Are you saying you have no EP gear,and no experiance with same? Tom. Quote Link to comment Share on other sites More sharing options...
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