Tony F Posted June 3, 2014 Share Posted June 3, 2014 Hopefully one day Colin = **LINK** Plummet is it a Trabby ? LOL I served in West Berlin in the 80's and on my many trips to East Berlin those little monsters were everywhere Tony Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted June 3, 2014 Share Posted June 3, 2014 Thanks for the link Tony, I didn't know that project was still going, they've certainly got a mountain to climb. I visited the Checkpoint Charlie Museum in Berlin about 10 years ago, in there was a very well constructed micro-light that had been built by someone in East Germany who then used it to fly over the border to escape to the West. It was fitted with a Trabant engine, which I think was a twin cylinder 600cc two stroke? It looked as if it had been made for the job, compact and obviously light. Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted June 3, 2014 Author Share Posted June 3, 2014 Hi All, I been busy again today, concentrating on the undercarriage and nacelles Formers for the outer engine nacelles Nacelle core sides This took a little time and adjustment to get right but I'm happy with the layout it seems to work on paper Inner nacelle core side may need a little fine adjustment Front view of inner with undercarriage The formers for the inner engine nacelle And here's one I made earlier for my Nijhuis Beaufighter that I'm currently building . I going to use the design but a bit bigger, that's a 3 1/4" wheel in place, looks tiny. Regards Robert Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted June 3, 2014 Share Posted June 3, 2014 now that looks special sir. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted June 3, 2014 Share Posted June 3, 2014 It'll be worth it in the end! Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted June 5, 2014 Author Share Posted June 5, 2014 Hi All, Just had my plaster cast removed from my hand today, been told I will never get full movement back again. Having been told this on getting home I grabbed my tranny and checked out if I could manage the sticks OK and yes I can now I get get back designing without a lump of fibre glass on my hand although I have little movement in my thumb but it will increase. Also, can resume building my Beaufighter I am going to keep this going and it will be my next build. Regards Robert Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted June 5, 2014 Share Posted June 5, 2014 Good on you Robert, positive thinking! I'm looking forward to seeing the Beaufighter in the meantime, another plane with a load of character. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted June 5, 2014 Share Posted June 5, 2014 Looks good and glad to hear you are on the mend.. M Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted June 7, 2014 Author Share Posted June 7, 2014 Hi All, Progress so far. Over the last couple of days I have been working on the wing section and tail section and I am now happy with what I have an almost scale wing section which is thicker than the section I had considered and a symetrical tailplane. I am going to keep the incidences as per full size. The original wing section is shown dotted. I have also altered the wing slightly now having wing sections for the whole wing I have increased the size of the main spars from 6 x 6 obeechi to 9 x 9 hard balsa reducing down to 9 x 6 from mid - aileron as the section starts to slim down a bit, webbing still remains at 1/16th vertical grain. The rear spars remain at 6 x 6 hard balsa. Regards Robert Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted June 7, 2014 Share Posted June 7, 2014 I'm sure that you've got that right Robert. Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted June 17, 2014 Author Share Posted June 17, 2014 Hi All, Just to let you know that I been doing a bit on the Stirling. No drawing just stirring up the old grey matter and calculating the correct CoG. My original position was a guesstimate, but I wanted to know for sure, so I have looked in a book that has been sat on my workshop shelf for years and blown the dust off. If my calculations are correct then my original guesstimate was 30mm forwards of the calculated position. after I re-checked it. The book I used was I bought this when I designed my original Stirling years ago. However, assuming that the laws of physics have not changed then the calc's must still work. Now I would not mind if anyone out in the forum could concur that I'm right and not made a silly mistake. The formula used is the Mean Aerodynamic Chord (MAC) From reading the text and making the following measurements:- 1. The length of the mean cord being 320mm using the method in the sketch above. 2. The length of the tailplane mean chord being 170mm 3. Distance from 15% along the wing AMC to 15% tail AMC this being 953mm 4. Wing area = 576000 mm2 5. Tailplane area = 1326000 mm2 With these measurements then A. Divide the tail area by the wing area = 0.23 B. Divide the distance from 15% along the wing AMC to 15% along the tail AMC by wing AMC = 2.9 Now with the above results plot out on chart below B. Now, I have plotted out the line on the chart above, it's the top one. To get it as accurate as possible I measured between 0.2 & 0.3 by 10 then by 3 to get 0.23 and likewise for 2.9. The intersects at 31.5% of the mean chord which is 100.8 mm Having done this on the plan and measured from the spar which runs straight across the wing and not with the sweep I have measured at the fuselage sides it is 128 mm from the leading edge keeping parallel to the spar. In doing this I have just become aware of a mistake that I made last night, and that I had measured 100.8 mm from the root leading edge. Having re-checked now moved to 128 mm from the leading edge. Easily put right only a pencil line to rub out . would have been a bit nose heavy to say the least. Whilst measuring I also measured the other surface areas Fin; 33744 mm2 with rudder Rudder: 13260 mm2 Elevator: 28800 mm2 Sorry that this has been a little on the boring side but I needed to get it right. I'll be a bundle of nerves on the maiden flight anyway, just trying to make it more pleasurable or one less thing to worry about. One thing I have done is made a set of tail ribs from some off cuts from the Beaufighter. Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted June 29, 2014 Author Share Posted June 29, 2014 Hi All, Just thought I would share with you this photo I came across whilst looking for something else. This is I believe the only photo I have of the first Short Stirling I built way back in the late 1990's at 65" span. Although I['m sure I took some when I took the completed airframe to a local show at Margam Castle, Port Talbot. but can I find them not anywhere. My Beaufighter is coming along fine now so not much longer to wait for the build to start. Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted August 10, 2014 Author Share Posted August 10, 2014 Hi All, I've not forgotten this thread. It won't be too much longer to wait now. The Beaufighter is almost ready to paint. I'll be taking off the quantities for the balsa and ply in the next week or so. I have made the templates for the formers and wing ribs, R1 is quite a size. Before building starts I want to copy the drawings onto A0 paper so I've got a copy of the prototype and to tidy up the drawing. Regards Robert Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 10, 2014 Share Posted August 10, 2014 Are you sure the Sterling had its wing 'chopped'. **LINK** In fact the spans of all three was similar. The Sterling was just rather bigger so the wing span looked small but it was designed to perform as a cargo transport and a 24 seat troop carrier as well! In trying to meet such a specification it was never going to compete with the very dedicated 'bomber only' Lancaster. Quote Link to comment Share on other sites More sharing options...
cymaz Posted August 10, 2014 Share Posted August 10, 2014 Flew a couple of weeks ago at the Truro club Scale Competition Scratch built using 2x25 and 2x20 2st I think Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted August 10, 2014 Author Share Posted August 10, 2014 Thanks Cymaz, Wow very impressive, great flying shot and very inspirational. The cowls and canopies will need a bit of thinking, any idea who made the Stirling, I could do with a pointer in the right direction as far as the canopies are concerned especially the main cockpit. I never made them before. Simon, I have the drawing of your link, I have used this info for reference. Regards Robert Quote Link to comment Share on other sites More sharing options...
cymaz Posted August 10, 2014 Share Posted August 10, 2014 I do, indeed, know the bloke who built it.....he's our club secretary I will ask if you can contact him Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted October 14, 2014 Author Share Posted October 14, 2014 Hi All, I've not forgotten this project but my Beaufighter is taking a little longer than I thought plus I'm adding a bit more detail as well. I have looked at my plans and made a materials list ready to order up The list is as follows:- 2no 48" x 4" X 1/8th" Balsa fuselage sides Sheet Balsa 36" X 4" 24 no 1/16th 21 no 1/8th 4 no 3/16th 3 no 3/8th 3 no 1/2" Strip / Hardwood 4 no 1/4 X 1/4 4 no 3/8 X 3/8 hardwood 4 no 1/2 triangle Ply 1/64th 4 no engine cowls 1/16th 2 no 18" X 3" X 2" 1/8th 4 no 100mm dia discs (bulkheads) That's enough to get the basic airframe built The cowls will be 2 layers of 1/64th ply wrapped around a balsa frame with 1/2" fronts shaped at the moment, what I need to do is a little research into the size of motors to get the final position of the engine bulkheads. That all for now, I'll let you know when I ordered the materials Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted October 19, 2014 Author Share Posted October 19, 2014 Hi All, I am going for a total re-draw and put it on A0 paper instead of lining paper, the basic design is fine just some fine tuning here and there. I now wished I could use CAD!!! I also need to alter the nacelles a little as I have not allowed enough distance for the motor and mount. I would like to thank Puffin Models and George of 4 max who replied to my enquiry regarding motor set up's ESC's and batteries. That's all for now, just ordered some A0 paper and go and sharpen my pencils Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted October 20, 2014 Author Share Posted October 20, 2014 Hi All, I had to cut short the last entry last night. Going back to the motor selection here are the suggestions from John at Puffin Models and George from 4-Max John suggests the following, "At the weight you quote, (8 1/2 lbs), the Ray C3530/14 is an appropriate choice on 3S batteries....... If you concerned about the weight running away then the RAY C3536/08s would cope with the greater weight (easily 10 lbs and more). Do check you appropriate prop clearance, and either use OPTO controllers, or if you are using BEC controllers, fit them using servo extension leads that have the red lead cut to isolate the BEC circuit, and use a RX battery." George suggests as follows, "8.5lbs is quite heavy for this model, most TN Lancs come out between 5 lbs and 6.5 lbs depending on detail. As you expect 8.5 lbs I suggest the same setup as I have in my TN Sunderland as it has quite a lot more power than the Lancaster setup....... ....The sunderland weighs around 7lbs and has enough power to climb out ar around 60 degrees so will have plenty of power for a 8.5 lb Stirling. I would suggest that you concentrate on keeping the airframe as light as possible especially the tail end and aim for 5.5 lbs to 6.5 lbs as it will fly slower and look more realistic, land slower and less likely to stall." Once again I would like to thank John and George for their advice and suggestions for this project. Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted October 28, 2014 Author Share Posted October 28, 2014 Hi All, A quick update on progress so far. I have re-drawn the tail feathers with adding lightness in mind the outline has not changed and the stabiliser has not changed in design at all, with 1/16th (1.5mm) ribs and sheeting. The elevators I have added lightening holes these are an open structure with a 1/16th core. The fin and rudder have been on a diet. gone is the 3/8th (9mm) sheeting and in is a 1/4" (6mm) frame sheeted in 1/16th balsa whilst the rudder now has the same construction as the elevators with a 1/16th core and 1/16th ribs. I have also been working on the fuselage but still a work in progress drawing wise again looking reducing weight. Balsa wood has been purchased. I have mail ordered the bulk of it plus I took my scales to my local model shop and bought the lightest I could (7 grams a sheet of 1/16th x 4 x 36" just to give me some choice. Servos and electric setup purchased just retracts to go. With all of the balsa, servos and electric set up plus I know the weight of the retracts I am just over the 8 1/2lb target weight. No allowance for covering as yet but this should come in with the off cuts of balsa. Taking 8 1/2lbs weight plus a wing area of just 6sqft gives a wing loading of 22.6oz/ft, it will fly if my maths are right!! That's all for now back to the drawing board as they say plus I'm going to start building the tail feathers shortly. Regards Robert Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted October 28, 2014 Share Posted October 28, 2014 sounds good to me. can't wait to see this one progress. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted October 28, 2014 Share Posted October 28, 2014 Wonderful Robert, slow but sure, get it right. Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted October 28, 2014 Author Share Posted October 28, 2014 Thanks both, I must admit this has been a little slow to get started, I do like to finish one project before I start another and the Beaufighter has been clinging onto the building board for a little too long now, I been let down by one supplier for my decals and the other put the wrong ones in my letter, all being sorted out now. My better half has informed me this evening that the forth coming maintenance tasks for the next year are somewhat extensive and involves me to re-locate my work room to the attic. I have dragged my heels a little on that score in finishing off the attic flooring and enlarging the hatch. I'll do these attic before any serious building starts. Just where to put everything in the transition!! and how do you get an 8' x 3' building board through a 2' sq hole without cutting it.??? Regards Robert Quote Link to comment Share on other sites More sharing options...
Robert Parker Posted November 9, 2014 Author Share Posted November 9, 2014 Hi all, I finished the Beaufighter yesterday and she looks great Last night I bought the retracts, I now have all of the hardware for the project, now there are no excuses, I have even made a temporary building board in the attic for the new year when I have to more. Whilst in the attic I seem to have more unmade kits than I thought!!! Today, will start the fin and rudder. That's all for now Regards Robert Quote Link to comment Share on other sites More sharing options...
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