thierry laurent Posted October 30, 2023 Author Share Posted October 30, 2023 1 minute ago, iaf-man said: That's called "stereometry" in drawings' language,if I remember correctly-laying out a 3d object in 2d drawing You can still put a red FOD ground plug and be done with it I know as I finally found some pictures of Tunnan airframes in Congo with FODs but it was not that common and I really prefer the look of the plane without them. Moreover, logically FODs should be added on the exhaust AND intake and I already dedicated a noticeable amount of time to solve the intake area. Accordingly, I'm somewhat reluctant to hide it now! And, finally, that exhaust with the pointy cone end is so distinctive I would like to reproduce it! Call me a masochist! Actually I think anyone trying to assemble fully that kit must be a masochist! iaf-man and fab 2 Link to comment Share on other sites More sharing options...
Derek B Posted October 30, 2023 Share Posted October 30, 2023 Nice work Thierry, just the sort of thing that I would do! Plastic card should work OK, but you could also consider using thick aluminum or lithographic sheet as well? This would meet your weight requirements whilst still look scale in thickness (you can always 'joggle' the joint; the real part was probably a single or two part sheet forming welded together). Derek Link to comment Share on other sites More sharing options...
thierry laurent Posted October 30, 2023 Author Share Posted October 30, 2023 22 minutes ago, Derek B said: Nice work Thierry, just the sort of thing that I would do! Plastic card should work OK, but you could also consider using thick aluminum or lithographic sheet as well? This would meet your weight requirements whilst still look scale in thickness (you can always 'joggle' the joint; the real part was probably a single or two part sheet forming welded together). Derek Thanks Derek, My wife proposed me the same idea of using metal sheet! I'm keeping that option as a back-up scenario. This would ease the shaping but complicate hiding the seams with the other parts to add at both ends. Wait and see... Derek B 1 Link to comment Share on other sites More sharing options...
thierry laurent Posted October 30, 2023 Author Share Posted October 30, 2023 (edited) The tip of the Revell turbine cone was too blunt. After some careful sanding I think I restored a far better pointy profile: https://i.imgur.com/6MvpEfR.jpg Edited October 30, 2023 by thierry laurent R Palimaka, LSP_Kevin and Derek B 3 Link to comment Share on other sites More sharing options...
thierry laurent Posted November 1, 2023 Author Share Posted November 1, 2023 Hi guys, Some slow progress but an important step! The exhaust chamber issue will soon be behind me... I started with my DSPIAE cutter to create the rear structure of the exhaust. I did not want to use the Silhouette as the plastic is thick (1mm) and that manual solution was quicker than laminating 0.3mm circles. Here's the result after cleaning the parts with some cutting and sanding work. No need to be perfect as this is just intending to join the turbine rotor and cone support and the chamber. And you can see behind that the conical exhaust chamber is done! This was more complicated than I hoped. I wanted to use 0.5mm plastic to have a little bit of rigidity. Using 0.3 would have been far easier to shape the cone but I was afraid glue would have damaged or distorted the internal (visible) side close to the seam. So, this was a trade-off... I tried different techniques, including hot water to help in rolling the truncated cone but none was efficient. Finally, I glued some plastic "teeth" on the external side of both edges. They were positioned on each side to interlock together. When fully dried, I tried to roll the part as much as I could, put the shaped but still unglued closed cone on the Sea Venom kit one and secured it with rubber bands. After one night, there was far less tension in the part and it became possible to glue the teeth together and the seam from the internal side. Not very easy as the plastic part acted as a spring but with some elbow grease, time and a lot of glue I succeeded in keeping both edges together. Done! As you can see, thanks to that technique, the internal seam is quite clean and, located at the top, it will be close to fully invisible. The main issue is solved. I will use the rear part of the Fly exhaust at the external end. Now, I still have to copy the turbine rotor and cone in resin to locate them between the two plastic circles I made but I'm sure this will be a piece of cake in comparison with that exercise! Building some kits is really a fight... and no doubt that one is in that category... I still have to detail the cockpit bulkhead and replace the molded details on the IP coaming but this is standard work. The very last challenge will be the landing gear. Actually this will be a BIG challenge as its design for the front and main parts is the most stupid one I have ever seen in a kit (and this comment may be an understatement)! Hopefully, in the worst case, I will rely on jewellers I know as they just started using the lost wax casting technique! Wait and see! Fanes, R Palimaka, Mark_C and 7 others 10 Link to comment Share on other sites More sharing options...
R Palimaka Posted November 1, 2023 Share Posted November 1, 2023 Don't know how I missed this build! Excellent work solving some frustrating problems in the design and engineering of the kit. I just added a pile of "likes" for you. The Tunnan is probably my favorite jet subject, such a distinctive shape. I've been considering buying the Fly kit and will be following your efforts. Great work so far, and good detective work too! Lots of excellent information for anyone building this kit. Richard thierry laurent and Derek B 1 1 Link to comment Share on other sites More sharing options...
iaf-man Posted November 1, 2023 Share Posted November 1, 2023 6 hours ago, thierry laurent said: Hi guys, Some slow progress but an important step! The exhaust chamber issue will soon be behind me... I started with my DSPIAE cutter to create the rear structure of the exhaust. I did not want to use the Silhouette as the plastic is thick (1mm) and that manual solution was quicker than laminating 0.3mm circles. Here's the result after cleaning the parts with some cutting and sanding work. No need to be perfect as this is just intending to join the turbine rotor and cone support and the chamber. And you can see behind that the conical exhaust chamber is done! This was more complicated than I hoped. I wanted to use 0.5mm plastic to have a little bit of rigidity. Using 0.3 would have been far easier to shape the cone but I was afraid glue would have damaged or distorted the internal (visible) side close to the seam. So, this was a trade-off... I tried different techniques, including hot water to help in rolling the truncated cone but none was efficient. Finally, I glued some plastic "teeth" on the external side of both edges. They were positioned on each side to interlock together. When fully dried, I tried to roll the part as much as I could, put the shaped but still unglued closed cone on the Sea Venom kit one and secured it with rubber bands. After one night, there was far less tension in the part and it became possible to glue the teeth together and the seam from the internal side. Not very easy as the plastic part acted as a spring but with some elbow grease, time and a lot of glue I succeeded in keeping both edges together. Done! As you can see, thanks to that technique, the internal seam is quite clean and, located at the top, it will be close to fully invisible. The main issue is solved. I will use the rear part of the Fly exhaust at the external end. Now, I still have to copy the turbine rotor and cone in resin to locate them between the two plastic circles I made but I'm sure this will be a piece of cake in comparison with that exercise! Building some kits is really a fight... and no doubt that one is in that category... I still have to detail the cockpit bulkhead and replace the molded details on the IP coaming but this is standard work. The very last challenge will be the landing gear. Actually this will be a BIG challenge as its design for the front and main parts is the most stupid one I have ever seen in a kit (and this comment may be an understatement)! Hopefully, in the worst case, I will rely on jewellers I know as they just started using the lost wax casting technique! Wait and see! Didn't you look here?no good? https://www.resin2detail.com/product-page/1-32-j-29-e-f-tunnan-seamless-afterburner-and-exhaust-32083 Derek B 1 Link to comment Share on other sites More sharing options...
Derek B Posted November 1, 2023 Share Posted November 1, 2023 Nice solution work Thierry, well done. Derek thierry laurent 1 Link to comment Share on other sites More sharing options...
thierry laurent Posted November 1, 2023 Author Share Posted November 1, 2023 1 hour ago, iaf-man said: Didn't you look here?no good? https://www.resin2detail.com/product-page/1-32-j-29-e-f-tunnan-seamless-afterburner-and-exhaust-32083 Good for the J-29F with afterburner but alas not for the J-29B! The really frustrating part is the fact he initially made more than 90% of the work to create the initial reactor when he stopped as he realised he was actually willing to make the late one... iaf-man 1 Link to comment Share on other sites More sharing options...
fab Posted November 1, 2023 Share Posted November 1, 2023 Well done Thierry thierry laurent 1 Link to comment Share on other sites More sharing options...
thierry laurent Posted November 2, 2023 Author Share Posted November 2, 2023 Hi again, I was quite lucky as the first resin casting was successful. I really love that reusable blue stuff rubber! The resin parts are not very sexy but OK for what I wanted to obtain and I avoided all the dreadful small air bubbles: You can see now all the parts required to build the full exhaust. This inludes the witch hat (particularly relevant for Halloween don't you think so...?) Sorry for the crappy pics but the lighting conditions were quite bad. Normally, there were arms between the rotor cone and the sides of the chamber but I do not know if I will add them. The most important feature is the visible cone tip and this is exactly what I wanted to get. I'm not sure the other features will be visible but that one is! If you still had doubt, the dry assembly picture hereunder shows it. This is exactly why I wanted to reproduce the correct chamber geometry. To me, the only other acceptable option was FOD covers. I'm happy as I can now move to other challenges! denders, Fanes, Cycling Guy and 8 others 11 Link to comment Share on other sites More sharing options...
Derek B Posted November 2, 2023 Share Posted November 2, 2023 Derek thierry laurent 1 Link to comment Share on other sites More sharing options...
Troy Molitor Posted November 4, 2023 Share Posted November 4, 2023 Well done Thierry. That looks awesome. thierry laurent 1 Link to comment Share on other sites More sharing options...
MikeMaben Posted November 5, 2023 Share Posted November 5, 2023 thierry laurent 1 Link to comment Share on other sites More sharing options...
R Palimaka Posted November 5, 2023 Share Posted November 5, 2023 Good work dealing with that issue! It feels good when you finally solve a problem and you can move on with the project...and like you said, on to other "challenges". Richard thierry laurent 1 Link to comment Share on other sites More sharing options...
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