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Beanie you MiG looks very cool!
So, this is step by step, so I'm going to put a lot of photos in this thread. I did EDF mount and reinforcements in rear part of fuselage Plans for upper part of fuselage is ready Because I design my planes in sketchup without thickness of foam, I have to trim them now. Cutting, trimming, and gluing. Technique simmilar to planes from paper. |
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Front module with cone.
Here I also cut out all the frames taking into account the thickness of the foam plating. Mostly I use 7mm insulation foam, so all parts must be trimmed. This was quick. All parts are cut out. Cone is from the paper As you can see there is not much room for real intake. I can cut only small holes for electronics cooling. I really wanted to do scale cone sacrificing intake for EDF. Will see if cheat hole at the bottom of fuselage will be enough. |
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Last edited by robertus; May 24, 2020 at 09:44 AM.
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Back to the wings and EDF pipe.
I'm developing an inlet tunnel at hot. It wasn't in 3D plans, I will add this to the plans later The stabilisers are glued to fuselage at the moment. I left some more material when was cutting them to attach them to the fuselage There is also a carbon rod inside the stabilisers for pivoting. I couldn't decide which line was better so the rod is in the middle. I hope this is a good point of mounting. In the last photo the complete upper part of the outlet tunnel is already mounted. I also made this triangle strengthening the cheat inlet between the frames. Must add this to the plans as well. I write such things that if someone wants to build something out of my plans (not only this one but all my plans in rcgroups are the same style), he must be aware that these are not PnP plans, that "just glue them and go to the air". You also have to think a little and come up with your own, better, solution for various problems. |
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ah, very interesting way of doing the EDF. i'll have to retrofit mine if u get this working. does the FW MiG-21 do the same thing? i thought FW used cheater holes on bottom. is most of the inflow coming from the bottom?
do u have to add a scoop or something on the bottom to direct more air in? great job on the nose cone! it looks tons better than mine. -beanie |
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Thanks Beanie, Keep your fingers crossed, i hope this idea will work.
FW solution was inspiration for me. In their MiG, bottom inlet is much bigger than EDF size, so I think this is the main inlet duct. picture from here: https://www.rccanada.ca/rccforum/att...2&d=1479090843 |
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A vertical stabilizer will be inserted in the gap between these two foam stringers. This, plus the thickness of the sheathing foam should stabilise the fin.
Now I'm sheeting the fuselage. I', gluing small foam stripes to help me positioning sheets. Upper part of the fuselage isl covered. I leaved the first segment, unfolded the electronics and there probably accumulator will be, more or less. Calculated CoG is on first carbon tube reinforces wing. |
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Last edited by robertus; May 24, 2020 at 02:29 PM.
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Looks very good so far, also enjoying your videos and learning from them. i hope the bottom inlet will be enough air intake, i have built a similar mirage 2000 but out of depron, the guy who designed it bends depron foam. with heat, i am not suer if this is useful for the foam you use, but here's a small video, it works really well to make round parts.
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I use 7mm insulation foam for this model, it is used for wall insulation from inside the building, but this is the same type of foam as a depron - XPS.
Stabilisers are made from 9mm depron. For bending foam i use edge of the kitchen countertop, fingers and rolling pin. Heat also helps, and makes things quicker, but I found that high temperature makes depron fragile.
In smaller object, temporary I'm adding duct tape outside the sheet which I bend. It prevents cracking. In the movie I couldn't do that because of printed depron. Hair dryer is at the end of my list. |
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Last edited by robertus; May 25, 2020 at 12:52 AM.
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