Yeah me too. This stuff'll swirl around in my head while I finish the wings.
Help! How do i make molded planes?
- Thread starter RossFPV
- Start date
Yeah me too. This stuff'll swirl around in my head while I finish the wings.
danskis
Master member
Here's how Jack (Niez13) of 13th Squadron makes skins.
(894) Sussing out fuselage 'Cone' plans | FliteTest Forum
(894) Sussing out fuselage 'Cone' plans | FliteTest Forum
I have no difficulty making any kind of formers, my problem is finding if they're strong enough for my purposes. I don't want to waste time and materials making them to light, or to heavy trying to find out if they're strong enough, but I MAY have to experiment.
The way I did it carving xps worked well. It was just too heavy, but there's more hollowing that I could do. Formers may be the answer, but I won't need to make that decision for a while yet.
It's a good link. Extra info is always helpful.
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quorneng
Master member
I am a great believer in the "air weighs nothing principle" so as much hollow as possible is the way to go.
Probably my most extreme attempt was a scale VTO EDF rocket/plane, a V2 with wings. It was actually built and flown right at the end of WWII. There is even a period video on YouTube of it taking off.
To work at all it was going to have to be really light so used planking over thin Depron 'ring' formers but each reinforced with 1mm balsa around the inner edge.
I also developed a way of building each fuselage section vertically as one piece.
Looks ridiculous to start with but once the top and bottom formers are in and correctly positioned with the four planks in place it permanently sets the geometry so the rest of the formers can be simply glued in place at the already marked positions.
It is then just a case of adding planks on alternate sides to equalise any forces.
All done in 2 mm thick Depron but the result in an incredibly light but stiff structure.
The tapered nose and tail sections were done in the same way although the tail was the most complex as it carried the 4 fins, the 70mm EDF with four big flush inlets.
With the heavy EDF right a the back the 1800mAh 4s had to go right in the nose along with the ESC and 4x5g servos connected as elevons and rudderons meaning all four tail surface acted for roll control to help counter the considerable torque from the EDF.
It weighs 23.5 oz ready to go with a take off thrust of 44.5 oz so it gets away pretty quickly with a 0.9 g vertical acceleration! Such a delicate airframe is speed limited so you have to throttle back just a few seconds after lift off.
The video is edited but the flight was nearly 5 minutes long.
More an exercise in lightness than a truly practical RC plane but the take off is impressive and somewhat surprising it flies very nicely.
Probably my most extreme attempt was a scale VTO EDF rocket/plane, a V2 with wings. It was actually built and flown right at the end of WWII. There is even a period video on YouTube of it taking off.
To work at all it was going to have to be really light so used planking over thin Depron 'ring' formers but each reinforced with 1mm balsa around the inner edge.
I also developed a way of building each fuselage section vertically as one piece.
Looks ridiculous to start with but once the top and bottom formers are in and correctly positioned with the four planks in place it permanently sets the geometry so the rest of the formers can be simply glued in place at the already marked positions.
It is then just a case of adding planks on alternate sides to equalise any forces.
All done in 2 mm thick Depron but the result in an incredibly light but stiff structure.
The tapered nose and tail sections were done in the same way although the tail was the most complex as it carried the 4 fins, the 70mm EDF with four big flush inlets.
With the heavy EDF right a the back the 1800mAh 4s had to go right in the nose along with the ESC and 4x5g servos connected as elevons and rudderons meaning all four tail surface acted for roll control to help counter the considerable torque from the EDF.
It weighs 23.5 oz ready to go with a take off thrust of 44.5 oz so it gets away pretty quickly with a 0.9 g vertical acceleration! Such a delicate airframe is speed limited so you have to throttle back just a few seconds after lift off.
More an exercise in lightness than a truly practical RC plane but the take off is impressive and somewhat surprising it flies very nicely.
quorneng
Master member
danskis
No jig but I did use a pair of engineers squares to check with lots of eye ball that the top and bottom formers were exactly above each other.
It was the fact that the V-2 body has no flat surfaces anywhere so I was keen to achieve a really smooth double curve as the thin skin meant any significant remedial sanding would be out of the question.
To be fair I did practise the construction technique by building a slightly smaller one first with a smaller EDF. Not VTO capable but simply flown as a hand launch to check the effectiveness of the elevon/rudderon control system.
The bigger one actually flies rather better as a RC plane!
No jig but I did use a pair of engineers squares to check with lots of eye ball that the top and bottom formers were exactly above each other.
It was the fact that the V-2 body has no flat surfaces anywhere so I was keen to achieve a really smooth double curve as the thin skin meant any significant remedial sanding would be out of the question.
To be fair I did practise the construction technique by building a slightly smaller one first with a smaller EDF. Not VTO capable but simply flown as a hand launch to check the effectiveness of the elevon/rudderon control system.
The bigger one actually flies rather better as a RC plane!
Very nice work! Sorry if I sounded flippant about designing formers earlier. I spent consierable time learning how to do the traditional three view drawings of sailboat hulls and those formers, so these don't seem so difficult in comparison.
Bigger is nearly always better. If something is off by a 32nd of an inch, that's a larger measurement relative to a smaller size. Same goes to an ounce of measurement....or a degree....the weight ratio, etc.
If you got the WCL number on each, you might see the difference.
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