OLD SCHOOL RCM Magnum 40: Wing Ribs too!

Mutley

Well-known member
Well here it is, its an Old RCM plan (Magnum 40) Aiming to be converted to FT foam board build, via inkscape.

backstory: I was at my folks house this past Halloween to see my nephews, and spotted an old plane in th e basement that my dad and I flew when I was 13 years old. This was a balsa and monokote with a nitro super tigre 2 stroke "Hot Dogger" of a plane...ahh good ole' days..

I thought, wouldn't it be cool to capture those good old memories via flite test foam board?

Here is the plan. I am vectorizing to have it be laser cut, and modifying it to be covered in molded ft foamboard, fuse and wing. If you look close, most of the fuselage is constructed in 3/16" balsa sheets, which is exactly the same thickness as FT foamboard.

I think the wing will be fun and challenging to bend into the traditional (experimental) "reflex" airfoil shape as seen. It reminds me of the p-51 laminar flow wing a bit, no?

I've noticed a lot of ft kits don't really use ribs. Maybe they don't need to, but I'm an old school r/c'r and I am looking forward to putting half the ribs in the wing (I think it calls for 18 ribs, I will have about 8-9 or so ish in my wing.

Magnum40-pdf-3.jpg
 

Mutley

Well-known member
Here is some detail of the reflex airfoil; modified wing rib shape, reduced to fit 3/16 FT foam board wrap around. Still deciding what to do with the trailing edge stock and aileron attachment. The blue box is the foam board aileron
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Scotto

Elite member
Here is some detail of the reflex airfoil; modified wing rib shape, reduced to fit 3/16 FT foam board wrap around. Still deciding what to do with the trailing edge stock and aileron attachment. The blue box is the foam board aileron View attachment 231917
If its not too late I have an idea for the ailerons. Leave the paper on the inside for the last 3 inches or so top and bottom. Bevel the top and bottom and leave the hinge in the middle then iron it to shape.
 

Mutley

Well-known member
If its not too late I have an idea for the ailerons. Leave the paper on the inside for the last 3 inches or so top and bottom. Bevel the top and bottom and leave the hinge in the middle then iron it to shape.
you literally read my mind!
 

Mutley

Well-known member
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The firewall was a little thin for the KDE, put dowel rods behind the nylon spacer offsets
 

Mutley

Well-known member
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Horizontal Stab. Reinforced with 1/32 ply strip cut out on Band Saw. LE of stab is taped with blue painters tape for durability and protecting foam from spray paint finish