Jeremy Harris
Member
Hi, first off, I'm new here, so please be gentle...........
I've already had a hand in designing a kit aircraft using conventional construction, and am now working up a design for an ultralight flying wing. For reasons that have more to do with the new deregulated category rules here than anything else, I'm aiming for an extremely light empty weight, just 65kg.
As always with aircraft design, I want it all, light weight, good handling and excellent performance. I've sorted out the primary structure, modelled the wing, done the stress stuff, got a light weight engine (just 13kg, including prop) and have been hunting around for a quick and easy way to make a fuselage, which is really nothing more than a pair of humps in the wing centre.
Anyway, I had started down the path of using a foam core, carved to shape and then covered with epoxy glass, Rutan style, when I spotted this website (it's about boats): http://members.ozemail.com.au/~storerm/Balsacanoe/Balsacanoe.html
This got me thinking, so I spent a while today doing some experiments with balsa and epoxy. The neat thing is that getting fair 3D curves using this method is easy and making the frames is pretty simple as well. Overall the weight looks good, certainly no heavier than using foam/epoxy glass, as long as you make sure you prime the balsa with a very, very light coat of epoxy, let it start to cure, then glass it in the normal way (this stops the resin soaking into the wood too much).
Anyone any thoughts on this construction method?
I should add that the seat and landing gear loads are taken by a central spine, so this balsa/epoxy/glass structure doesn't act as primary structure.
Jeremy
I've already had a hand in designing a kit aircraft using conventional construction, and am now working up a design for an ultralight flying wing. For reasons that have more to do with the new deregulated category rules here than anything else, I'm aiming for an extremely light empty weight, just 65kg.
As always with aircraft design, I want it all, light weight, good handling and excellent performance. I've sorted out the primary structure, modelled the wing, done the stress stuff, got a light weight engine (just 13kg, including prop) and have been hunting around for a quick and easy way to make a fuselage, which is really nothing more than a pair of humps in the wing centre.
Anyway, I had started down the path of using a foam core, carved to shape and then covered with epoxy glass, Rutan style, when I spotted this website (it's about boats): http://members.ozemail.com.au/~storerm/Balsacanoe/Balsacanoe.html
This got me thinking, so I spent a while today doing some experiments with balsa and epoxy. The neat thing is that getting fair 3D curves using this method is easy and making the frames is pretty simple as well. Overall the weight looks good, certainly no heavier than using foam/epoxy glass, as long as you make sure you prime the balsa with a very, very light coat of epoxy, let it start to cure, then glass it in the normal way (this stops the resin soaking into the wood too much).
Anyone any thoughts on this construction method?
I should add that the seat and landing gear loads are taken by a central spine, so this balsa/epoxy/glass structure doesn't act as primary structure.
Jeremy
