HumanPoweredDesigner
Well-Known Member
I'm really considering aluminum structural skin for my designs.
I think if foam is cut thinly enough, maybe I would not have to hot wire it to the shape of the ribs. That would save a lot of effort. I wonder if it can be bought cheaply in stacks of many thin plies. If not, straight hot wiring of blocks should not be too hard... unless the thin layers would just melt. Can I hot wire foam 1/16" thick or less so it is very flexible?
1. I'd start with some kind of a web running spanwise, shaped like a truss composed of a sandwich. Then light sandwich ribs too that are a bit higher in back since in back there will just be one layer of skin.
2. Step two: Lay out my 0.004 inch aluminum foil. Hopefully it has not dents on it.
Glue bottoms of flat bottom ribs with epoxy and lay them on the foil Add thin balsa wood strips next to the junction to distribute pressure, grain at 45 degrees.
3. Once glue is set, put more around the rest of the ribs, up to past the spanwise web where the rib height jumps. Wrap the rest of the foil around that, carefully so no dents.
4. Once dry, spray adhessive on the aluminum and wrap thin foam over it.
-----I forgot: the ribs gett thicker on the bottom too past the span web. Only one layer of aluminum in back.
5. If you have to use thin layers to get good flexibility, spray more adhesive on that layer and add the second thin layer of foam.
6. Now put epoxy on the trailing ribs on bottom and spray adhesive under the foam. Set on top of the second layer of foil.
7. Once dry, spray adhesive on the rest of the foam and add epoxy to the top trailing ribs. Wrap the aluminum around on to them and let the glue set.
Do you think that would make a rigid, efficient wing? At the sheet metal junctions, I'd glue on overlapping strips. For 0.004" a 1 inch strip would give 1:100 on both sides of the junction. And I could do the other side too if I make the foam thinner there.
I'd still have flying wires.
I think if foam is cut thinly enough, maybe I would not have to hot wire it to the shape of the ribs. That would save a lot of effort. I wonder if it can be bought cheaply in stacks of many thin plies. If not, straight hot wiring of blocks should not be too hard... unless the thin layers would just melt. Can I hot wire foam 1/16" thick or less so it is very flexible?
1. I'd start with some kind of a web running spanwise, shaped like a truss composed of a sandwich. Then light sandwich ribs too that are a bit higher in back since in back there will just be one layer of skin.
2. Step two: Lay out my 0.004 inch aluminum foil. Hopefully it has not dents on it.
Glue bottoms of flat bottom ribs with epoxy and lay them on the foil Add thin balsa wood strips next to the junction to distribute pressure, grain at 45 degrees.
3. Once glue is set, put more around the rest of the ribs, up to past the spanwise web where the rib height jumps. Wrap the rest of the foil around that, carefully so no dents.
4. Once dry, spray adhessive on the aluminum and wrap thin foam over it.
-----I forgot: the ribs gett thicker on the bottom too past the span web. Only one layer of aluminum in back.
5. If you have to use thin layers to get good flexibility, spray more adhesive on that layer and add the second thin layer of foam.
6. Now put epoxy on the trailing ribs on bottom and spray adhesive under the foam. Set on top of the second layer of foil.
7. Once dry, spray adhesive on the rest of the foam and add epoxy to the top trailing ribs. Wrap the aluminum around on to them and let the glue set.
Do you think that would make a rigid, efficient wing? At the sheet metal junctions, I'd glue on overlapping strips. For 0.004" a 1 inch strip would give 1:100 on both sides of the junction. And I could do the other side too if I make the foam thinner there.
I'd still have flying wires.