reaper0995
New Member
First off, yes I know there is already a thread on this, but it has a LOT of posts and wanted to start on a new idea and thread.
So the basic idea is to make a structure out of something cheap, like aluminum, and then suspend it into a mould and pour a foam inside it to make the wing shape. This will be referred to as the 'core'.
CONCEPT:
If the core structure could be made with tubes and waterjetted parts, then it could be made very cheaply. Tube is also very cheap. By using foam, the structure of the wing doesn't have to be incredibly perfect and highly aligned, since there will be no rivets to hold on the body panels. The main load would ultimately be carried by the aluminum structure (or carbon tubes, etc), but the foam would fill the space between the structure and the airfoil, lets say ~1 inch thick. My current thought is to base the idea on the Dyke Delta or something similar. The entire wing and under belly can be done in one poured foam mould.
DESIGN:
The Dyke Delta has a wing surface area of 173 ft^2, an arbitrary guess is about 4in on average thickness (since some areas are way thinner and way thicker, total guess though). So that would make the wing about 58 cubic feet. The lightest foam from this site:
is 2lbs per cubic ft, so 116lbs in foam. This idea would mean that this step would be the wing and structure of the entire aircraft. It would still need an engine, canopy, vertical stabilizer (perhaps foam as well), interior, landing gear, etc. But the overall airframe could be made quickly and cheaply, and I am imagining quite strong.
SKIN:
As for needing skin, it would kind of depend... There is chance that the foam would have an acceptable surface finish out of the mould. If not, several options can be considered. 1)Fiberglass before mould halves are combined and poured, 2)fiberglass after part is removed similar to a surfboard, 3) something similar to the thin heat-on skin for rc aircraft, 4) other ideas.
POWER:
This is really more of a guess than anything, but perhaps a motorcycle style engine? They have transmissions in them stock, could gut them except for gear of choice. If you look at something like the hayabusa, it makes about 180hp stock at its max... I have driven my turbo hayabusa on the highway for several hours at a time at 5000rpms, though not much throttle (doesnt need much for bike). But with sufficient cooling this could be an option.
This offers an interesting concept though, if the aircraft design calls for huge power at takeoff, then the engine can do 180hp, then once airborn throttle back to 70-80 or so. Maybe with a small turbo setup do 100hp at 5000rpms steady state. They weigh about 175lbs ready to go (fuel, fluids, exhaust, etc). This can probably come down quite a bit with some components replaced. We made an intake for a motorcycle once at 2-3 lbs total weight, stock system was around 10lbs. It was also easy to make and cheap.
Conclusion:
Tell me what you think of this idea. Once again the overall idea is that a cheap core structure is built and and the complex airfoil and under-body shapes are filled in a single pouring of foam (core suspended inside foam).
So the basic idea is to make a structure out of something cheap, like aluminum, and then suspend it into a mould and pour a foam inside it to make the wing shape. This will be referred to as the 'core'.
CONCEPT:
If the core structure could be made with tubes and waterjetted parts, then it could be made very cheaply. Tube is also very cheap. By using foam, the structure of the wing doesn't have to be incredibly perfect and highly aligned, since there will be no rivets to hold on the body panels. The main load would ultimately be carried by the aluminum structure (or carbon tubes, etc), but the foam would fill the space between the structure and the airfoil, lets say ~1 inch thick. My current thought is to base the idea on the Dyke Delta or something similar. The entire wing and under belly can be done in one poured foam mould.
DESIGN:
The Dyke Delta has a wing surface area of 173 ft^2, an arbitrary guess is about 4in on average thickness (since some areas are way thinner and way thicker, total guess though). So that would make the wing about 58 cubic feet. The lightest foam from this site:
is 2lbs per cubic ft, so 116lbs in foam. This idea would mean that this step would be the wing and structure of the entire aircraft. It would still need an engine, canopy, vertical stabilizer (perhaps foam as well), interior, landing gear, etc. But the overall airframe could be made quickly and cheaply, and I am imagining quite strong.
SKIN:
As for needing skin, it would kind of depend... There is chance that the foam would have an acceptable surface finish out of the mould. If not, several options can be considered. 1)Fiberglass before mould halves are combined and poured, 2)fiberglass after part is removed similar to a surfboard, 3) something similar to the thin heat-on skin for rc aircraft, 4) other ideas.
POWER:
This is really more of a guess than anything, but perhaps a motorcycle style engine? They have transmissions in them stock, could gut them except for gear of choice. If you look at something like the hayabusa, it makes about 180hp stock at its max... I have driven my turbo hayabusa on the highway for several hours at a time at 5000rpms, though not much throttle (doesnt need much for bike). But with sufficient cooling this could be an option.
This offers an interesting concept though, if the aircraft design calls for huge power at takeoff, then the engine can do 180hp, then once airborn throttle back to 70-80 or so. Maybe with a small turbo setup do 100hp at 5000rpms steady state. They weigh about 175lbs ready to go (fuel, fluids, exhaust, etc). This can probably come down quite a bit with some components replaced. We made an intake for a motorcycle once at 2-3 lbs total weight, stock system was around 10lbs. It was also easy to make and cheap.
Conclusion:
Tell me what you think of this idea. Once again the overall idea is that a cheap core structure is built and and the complex airfoil and under-body shapes are filled in a single pouring of foam (core suspended inside foam).
