mstull
R.I.P.
In the course of designing a super light weight U/L, I stumbled upon an idea for tips and roots. Continue the (ladder frame) spars (about a foot) past the last rib, and just connect the ends of the spars with an oversize compression rib, that's strong enough to take the fabric tension. If it's close to the same diameter as the spars, it can be attached with simple gussets.
The ends of the wing wouldn't have an airfoil. But very little efficiency would be lost, since tip losses spoil the lift on the outer foot or more anyway.
They would be very simple, light weight, and inexpensive, and wouldn't require any special materials. I've always dreaded making tips, knowing how much strength and bracing they need. I've typically spent way more time making tip and root ribs than all the rest of the ribs put together. These would be so easy to fabricate, and only a little less aerodynamic than the other common solutions.
********
Even though I'm not building a new U/L this winter, I haven't stopped designing them. I can't seem to design anything that would all-around perform better than my present plane. So I can't quite justify all the work and expense to make a new one.
This super light weight U/L is designed to come in 90# under the weight limit. The lighter weight, and flaperons over 50% of span, allow small, very light weight wings to pass the stall speed limit. It uses a PPG pusher engine, and my usual cockpit. It would be inexpensive and easy to build with no welding.
The ends of the wing wouldn't have an airfoil. But very little efficiency would be lost, since tip losses spoil the lift on the outer foot or more anyway.
They would be very simple, light weight, and inexpensive, and wouldn't require any special materials. I've always dreaded making tips, knowing how much strength and bracing they need. I've typically spent way more time making tip and root ribs than all the rest of the ribs put together. These would be so easy to fabricate, and only a little less aerodynamic than the other common solutions.
********
Even though I'm not building a new U/L this winter, I haven't stopped designing them. I can't seem to design anything that would all-around perform better than my present plane. So I can't quite justify all the work and expense to make a new one.
This super light weight U/L is designed to come in 90# under the weight limit. The lighter weight, and flaperons over 50% of span, allow small, very light weight wings to pass the stall speed limit. It uses a PPG pusher engine, and my usual cockpit. It would be inexpensive and easy to build with no welding.
