billyvray
Well-Known Member
In looking at a website regarding constructing an all-composite version of a KR-2, I noticed something in the construction of the wing that raised a concern.
In the attached photo you see a spar, with a foam sandwich rib bonded to it. All foam is Last-a-foam. The spar is constructed with graphlite rods as the caps, and glass webs. You can clearly see the dark graphlite strips. Then, a secondary foam web piece is bonded on top of the cap - notice it matches the rib height, where the skin will be bonded. It is glass-wrapped but the spar caps are not out at the skin structure....
This does not appear to me to be a good way of joining these surfaces. I know the spar could be designed to handle the loads, but I do not see that this as an adequate way of tying the skin and ribs to the spar caps.
I've never built a composite airplane. I've never designed one. Tell me I'm wrong....
Bill
In the attached photo you see a spar, with a foam sandwich rib bonded to it. All foam is Last-a-foam. The spar is constructed with graphlite rods as the caps, and glass webs. You can clearly see the dark graphlite strips. Then, a secondary foam web piece is bonded on top of the cap - notice it matches the rib height, where the skin will be bonded. It is glass-wrapped but the spar caps are not out at the skin structure....
This does not appear to me to be a good way of joining these surfaces. I know the spar could be designed to handle the loads, but I do not see that this as an adequate way of tying the skin and ribs to the spar caps.
I've never built a composite airplane. I've never designed one. Tell me I'm wrong....
Bill
