Working on a pa-18 wing that was partially built. I decided to take the wing apart and start over for a few reasons.
In measuring/locating holes for all things drag struts, butt hardware, strut attach points, rib locations and looking at the piper drawings and sturm's drawings I made a discovery which is baffling. I'm sure this confusing only because I don't know the whys....
From what I have seen (which is not much compared to others) quite a few people build wings on sawhorses. Ie, a FLAT resting place so the bottom of the front and rear spars would rest on the sawhorse. And some hieght adjustment would be made to the wing tip rear spar for washout. Makes sense.
Looking at drawing 10645 you can see where the rear spar sits quite a bit lower than the front spar even though this illustration is in a vertical presentation.
what I find confusing is, why the ribs are constructed with what appears to be a flat bottom and the voids where the rib slides over the front and rear spars are SQUARE to the bottom edge of the ribs leading me to believe the bottom edges of the front and rear spar should be on the same plane. Yet according to the drawings they are not on the same geometric plane.
Can anyone provide pics, explanations to this.
thanks in advance...
-MB
In measuring/locating holes for all things drag struts, butt hardware, strut attach points, rib locations and looking at the piper drawings and sturm's drawings I made a discovery which is baffling. I'm sure this confusing only because I don't know the whys....
From what I have seen (which is not much compared to others) quite a few people build wings on sawhorses. Ie, a FLAT resting place so the bottom of the front and rear spars would rest on the sawhorse. And some hieght adjustment would be made to the wing tip rear spar for washout. Makes sense.
Looking at drawing 10645 you can see where the rear spar sits quite a bit lower than the front spar even though this illustration is in a vertical presentation.
what I find confusing is, why the ribs are constructed with what appears to be a flat bottom and the voids where the rib slides over the front and rear spars are SQUARE to the bottom edge of the ribs leading me to believe the bottom edges of the front and rear spar should be on the same plane. Yet according to the drawings they are not on the same geometric plane.
Can anyone provide pics, explanations to this.
thanks in advance...
-MB