Some wing progress

I needed a good weekend off from work ... busy week.  But it turned into some quiet and productive time spent on Goat.  It also helped that the weather in DC was sunny and around 75F for highs so the garage was comfortable.  Nice to be back outside.

Started with the wing at this point on Saturday morning.  Clamped a straight-edge to the wing root brackets on the right and then used a (pretty much) flat floor and a quick-square to make perpendicular marks for the wing tube retention rivets.

With the tubes in this position, it's also possible to make tangent lines atop the spar tubes using a long straight-edge.  Geometry is starting to talk again as it comes together.  Those first few marks were the hardest to sort out.

 I did find one tiny "error" in the drawings.  I'm putting error in quotes because it isn't huge, but did make me pause long enough to get it right... the compression rib between the spar tubes have the hole closest to the spar at different distances.  Sparing you the math, the LE hole is 0.25" from the end of the compression rib and 0.375" from the other end of the compression rib.  All the other drawings have holes at 0.375", so I'd recommend lengthening the LE brackets by 1/8".

 First time with a big mock-up of the wing half and struts.  Okay, so I've officially decided to go with the strutted version of Goat rather than the cable-braced version.  Not only do I think it looks cooler with struts, I've read enough suggestions from Sandlin and others the strutted version is likely less drag (provided the struts are faired of course).  I'm cool with less drag.

The choice to go strutted has some other structural implications.  My cabanes were set up with the cable attachments, so it'll take some reworking for strut attach brackets.

It's also starting to sink in how large this wing is going to be.  I took some pictures of the full 36' span and it seems gigantic!  It's so big, the pictures of the full span were either washed out or really dark.  Guess you'll have to wait for me to get the whole thing assembled for a full-span shot ;-)

Trailing edge wing root area.  Pretty neat seeing all the bolts and load paths here.  Busy. 

 Leading edge wing attach area.  Lots going on up here.  Can lose the upper bracket since struts don't need a king-post.  Every ounce counts.






Edit: Sandlin asked a couple questions about the wing load test and the AVL analysis.  First, I heard back from the load test poster who said it sadly wasn't a Goat wing.  I am definitely planning a load test of my own though, so we'll have some real numbers.  Second, the AVL analysis is primarily for stability and control analysis.  I haven't touched the model since, but will post it here for others to play with.