The stiffeners for the test wing arrived, they are amazing!
The panther spar is typical in design in many respects. It uses a 6061 T-6 AL angle as caps that are riveted to the spar web. The wing skins rivet into the angle as well. The inner portions of the spar where loads are very high have several layers of strips which carry the cap loads. As you progress out, and loads lessen, these strips taper and step down. At the point where loads are light enough and the angle cap can carry the entire load, the further out these caps can be tapered. Panther spars are somewhat different than other in that the flange strips and webs and vertical stiffeners have all been incorporated into CNC machined stiffener plates. It has 3 .250 thick plates, a .063 inner web and a .032 outer web. The rivet holes in these only require reaming the final .010. The angle flange strips in the kit wings will be predrilled as well. So to assemble you will remove the parts from the box, cleco together, ream holes to final size, debur and then rivet. The plates have the wing mount pin holes reamed to the proper size. The jig welded forward fuselage also has the mount holes pre-drilled. Combine these two and you have the typical critical step of rigging wing to fuselage and drilling accurate holes already finished for you!
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The spar should be riveted up mid-week!
We are also working on the rudder pedals, toe brakes and control stick.
Photos coming soon.
We really like the ease of constructing the flat panel rear fuselage of the Zenith and Sonex, but the sharp lower corner looks… well it looks a little un-finished. We wanted a little improvement in appearance without a major increase in work. You can see a photo of how we achieved this. Construction of the rear fuselage has begun with longerons cut. We took a minute to make a sample skin/longeron section to show how we are doing it. The ¼ radius on the longeron is very simple to do with a router and only took about 20 minutes, plus 10 to sweep the chips of the floor. More soon!