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Step Zero

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dhebda

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Greetings, all!

Santa brought a delivery from Steen Aero and I just ordered the builder’s manual from @Beej. I’m not ready to start building airplane parts yet (learning to weld should come first), but I intend to start slowly by making a forward fuselage/cockpit mock-up as suggested by Tony Bingelis. I figure I can work out some of the truss geometry with wooden dowel rods and plan an instrument layout in a reasonably small portion of my workshop before going off the deep end. And if BJ's suggested order of build starts with the wings as is suggested by his table of contents, I'd be more likely to start with some ribs before full retirement from the day job.

I’m sure you’ll hear plenty of dumb questions from me as I move along, but so far everybody seems extremely helpful … so thank you in advance. And feel free to mock me when necessary. Before you all hassle me about measuring with a micrometer and cutting with a hatchet … I know. Point well taken. I harbor no illusion that I’ll be able to build a Skybolt to the same accuracy as a Super Hornet, but I need to know the target: aim small, miss small.

In the builder’s guide from Steen, there is a recommended modification to the upper longerons in the cockpit area to provide a straight line for canopy mounting. Am I interpreting this correctly (red lines)? I have also included the additional members show in the Dec ’76 edition of Skybolt News to provide a mounting point for the rear instrument panel and forward shoulder restraints (green lines). Looks like a +3 lb modification, but we'd need to support that instrument panel anyhow.
cockpit_upr.jpg

When I do this for real, the builder’s guide suggests building the sides flat and then bending them to converge at the tail. My question: if the bend in the top and bottom longerons don’t happen at the same station, the upper longeron won’t remain on a waterline. If I didn’t make the mod described above, the top longeron would bend at station 51 and the bottom at station 57-1/8. Wouldn’t that make the upper longeron slope downward toward the tail? If I make the double-bend described above, doesn’t that just complicate things? Too small to notice?

Has anybody begun work on the D model? I was talked out of getting that addendum when I called Steen, but am seriously considering blazing that trail. Do the cabanes attach in the same locations, or is there a significant difference to the top view near stations 24-30? If you have a scan of that part of the plans, I still promise to buy them from Steen if I go that route.

My mock-up won’t go all the way back to the tail (will stop at station 99), but I’d like confirmation about how the longerons mate the tail post. I saw the detail on sheet 4 and even more in Skybolt news for the upper longerons … but what about the lower ones? Is my interpretation below correct? Of course, there will be some carving of one longeron to make that weld cluster come together.
tailpost_lwr.JPG

Final question: Is there a good thread on this forum for fuselage truss layout? I read @taff 's photo-journal of his wing build, and it left me super motivated.

Hapy new year to all,
Derek
 

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