New Builder Plan P412

[ScottS]

New Builder starting on the fuselage, from Amboy Wash. I've built a Kitfox and a Sonex which I'm currently flying, looking to get back in the low and slow flying again. fuselage bottom frame is done, now starting on the top frame, the question I have is between station L and N if you put a straight edge along the outside of the frame it bows inward, possibly is this for flap clearance or is the 25" width at station M incorrect? Hopefully I posted this in the right place, I couldn't find any posts regarding this topic.

Thanks,
Scott Patrol plan 412

[ScottS]

This shows up on plan page 18 top frame, then on page 19 cross section sta. E-M shows the 25” length.

[Ed Welfred]

The 25" measured at station M is correct. Each section of the longerons from P to N then N to M and then from M to L are straight. It is the points at N and M where the bends occur. The points at N and M have bends going in two directions. If you are building from a kit either Marks or VR3 the longerons will be prebent and you only have to rotate them until every thing lines up. If you are not building from a kit then bending this area is a challenge. The longeron from station L to the tail post does get a gentle curve. Also note that the longeron from P to N is not parallel to the centre line or to the datum that runs from station B to D on the lower longeron.
Attached are pictures of my layout. I purchased a tubing kit from VR3.

[MaconGeorge]

What kind of TIG welder are you using?

[ScottS]

Thanks, I will keep moving forward. Building from scratch. bottom and top sections mostly done, be ready shortly to put in jig.