Fuselage sides aligned and then tack welded at rear of longerons. Bottom longerons from 0 to 48 located on bench. Spacers to set top of firewalll and rear spar carry through. Tie bar to get centre of cross members directly over centre line using plumb bob. Lower cross members as 24 and 48 tack welded in place. Front spar carry through tack welded in place. Everything aligned so far!
There is some confusion over the datum for the width measurements in both the ACS plans and the originals from Wittman. Measuring longeron tubing centre to centre
I'm using 40" for the two spar carry thoughs and 37" for the firewall top cross member and 34" for the firewall lower cross member. The lower cross member at station 48 is 38" and of course the longerons come together at the rear fin spar at station 174 7/8. All other cross members will be filled in following the natural curve of the fuselage sides.
There is some confusion over the datum for the width measurements in both the ACS plans and the originals from Wittman. Measuring longeron tubing centre to centre
I'm using 40" for the two spar carry thoughs and 37" for the firewall top cross member and 34" for the firewall lower cross member. The lower cross member at station 48 is 38" and of course the longerons come together at the rear fin spar at station 174 7/8. All other cross members will be filled in following the natural curve of the fuselage sides.
