Saturday, August 16, 2008

Spar braces

Build hours: 577

The spar has been positioned and attached temporarily to the bottom angle. The outer spars have to be made and matched to the center spar before the center spar can be fastened permanently. The spar braces were made and ready to rivet. The edges of the spar braces were rolled over to give a more finished look and provide additional stiffness in the process.

The spar brace edge required notching to set on the spar caps.

This shows the spar brace bend angles required to match the fuselage and the bend on the outer edge. The blank had additional width for bending in the brake. After bending, the extra material was cut back.

The wooden brake works well for aluminum up to .025 and even short pieces of .040 but it was not up to the task of bending .062 2024T3 across the grain. A 17" brake made from leftover 1/8" steel angle was cobbled together. The platten has a 3/16" radius which is required when bending .062 2024 in the T3 condition (3X thickness).