Spar Fabricating

9/5/2006

I started the left wing yesterday. I squared out the spar apertures on all the ribs [the router leaves a small radius in the corners] using a jigsaw with a metal cutting blade [seems to leave no tear-out in the 12-ply].

The spar material was then ripped on the table saw to the angles required using an adjustable bevel square. The cut angle is not the same on both spars, I think the front was 6.5 deg, the rear spar being something like 5.5 deg.

I marked of the spar stations together, this of course ensures constisancy and accuracy. Marking out the spar tips is a bit of a pain as I recalled from the last time [right wing], but was easy enough to cut with a skilsaw once I got my head around the measurements. This time I cut and fitted the ply doublers for the spar butt fittings. This will make it easier to drill the holes for the spar butt brackets via the drill press.

Note: The pic show C-clamps [we call them G-clamps in the UK] on the doublers, these need to be lightly clamped, otherwise you'll end up with glue-starved joints.