Monday, 9 March 2009

Ailerons and Skylights


Just a quick update on the progress of the 2nd aileron. Firstly all the ribs, leading edge, trailing edge and hardware have been cleaned, etch primed and epoxied and are ready for reattaching to the spar. The spar has had some repairework carried out to fix the crushing similar to the first spar. There was also a minor crack running lengthways along the spar from the but, about 6" long and about half the depth of the spar. This will be patched as the majority of the crack lies under a plywood reinforcement plate. The spar had a second coat of varnish at the weekend so I shall be able to start reassembling the aileron next weekend (although I may have to do some gardening as well!).


In the mean time, I progress with the skylight woodwork.

Lets refresh our memories of the old skylight. It extended from the windshield back for nearly two bays, held in place by wooden formers and steel angle (see below).

The second bay does not increase the viewable area and just adds to the weight of the aircraft for no advantage; so on the rebuild I
will stick to a single piece skylight covering the first bay only.

The frame will be made from the same Ash plank used to make the door frames, using the existing frames as a template. These are rough cut with a band saw then shaped with a spoke shave and finished by sanding. Various notches where cut with a fine chisel.

Some time later after many trial fits, the basic frame sits on the fuselage. Note that instead of using a piece of steel angle on the sides, I'm using 1" thick wood (still much lighter).

My plan is to fix the skylight (3mm clear acrylic sheet) to the frame by embedding a threaded insert (below) into the underside of the frame that I can screw into. In addition I will have four internally threaded steel tubes welded to the cross frame of the fuselage which will suport the skylight and give it some rigidity

I hope to pick up the acrylic sheet next week which will be cut to shape, drilled and used to determine the location of the threaded inserts.

Next week I'll try and update you with the aileron reassembley and possibly a bit more on skylight progress. Untill then happy flying.

1 comment:

Skylight Specialists inc. said...

Just make sure you have a large enough whole where the screw goses throught he acrylic so that when it expands and contracts it won't crack it.