Sunday, 5 October 2008

New Door Hinges

Three pictures showing the manufacture of new door hinges. The original hinges were fixed with four small bolts to the wooden door frames. These had worked loose over time as the holes elongated so I've decided to replace the old hinges with a set that will be welded to the fuselage frame. This idea came originally from Rob Lees when he restored G-BREY.

The template was made from needlework template sheet which is a fairly stiff plastic sheet marked out with a grid pattern. I was able to bend it round the original hinges which gave an acurate measurement including the 90 degree bend which would need duplicating in the new hinges.

The hinges are made from 0.063" 4130 steel.

The hinges after adding the 90 degree bend.

Offering up the hinge to check alignment with the hinge on the door. The hinge was deliberately left 'long' because it will have to be fitted to the curve in the fuselage tubing. The door and frame will be used to get an exact fit when welding although I'll use the old door frames and not the new ones when tack welding the hinges in place.

New Door Frames

Mid September and I receive an 11 foot length of 2"x8" Ash wood which will be used to replace the old door and skylight frames. I've decided to go for the door frames first as they are in some respects easier to manufacture.

The first task was to cut a set of 1/2" deep blanks from which each new frame would be cut. After some head scratching we (myself and a good friend David who has an aladins cave of a workshop with all manner of equipment) managed to get 9 blanks from a single 4 foot length of Ash.

The original frames were used as templates for the new frames, in hindsight I should have spent more time studying the old frames as there were some defects which although not serious or problematic (after all the old doors fitted OK) have to some extent been copied onto the new frames.

The new frames were cut using a small band saw and jointed by hand. To provide the required strength and regidity, the frames were screwed and glued and left to cure in situ. Two pairs of hands make this job a lot easier, in this case my farther John spent two days helping.

The frames still need finishing off which will include a slot for the door catch, sanding down, varnishing and final fixing although this will be left until after the fuselage is beed blasted and primed.

The doors are slotted into the frames to check that all is well. I'm happy that the fit is snug and when finished the doors will not be draughty as long as some door seal is used.

Not much of a gap here.

I'm still working on the aileron and have started the metalwork for all the bits that will need welding onto the fuselage. This is because I would like to finish both ailerons (minus the covering), get various bits welded onto the fuselage and crack on with the interior before the end of the year. Next up, the door hinges.