Monday, October 16, 2017

D-type: making a hinge for the fuel filler cap

A while back I ordered a couple of different types of hinges from Model Car Garage, and I decided the Jag's fuel filler cap (a separate part in the Profil 24 kit, and built into the tail fin) would make a good guinea pig for a first try.

I had previously watched a series of 3 videos online (first one here) which laid out the basic principle of using the piano hinges. (MCG also makes door hinges for hot rods which appear to be quite different). The video is highly recommended, at least the first one; the presenter is very good but does tend to ramble a bit, and the videos drag a bit.

In particular pay attention to the calculation around the length of the hinge fingers versus the circumference of the pin. Best to be a bit on the short side so the finger doesn't interfere with the hinge plate that will be the glued surface. The wire in the kit has a diameter 0.016"; the circumference would be 0.016" times 3.1416, but you probably want 0.016" times about 3.

Next, if you are an old guy like me, you'll want a 4X desk lamp or a pair of those dorky magnifying goggles with the integrated lamp to see what you are doing. This goes well beyond what the trifocals can accomplish!

So it turned out fine in my view; next is sorting out the cosmetic appearance. The question is obviously how often can I open and close this without it breaking...

UPDATE: The hinge did indeed fail, partly due to enthusiastic handling on my part, and partly due to the issue of which way you will fold the hinge. See the drawing; there is clearly one direction in which the hinge tongues have to fit into the space between the opposing tongues and the hinge plate, and this direction, the probability of bending the tongues in the wrong way is high. So I installed the new hinge in the opposite direction.

Hopefully this is clear ... drop me a line if not.

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