Small Title

F501: Working Headlamps


Photo: F500-46.jpg (9K)

The body of the lamp is a household mirror fixing screw cover (the hemispherical chromed type with a screw thread inside). I snipped the screw thread down to about 3mm and ground the cut end smooth with a mini abrasive wheel. This forms a flat stub to which the bulb's glass envelope will be Araldited to keep it in position.

I glued a 4mm slice of 13.5mm aluminium tube to the lamp shell using Araldite Rapid to form the headlamp rim. Then I drilled two holes in the rim, one to take a 6BA screw thread, and the other, close to the first, large enough to accommodate the insulated base of a 6v. grain of wheat bulb - but not so large as the bulb itself. A 6BA thread was Araldited into postion to form the mounting post.

Loco Headlamp

I sprayed the lamps matt black with a silver rim and inside "reflector". Next, after feeding the wires and most of the insulated base through the second hole, I glued the grain of wheat bulb to the stub with a blob of Araldite . This keeps the bulb filament aligned in the centre of the "reflector" and stops the bulb glass envelope floating to the surface when the lens casing is filled with clear resin (Yep, resin).

The resin is the hobby type used to make clear paperweights. I fixed a 4" length of clear plastic tube to a plastic syringe. This was used to draw up a small quantity of resin (after mixing with hardener) and to slowly fill the lamp casing a drop at a time so no air bubbles form. When the resin was level with the lamp rim I added just one more drop. This extra drop exploits the viscosity of the resin to retain a convex lens surface when hardened.

The picture shows the headlamp in position and illuminated with the running lamps.

The photographs and text on this page are copyright (c) Paul Backhouse 2000 and may not be reproduced or distributed without the owner's permission.


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