Project light is nearing completion

I have only one step left to complete my light. It has been a long slow process. Since most of the materials are expensive or annoying to source, I have really been taking my time. Ironically riding to work has slowed my progress since it has made trips out at lunch not possible, but some rainy weather has meant I have driven in a few times and so had the chance to go buy some switches and screws etc.

My main concern has been attaching the heatsink to the cup. After much umming and ahhing I decided to go with simple self tapping screws. I bought some stainless steel ones (designed for sheet metal) because I figured they would be the strongest. I drilled two holes in the bottom of the cup on either side of the large hole which admits the LED, then I marked, punched and drilled the 2.5 mm holes recommended by the packaging for the self tappers. 4 screw head twisted off later, I enlarged the holes by half a mm to 3 mm and they tapped nicely. This made sense in the end since the recommended pilot hole size was for sheet metal, not solid aluminium.

Next I drilled a 5.5 mm hole in the side wall of the cup to admit the wires. On my next shopping trip I bought some switches, which the wire hole was the perfect size for. So I drilled another hole for it and then another 2 5.5 mm holes for the mounting bracket. One word of advice on working with stainless steel: Start with a small pilot hole, keep the drill speed low and the enlarge the hole with successively bigger bits.

The bracket I am using is a standard reflector bracket which Paul at Smith Cycles gave me for nothing, it is perfect.

Here is a photo of the cup all put together:



Here is another showing the heatsink, it looks a little like some weapon from a dodgy sci-fi movie.