It gets quite dark up here in Seattle during the winter, and I would still like to ride a day or two a week to work (when it isn't raining of course...).
I though you might like to know what I'm looking at for my system. This is what the exploded view of the main components look like:
This is a PVC "union" fitting for 1 1/4" schedule 40 plumbing pipe. The unit comes with the front cap and main body. The end cap is extra. I cut up the rubber slip ring to make two beveled gaskets. The bulb is a MR16 narrow spot. The glass cover is from a flashlight parts bin. Total cost so far, about $10 US. These parts come from Eagle hardware (like Home Depot). This is what the unit looks like when assembled:
The bulb fits perfectly. And the back:
After machining the parts a little on a lathe at work, they look like this:
Looks kind of "high-tech", huh?
I tried it out with a 120 to 12V converter that I have lying around to run my old car stereo in the garage). It gets very hot, so hot that the plastic gets soft and the gaskets start to "smoke". I switched the gaskets out with O rings and they seem to work better. I will however, have to provide some vent holes...
I can get a 5lb. 7 Ah 12V sealed lead-calcium battery from Hobbico here in the States. These are used by R/C modelers to runs their engine starting motors. I figure I can run two of these lights easily for the 45 minutes I need to get to work. This will cost about $18 US plus shipping. I am now figuring out how to build a mounting bracket for the two lights. A lit, amber toggle switch for each light will help motorists to see me from the side. A little primer and some black paint and it will look like a molded part.
I will have both a narrow spot and a wide flood. That should give me great peripheral and distance vision, even on the darkest part of my ride. I use a Vista light flasher in the rear. I figure that by the time I'm done, I'll have about $60-$70 US into this when they're finished. That will be far less than the $200-300 US that I would have to pay for a comparable system and mine will be 40W total, way more than those expensive store-bought lights, plus the satisfaction of a DIY project.
Thanks again for your inspiration.
I tried an experiment tonight. I was in my garage looking at my messy bench when my eye came across my Ryobi 12V drill battery and the "light" went on.
I got one of my lights and hooked it up to the battery and it ran for about an hour. I think that a 14.4V would be better, it would give more leeway. My idea was that one could make a light that is basically a drill battery with a light attached that could drop into a recepticle on the bike to use it and then drop into its charger to charge. I was hoping that I could run two 20W lights off of the Ryobi 12V, but the one maxed it out. I think that a smaller wattage bulb would probably work better. However, the smallest I have been able to find at my local Eagle/Home Depot is 20W.
The thing about the drill batteries is that they are readily available, fairly compact and most importantly, they are meant to be drained and then recharged.