If you've seen my previous featured instructable, you know that I like to make bright LED lights that are helmet mountable. I thought my last one was pretty good, and at the time it was the best helmet mounted bike/ski light I could get for the money and effort. Well, it just so happens that a few months ago I was browsing the many different wares at my local Costco when I discovered much to my horror a bubble wrap package that contained, for the insanely low price of $29.99, three 200 lumen flashlights that are not only brighter than the one I made but also more weatherproof, shock resistent, and reliable than anything I can build. Realizing I was beaten, I bought the three flashlights and a big ol' stack of AAA batteries and went home to find a new hobby. I paused to look for a helmet mount for one of these things before gathering my tools and workbench into a giant garbage bag and heading to the knitting store for some yarn and crochet hooks.
Boy was I pleased to find that there was still a use for my craftiness after all! I found a lot of DIY solutions utilizing velcro that didn't look particularly stable or adjustable. I saw some 'universal' mounts out there that looked flimsy and dubious just from the pictures. Nobody had anything that utilized the O-ring trick, which surprises me considering that so many biking accessories (from lights to speedometers, what have you) have gone the O-ring route, because it just makes so much sense. Overall, it didn't look like anyone was really trying all that hard to make this work. It seems there just isn't any incentive for bike light manufacturers to build and sell a cheap accessory that would essentially render their entire high end, higher margin product line of over priced bike lights obsolete. Go figure!!!
"Well then," I thought, "Maybe I'll just postpone burning my workbench and tools in one giant pile next to the duck pond for another day or so and see if I can come up with a solution that will make me look at least as brilliant and innovative as I looked in the last instructable."
So I got to working, and re-using the O-ring mounted base I created for my last light, I came up with an adjustable mount for one of these venerable, screaming good deal, bright lights. I think that, combined with a good 900 lumen bar mount light, this should brighten even the darkest trails when I want to do some after work biking or skiing in the dark depths of Winter.
The big advantage this approach has over just about any other mount I've found for any sort of light is the big wing nuts that operate the tilt mechanism. Most light mounts have some claptrap with a screw and some sort of nylock nut or similar device that is always either too loose or too tight when you're covered in mud, it's snowing, and your flat blade screwdriver is on your Leatherman which is currently in the top of your pack which you would have to take off in order to retrieve. Why should you have to be getting out a tool to adjust your headlamp anyway? And shouldn't the tilt be something you can adjust quickly and the lock into place? Also, everyone knows that tiny screws and nuts are intrinsically predisposed to work themselves out of place and onto the ground only in the dark and only over rock slides and gravel piles. So why not go with a design that's a little less stupid? The mechanism I have devised can be easily adjusted even with the most be-gloved or be-mittened hands.
Step 1: Get a rough idea of your dimensions....
The first thing you'll want to do before bending, drilling, or soldering anything is to get a rough idea of where bends are going to need to happen. I did this the same way I did it in my last Instructable, by using cardboard from a cereal box.
I like to use brass to make things, because brass is easy to solder, easy to machine, easy to bend, and relatively strong and durable with a high fatigue life, meaning there's a lot of room to screw things up and make extra bends. That being said, you should always do a dry run with a piece of cardboard first, just so you don't end up with an ugly, wrinkled mess by the time you're done putting things together.
So, figure out approximately where things need to bend in order to wrap around the flash light you're working with. Perhaps the most crucial part is to remember to make the loop going around the flashlight slightly smaller than the actual circumference, because you'll want some room to tighten things down. Rough everything out, including where the screw holes will go.
If I were doing this again, I would have used just one bigger screw instead of the two little #8 screws. This is because as you tighten one, the other loosens and it's nearly impossible to get it right. Also, as is evident in the final product, there isn't a good way to get a screw driver to the screw once they're in, so I would probably want to solder in the screws and not the nuts, and find some way to use a wingnut for this part of the mount as well. Alas, I was in no mood to leave the apartment and go to the hardware store, so I just used what was lying around in my parts bin. So this is a somewhat imperfect solution, like so many things I do.
Once the cardboard looks like it's an approximation of something that maybe, just maybe, could work as some sort of mount, proceed to mark all the sharp bends with a sharpie (tee hee) and then transfer that with the utmost precision to your piece of metal.