Instructables

Lightweight Headlamp from Cheap, Readily Available Parts

Featured
Picture of Lightweight Headlamp from Cheap, Readily Available Parts
100_0861.JPG
100_0862.JPG


Night skiing is really popular where I live, and while the ski resorts are adequately lit on piste at night, they are, obviously, not lit in the trees. Well, just because I can't manage to get to the resort during the day doesn't mean I shouldn't be able to enjoy a little tree skiing. Most commercial headlamps contain at least one if not more deal breaking issues, prohibitive pricing being one of those deal breakers. Home built headlamps can be really good, but often the designs I see online require the use of a lot of tools and ample shop space. Some of us are liberal arts majors who spend all our meager income on lift tickets and/or can't manage to hold on to one job long enough to afford to live in a house with a shop.

I don't have access to a CNC machine, a shop, or fancy tools, so I set out to design a headlamp that could be built in a spare bedroom of an apartment out of readily available parts that didn't require exotic tools or materials. Everything is available online and at either a good hardware store or a hobby shop.

The other considerations I had in mind are size, water resistance, and the ability to pocket the battery pack. The light runs off an inline resistor rather than an electronic driver so the input voltage can be 4.2 volts, which is the output of 4 rechargeable AA batteries. This is important because we skiers have to keep our batteries in our pocket so they stay warm, which means they have to be in a small enough package to fit inside a ski jacket pocket alongside snacks and a cell phone without making the skier look like a conspicuous shop lifter.

I also wanted the cabling to be cheap, detachable, and intrinsically strain relieved. That meant using RCA plugs for the power connectors so I could just use audio cables for the interconnects. This also obviated the need for a switch as I can just disconnect the cable when I want to turn the lamp off.

The whole assembly needed to not cannibalize straps and stuff from other headlamps. This meant I had to come up with a helmet mount that tilts as well. On top of tilting, it also needed be adjustable with gloved hands and able to be locked in place once at a satisfactory angle. I kind of like my solution, which is to utilize big ol' brass wing nuts and brass machine screws.

Here's a video of the headlamp in action at Skibowl.
 
Remove these adsRemove these ads by Signing Up
CobyHoff3 years ago
2 10cm lengths of 5/8" ID PVC pipe would hold the 4 AA's. That would be easy to waterproof. Or maybe the covered 4 battery holder from this link at Digikey.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SBH341AS-ND
Litium Batteries! they are great!
josefski (author)  Emiliano Valencia3 years ago
Thanks for the idea; I like lithium batteries, but one of my self imposed constraints is that it needs to use the most readily available, field replaceable rechargeables possible, so I think I'm stuck with the nimhs. Cheers!