I’m looking to build my own outdoor headlamp from scratch. I’ve been 3D printing & sewing for years so I can make the entire shell & elastic headband myself. I’m thinking of getting some medium-powered strip LEDs, coating them in clear flexible epoxy of some sort for waterproofing & shockproofing, and encasing in the printed shell (maybe with a thin copper strip on the backside for heat dissipation, but maybe I’m just being paranoid about overheating and that’s overkill). I’m also comfortable with the extra weight of a back-of-the-head power supply.
The primary goal is all-day-long low illumination, not maximum power. There are good work/construction headlamps out there, but I’m not able to shell out 100USD+ (double in my local currency) for a headlamp that will last 12+ hours, and I have plenty of experience with small soldering projects.
The parts I’m a noob on is the driver & circuit board. I’d like to make the led strip usb-c rechargable (or hell, maybe even a 5.5mm jack connector with a dedicated ac-to-dc power supply) with a LiFePO4 battery (better resistance to temperature, non-explosive failure & good for low-draw use compared to Li-ion), and I’d ideally like to have 2 or 3 light intensities (I could probably cheat and just change the number of leds that light up rather than use variable power).
What would the usecase be?
On the one side, you write like you work underground and have explosions all day long around you, on the other hand I read 3d-Printing and selfmade straps.
Why not just buy a good headlamp and carry some spare batteries with you?
A Sofirn HS20 isn’t directly expensive and 4 more 18650 are neither.
There is a newer version, the HS22, but that one I dislike because you can’t open it. One of the newer generation Sofirns that you can’t repair without destroying it.
And for: “better resistance to temperature, non-explosive failure & good for low-draw use compared to Li-ion”
You wear that thing on your head, so even if it’s -20°C it won’t be that cold for the cell. I haven’t heard of a exploding LiIon in quite some time, so I don’t see that as a negative for LiIon. And low draw - if we’re not talking about 20mAh, you can disregard that point.
Shockproof doesn’t mean explosions, it just means rugged, basically. You wouldn’t be able to step on your computer mouse with 10lb steeltoe winter boots, for example, but you could do so with a shock-proof phonecase. Or drop it from a height. The usecase is construction, so outdoors, extreme dust/debris/solvents, pouring rain, likely experiencing the occasional impact/crushing force of metal-on-helmet.
And yes, 3d printed nylon/abs can certainly be quite resilient, if designed and printed properly, just as anything homemade, and the limitations of FDM can be overcome by annealing. As for sewing, there is zero difference in the manufacturing process between diy and mass-produced. There’s nothing magical about products made by companies, it’s all just human beings making things. I even have an “industrial” sewing machine, which certainly makes the process easier but the end result is no better than what a skilled artisan can do by hand.
Carrying extra batteries means charging all of them every single day, so at that point I might as well just buy 3 dollar store headlamps and swap them. The point is to avoid the hassle, not to mention the risk of having a lithium ion cell in my pocked getting covered in gravel, paint, cement dust, mud, soaked in rain, etc, all day every day.
Whether you charge one or three batteries, you are going to have to do it every day. Unless you have many more spares.
Do NOT carry any loose batteries in your pocket.
Wurkkos has a pretty good sale on the HD15 for the next few days. On their site $22.
Separate spot and flood. The flood is reasonably wide. Get the 4000k. Get some spare 3500mAh batteries.
It’s more than sewing. You need the buckles and adjustment bits and a way to clamp or hold the light on the strap and you need to be able to adjust it up and down.
Don’t try to reinvent the wheel unless you have a really good plan.
I’m not hearing a really good plan.
btw what does “low lumen” mean to you?
low lumen and a wide angle would mean not a lot of lux if it is what I call low lumen, so <100.
For that, you probably won’t even have to change the battery.
Do I understand this correct, you essentially want to reproduce something like this (just without the little spot thingy), just in rugged:
I think your idea is fairly straightforward and achievable so long as you keep the expected lumen output low so as to not have issues with LEDs overheating.
Do you have an idea for how many lumens you’d want? Can then back calculate number/size of cells required.
It would be easier to source an off the shelf LED driver for “regular” lithium ion than Lifepo4, given the extensive use of NMR etc chemistries. Lots of driver options from Kaidomain, convoy, etc with various mode options and power outputs - you’d just have to figure out the 3D printed housing and wire it up with the cells and LEDs.
