I really like the Sofirn SP40, but I really hate the headband. It squeezes my head real hard; it is impossible to adjust the angle of the light without accidentally unscrewing part of it; it is hard to remove the light from the headband; it won’t hold the light with the 18350 tube; and the light is not centered on my head.
For my use, the 18350 tube is perfect. I do a lot of close-in work and always have access to a charger, so I don’t need super-bright turbo modes, or really long runtimes. Because I do a lot of close-up work I need the light to tilt up and down easily. I also need the light to be pointed where my eyes are, not a couple of inches to the side.
I designed a clip-based pop-in, pop-out holder. It is a little weird in that the plastic part of the holder sits asymmetrically on your head so that the emitter is centered. Inside the clip area there is a carved out portion to accept the knurled portion of the barrel. Because the knurling doesn’t touch the clip the up and down rotation is very smooth. You could use this with the long tube, but you would need to sand one side of the clip because the long tube has continuous knurling. I have tried it with the long tube. It works, but feels a bit lopsided.
I made the elastic holders with splits in them so that the bands can be added and removed without sewing. These splits make the holder a bit weaker, but I haven’t had a problem with it breaking and have been using it daily for several weeks. Don’t go base jumping with it. I used the Weltool Elastic Headband replacement that is available on Amazon. It is way more comfortable than the stock band.
Here is the link to Shapeways where you can print it. Sofirn Sp40 Short Tube Headlamp Holder (BFGFXV5G9) by bookeranddax
I made it so you don’t have to use Shapeways, you can just download the STL, but I figured some people might be new to 3d Printing and would appreciate the simplicity. BTW, I couldn’t figure out how to make it printable without adding a markup. If you print it there I make $1. I can re-design if you want. If you do download the file it is printable via FDM (I have included a picture of me printing it on my Ultimaker in ABS).
Be warned, however, that I don’t recommend FDM. This item needs strength in all three directions and FDM has z axis strength problems in thin section. FDM is great for proof of concept, however, and is fast and cheap. Orient it like you see in the picture, use 0.2 mm build height (stronger) and use ABS (heat will deform PLA). I would also scale the model to 100.8% to account for ABS shrinkage. Really, this should be printed in Nylon, preferably MJF (which is what I specified in Shapeways). Lemme know what you think.
