CLOSED 2018 Yuji 3200K high cri 5mm LED group buy

[tech25]

Gotcha thanks. I'm going to pick up some 2032s. I prefer longer runtime.

 

[PJ]

I picked up a few Maglite M25IT incandescent 2C lights from Target abput a week ago. These things were made for 5mm LEDs. The bipin bulb and the 5mm LEDs are roughly the same diameter and the hole in the reflector is about 8mm I cut the leads down to the length of the bulb in the light and fired it up. No real hotspot but it looked promising. I took another and cut the longer lead flush. Oh yeah! Now I can focus it and get a hotspot.

Intrigued, I dug up a Maglite 2 cell bipin bulb/adapter I got from Home Depot for a penny and put the cut-down Yuji in an older PR based 2C Mag. Works fine and I got the familiar ring-y focusable Mag beam pattern. I checked this one and it was drawing about 46 mA with new Diehard/Dorcy alkalines. This is overdriving them but I think someone did a test and they seemed to be able to handle 50 mA fine.

 

[Hondo]

Cool PJ, the only PR/bi-pin adapters I have found were too expensive, I'll just solder the LED into a gutted PR bulb shell. Put that sucker in a 2D incan Mag and you'll have light until spring! I have a Rayovac 2D Industrial with a cut-down MJLED soldered in to a PR can, and while it seems like it will run longer than I'll live, I can still switch to a boosted MJLED "bulb" from the spare bulb holder and have high brightness again from near-dead batteries. A real zombie apocalypse special!

I like having lights for these that focus for versatility. My Rayovac 2AA is a bi-pin bulb drop-in, once I drilled the reflector opening up to 1/4 inch. Good focus, decent throw. My Gerber Infinity Ultra gives a zero-spot full flood, even though I polished the "reflector" in it when I had first modded it with a Nichia. So it just depends on the angle of the reflector walls and the depth of the LED in it as to what focus you will or won't get.

 

[PJ]

Dec. 23. The ML25IT is still going. I checked the current at the tailcap almost exactly one week after I started it and it was 8 milliamps. Output was dimmer but still usable in candle mode.

I took a Yuji and sanded it with 1500 grit sandpaper and put it in the older 2C PR based Mag. The hotspot had a dark hole in the middle when I dialed it in. I messed around with a few times at different distances to indoor walls and it did not go away. I put the unsanded one back in and it worked as before. I expected to lose the hotspot by sanding it but didn't expect to add a donut hole :thinking: When I get a chance I'll put the sanded one in the M25IT and see what happens.

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Dec. 27. The ML25IT is still going after 12+ days. I checked the current and it was 4.6ish mA. I swapped the sanded LED into this one and it blurred the hotspot a little but it seems about the same.
I took the sanded LED and put it back in the 2C PR based light and fiddled around with it. The hole in the hotspot can be dialed out on a wall about 3 feet away but stays at about 7 feet.
I also found that you don't need to trim the longer lead on the LED for these to work. I tried one in both lights, just plugged it in and they worked just fine.
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Jan. 4, 2019. Still going. I checked the current a few days ago and it was about 3.4 mA. Output is similar to an LED votive candle but still usable. I can dial it in to a hotspot and it throws across a 17 foot room. I'll have to throw one in a 2AA Mag and see what it does.

 

[PJ]

The Mag 2C ML25IT I started on Dec. 13 is still going with a 60 degree 3200 Yuji. It is pretty dim but it works fine around the house for dark adapted eyes.

Nice thing about the Mag is that it can be shut off by unscrewing the tailcap so it can be used without the head.

 

[iamlucky13]

Awesome! Thanks for the sharing your runtime test.

 

[PJ]

I finally stopped after 3 months. The light was still going but I didn't want to risk the batteries leaking. I'll have to scrounge up some new batteries and keep this ready for bad weather. Nice thing is it can be left on all night.

 

[tech25]

I get a very impressive focus and hotspot out of my Rayovac plastic bi-pin incandescent host, BTW. The wide beam is getting plenty of light on the reflector to produce a decent amount of throw, for a single 5 mm that is. And the beam is quite smooth with very minimal artifacts. Helps that it has a faceted reflector, which acts like a good orange peel surface.

I tried this today, it's a fun light that can be useful but I still have to play with the focus a bit. I'm currently loving the warm soft beam but it's a bit ringy.