What did you mod today?

Yup, I definitely meant “better than the D25’s stock UI”. Thanks Dale, I just added clarification.

gChart that’s an awesome mod :+1:

Did a emitter reflow on a Coast HP1 today.

I have two of them, given as gifts some time ago. And they rarely see any action.
Mostly because they have a horrible cold white blue 6000K+ish emitter.
And they are zoomies, which I’m not a fan of.

Now, given my recent “level up” into the world of reflowing, why not give one of them a proper emitter.
I had a SST-20 J2 JC1 2700K CRI95 laying around, mostly to test how Luminus’ take on a 2700K performed.
swip swap and the SST20 was reflowed to the tiny custom copper PCB the HP1 uses


The PCB is being pressed down to the shelf via the plastic “thing”

Comparison GIF

Sequence:
0: D4 219B 4500K
1: HP1 2700K flood
2: HP1 6000K flood
3: HP1 2700K throw
4: HP1 6000K throw

2700K is of course a novelty, its very very warm. But at least it’s better than the CW, and now has 95CRI :smiley:

Hacked together a 4.15$ C8 and an e-switch TC driver running Anduril. It kind of works, still has issues and I’m not even sure if this is a heresy or not.

Interesting. Pics or additional details? How do you have it wired up?

A C8F host is so cheap, easier to go with a light already setup for e-switch. Just wish they made a 1 LED version of the C8F host. Would be a cheap mod for sure.

Only a driver pic so far, it’s still quite a mess. I’ll do a writeup if I get this to work reliably.
The setup basically is this: there’s a ~100R bypass resistor in the head parallel to the LED so that the body functions as the positive pole (when the LED is off). In the tail, there’s a 47µ filter cap behind a diode. You rely on PWM to keep this cap charged, this means you have to stay below a certain duty cycle. The rest is pretty much a standard ATtiny 85 driver 1+n+FET(w/shunt).
I’m still having issues at the top of the ramp (µC resets) so my max duty cycle is probably too high. I also suspect 18kHz PWM might cause instability. May be a sketchy diode or too strong pulldowns, maybe the springs need bypassing. Maybe bad Anduril config, it sometimes steps down like it’s thermal throttling but I’ve got thermal management disabled (and thus can’t even re-calibrate the temperature.) :question:
I pretty much had it stable when running from a lab supply so the error can’t be that far.

This won’t win any beauty contests…

Yes but where’s the fun? It already exists, and anyone can have it.

Ohhh, ok - you are doing what CK did with a Folomov 18650S custom driver mod. This is pretty cool!

Maybe Anduril is doing LVP stepping down, not thermal? Is it getting good batt+ voltage?

Hope you get it worked out, this would be really nice! How you doing the PCB stuff? It's not OSHPark you got there.

I see our typical parts for the FET gate resistors. Not sure what those 10K's are doing though, maybe that 1K is for the AUX LED.

Yes I suspect it doesn’t get a good supply. “Good batt+ voltage” is relative when it has to get drip-fed through a resistor and a diode…
1k is for the switch LED, 10k are pulldowns for the 7135s (the ATtiny only has internal pull-ups so this was intended for stability but may not be needed at all. ) The cap and the RST pullup are tucked away under the µC.
It’s made 90s- style: laser printer, glossy paper, clothes iron, FeCl3. If I don’t rush it I can get down to 0.5mm pitch. Downside: 2-layer gets tricky; upside: lead time is half an hour or so. Costs: a few cents.

Wow, making a PCB in a 1/2 hour for a few cents ain't bad.. I'm not familiar with this technique but I'm gonna ask around for sure - nice ! :BEER:

I’ve heard of that, but never tried it. I think CRX used it in this year’s OL contest.

  • Print your traces on glossy paper using a laser jet
  • Use an iron to transfer the toner to the surface of a copper-clad PCB
  • Soak the PCB in the solution. All areas not covered by the toner will have the copper eaten away
  • Clean off the board, removing the toner
  • You now have a custom PCB (but no solder mask or silk screen… or vias)

I’m interested in how that was done. Homemade PCB in 1/2 hour for a few cents? … sounds lovely!!! :heart_eyes:

My buddy EE here said he was etching his first PCB's before high school - we're talk'n the 70's. There's not much to it really, but without simple small thru holes, it can get dicey for us. You still have to design your circuit layout and use a graphics app to draw it (probably a PCB design app). Old days with bigger parts and fatter traces, you could use a permanent marker to write directly on the PCB for etching out the copper.

:+1: Aye, that’s how it’s done. Some people use a laminator to fuse the toner to the PCB, it makes it a bit easier (If you’re too hot or apply too much pressure, the toner gets squished and spreads out - this happened here but not too bad. If too little, it doesn’t stick.)
2-layer can be done but getting both sides aligned can be tricky and overall it’s more complicated. If I can get away with it, I try to cram everything onto one side (except for filter caps etc.) In this case, the other side is just 2 milled concentric rings.

On vias - some people have come up with DIY methods for plated through holes (PTH), but again, it’s quite involved. It’s an electroless copper method where first you have to coat the inside of the holes with ITO or conductive silver plus some sort of catalyst before plating. I don’t think it’s worth the effort for small one-offs like this one.
Another way would be rivets like these - looks sensible for bigger connections. I just use a short piece of copper wire.

If I needed a full sheet of identical drivers - involving large amounts of routing - or a large PCB in general, I’d go with OSHpark or similar. But for small ones like this where not much can go wrong and you can check for errors in a minute, this is okay. And you can practically do it on the kitchen table (if the woman is not at home :smiley: )

First time modding a flashlight today, was pretty fun and surprisingly easy.

Emitter swap on a BLF Q8 to some 5000K LH351Ds, swapped the switch LEDs to orange, and flashed Anduril. All in all a productive evening.

First experience with the LH351Ds too, ordered them from Arrow after reading some favorable reviews and I’m happy I did. The tint is far nicer than the stock XPL emitters.

Nice Q8 mod, I like the orange switch led’s. :wink:

That is a nice Q8 mod, but wondering how/why the 5000K 351D's look so much better than the 5000K 3D XPL's shipped with the BLF Q8 unless they changed them. From the maukka tests, it's hard to tell: https://budgetlightforum.com/t/-/48542, but the LH351D appear to be above the BBL, but not really sure, and I don't know how the XPL 3D's compare.

The Samsung emitters make a cleaner neater beam in my experience. I’ve only used about 70 of them so far so I could still be on the learning curve…

What DB Custom said, essentially. I found the XPL 3Ds to have an off-white tint with a bit of green mixed in and a rather unpleasant tint shift in lower outputs. The Samsungs on the other hand produce an extremely clean, pure white beam at all outputs from what I can tell, and are also high CRI which adds to the noticeable difference.

Same thoughts about the XP-L HD 3D.