This is a relatively simple, straight forward mod of an Amutorch AL1:
The AL1 hasn't gotten much attention. I think it's just from not being featured much by Amutorch, either in giveaway sponsored reviews, group buys, or on social media. It's a bit on the heavy bulky side for a headlamp, so I'm glad they don't even mention it, and just list it as a right angle light. See the manufacturer's listing: https://www.amutorch.com/products/amutorch-al1-titanium-right-angle-flashlight1100-lumens
I bought this one from Banggood back in August of 2019 on the "4BLF" discount code, paying about $30 plus shipping. It's no longer available on BG though.
The light features an aluminum head, supposedly titanium tube, SMO reflector, pretty nice-feel top mounted switch, with a deep pocket clip, and takes an 18650. The overall quality is pretty decent. Titanium is expensive, heavier than aluminum and lighter than SS. However, when you design with titanium, the idea is to use less of it to get an equivalent strength of aluminum, but that's not what they did here. It appears the battery tube base is actually thicker than most rt. angle aluminum lights, so the light comes in rather heavy at 90.1g. This compares to 65.2g for the Sofirn SP40, or 73.5g for the Eagle Eye X1R. If it worked reliably, swapping the titanium tube/tail with an AX4 tube results in a weight of 71.4g.
Personally I wouldn't use this heavyweight for a headlamp anyway, but I do like using right angle lights, and this has a more uncommon SMO reflector, so want to get a little throw out of it. Decided to go with a FET+1 driver with a sliced 351D 4000K, though never sliced a 351D before, there's been a few on BLF touting how well they come out.
Threaded bezel was simple to remove, appears to be alum, not SS:
Grnd and switch wires, simple - no AUX LED's, no screws for the MCPCB:
Glued driver - very common nowadays:
No need to remove the switch PCB. "K" is the identifier for the switch on these Chinese boards (seen it many times):
Stock driver, lots of parts, appears to be amp regulated, Microchip PIC12F683. Notice the cap in the lower center came off it's pad? This is from using a solder pick tool thru the reflector hole to push on the driver to break the glue seal:
Basic parts, the 20 mm DTP MCPCB is 1 mm thick, so decided to keep the stock one and reflow the 351D on it:
Used an approx. 1 mm thick washer and razor blade to do the slicing. Took a few passes to get it level. To me, 1 mm off the MCPCB was about right for this LED:
This is a DDm-20 driver from OSHPark, designed by DEL. Happen to have one laying around with a SIR800DP. Downloaded Anduril2, rev 579 from 2020-10-31 with minor config changes for a FET+1 setup, like the Emisar D4.
Used one of Hank's beryllium copper springs since it matched up well with the original in height and stiffness:
Mounted with Arctic MX-4, sanded backside of MCPCB to 2500 GRIT:
I see you...
All wired up. Before soldering the LED wires, I tested the driver with the AL1 switch wired up, using an external mounted LED and external battery, just to sanity check. The stock wires were about 24 AWG, replaced with 22 AWG wires. The tail has a copper looking spring, and with the beryllium copper driver spring, I didn't add bypasses. I don't see a need to squeak out every microamp on this build. Planning on using a 3500 mAh cell like the 35E:
Here's a wall shot. It's close to real life, but in real life, the hot spot looks better defined with a slight ring around it. The tint is slightly improved over unsliced. I compared the beam of a modded C20C with a 351D 4000K, SMO reflector of about the same size, about the same amps and the Al1 had a tighter hot spot, better tint in the beam (no pic though)
Room has no other light source, AL1 on a low setting:
Set at max/turbo:
I'm impressed the way this turned out. It's close to the beam tint of a XPL-HI V2 5D (one of my favorites) but not quite as rosy but still a nice milky white with little to no yellows. The consistency is the same though, which I love about the 5D XPL-HI's.
Comparing throw, using a 35E cell in each light:
AL1, sliced 351D 4000K: 12.5 kcd (224 meters)
C20C stock 351D 4000K, SMO, same reflector width, slightly higher amps: 7.75 kcd (176 meters)
This result is about what I'd expect from seeing how the beams compare. It's a significant jump I assume came from the slicing.
I didn't bother with lumens because I can't be sure of an accurate reading in my PVC light box on rt. angle lights - I could fiddle with some thing to see.