Here is my entry for this year’s BLF OL contest. It is a last minute entry and I hope to finish it in time. I spent the last two days searching for a suitable flashlight and starting to modify it.
The flashlight host will be the following:
It is a Chinese no-name flashlight which uses four 18650 and what seem to be three XHP70. The build quality is not bad. I think it was produced by Haikelite because it uses a Haikelite battery system.
The reflector looks quite bad. As I happen to have a triple reflector with similar size and almost the same distance between the leds I will replace it.
Also, I will put three XHP70.3 and a new driver in this flashlight.
The new reflector is too big for the flashlight but it has an unnecessary edge that I cut away with a hacksaw. I also drilled out the holes of the reflector to 10mm so that the XHP70 will fit.
It still doesn’t fit so I will file the pointy parts of the edge away.
I disassembled the flashlight, removed the driver and unsoldered the leds from the MCPCB. In the following photos the leds are just placed losely on the MCPCB to show you what it looked like.
Initially I thought the leds were real XHP70.2 but given the rather low price of the flashlight that would be too much to expect. These leds are just a tiny bit smaller than XHP70’s and have the square and circle marking on the opposite site. The soldering pads also have a slightly different size.
As mentioned already the flashlight will get a new driver and new leds.
Old vs. new driver
Old leds vs. the new XHP70.3 90CRI
Two of the XHP70.3 have 5000K and one has 4000K color temperature, both with 90 CRI.
Yesterday I filed the edge of the reflector until it fit the flashlight.
It turned out quite round. The individual reflectors are larger than those of the original reflector and it looks definitely better. It is also lighter because the original reflector has a lot of aluminium between the reflectors.
Next, I soldered the 18AWG cables and a spring to the driver. I had reflowed this driver a while ago together with two others. It is always better to solder a few drivers together because then you need to open every bag of SMD resistors only once. I flashed Anduril 1 on the driver.
I reflowed the three XHP70.3 onto the original MCPCB. I tested with the multimeter that it is a DTP board. I was in doubt because it has some weird traces on it.
The flashlight does not have an integrated shelf (head and shelf all in one piece) but a screwed in aluminium piece. I enlarged the hole for the cables with a file and smoothened the surface with fine sand paper.
A screwed in shelf is not optimal for the heat transfer but you got to work with what you have. I removed some anodization from the edge where the shelf sits, put some thermal paste on it and screwed the shelf back in.
The final steps to assemble the flashlight are to put thermal paste on the shelf, insert the MCPCB and solder the cables to it.
I soldered the switch cables to the driver. They were well labelled so I didn’t have to find the right cables with trial and error. I used the green switch led and didn’t use the red one.
The flashlight head was working already yesterday but the flashlight didn’t turn on with batteries. So I had to do some troubleshooting today. It was a contact problem so I had to put some solder on the outer ring of the driver and use a longer spring, a silver plated spring from the third BlueSwordM group buy. I also put a copper wire ring underneath the shelf for additional heatsinking.
The flashlight is finished and working well now. Here are some impressions and whitewall beamshots. Later today I will also post a few outdoor beamshots.
From left to right: Modified flashlight 3x XHP70.3, Astrolux MF01S, Convoy 3X21B
From left to right: Modified flashlight 3x XHP70.3, Haikelite MT09R, Convoy C8+
Front view from left to right: Modified flashlight 3x XHP70.3, Haikelite MT09R, Convoy 3X21B
The beam on a white wall looks round with a white hotspot and a bit of yellow tint shift. The tint shift is visible but it doesn’t bother me. High CRI XHP leds tend to be a bit greener but this flashlight is more neutral than green. It is not nearly as rosy as the SST20 4000K or the XHP70.3 Hi 5D but I have a flashlight with three XHP70.2 90 CRI which is greener (see comparisons below).
From left to right: Modified flashlight 3x XHP70.3, Astrolux MF01S SST20 4000K, 7th OL contest modified flashlight 18x LH351D
From left to right: Modified flashlight 3x XHP70.3, Haikelite Q30 3xXHP70.2 5000K 90CRI, Convoy 3x21B 4000K
The color temperature is somewhere between 4200K and 4500K.
This flashlight will be stored in a big Convoy bag.
Here are the outdoor beamshots. Weather conditions are not ideal for beamshots as it is raining. The settings are 2.5s, f7.1, ISO400. The big tree is 100m away, the last tree in the back 150m.
The flashlight is now finished. I’m glad I was able to finish it in time even though I started only a few days ago. Everything worked well without major setbacks.
Thank you very much to everyone who read my thread and commented, to the organisators, the judges and the sponsors.
Great last minute entry the build looks great, i like the tint mixing, you didn’t want too use the HI instead of the HD? The reflector looks like a decent size?
Really cool build, I am curious why you used HD instead of HI, unless you were just going for a floody beam.
It looks a lot brighter than the MT09R in the beamshots, despite an identical battery setup and similar emitters.
I’m curious for numbers, if you have a way to measure lumens or candela.
Also, where did you get the host? It has the look of the early-2010s enthusiast flashlights that I happen to like.
Yes, I could have used the HI but the XHP70.3 HD was what I had on hand and I wanted more lumens in this flashlight. The bins already go from P2 to N2 or M4 if you use 90CRI leds. Using the HI version they go down to M2. I have some other flashlights with smooth reflectors in which I will use the HI XHP70.3.
The beamshots could be a little misleading because the batteries of the MT09R were not fully charged. I will try to get some additional beamshots this weekend. I can’t measure lumen or candela, though.
I got the host from a Chinese shopping platform, shipped to me by a Taobao agent. You might be able to find it on Aliexpress, too.
Here are the promised beamshots. The Haikelite MT09R and the MF01S got fresh batteries. You can see that my modified flashlight is similar in brightness to the MT09R but has less throw.
As the deadline for the challenge is already over these photos don’t count for the judging process.
Here are some impressions and whitewall beamshots. Later today I will also post a few outdoor beamshots.
