Review: SingFire SF-328 (with some light modification)

SingFire SF-328

In this review we will have a look at another member of "singing" family but this time in single XM-L + SMO configuration,
we will dissect it like a frog, inspect all its parts and also take a look at its modding capabilities :)

Lets first take a look at what manufacturer offered/advertised:

Manufacturer's specification

LED type:

1 x XM-L T6 (600 lumens)

Supported bat.:

1 x 26650

Switch:

Tailcap reverse clicky + Side - micro switch

Modes:

High->Medium->Low->Slowly strobe (actually SOS*)

Reflector:

Aluminum smooth

Body:

Aluminum+Stainless steel Color: black(mate*)+silver

Lense:

Glass lenses

Accessories:

English user manual, lanyard

Overall dimensions:

Diameter: 55.0mm (head), 36.5mm (tailcap),
Length: 198.0mm
Weight: 339 gr (without battery)

Supplier:

www.dx.com

Price:

US$34.52

Flashlight arrived in, I would say, standard SingFire package, cardboard box + bubble wrap, certainly not the best but far better protection than usual "flashlight in envelope" surprise:

Inside of the box there was a flashlight, lanyard (that I misplaced right away, that's why you don't see him) and of course, always fun to read chinese/english user manual.


First impressions are nice, it's big and heavy, "SS" bezel ring gives it a stile, reflector is really nicely coated, no fingerprints inside :) dust particles but that's going to change since I am going to open this Fire :D. BTW bezel ring is not actually stainless steel because it does not attract magnets, not even slightly. I suspect it's some kind of alloy, chrome plated and brushed to look like SS, in that case it is doing excellent job.

Logo is kinda weird looking, not sure if this was attempt of 3D printing or just engraving laser misalignment. Maybe shadow effect :D

And again, as in the case of SingFire SF-326 they did not spare aluminum, 352 grams without battery. Notice the 26650 -> 18650 adapter, not sure if they meant to send it or it's "nowhere mentioned" part of the package but it sure comes useful if you don't have KingKong-s.

While I am at the battery adapter, this one is pretty loose, can fit protected batteries no problem but the rattling will be there no matter what, which is of course easily solvable...

Tailcap assembly is completely identical to SF-326, easy to disassemble and maintain

While I had it all disassembled I done a small modification: added some solder to outer contact ring, soldered braided wire (so called goot wick) and also soldered brass contact pin to the spring, can't go wrong with this mod.

All threads are square cut, not anodised so no lock-out function but because way that switches work you won't be needing lock-out. No lube on threads either...

Front side reveals previous generation XM-L T6 emitter inside of the centering ring but also plain&regular glass lense, no AR coating.

Inner surface of the reflector is actually pretty nicely and evenly coated, I would say almost perfect and it has a 12mm hole perfect for MT-G2 emitter unfortunately because of interestingly weird reflector design implanting an MT-G2 emitter would not be easy task at all, piti, so nice & big hole unused to it's full potential :D

Only place where I found grease but there was enough of it for entire flashlight lol.

As you can see, pill with the LED is very small and it is screwing down into the reflector body and that means that the most of the heat will be transfered to the reflector first and then from the reflector some of the heat will go to outer flashlight body but since it is not tight fit (reflector is lacking about 0.5mm in diameter to be a thight fitt) there will be a heat build up. To remedy this I sliced about 5mm wide and 150mm long copper foil (that I extracted from dead 18650 cell <- blast from the past :D) coated it with thin layer of thermal grease so it would stick and coiled it around the reflector, the part where the heat hits first (didn't took pic of this unfortunately, my fingers were all messy from thermal grease).

Since this flashlight utilise identical switch configuration as SF-326 does it has the same issue: when disassembling the driver and emitter you have to be very careful not tu damage contact wires for switch and indicating leds that are on the switch because repairing that will be major pain.

Finally let's take a look at the driver, that will be interesting to most viewers (same scenario as with the switch, since I had it out of the flashlight I took this opportunity to solder piece of braided copper wire and contact pin to the driver spring):

Upon closer driver inspection you may notice that this is actually identical driver (DZY003A) as in the SF-326 which is 3 x XM-L... Only difference is that SF-326 driver had stacked resistors at R6 position which means lower resistance and higher current to the leds.

As per SF-328 there were two resistor (to play with) R150 = 0.15 Ω and R200 = 0.2 Ω, they are in parallel so that would make 0.0857 Ω of total resistance. Accidentally I managed to find one R100 = 0.1 Ω and lower the total resistance to 0.066 Ω. I could comfortably replace R200 with R100 instead but...

BTW. I also slightly upgraded LED wires from 26AVG to 22AVG, nothing special...

Anyway, this component hiding by laser etching them is kinda ironic, Chinese that are copying anything and everything, are hiding components so they would not be copied

User interface is identicat to SF-326 (since the driver is identical):

to turn on the flashlight you click the tailcap reverse switch and that's all that tailcap switch does, on and off. Flashlight always starts in HIGH mode but one short click on the side switch will get you to Mid, then to Low mode and after that SOS mode. After SOS mode there is a Standby regime, emitters are off but indicator led i on... If you don't like SOS there's a way to avoid it, just tap lightly tailcap switch to break the current flow and you will instantly jump to High mode, this will also skip the standby regime thou...

Every time you power on the flashlight with tailcap switch red indicating led in a side switch will blink twice while checking the battery voltage (which takes 2 seconds) and if there is a suficient juice it will switch to constant green indicating led. Voltage measurement is done under load because as soon as you turn on the flashlight it's in max mode.

(Red indicating led, green indicating led and GITD demo)

BTW for this flashlight you don't need moonlight mode, it is enough to leave it in stand-by with green indicator led on and that can serve as moonlight :)

Current draw table:

Cell @ 4.2V

Stock light

After modification

MAX

MID

LOW

MAX

MID

LOW

Samsung

ICR18650-26FU

2.56 1.10 0.21 3.28 1.38 0.27

Panasonic

NCR18650PF

2.57 1.13 0.21 3.42 1.47 0.29

Nice performance bump but nothing special, I should have replaced R200 resistor instead of R150 or I put two R100... maybe next time...

Beamshots:

MAX mode, 6.5s, 5s and 4s and then the same with 10X zoom

MID mode

MIN mode

Two additional photos, beam angle and spot size:

Here is a pwm demo (I am not sensitive to PWM but, as you can see, camera reveals it):

Nice review, that’s an interesting walking path you have there.

Thanks, I have yet to add my comments and impressions after some use.
Walking path is nice quiet place where I can do weird things :stuck_out_tongue: like taking photos of flashlight light beams, no one around to call the cops :bigsmile: