Sofirn SD03 diving light, first thoughts

Are you joking?

I’m not entirely sure what purpose my customers use them for.

No, I resell them :slight_smile:

Ya know, BLF ought to try to qualify as a dealer/middleman to capture some of the discounts offered to resellers.
Just sayin’.

Funtastic wrote in the SD05 thread:

Burns a bit, don’t it? But hey, “the more you pay, the more it’s worth.”

More discussion of the SD03 continues in that SD05 thread.

Ah, I missed the triangle indicating a pulldown menu for shipping options, but they’ve preselected the least expensive for my orders (Singapore Post, $1.16 for a single light)

I should mention that price excludes shipping price and only express is available so it’s only cheap for large quantities.

As a reseller I hardly get much of a discount but because this item is discontinued it’s a different story. Prices usually equal a group buy price

What do y’all think about putting a little bit of lubricant into the grooves of the switch ring, to hopefully keep grit out?
One problem I can foresee with this design is cleaning out the moving parts eventually.

Had given it some thought. It’s a double sided dilema. Grease will trap sand and other foreign material. Having nothing should be easier to clean out, providing the moving spaces don’t wedge the particles. But the feel is not very smooth (slack).

Be very careful removing the magnetic switch as there’s a tiny spring and ball bearing underneath that’s easy to lose. The spring shot out and took me 30min to find

I guess I’m waiting for someone to disassemble the switch section of the light and show me how it’s done.

Unscrew the head. Put the light IN a towel, completely covered up. You don’t need to see the for the next step.
Note exactly how the magnetic control ring is made, so you know the front vs. back. It’s not quite symmetrical. Not SURE this is critical. I did not try it both ways. but the magnets need to align with internal sensors to work right. If you get it wrong, simply reverse the assembly position.

Slowly rotate and pull the magnetic ring toward the front. At some point the ring will clear the spring loaded ball bearing and they will pop out, both most likely. This is why you need it covered, to catch the parts.
Keep pulling and wiggling. The ring now needs to slide over the 2 O-rings behind the front threads to come off. You can remove them beforehand if you don’t want this little bit of extra resistance. Either way is fine.
That’s it.

The ring has 2 magnets in cut slots. The spring goes in the hole with the bearing on top. I DO plan to dive the light so I packed the spring hole and magnet holes with silicone grease. I’ve had some cheap dive lights like this that used low carbon steel and the spring/bearing/magnets all rusted out in a year. It’s essentially impossible to fully flush out all the saltwater from these deeply buried crevices after a dive.

Silicone grease in the spring + bearing hole helps hold it in place for assembly. Slide on the magnetic ring (remember orientation) > when it bumps up against the bearing compress the spring with a thumbnail and slide it fully on. If you don’t feel completely confident of your skill, or you have not greased the spring + bearing you might do this inside a big paper bag so they don’t get away with a slip.
Replace and lube O-rings if removed. Check for any kind of lint or debris that might compromise water tightness. Replace the head. Put in a battery and test.

One thing to note is, don’t lube the front threads of the battery tube. There’s no retaining ring giving a good connection and it relies on clean threads. Lube orings well but keep it off the threads. Had 5pcs start flickering and couldn’t figure it out for awhile.

Ended up grabbing 30pcs instead of the previously mentioned 50.

Addendum to my instructions on the magnetic ring removal. The [battery tube] @PiercingTheDarkness mentions is the long piece that the battery is installed in, NOT the front part you need to remove to take the magnetic ring off. The front threads on the battery tube are not anodized.
The part in front of that has anodized threads and you can grease it well, and probably ought to.

Great information. Thanks y’all.

Did a burn test on high in a tub of water. A 2400mA (tested, not protected) cell lasted 90+ minutes on high. At the end it started blinking for a bit, then simply went out. Seems to be an inherent low voltage cut-off. Cell measured 2,91v when checked.

Finally got mine. Very nice flashlight for the price (recent discount). It is a bummer that there’s no lockout. While the selector ring is notched, it could be rotated by accident. I don’t plan on changing the emitter. The glass has a film on the inside… but it’s more of an annoyance—I doubt it’s affecting the lumens output much. No knurling except for the control ring, so I added a bicycle inner tube segment to the body. It was tough getting it on! Took me about 30 mins while I watched a TV program. But now it has good grip while still looking nice. Looking forward to testing this while snorkeling this summer.

Above.

“” No knurling except for the control ring, so I added a bicycle inner tube segment to the body. It was tough getting it on! Took me about 30 mins while I watched a TV program. But now it has good grip while still looking nice.“”

For that, I have lotsa shrink wrap tubing of differing dia. Colour, lengths,
from Fishing rod MFG days.
Just remove head unit. tail cap. Cut and slide on the Wrap, in colour to suit.
Then warm it up with a heat torch.
Careful… Ally holds heat for loonger.
OR Self amalg tape does same job.
But tends to UNwrap from finishing end if not, (me) O,ringed down to hold.
Small overstretched O ring.
I often add a coupla small thin o rings to any torch with grooves round casing
for extra grip too. (ie S2) and early shiny C8’s.

Yes, heat shrink wrap tubing is possible, but the bicycle inner tube is more resilient & grippy, in my experience. It came out well actually. O-rings won’t hold well because of the curvature… but the bicycle inner tube is on so tight, not worried. Actually, one could cut it a little short and then use a single wrap of grip tape. The only problem with grip tape is that over time, the material will shift and expose a sticky adhesive.

For people who want some more info. YouTube is full of instruction video’s of nice young ladies who show you how to shrink wrap a banana.

And Macka17: congratulations with your birthday. Please take good care of yourself and the missus.

Thank’s Henk.

Hey all.
My 03 came Monday. I installed a Samsung 30Q. All good. works fine.
Yesterday I stripped and cleaned all 4 threads, then used w/proof grease on the 3 recommended.

Hmmm. NO Light now.
Sw rotates.
Multi on base of battery and side of case shows the 4+v. With NO show on exposed led.
Rotating sw shows voltage on each click, on batt base/case side contacts.
Changed another full charged Samsung30Q, but still no show on led.

I’m no sparky just a fiddler. Have I stuffed it somehow?