An SK-58 for my car

I like a 14500 size light in my glove compartment. Sipik SK-58s and there clones are still available and are my favorite light of that size. But I am now avoiding lithium ion cells with boost drivers, because it would be too easy to over discharge the battery. So I tried a Nanjg 105c 6*7135 two group 17 mm. driver in the space below the pill. The battery didn’t fit in, as it did with an SK-68 clone. SK-68s, or at least that clone, must have longer battery compartments than SK-58s do. Fooling with springs and even shortening the pill didn’t make it fit. I need a 15 mm. driver and extra space for the 7135s on its bottom. So I transferred all components but one 7135 to a BLF SK68 board from OSH Park (without stacking).

Then I made a ring, like the heat transfer rings I have made for an SK-68 and an other SK-58, but longer. It is 4 mm. wide to fill the gap between the pill and the thick part of the body, plus a little (1.7 mm.) to keep the pill from screwing down all the way and make more battery space.
I also filed the coatings off an old star, to raise the star and led a bit, to partly compensate for the XM-L2 (unknown bin) being closer to the star than the OSRAM was.
I used a malleable copper wire/solder composite again.

Click on an image to see it full size.


After some trial, I found that the ring needs to be about 4 mm. long to allow some increased length, after filling the design error gap between the pill and the thick part of the body. And 17 mm. outside diameter to fit inside the threads that attach the pill to the body. And 15 mm. inside diameter to fit around the bottom part of the driver.


Unprotected cells now fit, but I want a protected cell for this environment. There is enough thread in the tail cap to hold a protected cell, now. I put a 1 mm. split ring between the body and tail cap to provide the needed space.

My way of fabricating rings is labor intensive, so someone with better equipment and material should make some of these rings and sell them. The 58 is an old model, but the SK-68 is very current and should be even more so with its worst, known, design error fixed by the ring.

Nice work. Takes longer than you'd think making such little things.

Excellent build!

Clever mod :)

> someone with better equipment and material should
> make some of these rings and sell them.

I’ll commit to buying as soon as someone’s selling.

There used to be multiple versions of the sk58 ... I've always liked this little light .At one point it came in silver ? black and a brown . who carries them at this point ,any ideas ?

last one i had i baked and it changed color really fast and went brassy/gold. Not a pretty color .it is so lightweight it came out very poor where the sk 68 was a really pretty chocolate brown ..

Think I'll go bake a few lights tonight :)

I’ve modded a couple SK58s.

Beautiful host. Looks and feels far better in the hand and the pocket than an SK68. I’ve gotten Nanjg 105c drivers to fit, but it’s awkward. The driver’s edges have to be filed down and the hole board floats below the bottom of the pill. Original poster’s way looks much more reliable.

Incidentially, it’s not that hard to make a beautiful looking silver SK58. Soak the aluminum parts in Greased Lightning to strip off the anodizing, then sand it progressively finer sandpaper, and finally polish it with your choice of metal polish (I use Blue Magic). Looks much better.

Here’s some pictures of one of my modded SK58s (on the right) next to my current EDC, my modded Aleto N8 (on the left):

Both lights had their anodizing stripped and were recoated with Duracoat. This was my first time using Duracoat. I didn’t know about the trick of preheating the parts prior to spraying to prevent runs, so the Duracoat isn’t perfect. But it doesn’t look too bad and seems fairly durable.

The SK58 in the pics has the following mods:

  • Replaced driver with 3 amp 3-mode off-time memory Nanjg 105c driver from Mountain Electronics. Custom modes (moonlight, 25, 100) with a 2-minute turbo timer from max power. Had to sand the edges of the driver down and add contact tabs above the driver. Also inserted a ring below the driver to help provide negative contact and enlarge the battery compartment.
  • Sawed off the top of the pill and attached a copper platform for the star with a copper heatsink behind it.
  • Replaced emitter with 20mm triple Noctigon with 3x Nichia 219B high-CRI emitters.
  • Glued the sliding bezel to the body with Arctic Silver thermal adhesive. The modded light is not a zoomie.
  • Optic is Carclo 10511 with front face polished. Got a replacement bezel ring from another flashlight to hold the optic in place.
  • Replaced switch booth with a blank colored one and solder braided the tailcap spring.
  • I run it on Kinoko IMR 14500. However, the battery compartment is deep enough to hold protected 14500 cells.
  • Entire light is 92 mm long.

The light next to it is my modded Aleto N8. It has the following mods:

  • Driver replaced with Nanjg 105c with DrJones lumodrv with Comfychair’s FET mod.
  • Added copper heatsink and platform below the star.
  • Replaced star with 16mm Noctigon with dedomed XML2.
  • Installed exterior side electronic switch. Removed tailcap switch and shortened body tube and bezel.
  • Widened interior of bezel ring and replaced stock long focal length 18mm aspheric lens with shorter focal length 20mm aspheric lens.
  • Added rubber grips on body and bezel taken from some cheap Nebo flashlights. The grips are in slots that were filed into the body and head prior to duracoating. The rubber is also glued in place with plastic superglue so it doesn’t slide.
  • Entire light is 95mm long.
  • I run it on protected 3400 mAh 18650. With the current lens, in spot mode I measured this light at 31,000 lux…. not bad for a light about the same size as a Zebralight SC62.

I really like the feel in the hand and the pocket of the SK58, but I also like my modded Aleto. The Aleto is barely larger than SK58, but holds a larger battery and has much more throw.

I’m considering switching back to a fresnel lens on my Aleto. If I do this I can shorten the entire light to 90mm, which is 2mm shorter than the SK58. However, peak lux drops from 31,000 to 20,000. The fresnels I have just aren’t nearly as effective as aspherics at focusing light.

So the ring should be “about 4 mm. long …17 mm. outside diameter … And 15 mm. inside diameter”?
So if I can find a copper tube with that OD and ID and cut off a 4mm chunk, that would do it?

You can also just get a piece of copper sheet, cut it into a strip and bend it into a ring.

Yes that is probably the best way to do it. You might have to adjust things with a file, because I had a snugger fit than the measurements I gave.

Sounds great. I have one with one 219B, mostly for indoor use, but three in a light that size is something!

I have silver sheet left over from a jewelery class. If I had better cutting tools, I might have done it that way.

Huh. Come to think, I have a cheap old flat stock rolling mill from doing sculpture 30 years ago.
And a micrometer inherited from a friend’s grandfather.
And some big sheet metal shears.
Seems possible.

That would be nice to see!
Copper or soft aluminum would be best, because they have very good heat conductivity and are soft enough to conform to the shapes of the pill and battery tube to make better contact.
My copper/solder composite probably would have been better with 99% tin solder, instead of 60/40 tin lead. I think tin is softer and probably has better heat conductivity than the alloy.

Lots of SK58s show up with ’oogle, for sale, from around $6 — any advice about quality or predictability buying one?
Are they variably copied like the SK68s, some good, some bad and some horrid?
(I got one SK68 with a solid pill — excellent — out of about 10, the others were … not excellent)

I don’t have any bad SK-58s. The two that I have modified say Sipik on them and have solid pills. The knurling is always great, but maybe not uniformly so. I recently tried to order a silver one and was told they were sold out. I don’t have any favorite place to get them. I recently gave away one that I bought with an XR-E in it. I have one on order from DX supposedly with an XR-E and three modes, but the last one turned out to be a standard SK-58.
I am trying to avoid lithium ion batteries in lights with boost drivers now, because it must be too easy to run the battery down too far. So I am modifying those I want lithiums in.

The place I have gotten the most SK-58s is Price Angels which has now somehow merged with http://www.popkind.com . At least the last one of these has very nice knurling, a solid pill and says Sipik on it. They are the original one mode Osram model. I have two more on order, so I will see if the quality survives the transition to Popkind. The ones I have bought elsewhere recently aren’t quite as nice, are not as described and cost more.

On first putting my hands on a SK58 today, I definitely like it better than either the 68 or the “#3” zoomies.

Emitter and driver swap obviously needed, but it’s a solid host, no pocket-eating sharps, got a side-to-side hole for a string/ring so it’s possible to attach something to it without ruining tailstand.

Heck, if someone wanted to build these with less blue emitters and a decent driver for resale, I’d think them the ideal gift flashlight.

If you want a smoother, more uniform appearance, try swapping in the tailcap from an SK68 onto the 58. You won’t be able to attach a lanyard, but it looks better and is even more comfortable for pocket carry.

I got one more today, maybe from Focalprice, though the packages don’t say who sent it. It says Sipik on it, but is otherwise like the last one I got that didn’t say Sipik. The phosphor covers the bottom of the dome and is much bigger than the LED die itself. In throw mode that makes a yellow circle around the die image. It has three modes, not listed for any I ordered, unless I guessed wrong about which came from Dx. It is clearly an Osram LED but appears smaller than that in a previous one. The knurling is good, as always, but not superb. Not much pattern on top of the knurling squares. It draws about 1.5 A on a new 1.6V alkaline. As always, the knurling is finer on the sliding head than on the body, to make it easier to zoom.
For alkaline or Ni metal hydride cells, I don’t see much to improve. The Osram, I think, gives off less total light than an XP-E but seems to have more throw.