Smallest Possible E-Switch Light/Host

Hi all,

Title says it all really. I'm looking for a light that uses an electronic switch (so modes can be changed without cutting power), however I want it to be as small as physically possible. A good example would be the O-Light S10 Baton, though smaller would be even better.

I don't care if it's side mounted or tail mounted or whatever. I have no battery preference either.

Just an e-switch, and tiny.

Any suggestions?

- Matt

The Nitecore EC1 might be a hair smaller.
EDIT: You might want to look at the Spark SF3 as well.

Thanks. I may end up using the head from a host and making my own battery tube...

Roche F6, with the tube sectioned/shortened to fit a 18350? It would end up a bit under 3.1", just about the exact same length as a Solarforce Z1.

I have a Spark SF3. Great light, but the Olight S10 is smaller.

Another good choice is the XTAR WK42. It’s slightly longer and narrower than an S10.

If you’re looking for a mod host, the WK42 is also much better than than an S10. The Olight S10 has a pill, the WK42 does not.

The Olight S10 is looking more and more like the host I should use. At 70.5mm in length (stock) it's the smallest by far :/

I prefer the XTAR WK42 to the S10. Comparing them:

The S10:

  • The S10 has a removable pill. The pill has no threads and goes in relatively loosely. As such, heat transfer to the outside of the body isn’t great so if you’re going to heavily drive the light, it’s not a great choice. You might be able to fix this somewhat by making a new pill, or adding some foil or metal tape around the old pill to increase the tightness of the fit.
  • Due to it’s internal pill construction the S10 won’t easily accept a 17mm driver. A Nanjg 105c may fit, but you may have to file the edges down a lot.
  • The S10’s head is wider. It accepts a 16mm star but could probably be modified to accept a 20mm star. I think there’s room in there to put in a 20mm Noctigon with triple XPG2 or Nichia 219 and a Carclo triple TIR optic. However… when run on just one IMR 16340 cell it won’t be that bright. You really need an 18650 if you want high brightness for triples like this. If you want to put in a triple, then the S10 may work, but the WK42 won’t.
  • The S10 is shorter than the WK42, but is also noticeably wider. Personally, I think the WK42 feels better in the hand and in the pocket than the S10. I think it may also be lighter than the S10, though I haven’t verified that.

The XTAR WK42:

  • The head width is wide enough to accept a standard 17mm Nanjg 105c. For mine I drilled out the screw posts for the old driver and the ledge around the edge of the head that the old driver rested on. This allowed room for a Nanjg 105c to comfortable seat in place while still letting the body tube screw in fully.
  • The interior of the head near the driver is actually a bit wider than a 105c. I put solder braid along the edges of the new driver to fill in the gap.
  • The top of the battery tube makes negative contact by hitting the edges of the driver. This makes getting a good negative contact easy. No need to try to solder a driver to a pill.
  • The WK42’s head has plenty of room under the switch. I made a small switch platform out of a piece of sheet plastic and then super-glued a new switch to it. A tiny disk of aluminum sheet on the top of the switch button to get the proper depth and it was good to go. No need to glue the switch to the side of the driver… there’s a shelf for the switch platform.
  • The star sits on a removable aluminum disk. It’s very tightly press-fitted in place. I don’t think it necessary to replace this with copper, but it wouldn’t hurt to add some thermal grease at the edges.

The only mods I’ve done on my S10 are to replace the lens and the emitter.

I’ve rebuilt two WK42s though, each with 3.04 amp Nanjg 105c with DrJones lumodrv firmware, new switch, solder braid tailspring and XML2 neutral emitter on Noctigon. I’m quite pleased with how they came out and the mod wasn’t that difficult (though still above beginner difficulty). 3-4 hours to do the entire mod per light.

If you want to get even smaller, another option would be to convert a small twisty into an electronic sideswitch light.

You could use the same technique I used on my Aleto N8 Modding the Aleto N8

With the Aleto, I converted a light that normally has a tailcap clicky switch into one with an electronic sideswitch.

You might be able to use the same technique to convert other lights, like a 4-sevens mini 123.

Now THAT'S an idea. Thanks for the overview of the two lights, and the link to your project page. I happen to have an old busted Mini CR2, and a Mini 123 that's playing up. Might have to get creative ;)

Are you looking at a particular cell type, body length vs diameter? It would be fairly simple to cram the driver, e-switch, and led into a AAA/10440 slug for a Minimag. Likewise for a AA Minimag. Really small I could make a brass solitaire copy ~60mm with a 10180 cell and e-switch. I’ve already done one without the switch at ~50mm. A tiny10 with an irlm 2502, 10180, xp-g2 or Nichia and e-switch in a 55 mm host would be pretty cool. 14250 is another possibility. How small is too small?

No specific host in mind. I EDC a Quark Mini CR2 on my car keys, and about as large as I'll go on those keys is a Mini 123. I'm going to look at modifying my busted Mini 123 for now, but if that doesn't work out I'll go for the S10.

Thanks for this. I destroyed the driver of my new wk42 trying to add a capacitor ;( and have been having a rough time getting a nanjg to work… I’ll miss the indicator light and the cr123 compatibility but will not miss the PWM.