Super-small 18650 zoomie - quick review and mod

Very cool mod! I've been following your progressive builds and each one is more advanced than the last. Your momentary switch idea is very cool, something I've wanted to try for a while but just haven't found the time to do it the right way yet. I'm looking forward to seeing your results.

I've got a few of these in the AA/14500 version which I like quite a bit, much more actually than the SK68 due to the smaller and lighter form factor. If there was only one in silver or black I think I'd have to try one of these as well!

Be aware that the lumodrv's fast PWM may cause problems with the FET. The reason I say 'may' is that with an added inline resistor between the FET gate and MCU the 70N02 FET will generally work alright but not out of the box. I recommend starting with a 75 to 100 ohm resistor and going from there if thing don't work right.

Lumodrv uses 9 khz PWM. It works perfectly with Comfychair’s FET mod.

The driver I put inside my modded Sunwayman C20C XPG2 triple a month ago is a Nanjg 105c with DrJones’ Lumodrv and Comfychair FET mod. All modes work perfectly. :slight_smile:

I admit, I’m not a fan of the gold. I’d have preferred black for its more discrete looking color and better thermal management. If anyone finds a black one let me know. The ONLY version of this light I found anywhere is the one on Ebay. Hopefully, the more traditional suppliers like DealExtreme will start carrying it in other colors.

I might make the light silver by using Greased Lightning to strip off the anodizing. Plain aluminum also has the added advantage that any grinding or filing I do to the exterior of the body will blend in. Once it’s all done I’d polish it up for the polished aluminum look.

Would you be able to take a pic of the 18650 vs AA/14500 side by side?

I’m a sucker for these 14500 v 18650 v 26650 version lights. :slight_smile:

That will be an extreme mod! I'm looking forward to the result. I hope that the thin host can handle the heat to some extend

Sounds great. Quite a make over underway. I really like the form factor of that light.

This should be a real pocket rocket.

Here’s a comparison showing the 14500 and 18650 ones side-by side.

NOTE: Both of the lights in this picture have been modded and both are a few mm shorter than stock. The stock 18650 version is 108mm long. At the time this picture was taken I’d reduced mine to 104 mm and filed off the top row of heatsink fins and the bottom of the sliding bezel.

Since taking this picture, I removed all the gold anodizing with Greased Lightning and filed down the tailcap. It’s now down to 102 mm. I also broke into the tailcap and replaced the green tailcap boot with a flatter black one. The light now tailstands with the tailcap boot flush with the bottom of the tailcap.

The next step will be to replace the current driver with a DrJones lumodrv driver with FET and install the side switch. If that attempt works out, I plan to then remove the tailcap switch, which should shorten the entire light to around 95 mm.

I’ve also ordered a checkering file which should help me to increase the grip on the tailcap and head, and possibly the body. I’m considering buying an Enco hand knurler, but am concerned it might squish such thin aluminum rather than actually applying knurling.

I’m fairly pleased with the beam pattern on the modded 18650 light with its dedomed XML2. In flood mode I measured the beam angle at 89.5 degrees wide… which makes it wider than the spill from many reflector flashlights including my Zebralight SC62d. In spot mode, the image of the emitter is noticeably more intense than my modded 14500 light which has a dedomed XPG2 at 3 amps.

Unfortunately, I a damaged the phosphor at the corner of the emitter trying to remove some debris. Fresh emitters are on order.



Can you please, add the link for us.

Thank you

Here you go:
Ebay listing for slim 18650 light

Thank you very much


would either firelight or rmm be willing to mod one of these?
i really like the form factor and want to add it to my arsenal.

I’ve done a bit more work on modding this light. It’s still not complete, but here’s what it looks like now:
That’s the modded slim 18650 (According to the lettering on the light it’s an Aleto N8) standing next to an unmodded Sipik 68.

The latest modifications I did:

  1. Removed gold anodizing with greased lightning.
  2. Filed down bottom of tailcap to make it smaller and flush with body.
  3. Replaced driver with Nanjg 105c with DrJones lumodrv firmware and Comfychair FET mod.
  4. Replaced the driver spring with 3 copper disks.

Next up was connecting and installing the contact for the electronic side switch. I needed to rig an electrical contact from either side of the driver to an external momentary switch and then to the body of the light. Not so easy on a light with a pill. And except for a rechargeable hand drill, I have no power tools. This is what I did:

1. Drilled and filed a hole approximately half a cm wide in the body just below the sliding bezel. This hole is revealed when the bezel is extended. It passes complete through the body into the battery compartment just below the driver.
2. Soldered a short piece of old solid-core wire to the “4” star on the driver. When the pill is screwed in, this piece of wire lines up with the hole and can be fished partially through with tweezers. I put a little arctic alumina over the wire around and below the 4-star so that if the wire gets torqued screwing or unscrewing the pill it won’t damage the driver.
3. Filed down part of the outside of the body in a line between the hole and the heatsink fins. This is so I could rig an electrical contact on the outside of the body without having the sliding bezel hit it when the bezel is retracted into flood mode.
4. I needed a flat contact, so wire was out. I used kapton tape on the bottom, then a strip of thin tin sheet (chosen because it solders easily), and another layer of Kapton tape on top. Super-glue gel around the edges to make sure the tape stays put. One end of the tin strip goes into the hole and angles down. The other end goes to the heatsink fins and rides up over them before stopping.
5. The small piece of wire connecting to the 4-star goes into the hole, then turns 90 degrees towards the tailcap before touching the tin strip. Soldered it in place.
6. Filed off the top of the heatsink fins below the switch. Put down some Kapton tape for insulation then used arctic alumina to glue on a tiny momentary tact switch I got on Ebay.
7. One of the contacts at the front of the switch was soldered with a short piece of wire to the tin strip.
8. To connect the switch to the body I drilled 2 small holes in the body, bent the rear switch pins downward and loaded them up with solder, then wedged the pins into the small holes.
9. Anchored the switch in place with more actic alumina.
10. I then made a switch cover using the rubber boot from a cheap plastic Duracell flaslight from the local drugstore and a piece of aluminum sheet. Screwed it down with some small screws I had. The rear of the switch plate is also glued on with superglue gel, but can easily be removed to service the switch if needed. I tried different stuffing in the switchboot to fine-tune the pressure required to activate the switch.
11. I sealed up the contact wire hole with more Kapton tape and a little arctic alumina. Servicing the pill o-ring will be a pain, but isn’t impossible. I’d have to unseal the Kapton tape and arctic alumina over the hole to reveal the solder, desolder the contact wire, then unscrew the pill. Then repeat the process in reverse. Fortunately, the o-ring is large, so I don’t expect frequent servicing to be needed.

I’m pretty pleased with how this light is coming along.

The light is now fully functional in its current form. The sideswitch works great. Easy enough to activate, but still stiff enough that accidental tailcap activation is unlikely. It also doesn’t protrude much, but is enough to act as an anti-roll device.

The battery compartment accepts my 18650s with no issues. The contact wire doesn’t touch the battery. It would be nice if the switch were further forward, but can’t have everything. At 102mm x 24mm it’s already probably the smallest 18650 zoomie around. And it’s around 5 cm shorter than the next smallest 18650 zoomie with a sideswitch!

Still to do:

  1. Since the sideswitch works so well, the tailcap switch is no longer needed. If I remove the switch mechanism I can file down both ends of the tailcap and the back of the body. This should allow me to shave off 5-7mm from the total length of the light (about the length of the tailcap in the picture above).
  2. Some knurling would be nice. I don’t have a knurler, but have a checkering file on order. When it arrives I plan to use it on the tailcap. Possibly also on the curve portions of the body, but I’m not sure how well that will work. This light is thin and unlike a knurler, a checkering file removes the aluminum. Might be too thin for that.
  3. I haven’t decided if I’ll polish it up once done or leave it with the unpolished look.
  4. I need to replace the emitter with an undamaged one when it arrives. Fortunately, doing an emitter swap should be easy as the light accepts a standard 16mm star and the lens unscrews from the front.
  5. I might try touching up with a silver pain pen the little of the visible arctic alumina below the switchplate and the kapton tape in front of the switch. Not sure I want to do this though. It’s not very visible

wow! Great mod!

That is beautiful. It looks like it came with a side switch in stock form.

Interesting. Perhaps they are only testing whether a market exists.

Looks really nice! You might want to replace your sk68 with the AA baby version of that light:

How hard was it to get the gold off? I just waited awhile, and the SRKs started coming out in black after a few months, but silver is nice too.

Getting the gold off is extremely easy.

Get a bottle of Greased Lightning from the local hardware store. I got mine from Home Depot. It’s a cleaner/degreaser.

Put some in a plastic or glass container, then immerse the parts to be de-anodized (for this light, the gold bezel, body and tailcap with all electronics, o-rings and lenses removed. Then simply wait 60-90 minutes and remove. Rinse off the Greased Lightning with Water and you’re done. The anodizing should be gone.

The matte look in the pictures is shown exactly as it came out of the Greased Lightning. However, you can get fine sandpaper and metal polish if you want a polished finish.

I made a build thread including beamshots for this mod in the DIY forum:

Aleto N8 build mod thread

I measured the beam angle of this unmodded light at 56 degrees. Not bad for a stock zoomie, but inferior to the spill on a reflector light.