Awhile back I modded a Convoy S2+ mini to a triple. In doing this mod, I also expanded the interior of the battery compartment so that it fit 18500 cells with no changes to the exterior of the light other than the triple emitter. Here’s how I did it:
The stock pill is quite long and has a lot of empty space in it especially with a relatively flat driver inside. Rather than have all this empty air, I decided to shorten the pill so that the driver sits much closer to the emitter shelf. I could have instead installed a copper heatsink, but for this mod I wanted to see just how much power I could get into a small light.
Converting this light into a triple and running 18500 isn’t hard. The key to this mod are the adjustments to the pill. I did this with just handfiles, a variable speed power drill (no drill press), a cylindrical cutting bit with a smooth bottom, a vise, and some scraps of aluminum. Here are the steps:
- STEP 1: FLATTEN the top of the pill. The pill has a rim around the top edge designed to keep a 16mm star centered. That rim needs to be filed off in order to make room for the 20mm triple star. 20 minutes with a large handfile takes care of this.
- STEP 2: REMOVE the top portion of the pill threads. The top of the inside of the head isn’t threaded where the reflector was. This was fine with the stock aluminum single-emitter reflector, but a Carclo triple TIR optic isn’t as tall. If you mount the triple star and then Carloc optic and screw it in, it won’t set fully to the top of the light. The top portion of the pill threads will stop when they get to the unthreaded portion of the head. There are two ways to fix this: (a) use a spacer, or (b) file off the top portion of the pill threads so they no longer stop the pill from screwing into the unthreaded portion of the light. Since I was going for minimum size, I chose option (b).
I mounted the Noctigon triple star with optic on top, then screwed it into the light and took an approximate measure of the gap between the top of the optic and inside top of the head. Then I removed the pill and filed off the top portion of the pill threads to that measurement. I used a handfile with indoor stairway grip tape wrapped around the pill to protect the saved threads and make it easier to hold while filing.
- STEP 3: SHORTEN the back of the pill. Just file it down with large handfile. Or if you want to save some time, saw off part of the back with a hacksaw and then file it flat. Don’t worry about saving the little shelf for the driver… the plan is to make a new one. File a couple notches into opposite edges of the bottom of the pill so you’ll have a place to insert needle nose pliers when screwing it into the head.
- STEP 4: CUT a new driver shelf. I put the pill upside down in a large vise. Then I took a small scrap of aluminum sheet and bent it into a “U” shape with a flat bottom. The length of the legs of the “U” were about the height of the inside of the driver + a little extra for the driver wires. I then inserted this scrap into the bottom of the driver with the flat bottom of the “U” facing up. The purpose of this little scrap of aluminum was to keep the cutting bit at approximately the same height from the top of the driver.
Once this was in place, I put the cylindrical cutting bit in the drill and cut a new shelf for the driver. This only took a few minutes. It’s rough and not perfectly flat, but that’s ok… it doesn’t need to be perfect. It just needs to provide a base for the driver. Make sure to use a bit that has a FLAT smooth bottom with cutting edges on the sides only.
- STEP 5: ASSEMBLE the pill. Install the Noctigon triple emitter and wire it to the driver. Insert the driver and solder it to the pill. I placed tiny copper scraps in the solder joins between the driver and pill to help bridge the gap. I also removed the BLF17DD’s rather long driver spring and replaced it with a copper disk. Since I wanted max power I went with a domed triple XPL (originally 3C tint, but later changed to 3D tint) with widened Carclo 10507 optic. The driver is a BLF17DD FET driver.
- STEP 6: TAILCAP. I found I hadn’t quite shortened the pill enough for the light to fully close with a Kinoko IMR 18500 inside. I could have removed the pill and filed it down a little more. But rather than do that I decided to slightly modify the tailcap. A little filing to the baseplate below the rubber button, and a slight extra extra turn to the brass retaining ring were all that was needed to give me that last 1 mm. While at it, I also solder-braided the tailcap spring with 22-gauge wire.
Here are some pictures of the completed pill (apologies for the fuzzy iphone pics):
This light puts out a wall of light in a tiny package. Output at turn-on with a fresh IMR cell should be around 2500 lumens. Impressive in a tiny 84mm long pocket light. It gets hot really really fast. If you turn it on and hold it 1 cm in front of your hand, you’ll get a burning sensation in your hand almost immediately just from the emitted light (and your other hand will shortly get a burning sensation from the heat in the head). I figure an appropriate turbo timer is probably 30 seconds.
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EXTERNAL SIDESWITCH MOD IN PROGRESS
Of course I didn’t leave well enough alone and am still tinkering with this light. I replaced with the BLF17DD driver with a Nanjg105c modded with a FET and DrJones lumodrv electronic switch firmware. I drilled a small hole through the side of the head for the switch wire. This is soldered directly to one leg of a tiny tact switch. The other leg of the switch is bent down into a small depression drilled into the head and soldered in place with conductive silver epoxy. I tested it and it works! This is now a side-switch light! Here’s a picture of the work in progress:
Still to do:
- The switch is done, but it now needs a protective enclosure and rubber switch boot. This should be fairly easy to make with sheet aluminum and cutting down a standard switchboot. I have some ideas on how to do this switch. I’ll probably add a rim around the button to help protect it and make accidental pocket activation less likely (accidental pocket activation at 100% power would be BAD with this light).
- I might add a sliding cover over the switch button. Thinking of something that slightly locks in place but can be slid down with the thumb revealing the button. Not sure if I’ll do this, but would help protect against pocket activation while still letting the light be activated relatively easily.
- Tailcap mods. Once the sideswitch is done, the tailcap switch should no longer be needed. I plan to saw most of the tailcap off and replace it with a flat contact plate with a spring in the center. This should allow me to shorten the light by about 1 cm without affecting performance or battery capacity.
I’m also thinking about modifying a second tailcap by removing the switch and then mounting the backplate at the very bottom of the cap without shortening the cap. The goal would be to make a tailcap that lets me run the light on 18650. I think I can do this without making the light longer than than 86mm or so.