Surefire E2E Flashlight Mods

I bought a Surefire E2E because it was a good deal. I didn’t realize until I received it how much smaller it is in comparison to the Surefire 6P flashlights that I have. It’s about the same size as my JETBeam Jet-I Pro.

The E2E uses an incandescent lamp, the Surefire MN03 lamp assembly, with an output is 60 lumens. The output seemed a little low so I started looking for ways to make it brighter.

Fivemega, over at candlepowerforums.com makes two nice incandescent options for the E2E, a bi-pin socket and a Mini Turbo Head.

I’d rather use LEDs and I found that Veleno Designs makes a good option fits in the E2E head. The Veleno Designs E Series LED drop-in is machined from brass, has great heat sinking and uses a Cree XP-G LED. I ordered a 3 mode cool white model and while the output was great, the tint was a little green. The manufacturer said that most people order a neutral tint so they don’t have that problem.

I decided to order some neutral tint Cree XP-G LEDs from DigiKey to replace the LED. After I soldered the LED to the board, I trimmed the board with a Dremel so it was a little larger than 3.5mm x 3.5mm, so it would fit on the Veleno pedestal. It still had a green tint.

In a few discussions on cpfmarketplace.com, it was theorized that the E2E reflector was causing the green tint and it was a lottery whether the factory reflector had the green tint. Instead of buying a new bezel/reflector, I tried re-silvering the reflector. The tint was still green.

Because of the work involved in putting another LED on the Veleno drop-in, I decided to try to find a deal on a Surefire KX2 LED Conversion Head. When I received it after a week, the tint on my new KX2 was also green. I had also taken a very long way to get to a E2L Outdoorsman.

Determined to get the light I wanted, I disassembled the KX2 using a heat gun to release the ample amount of glue that Surefire used on the threads to hold the head together. I unsoldered the leads from the LED board, removed the two hex screws holding the LED board to the drop-in and pushed the LED board out.

I then unsoldered the old Cree XR-E and reflowed soldered in a new Cree XR-E (R2 bin). I reassembled the KX2 using Arctic Silver 5 Thermal Compound underneath the LED board and when I first tried the light the hot spot was off center. I centered the LED and because the threads on the bezel that holds the Surefire Total Internal Reflection (TIR) lens were no longer glued, I was able to focus the beam to a perfect hot spot. And finally I have a neutral tint.

Now that the KX2 is open, I could use another driver, maybe try a McR-19XR reflector or an XP-G LED; but it’s been a long road to get here, so maybe I’ll wait a while.

Flashlight Reflector Re-Silvering

The beam from my Veleno Designs E-Series LED drop-in my Surefire E2E had a green tint. I replaced it with a neutral tint Cree XP-G LED and the beam still had a green tint. Some people commented that the green tint was caused by the stock Surefire reflector.

Instead of buying a new E2E head, I removed the factory reflective coating on the head with solvent and tried using “chrome” paint to re-coat it. The Krylon Metallics Bright Silver (1401) paint was not reflective enough to be used as a flashlight reflector. With the E2E reflector six feet away from a white wall, the bulb just threw a giant white circle with no hot spot.

Next I tried Mona Lisa Silver Leaf. The leaf material comes in booklets of 25 (5.5″ x 5.5″) sheets. I used Gold Leaf Adhesive Size on the E2E head before applying the leaf. The size is a water-based adhesive that dries to a light tack before the leaf is applied.

The silver leaf is so thin that picking up part of a sheet will tear it. I just tried to get a large enough piece to cover the reflector then I burnished it lightly. There were some creases in the leaf, but since I wasn’t trying to get an absolutely mirror finish, the imperfections weren’t a problem. The reflector with the silver leaf has a nice hotspot. I’m not sure how the size (adhesive) will hold up to the heat.


Beamshot

Soldering High Brightness LEDs

A year ago I saw this Youtube video where Steve Dahl at DigiKey demonstrates a method of soldering high-brightness LEDs to a Metal Core Printed Circuit Board (MCPCB) using a heat gun.

Though I’ve seen an electric skillet used for reflow soldering, I decided to try using the above technique when I wanted to replace an LED on a drop-in. I ordered some neutral Cree XP-G LEDs from DigiKey, some 16mm circuit boards and some LodeStar solder paste.

I don’t have an expensive heat gun – just one for removing paint. I thought if I used my infrared thermometer, I could measure the temperature at the tip of the gun and when it was maintaining the correct temperature, I would hold the board/LED in the heat.

I put dabs of solder paste on the contact pads where the LED would be soldered and placed the LED on the pad. It doesn’t need to be precise because the solder will only flow onto the contact pads.

The Cree XP-G specs (PDF) have 215 degrees C (~419 degrees F) for Peak/Classification temperature. When my thermometer read that, I put the board in the heat. (In the video, they use 600 degrees, which seems way out of spec and may be the reason the board turned brown). In a few seconds the paste melted and the LED centered itself, just like in the video. I immediately turned the heat off and kept the fan running to cool the board.

In the photo, the bottom board has been soldered. The upper left board shows the amount of paste I used. The upper right board has the LED on it before soldering.

Malkoff M61 Modded Some More

After I put in a 3 mode 1.4 A driver in my Malkoff Devices M61 drop-in, I wasn’t too happy with the yellow/green tint of the Cree XP-G LED. I found a cooler tint XP-G and applied some Arctic Silver 5 Thermal Compound to the back of the LED board and used some Arctic Alumina Thermal Adhesive to hold the assembly in place.

Before I reassembled the drop-in, I wiped some hazing off the reflector with some chrome polish and inadvertently removed some of the reflective finish. I needed a new reflector.

I searched for reflectors for the Cree XP-G and found positive comments about Don McLeish’s McR-20 Seoul reflector. I ordered one from the Sandwich Shoppe and it was delivered in 2 days.

There is a recess around the top of the M61 heat sink that the top of the stock reflector sits in – that’s the flat part of the reflector. I put a GITD (Glow In The Dark) O-ring in the recess and it held the McR-20S reflector perfectly. The new LED is mounted on a thinner circuit board than the Malkoff board, which in this case helps with the reflector placement. The bottom of the reflector (with a thin insulator) rests on the LED board. The other end of the reflector is flush with the end of the heat sink.

The beam is very nice. Compared to a M60 or M30, there is less of a hot spot and more spill. The stock M61, IIRC, didn’t have as much of a hot spot compared to the McR-20S.

So far in this mod, I have destroyed the Malkoff M61 driver board and damaged the reflector. But now I’m happy with a drop-in that has a great heat sink, a great beam and three modes. It’s now in my current favorite flashlight, the Surefire C2.