A Leslie Wong Blog

Malkoff Devices designs and manufactures high powered LED flashlight modifications for Maglites and Surefire flashlights and their own Malkoff LED flashlights. Their products are so well designed and constructed that they are coveted by professionals that depend on their flashlights and enthusiasts that appreciate their quality.

I bought my first Malkoff Devices M60 drop-in five years ago. The M60 drop-in had a Cree X-RE LED (Q5 bin) and Khatod 6 degree optic. This drop-in output 180 lumens driven at 1000 mA with a 2-3 hour runtime with two CR123 batteries. I wanted to update my M60 with a more powerful driver/LED combination.

In 2008, Cree XR-E LEDs were delivering 220 lumens at 1000 mA. In December of 2012, Cree introduced the XM-L2. Driving the XM-L2 U2 bin at 1000 mA will produce about 412 lumens. At 3000 mA, the XM-L2 will produce over 1000 lumens.

Multi-mode flashlights are more useful for me so I decided to use an 8xAMC7135 (2.8A) multi-mode driver and a Cree XM-L2 (U2 bin). The multi-mode driver has four configuration options, selectable during the build by grounding one of the four “stars” on the rear of the circuit board:

Because of the robust nature of the Malkoff drop-in, disassembly is basically destructive. The stock circuit board is potted and the LED MCPCB is securely glued.

To get the 8xAMC7135 driver board to fit in the Malkoff brass heatsink, I had to slightly reduce the 17mm diameter of the circuit board.

To solder the LED to the MCPCB, I used a lead solder paste with a SMD hot air rework solder station at 220 degrees C for 40 seconds. After applying some Artic Silver 5 CPU Thermal Compound to the bottom of MCPCB, I glued it to the heatsink with JB Weld.

After some research on reflectors, I chose the McGizmo McR20J (Joker). A glow-in-the-dark o-ring holds the reflector very securely in the heatsink.

I compared this mod to the EDCPlus/IS X60L3 Triple XP-G2 LED P60 Dropin. The Malkoff mod has a very nice hotspot while the EDCPlus Triple has a broad floody beam. I like the nice hotspot the Cree XM-L2 produces with the McGizmo McR20 Joker reflector. It also has a decent amount of spill.

For this beam shot, I converted the original color image to black and white. The drop-in was about four feet (1.21 m) from the wall. On this off-white wall, there is a slight, but noticeable green tint from the beam.

I put the drop-in in my Surefire C2. Instead of wrapping the drop-in with copper tape, I used some thin aluminum stock as a shim. I haven’t done any runtime tests but after 10 minutes on 100% power, the C2 bezel gets warm but not hot.

Parts sources:
Malkoff Devices Drop-ins for Surefire and Malkoff
Cree XM-L2 LED
8xAMC7135 driver board at Shiningbeam.com (2.8A) and Illumination Supply (3.04A)
McGizmo McR20J (Joker) Reflector

I’m a big fan of Cree LEDs. I use them in almost all my flashlights. Last month, a Cree LED light bulb was introduced that replaces a 60 watt incandescent bulb. (Cree Press Release) The bulb retails for $12.97.

Specifications from Cree:

*Cree’s calculation of $1.14 yearly operating cost is based on 3 hours/day and $0.11 per kWh. Cree’s lifetime savings calculation is based on $0.11 per kWh when compared to 60W incandescent and 25,000 hour lifetime.

It seems that the Cree LED Light Bulb is only available so far from Home Depot. I bought my bulb online from Home Depot and with $1.17 sales tax and $5.99 shipping, the total was $20.13. When I first removed the bulb from the packaging, I was surprised that the light bulb’s envelope felt like it had a rubber coating. It has a standard North American Edison screw E26 socket. I replaced a 15W warm compact fluorescent bulb (CFL) that was in a table lamp with the Cree LED Light Bulb. The LED seems brighter.

When I removed the lamp shade to photograph the bulb, I noticed that the bulb was hot enough so that I couldn’t hold it – so despite consuming only 9.5 watts, it still gets very hot. There is a heat sink around the base of the envelope.

When I photographed the illuminated bulb, I set the camera’s color balance for daylight, so the yellow color of the light reflecting off the wall in the background is a good representation of what it looks like to the human eye.

For the chart below I used the following cost assumptions:
Incandescent bulbs: GE 60-Watt Reveal A19 General Purpose Incandescent Light Bulb (6-Pack) $8.77 ($1.46/bulb, 1000 hour life)

CFL bulbs: Feit Electric 15 Watt ( Mini Twist Dimmable Light Bulb (12-Pack) $104 ($8.67/bulb, 8,000 hour life)

LED bulb: Cree 9.5-Watt A19 Warm White (2700K) LED Light Bulb (1-Pack) ($12.97 25,000 hour life)

Cost of electricity from PG&E, about $0.13/kWh.

To get 25,000 hours with a 60 watt incandescent bulb, you would need 25 of them, at a cost of $36.50. The cost of 4 CFL bulbs for 25,000 is $34.68. The cost of the Cree LED bulb for 25,000 hours is $12.97.

There’s no question about the cost savings of the LED bulb versus incandescent. Total cost for 60 watt incandescent bulbs for 25,000 hours is $231.50. Total cost for 15 watt CFL bulbs for 25,000 hours is $83.43. Total cost for a 9.5 watt LED bulb for 25,000 hours is $43.85.

People who want to keep using incandescent bulbs may not be able to do the math or maybe they’re using them to keep their popcorn warm.

The Surefire Z32 bezel was used on the Surefire M2 flashlight and currently on the Surefire M951XM07 Millennium® Universal WeaponLight. The main design function of the bezel is to isolate the incandescent lamp assembly from weapon recoil shock. Since the shock mechanism reduces the heat dissipation ability of the bezel, I use aluminum shims or copper tape around the LED drop-ins to help dissipate the heat through the flashlight body.

The Surefire 6P, is to me, what a flashlight looks like (though I have moved on from incandescent lamp assemblies to LED drop-ins, such as this modified Malkoff M61). The stock Surefire 6P is 5.20″ (132 mm) long and the bezel diameter is 1.25″ (~32 mm). I like the current design of the Surefire Z32 bezel as opposed to the original design with the vented ribs. The Z32 bezel is about 1/4″ larger in diameter and about 3/8″ longer than the Z44 bezel that is standard on the 6P. With a Z32 bezel on a 6P body, it looks even more like a flashlight.

I’ve been using a Surefire E series bezel and a Veleno Designs E-Series tower module with a Vital Gear FB-1. I wanted a brighter light, so I bought a Vital Gear E to C adapter that enables the use of a P60 style dropin. When I screwed on a Surefire Z44 bezel, it made the front end of the light a little larger than I wanted.

Valiant Concepts makes the VME Malkoff Valiant Concepts Head that fits on an E series body and enables the use of a Malkoff Devices M series dropin lamp assembly. The VME head includes a lens for dropins that don’t have one but I use it with a Malkoff M60, which has a protective lens as part of the optic. I modded my M60 with a driver that enables three modes. The diameter of the VME head is slightly smaller than a Z44 bezel – 1 1/8″ vs 1 1/4″ (28.5 mm vs 31.6 mm) – which doesn’t sound like much but it makes a difference. With the modded M60, the flashlight is a lot brighter and also throws further than the Veleno Designs module.

I bought a used Surefire KX2 head for my Surefire E2D, so I had a spare Veleno Designs E-Series tower module in search of a flashlight. I found a Vital Gear FB1, which is a single cell, Surefire E-Series compatible body with a forward clicky switch.

I’ve been carrying this flashlight built with the Veleno Designs E-Series 3 mode, neutral white, tower module; a slightly de-pronged Surefire E-Series Defender head and the Vital Gear FB1 body. The Veleno Designs module is about 140 lumens on the brightest mode and it has a good low mode. The flashlight is very light, compact and is only about 3″ long (77mm). It’s a lot brighter than a Surefire E1L Outdoorsman and about 1″ (25.4mm) shorter.

When I read that Surefire was discontinuing the Surefire E2D flashlight, I found a good deal on a new one. I liked the ability of the E2D to tailstand, that is, on a flat surface, the flashlight will stand vertically on the tailcap.

I decided to make a couple of mods to the flashlight too – modifying the strike bezel so it wasn’t so sharp; changing the switch in the tailcap and replacing the incandescent lamp with an LED.

I wasn’t really in need of the defensive capability of the crenelated Strike Bezel®, so I used my Dremel’s cut-off wheel to grind down the bezel so it wouldn’t be so aggressive toward the inside of my pocket. I used a Birchwood Casey Super Black™ Touch-Up Pen on the bare aluminum.

I also wanted to install a McClicky switch because I like the lower pressure it requires to switch on. I’ve used the McClicky switch in a lot of my flashlights.

I read that the McClicky switch is a direct screw-in replacement in the discontinued Surefire Z52 twisty switch but using it in Surefire Z57/Z61 tailcaps requires some modification. I assumed the inner construction of the E2D tailcap was similar to the Surefire Z57/Z61 and the Z68 tailcaps.

Most of the E-series/McClicky modifications I found required a 11/16 x 20 tap to cut more threads in the tailcap to correctly position the McClicky switch. In trying to find a way of avoiding buying a tap, I realized if I removed some of the threads on the McClicky switch to reduce the diameter of the front end, I could insert it from the rear of the tailcap housing. The modded switch stops in the correct position against a rim that was already machined in the tailcap and is held by the stock retaining ring.

The last mod was to replace the 25 lumen MN02 incandescent lamp assembly with an LED. The simplest and most expensive way to do this is to buy a Surefire KX2C (200 lumen single mode) head or a KX2 LED Conversion Head (3 lumen/60 lumen dual mode). Surefire sells these two heads for $150 (USD) each. That’s what I did with my Surefire E2E (KX2) but I managed to buy it on eBay for considerably less. Before arriving at this point, it may have been better to consider the $189 (USD) E2D LED Defender® Dual-Output LED flashlight.

With the E2D, I thought I’d try the Veleno Designs Surefire E series incandescent to LED conversion three mode module. It’s essentially a brass heatsink with a neutral/warm Cree XP-G. The module fits inside the E2D bezel and the input voltage range is 1.8V to 5.5V (1 x CR123 or 1 Li-Ion rechargeable). I sanded the inner body of the flashlight with emery cloth so it accommodates a protected 17670 Li-Ion battery. The E2D flashlight is about .5 inches (12.7 mm) shorter than the E2DL.

The Veleno Designs module is “tested to provide 200 lumens of actual output.” Mine doesn’t seem as bright as my KX2 and I since I’m used to cool white LEDs, the neutral/warm color of this module seems green to me sometimes. I may get over it.

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.