Question on M30W in the Solarforce L2 18650

I received a Solarforce L2 host today, bored to take an 18650. I recently received an M30W from Gene, and wanted the tube to use with my 6P, which isn't bored to 18650. However, the Malkoff drop-ins are not making contact with the top of the Solarforce tube. I tried both an M60 and M30, and both are loose in the head. I had to end up wrapping a band of foil around the M30 so that it made contact with the top of the tube. Has anyone else had this experience with the Solarforce? Will the foil cause any problems with the connection? Is there a ring of some sort needed for Malkoff drop-ins in these hosts? This problem occurs in the Solarforce host, or if I use the head from the 6P.

Thanks in advance for any advice.

My Solarforce head that i bought to use on my 18650 body came with a silver ring that goes on top of the malkoff dropin so that it will fit properly.

ecallahan said:

I received a Solarforce L2 host today, bored to take an 18650. I recently received an M30W from Gene, and wanted the tube to use with my 6P, which isn't bored to 18650. However, the Malkoff drop-ins are not making contact with the top of the Solarforce tube. I tried both an M60 and M30, and both are loose in the head. I had to end up wrapping a band of foil around the M30 so that it made contact with the top of the tube. Has anyone else had this experience with the Solarforce? Will the foil cause any problems with the connection? Is there a ring of some sort needed for Malkoff drop-ins in these hosts? This problem occurs in the Solarforce host, or if I use the head from the 6P.

Thanks in advance for any advice.

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The diameter of 18650 body is bored quite wider than normal body, and that makes p60 drop-in sit further down in the body. You don't want to remove outer spring that comes with any drop-in, otherwise the drop-in fits loose. If your drop-in does not have outer spring, you may need aluminum foil or small metal ring that sits in between the drop-in and the body. Or you can place an O-ring between the glass and the drop-in. That will push drop-in a little down to the body to make a good contact.

I wrap my M30WF with aluminum foil till it fit in nice and tight.This way I am assured of proper heat dissipation.

Thanks for these responses. This may be a stupid question, but I thought aluminum foil reflected heat, instead of transferring it. So in my mind, I feel like I will be trapping the heat in around the module if I wrap it around the module. I'm sure this is wrong thinking somehow, can you explain why?

Aluminum foil is a heat sink.It will transfer heat to the body where there is the most mass.

It's a matter of radiant vs conducted heat. The aluminum foil does reflect radiated heat, due to it's shinyness, but aluminum itself is an excellent heat conductor. When the foil is folded over itself a few times and then tightly compressed betweeen the module and the body, it improves the thermal conduction signifigantly. Here are my measurements of my WLF, the M30 will likely show more benefit due to its higher operating temperature. I only did one set of measurements so they may not be 100% accurate, but I'm confident in the trend they show.

Baseline 3.9v IMR16340 m60wlf

Head: 85.6F
Body: 85.6F

no foil:

-----Head: Body:
05m: 91.60 90.60
10m: 96.30 95.50
15m: 99.50 98.40
20m: 102.1 101.8


Foil:
-----Head: Body:
05m: 94.40 92.50
10m: 98.00 96.40
15m: 101.6 100.7
20m: 103.5 102.4

I had a Solarforce L2 and experienced the same problem. To solve, I took a thick o-ring and put it between my M60 and the bezel lens. When I tightened the bezel, it then made good electrical connection. I bought the O ring from lighthound. It is the Novatac model EDC ring. Perfect fit and due to the M60's design, it did not black any of the beam. Hope this helps.

Foil seems to be working good for now. Thanks for the info on it being a heatsink. I also ordered some washers from Gene, and I'll probably use one of them when they arrive, maybe in conjunction with a little foil around the module also. I picked up some o-rings today, but they ended up being too small. May try the Novatac oring.

Solarforce L2 and L2m bodies are of excellent quality with great threads and Surefire compatibility. In fact, I'm very happy with Solarforce heads and bodies. Still prefer Surefire tailcaps/switches, though. Interestingly, the bezel rings (lens retaining ring) on many Solarforce heads are stainless steel and much higher quality than the lens retaining rings on Surefire's 6P head, which uses a really cheap PLASTIC ring!

Solarforce is really kicking butt with very high Surefire-compatible quality and a very low price.

A layer or two of aluminum foil works great snugging up the fit of the Malkoff module in a flashlight body and conducting heat from the lamp assembly to the body. I've used this aluminum foil fitting technique with Fivemega bodies and with Solarforce bodies quite successfully. Remember, the bodies of the vast majority of our flashlights are made of... aluminum!

DHart said:

Solarforce heads are stainless steel (vs. Surefire's 6P heads with a really cheap PLASTIC ring!).

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Oh no you did not. You just dissed on Surefire. J/k :twothumbs

My solarforce bezels and Malkoff including some DX drop-ins will only work when I wrap them in aluminum foil. This is completly normal. The aluminum helps with the heat a bit anyhow (the M60/M30 do not need it) but it is good to know it's there.