Fivemega 1x18650 body reliable w/Malkoff Lamp in SF head?

[DHart]

I've ordered a Fivemega 1x18650 body to add a Surefire Head and Tailcap to so I can run an 18650 cell with a Malkoff P7 lamp assembly. However, a fellow forum member mentioned to me that I *might* have some electrical contact reliability problems with the Malkoff lamp in a Surefire head when using on a NON-Surefire body, like the Fivemega. He wasn't sure if this potential contact-reliability problem was just with "el cheapo" bodies or to include the Fivemega bodies as well. Does anyone here have much experience with this set up?

Would I be better off cancelling the order for the Fivemega body and just going with a 17670 in a standard Surefire 6P or Z2 for this P7 lamp?

 

[Justin Case]

I am using a Malkoff M30 in a 1x18650 FiveMega body. It seems to work fine. I've shaken the light, run with it for at least 100 miles (including in the rain), checked for function while running, and the light has always worked. I am using a SureFire twisty LOTC and a G&P bezel. My spare SF anti-roll bezels leave a functionally unacceptable gap, but the G&P bezel leaves no gap (it might, but I am also using a SureFire bezel lanyard ring, so the G&P bezel has about 1 mm of leeway -- the SF bezels can't tighten against the lanyard ring so the lanyard ring is too loose).

 

[Yoda4561]

The issue is easy to fix, via an appropriately sized wire loop or some aluminum foil to provide a solid electrical path. In fact even with a surefire body I'd recommend the foil route on a weapon light or anything you want 100% reliability with, as even a small turn of the bezel can potentially break contact. With the foil in there it's nearly impossible to have an open circuit even if the bezel is completely removed.

 

[Bullzeyebill]

Just tried my Malkoff M30, which is same size module, and set up the same way except for driver, and it works fine in my Fivemega body, no contact issues. One issue, cosmetic, the bezel will not screw all the way down as it does on my SF bodies. About 0.07 inch (1.8mm) gap. I am using a SF bezel.

Bill

 

[DHart]

Ah. :twothumbs Thank you for the info. I hadn't thought of looking for another bezel... I was going to buy a complete new 6P incandescent (for $62) to obtain a Surefire bezel and tailcap to go onto the Fivemega body. I do like the Surefire tailcaps which have the push to light function. As for bezels, are there reasonably comparable bezels to match the Surefires for less money? Where do you guys go to shop for bezels and tailcaps? And, is there a little easy metal work that could be done to make the SF bezel screw down deeper onto the body? Perhaps file off a small bit of the end of the body?

So what's the aluminum foil trick? You just stuff a little piece of foil between the body and the head?

Sorry for all the questions... I'm working hard to get "learned up" around here! :thinking:

 

[bullfrog]

Keep and enjoy the FM body!

As per Yoda's post, its an easy enough fix if there are any issues. Here is a recent thread on the issue with the fix:

http://www.candlepowerforums.com/vb/showthread.php?t=218571

With that P7, and all the new drop-ins on the way, you'll be thanking yourself that you have the flexibility of running a 18 or 19mm battery

The FM body will keep many doors open down the road!
http://www.candlepowerforums.com/vb/showthread.php?t=218571

 

[Justin Case]

I got my G&P bezel from Lighthound. It's called "G&P Tactical Head for SureFire", part # GP313. I can't recall if I used the silver spacer ring that is included with the bezel. I don't think I did, but I'll have to check tomorrow to be sure. If the cosmetic gap isn't an issue, then you can go with the SF bezel. I use a bezel lanyard ring so if the bezel doesn't screw down far enough to tighten against the ring, I actually have a functional issue, not a cosmetic one. That's why I'm not using an SF bezel. But if you don't use a bezel lanyard ring, then there is no functional problem.

 

[Justin Case]

Malkoffs, if I understand the design correctly, use a solid brass heat sink shaped to fit the "lamp well" of a SureFire 6P and compatible body. But if the shape of the well differs, then you can get electrical continuity issues. The foil trick is a workaround for differing well shapes.

If you look inside of an SF 6P bezel, you'll see a metal shelf on which the Pyrex window sits. You could try machining some material off of that shelf.

This is why G&P supplies a silver spacer ring with their "tactical head". The G&P bezel doesn't have the metal shelf for the glass window to sit on. The separate spacer ring substitutes for the missing shelf. Generally, however, it seems that the ring is not needed.

 

[Sgt. LED]

Foil or my preferred solution of a wire ring will fix you up IF there is an issue. Bullfrog posted a fantastic pic in the thread he linked to that shows my preference. Post 13
If you want bezel options don't discount the Solarforce bezels.

 

[bullfrog]

Foil or my preferred solution of a wire ring will fix you up IF there is an issue. Bullfrog posted a fantastic pic in the thread he linked to that shows my preference. Post 13
If you want bezel options don't discount the Solarforce bezels.

Thanks Sarge

 

[Bullzeyebill]

Foil, to me has only been a heat conductive aid. Wrap thin strips of foil around the brass body of the Malkoff. Do not let foil touch the spring. Just me, but I like more of the heat of the module having contact with the walls of the body.

Bill

 

[etc]

I have 4 aftermarket bodies for SF:

2x18650 FM and Leef
2x18500 FM and Leef

After I ground down the M60 module to fit well in the 2x18500 Leef, it started having issues with 2x18650 Leef. Just not turning

No problems with FiveMega... I think it's a bit closer to SF specs, although I like the knurling in Leef better.

 

[Justin Case]

I checked my G&P bezel on my FM 1x18650 body and I use the silver spacer ring. The ring stands off the M30 optic from touching anything and the bezel screws down all the way (at least to the bezel lanyard ring, which is about 1mm diam).

 

[Bullzeyebill]

Foil or my preferred solution of a wire ring will fix you up IF there is an issue. Bullfrog posted a fantastic pic in the thread he linked to that shows my preference. Post 13
If you want bezel options don't discount the SolarForce bezels.

MrGman is reporting reduced lumens using SolarForce bezels vs Surefire bezels, even when the SolarForce bezel does not have the pointy cremelations. Pyrex window of SF, with coating, gets more light out. Not my opinion, what MrGman is observing during IS testing.

Bill

 

[Sgt. LED]

Yeah I forgot to mention the switch to coated UCL lens!