Solution for Malkoff Contact Issues in Surefire 6P's

[frankg]

I have a couple of Surefire C2's with Malkoff M61 and M361 modules in them. I have experienced instances where loosening the bezel just a few degrees causes a loss of contact between the module and the inside of the flashlight, and consequently the light does not turn on when I press the switch in the tail cap.

Below is a picture of an inexpensive, and very reliable way to prevent this from happening. The solution involves shortening a spring so that only about 1 1/2 coils are left. This spring is then slid over the outside of the Malkoff module.

The diameter of the spring needs to be very close to the diameter of the module so that when the flashlight is reassembled and the spring is compressed between the rim at the top of the module and the body of the flashlight, the "tail" of the spring that is pointing downward towards the flashlight's battery compartment will go into the bevel on the inside of the top of the flashlight's body. Because the tail of the spring fits into the bevel, the compressed spring has had no effect on my ability to tighten the bezel of the flashlight.

Note that the very tips of both ends of the spring are very slightly bend outwards to keep them from dragging on the module when the spring is slid over the outside of the module, and that a very short length of the "tail" of the spring is also bent upwards towards the top of the module so that it has a slight curve to it. This will allow the "tail" to slide easily in the bevel at the top of the flashlight's body should the module and spring turn while you are tightening the flashlight's bezel.

This solution will maintain contact even when the bezel has been loosened significantly.

The "gottcha" here is getting springs of with correct ID (inside diameter), and that are thick enough so that the "tail" doesn't want to go into the space between the module and the flashlight's body. I made the springs that I have in my flashlights by using a small brass jawed pliers to carefully bend a smaller spring and increase its ID. I know there are springs available on the Internet that appear to be the correct size and weight, but the company that makes them requires a minimum order of $50.
frankg

 

[scs]

You can also wrap the drop in with copper or aluminum.
Kinda surprised you need to do that, because I thought Malkoffs were designed to fit snugly in the first place, which precludes breaking contact.

 

[frankg]

Contact between the module and the flashlight body with the Malkoff's that I have is made when the completely tightened bezel pushes the taper at the bottom of the Malkoff into the opening of the battery compartment in the flashlight.

Copper and aluminum are certainly a simpler solution. But with copper tape you have to use just enough of get contact, but not so much that its hard to get the module into the body. And I have found aluminum foil compresses.

But the idea I shared is above is new, and it surely has some shortcomings that will manifest themselves over time.

 

[archimedes]

Oveready also sells a beryllium copper spring washer that works for this ....

 

[frankg]

I have some of the spring washers. When installed they rest on a small rim in the flashlight body at the top of the battery compartment (this rim is where the spring on the old P60 bulbs used to sit). I chose not to use a washer because the washer blocks the Malkoff module from going slightly down into the battery compartment the way it normally would. This causes the module to extend further from the end of the flashlight body, and so the bezel cannot be tightened down as far as it normally would. But they definitely are an simpler, more straight-forward alternative.
frankg

 

[jdboy]

I've used this same style mod for making a SureFire A19 extension work with an Oveready body. I also use it for making my Ti extension work on my Malkoff single cell body. Same concept but with less than a coil for both of my applications. For me it was as easy as sourcing the spring from a drop-in I received from MtnElectronics.

 

[Grizzman]

I've got an even simpler solution to this issue. After the head is screwed on and contact is made between the rear of the module and the battery compartment, wrap one hand fully and tightly around the head. Wrap the other hand fully and tightly around the body. Screw the two together using as much force as possible. Don't worry.....you're not going to break anything.

If the light will be subject to vibration or some other force, causing the bezel to still come loose (highly unlikely), insert your hands into leather gloves before performing the above procedure.

 

[teak]

Yes this...all that is needed. I have who knows how many 6p or similar hosts with m60's m61's etc and just tighten real tight. Never had an issue ever.

I've got an even simpler solution to this issue. After the head is screwed on and contact is made between the rear of the module and the battery compartment, wrap one hand fully and tightly around the head. Wrap the other hand fully and tightly around the body. Screw the two together using as much force as possible. Don't worry.....you're not going to break anything.

If the light will be subject to vibration or some other force, causing the bezel to still come loose (highly unlikely), insert your hands into leather gloves before performing the above procedure.

 

[Woods Walker]

I just don't loosen the bezel unless removing the drop in. Never noticed a SF bezel getting loose on its own. Never but I guess anything is possible. Has this actual ever happened to anyone on its own or is this an internet thing. No offense intended as I kinda like internet things.

 

[Seattle Sparky]

I just got my first Malkoff drop in, an m361 219b, and I am not happy about the way it fits in 6p host. Basically, the drop in is rattling back and forth inside the head without a battery in the body. Once battery is inserted, the rattle stops, as battery is pushing the drop in against the front of the head. This tells me that drop in has a poor thermal contact inside the head, not that it needs much heat dissipation with its ~200 lumen on high, but still it bothers me.
I am on a fence of either returning it or getting an MD2 host. I still wonder why would Malkoff advertize that it was designed for 6p.

 

[Woods Walker]

I just got my first Malkoff drop in, an m361 219b, and I am not happy about the way it fits in 6p host. Basically, the drop in is rattling back and forth inside the head without a battery in the body. Once battery is inserted, the rattle stops, as battery is pushing the drop in against the front of the head. This tells me that drop in has a poor thermal contact inside the head, not that it needs much heat dissipation with its ~200 lumen on high, but still it bothers me.
I am on a fence of either returning it or getting an MD2 host. I still wonder why would Malkoff advertize that it was designed for 6p.

How is that possible. The bezel tightens down on it assuring positive contact. i have used them in C2/G2/G2Z/6P. All of mine are rock solid though only have the M61/M60.

Edit. There should be a small gap between the bezel and body which doesn't harm anything. This gap is the space left over to ensure full tightening making the drop-in rock solid.

 

[Seattle Sparky]

How is that possible. The bezel tightens down on it assuring positive contact. i have used them in C2/G2/G2Z/6P. All of mine are rock solid though only have the M61/M60.

Edit. There should be a small gap between the bezel and body which doesn't harm anything. This gap is the space left over to ensure full tightening making the drop-in rock solid.

You are right. After your post I tried in it in a different 6p and it works as it should. Turns out the first 6p body wasn't bored correctly and had a retaining bevel ring partially removed. That created a small gap behind the drop in that enabled the rattle. I am going to use it as an excuse to get an MD2 now.

 

[Woods Walker]

You are right. After your post I tried in it in a different 6p and it works as it should. Turns out the first 6p body wasn't bored correctly and had a retaining bevel ring partially removed. That created a small gap behind the drop in that enabled the rattle. I am going to use it as an excuse to get an MD2 now.

Darn shame about your 6p. Also have a MD2 and it's built even stronger than the 6p. Get the Hi/Lo ring for the win!

 

[Seattle Sparky]

Darn shame about your 6p. Also have a MD2 and it's built even stronger than the 6p. Get the Hi/Lo ring for the win!

For now I plan to use it exclusively with M361-LMH 219B V2, that changes modes through clicky. Correct me if I am wrong but I don't believe the Hi/Lo ring is going to benefit this setup.

 

[archimedes]

Why not ?

 

[msim]

For now I plan to use it exclusively with M361-LMH 219B V2, that changes modes through clicky. Correct me if I am wrong but I don't believe the Hi/Lo ring is going to benefit this setup.

The Hi-Lo ring basically turns the M361 into a 6-mode drop in.

 

[Woods Walker]

For now I plan to use it exclusively with M361-LMH 219B V2, that changes modes through clicky. Correct me if I am wrong but I don't believe the Hi/Lo ring is going to benefit this setup.

You would get 6 modes!

 

[Seattle Sparky]

The Hi-Lo ring basically turns the M361 into a 6-mode drop in.

Then certainly it is a must addition.

You would get 6 modes!

Thanks for the heads up.

 

[etc]

I tried the copper tape solution, it's a pain and does not work very well long-term, tends to fall off eventually and the contact is still iffy.

the problem is the module was sanded for a better fit in 6P so there is no gap between bezel and the body. That was fine except that the connectivity became problematic.

 

[Woods Walker]

I tried the copper tape solution, it's a pain and does not work very well long-term, tends to fall off eventually and the contact is still iffy.

the problem is the module was sanded for a better fit in 6P so there is no gap between bezel and the body. That was fine except that the connectivity became problematic.

I think the gap is intrinsic and essential to the design of the Malkoff m60/61 in most hosts. The MD2 uses a retaining ring to insure positive contact so it doesn't need the extra spacing IMHO. The "Malkoff gap" is a strange thing with Flashaholics. Some like myself don't care as it doesn't harm the function of the light in terms of waterproofing etc etc etc. Others are bothered by it as there is a space which implies an imperfection. As it's all a mater of perspective I suppose no one is wrong.