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
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
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