just been doing some maths on the length of batteries....

ok thanks :bigsmile:

This assumes it works with the paperclip trick. Essentially what is happening is the brass plunger is getting pushed up to far jamming the switch. The same thing happened on my marsfire stl-v2.

First you need to disassemble the switch. This is generally done by sticking needle nose pliers in the 2 holes and twisting. Separate the brass plunger part. Then you take a file and file off the top 3-4 millimeters. If you want I can take some pictures.

I would say yes. I have 8 different brands of 18650 batteries. My Roche F12 works with only one of them. Some lights are just finicky about battery length.

yes thats exactly what i was planning on doing, first though im thinking i will take the plunger out and reassemble and try the switch back on with no plunger at all…. if this works the file is coming out!!!
this is the tailcap……

Female threading in the cap is anodized which means the battery tube needs to contact the retaining ring for the switch. If your batteries, when inserted in the battery tube all the way, do not sit below the lip of the battery tube you will not get the light to work no matter what you do with the brass plunger.

yes but i can feel that when the tailcap gets srewed on its that pertruding plunger thats wanting to stop it going all the way home… if i slightly unscrew the extension tube the tail cap goes on all the way so surely if i take a bit off the plunger its going to give me a couple more mm to play with??

Yes, it will that is what I did with my stl-v2.

thats the copy of the m3x right?? does my tailcap look similar to yours??

Yep, here a picture of mine is.

thats exactly what i was going to do… so was yours acting in a similar way and has this 100% fixed the problem??

ady, it could be a comibination of things. First of all if the battery you're using is too long, nothing else is going to help, and if your measurements are correct, they are. Try to get ahold of an 18650 that is actually close to 65mm long. I just ran down to the office and checked the length of a few:

Callie's, Hi-Max, Solarforce: 68.5mm
Trustfire, Xtar: 69mm
Ultrafire: 66mm

In my N-Light ST50, the Trustfire and Xtar will not work - the .5mm makes a difference. All other cells I have work in it. You might find that the battery length and/or removing the tailcap plunger is all you need to fix it. As JMac mentioned, too long and the unanodized portion of the body tube is not seating properly, or the spring is getting crushed.

Yep, it totally fixed the problem. Here the insides of the switch are.

Forgot to mention it but it also works without the brass plunger.

i think im going to take the plunger out first…. if this doesnt work ill have to buy MORE BATTERIES!!! i dont know anyone with any so ill have to get them…. the aw at 67.3mm are the shortest i can find. im really hoping its that plunger as its been bugging me for ages with this thing now!!!

Couldn't you just use unprotected batteries?

yes thats my first move before i start messing with it too much, im hoping this will solve it as its getting silly now lol

Have you tried taking apart the switch yet?

no as the light is up at my girlfriends but im off work friday so ill have all day to mess about with it then…. im actually tempted on going round just to take that plunger out and put my mind at rest!!!

Oh ok. Good luck!

thanks…. if this doesnt solve it ill be gutted, im confident its going to though.