Strange problem with NiteFigher f30c

Hi, the other night i had my nitefighter f30c out and it has a normal (head tightened) and tactiacal (head loosened) style ui.
when i had it in head loosened which alows two modes… turbo and strobe it was randomly switching modes. head tightened with 3 modes low med and high the light works perfect. it has square cut threads at the head and iv cleaned it, the head doesnt seem to wobble in head loosened ui but i keep getting it switching from turbo to strobe on me??
Any ideas on what the problem could be???

Sounds like it was to loose, if you turn it on with the head loosened and lay it on the ground does it keep switching modes?

It depends, sometimes its fine sometimes its constantly switching modes. im literally loosening the head by an 1/8th of a turn.

So it will keep switching modes even when sitting on the ground? Can you try putting a small spacer in it. (A magnet on the end of the tailcap spring will work well)

I actually tried my longest 18650 cell i had in it and it did seem to help…. i think the square threads could have a tiny bit of play in them causing it to loose contact and switch modes. id have to source some small magnets to try one on the end of the spring…

Not sure if there is a equivalent in the UK but in the US dimes will also work as a spacer. I'm gonna guess that the spring got shorter from constant compression.

Maybe but iv only used it maybe 6 times or so for around 45 minutes a time… its a shame as its getting to be my favourite light. is there anywhere to get longer springs from??

What's the length of the spring?

Hmm now that i couldnt say as iv left the light at the other halfs house as i was sick of fiddling with it lol. i may go pick it up tomorrow and have another look at it. it is also a spring in the head on this light. there is a review of this light here with some quite good pics of it.

Solved it :bigsmile: Got a nylon gasket to put inside the head with a hole big enough to let the spring through and i can now tighten the head up so its got good contact on the threads, i know this isnt the perfect fix for this but at least its stopped the problem… i only use turbo on this light so im well happy with the result as it will run constantly on turbo without getting hot. Thanks for the ideas on what could be the matter scaru :bigsmile:

PS… its a 22mm nylon gasket from uk gas fitting what i used :slight_smile: