Got two 2100’s this week.
Tried them with my Trustfire flames (protected and button-top) and nothing.
Put in an unprotected flat-top and bingo. For a while.
I’ve pulled them apart, cleaned everything and tightened everything up as suggested in other posts.
Although they seemed to work fine in the hand, once on my bike, they fail.
After stuffing around with them, it seems they run when either the head or tail-cap is loosened (unscrewed), but once tightened back up, they shut down.
Is the reflector making contact with the Led electrical points? If so it’s causing a short, that would explain why it works loosening the head. Easy to fix. Most flashlights have an isolation disk over the lead, a piece of plastic that ensures no electrical connection is made to the reflector. See below:
Or the inside of the tailcap needs tightening. Have you tried removing the tailcap and making a connection from the south pole of the battery to the inside or exposed threads of the body? It should light up, and doing so will confirm if it’s a tail cap issue.
Pulled the pill out again. The isolation disk had been placed crookedly, so a connection would have been made when screwed down.
I removed it and replaced evenly, but still having issues.
It would seem the diameter of the opening of the reflector may be a bit small (and/or the emitter is not dead-centre on 1 of the torches).
It was 7mm. I drilled it out to 7.5mm and that seems to sit it on the isolation disk better and give slightly more clearance around the emitter.
The original opening was pretty messy. I made sure I filed the edges smooth, once drilled.
So far, so good.
Interested to hear if this was your problem scaru.
There are (at least) 2 UF-2100s, an UltraFire and a UniqueFire. I have the UniqueFire and the Romisen G2 switch AlexGT mentions above does not fit (outside diameter of threaded part is about 1mm too wide). That switch came from ShiningBeam for $1.35, at this link:
just given them a quick run on the bike - all seems good.
Mine are the UniqueFires’s and the problem would appear to have been as noted in my last post.
They will only work with my unprotected flat-top batts though - no go with the protected button tops.
next test is to give them a real rattle on the MTB.
Bugger - Just knocked one over on the desk - same problem back.
It’s definitely in the head end though - something is shorting when the head is screwed tight.
I think that the length of the battery is putting pressure on the driver. Make sure the pill is nice and tight. Try using a shorter battery this should solve the problem.
I know it isn't the reflector shorting it out as I already checked that and I made sure everything was covered. Nor is it my batteries being to big as I use unprotected batteries in it so they are true 18650s.
I’ll guess that either the driver spring or the tailcap spring is too long.
When you screw the tailcap partway on it works. When you tighten the tailcap all the way the springs become fully compressed and mash on the driver. The spring in front may be shorting to the outter ring of the driver (- pad).
Solution: clip a turn off a spring and rebend the new first turn.
Also, look very closely at the driver minus connection to the flashlight body to make sure it has not been broken due to pressure.
I had problems with them on he bike because of changing modes. Yeah there are several models, and I think all have problems with changing modes whjile shapping.
Springs are too weak etc, and Uniquefire version doesnt have spring on the tailcap. I put big blob of solder on switch cap and i think I solved the issue. Rather annoying.
SOme others have spring in the tailcap but its pretty weak. SO when shaking longitudinally, modes change.
I found in both I could get some sideways movement if I gently held the spring and jiggled it in the pill.
Found a post elsewhere on BLF saying the brass ring that holds the spring base is pushed in.
Had a look through a loupe and there were a couple of gaps. Tapped the ring all round (lightly) with a screwdriver and rubber mallet.
Doesn’t jiggle now and both seem to be working ok again.
Just took them both for a quick 10 minute spin on a road bike (to the bottle-O ).
Both lights now seem stable.
As a bonus, put a protected button top trustfire flame in each, and they work!
Many thanks to all the posters for your input - I would have given up otherwise.
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