I use a split ring and “McGizmo” clip on little lights like that — either to clip them into a shirt/pants pocket or a belt loop.
These are good if you find them in stainless steel at a decent price (it varies a lot)
(link at that page no longer works)
Beware imitations made of zinc, pot metal, or congealed mouse sweat — they make them shiny silvery but not reliably strong)
I got one of these On The Road i3 zoomies the other day and finally found this thread. I already put a Nichia 219C in it.
Now I’m wondering what driver. I would like more output than it currently makes, and I’m not opposed to re-swapping the LED.
Looking at drivers and the space available in this small light, I’m not sure a multi-7135 driver will work. FET+1 drivers are often one sided and low profile. But the prevailing opinion (I haven’t tried it) is that N219C’s don’t do well with FET drivers. (BUT BUT - maybe this isn’t an issue for 16340 batteries, since they can’t do high currents like an 18650 can.)
So questions I’m considering:
1. What driver? (FET vs multi-7135)?
2. What SIZE driver? 15mm using spacer ring, or 17mm shaved down?
3. Keep N219C or put in something like an XP-L Hi?
Looking forward to hearing what mods have been friendly
There’s only one mod on this forum and he is very friendly indeed 
Sorry for the impatient bump, but I was hoping to order parts today…
What driver/LED combo do you all think would work well in this light? I like the N219C I’ve got in there (Mine also has that beautiful rosy tint that djozz took a great picture of), but am thinking due to the physical constraints of the light that I might use a FET driver and thus revert to an XP-L Hi emitter. Thoughts?
I did my first i3 mod back in july and posted something about it in the what did you mod today thread, if you had not read it already, does that contain some info for you? What did you mod today? - #1213 by djozz
djozz, I did see that and the main issue is that I don’t have a BLF A6 driver on hand. I ordered several back in November, but I’m currently in dispute with Banggood because their shipping status has not been updated since late November.
I was hoping to get a driver more quickly from Richard at MTN, but the MTN FET layout looks like it has less clearance at the edges to be sanded down like you did with the BLF A6 driver.
Or maybe it would work OK?
And the follow-up question becomes, can I keep the N219C even with a FET driver since the 16340 will never supply the kind of current an 18650 will? (looking at HJK tests, 16340s fall really flat at anything 5A or more.)
It looks like the Mtn driver will be fine, you only need to sand down the diameter by 1mm, which is 0.5mm around, if you sand it halfway the via’s in the ground ring it might just fit already, and the copper tracing is at most places continiuing under the solder mask, and there’s many back-up via’s near the FET.
The 219C is at its max at 6A, and survives up to at least 10A, the 16350 will not even deliver the 6A so you will be fine. Of course you will have to monitor the heat at the maximum setting, there’’s not much mass and surface area in the i3 to spread and get rid of the heat.
As a noob I feel like I’ve said this a lot, but I mean it each time - thanks!
tiny, but i have given up 16340s - they just don;t have enough energy, i end up changing them 3 times a week, and STILL having to limit my use of ‘high’ modes…
wle