When can I send you some drivers ? Well done
i have one keygos m10 made with one nanjg8 3.05 amp 4groups
here buy the part 20mmto 17 mm 6 days shipping!
greets
Very cool! I did something similar with my first Trustfire 3T6 mod, except I used solder wick (1.5mm) instead of copper wire to built up the outside diameter.
:)
20mm Partition Boards for AMC7135 LED
5 packs for 1,5 $
https://www.fasttech.com/p/1138202
I need one of these if fasttech or a non fleabay seller was selling this i would be all over it
I saw a pic of this used, the driver was soldered to the back side with the spring coming though the center, but i get the feeling over time the driver will break the solder and you will be in the dark until you get home to your soldering station
Hope there is 21mm version soon.
You mean like this:
http://www.aliexpress.com/item/Freeshipping-21mm-expansion-board-for-flashlight-driver-10-PACK/1072001760.html
or in expensive:
http://intl-outdoor.com/2-pcs-contact-pcb-21mm-p-409.html
Ha, now I know what those boards are for 
But paying somebody $2 for 5 boards, hmm, plus it does increase the height which can be an issue for some pills.
Nice. Didn’t know they make those too. Guess ebay has more different things than the KD, DX, FT, …
Yeah You can use a copper solder wick as well, I have quite a bit of it but went with the wire. It may be easier to use the wick since it’s flat. Not sure how well it will hold on the driver until it’s soldered.
Let me try
A little pain to wind it, possible but has to be secured, held in place, and soldered, locked in soon. Did you wind it and solder it continuously or wind the whole thing and then solder it all? The wick may also suck a lot of solder.
But it should work, was my back up and may try it next time to use wick instead.
The adapter ring is nice, but pricey.
The wire holds on itself, it’s just a little tricky to solder since it will eat some heat when soldering it.
I guess most people wire up the secondary 20mm PCB?
How do you wire up the positive close enough?
What about other components on the driver boards that may short out with the secondary board? Would have to kapton tape it. Plus not all pills are very deep and every millimeter counts.
Or how about buying a copper 20mm pipe, and cut it to your liking;
not sure the thickness of the copper.
20mm one has a hole for the spring to pass through. Hopefully a cheap $2-3 for 5 kind. Meanwhile, I will still order from IOS.
I’ve used the same method as the OP but I’ll add my spin on the subject.
I’ve used 16-18 ga bell wire [its the single strand conductor wire used for doorbell wiring, hence the name].
Like Jack I use a 18650 btty as an armature to wind several loops, then cut them into individual rings
To solder the driver into the pill; tin both the wire ring and the driver outer ring w/ solder, USE SOLDER FLUX
Once cooled put a small amount of flux on the tinned areas
Fit the wire ring into the pill
Press the driver onto the wire, I use forceps to keep fingers clear of the work
Tin the hot iron w/ a dab of solder then solder the driver at one point, this will anchor the work
Now repeat soldering at two more points
You don’t need to fill the whole driver/ring w/ solder, that could overheat components and make later removal very difficult.
Practice, practice, practice. Use a HOT iron w/ a med-small chisel tip and keep it clean.
Ouchyfoot shows in this thread, how he solder the fasttech boards and it looks stable:
https://budgetlightforum.com/t/-/11120?page=1#comment-367597
Sorry, one more: I bought these: aliexpress - 20mm-to-17mm 10pcs, $3.85, $39 cents each, and they are nice. I've used them and it worked out well.
Appreciate the inventiveness of what you did here, JackCY - your custom built one is great when you absolutely need minimum clearance and to match mounting height.
This is really quality but hard work JackCY did...
It is very demanding and needs file work and fitting which could last for hours + driver takes a lot of heat while doing this way.
I tried those 20mm boards from IO(without center hole) but those from FT are much simplified and adopted to nanjg 105 C driver (you are finished in not more than 10 minutes :) )
And Ouchyfoot described at this thread page 4:
I also usually use the 20mm boards from FT (and stock them on my site), but I applaud the workmanship here! Like I always say... this is BLF, after all! A place where we can make our own unique creations and share them with each other, even if they aren't perfect!
Nice, brass is fine, price good 
If one needs that many or needs them that often. And they don’t sell them anymore. Wallbuys has them but does not list count, so one for $3.63 or so… no thanks.
Although the inner diameter is 0.2mm too small for the Nanjgs I have. Would mean filing and filing anyway.
The minimal size comes in handy, I put in more cable so I can just unscrew it, take the driver and reprogram it, no need to solder the wires off from the MCPCB. The cables fit but it’s a squeeze on them, not forced though.
Not that much time if you don’t add way too much solder.
Just dab a few places, not solder it all, couldn’t stop myself
Using the solder wick may be easier.
At WB too, but I think out of stock ATM, says they have 4 but won't let me put any in my cart.
http://wallbuys.com/Product/copper-ring-for-17-mm-to-20-mm-circuit-7307
Lol just edited it, yes this one, but I don’t see the count of them. Then there is the one on ebay for $1.99 per piece again? No thanks.
I prefer to do with what I have at hand, no fancy golden rings
yes that rings very nice too and cheap