On hosts that have pills without the notches, I use the edge of a small file to make the notches. Since the brass is soft and can be removed quickly, the process is very easy and you end up with good results.
Thanks for that. I’ll either do that, or if there is a bit in my Dremel kit that is good for making dimples, I may give that a try, as I’m using the dremel to take the tab off the driver anyway. I’ll probably end up doing that later today if the M2 arrives as the tracking says it will.
interesting feedback. I actually ground a couple of slots in the driver side of the pill after reading your earlier posts, so that was a lot of help. I agree that the body is pretty thin, but then again it’s small and light, so there’s always a trade off. We’ll see how well it stands up to abuse 
I just finished assembling the Convoy M2 host. The dimples in the retaining ring on the pill for it, and on the tailcap, are sufficient for my circlip pliers to get just enough purchase to make it work, so in that regard the M2 has been better than the S3. I’m thinking that the S3 is supposed to have better dimples but just suffered from an absence of QC at the manufacturing plant.
Was thinking bout buying one of the C20’s and they are sold out!
The OP version is available:
Also, more expensive options exist:
The Convoy S2:
http://www.fasttech.com/products/0/10002463/1277401-convoy-s2-diy-edc-led-flashlight-host
...and S3:
http://www.fasttech.com/products/0/10002463/1277402-convoy-s3-diy-edc-led-flashlight-host
...and this X-Power host with much more aggressive knurling:
http://www.fasttech.com/products/0/10002463/1278500-x-power-118650-edc-led-flashlight-host
Doesn't sound so good... See rest of thread below...
Thanks keltex those all look nice. I guess i have been over looking that x-power host. Thats a good looking light also.
Thanks
That's the one that's identical to the Xiaozhi light from CNQG. I finally got the clip installed on mine (very very nice, but what a pain to get those nuts on!) and have been fiddling with the tailcap switch. I hope they have a better sized switch with it (in FastTech's photos it's a black switch and mine is white - hard to tell, but it does seem larger than mine)! My switch is ridiculous! It's way too small and "floats" around inside the tailcap. Nice host though once the switch is fixed.
-Garry
Ok, I just finished re-assembling the tailcap switch on my Xiaozhi after a thorough cleaning of all threads and contact points. I managed to get my switch centered well and tightened the $%#@ out of the retaining ring to hold it in place tightly. It now work flawlessly (so far)! And to top it off, there is NO more driver whine (Nanjg 105c)! It used to whine annoyingly on low and medium and now I can't hear anything even up against my ear!
So the FastTech Xiaozhi gets my approval as a good solid host and manageable even if the switch is still too small.
-Garry
P.S. I didn't place an o-ring under the tailcap yet to allow tailstanding. Not sure if I want to touch it again though!
+1 here first one I ordered from FF tailcap pcb diameter was way undersized for the fitting after lots of adjustments its just acceptable, My initial impression perhaps they ran out of correct size switches.
second one ordered same problem…
So if anybody is contemplating getting one of these unless they have increased the diameter of the switch pcb be prepared for lots of adjustments and frustrations, good light spoiled by a poor 50 cent part.
YMMV
B
That xPower is one of the first I purchased, and is now the least favourite of the C20, S3, and M2 hosts that I have used so far. At 60 degrees it has the narrowest beam of the 4 (not meant as a negative), the second O ring often catches the tailcap when you are screwing it on and obstructs it, the head section caught one of the other O rings and simply tore it apart, the finish scratches very easily, on closer inspection the finish looks to me like it is a matte polyurethane powder coat (and the threads have no coating at all like the anodized lights do). It does not take a protected cell. Personally, I will not be getting another one as long as there are better choices, even at that price point.
Glad you got that puppy sorted mate. 
My Xiaozhi started acting up again and was cutting off and on (very annoying) and whining like crazy. I fixed her for good now!
I soldered the switch assembly to the retaining ring. Works great now! Wasn't hard to do either. The whining is there, but much quieter now. I also placed a thick o-ring under the tailcap (my first time doing so) but the tailcap keeps slipping through the o-ring. I have to take it apart again and try again later.
-Garry
That’s a good idea. My uf2100 is pretty whinny. Might try something similar.
I've spoke too soon. This damn light is a b%@&h! Losing ground contact at times, and tightening the tailcap is pushing the tailcap boot further back out of the tailcap end (which ruins the tailstanding). Tailcap boot is starting to tear. I've about had it! About to order a Convoy S4 and be done with it! It was said previously and they were right - they ruined an otherwise great light due to a $0.50 part! Argh!
There has to be a way to get it fixed, but I don't have a lot of time to screw with it.
-Garry
That sucks Garry. Feel kinda bad having sold you mine. 
Didn’t realize it was that finicky. Hope you can find a replacement switch or something.
Yeah, I don't blame you at all. It kinda got worse the more I played with it it seems. If I get the tailcap to stay working the way I want I may just remove the head to change the battery!
-Garry
I’m feeling worse after saying “oh yeah, its a fine light, buy it”. I read your post on the whine and had the light alongside me in the van, mine does not whine in the slightest, I strongly suspect we’re looking at two runs of lights, the first one assembled properly and the second run rushed together.
Back on topic I bought three of these hosts, assembled them with ld-25 drivers and xm-l 4c emitters, fasttech clips also screw straight onto these hosts with no mods what so ever. My stepson built one of them up as his first light build too, he’s eleven, so no one has any excuse not to try this out. These hosts only lack tailcap lockout to be perfect edc’s imo.
OP version is back in stock.