Convoy S2 head is 1.740" overall, and there's .800"(!) of unthreaded dead space in the front half!
I actually dont like the overall look of the light, not really a matter of color. I dont know what it is though..
How does the optic stay in place then? Is there a lip? Thats the problem with most lights you could cut down - no way to fix the lens after that.
/edit: 0.8".. that is 2cm or 20mm. :P On the D4 (stainless) its 16mm.
Yes, the lip is still there at the front (though greatly enlarged over stock, not wide enough now for an o-ring). Just the pointy bits were cut off the front, then cut at the other end to shorten. Both these lights were built originally for a different reflector, I would do them slightly different for the 3XP/TIR if starting from scratch.
Those slots are why I want this as a host.
V10 Ultra glow + Devcon 2 ton and slots are filled with nice glowy goodness. Plus the extra space will allow me to put a plug of copper in there and shift the driver towards the head slightly to allow protected cells to fit.
Fingers crossed it all works out.
EDIT:
Thanks for posting the picture of this host with the 3-up board and optic installed. I wasn’t sure how it was going to sit.
Hey Comfy, what’s the overall length with it in shortest form? What power level would you be running it at?
I bet you could sell some, maybe not 100, don’t know. But you just can’t find anything that size making that level of out the front power.
My chopped AA minimag should be here today, I’ll see if I can fit my pill into it and perhaps it’ll run at around 1000 lumens at 3” or so total length. 
Might even shorten it more with a tailcap clicky. 
I have and reviewed the D4/Xiozhi/X-Power light.
That’s what I mod for Nichia triple. You can find the spacer measurements I talked about on previous pages but once again minimum is 2.5-3mm spacer and maximum is 15.5mm.
The threads don’t go far enough without using extra glass or something. So you do need a spacer below the MCPCB. I use copper that I have.
Don’t buy from fancyflashlight as their tails have too high button cap/boot what ever it’s called the green silicone button. And the PCB of the switch is too small. But you should be fine from FastTech or elsewhere.
The light is in parts so ask away if you need some measurements.
I have Carclo 10507, the narrow clear and alu MCPCB for testing before Noctigon arrives.
I used protected and buttoned battery and Nanjg 105c for measuring.
I did cut, sand and polished the pill so it can take 20mm boards or a 20mm spacer instead of 16mm.
Having tools, this is not hard to do, people might like it, but then again, you need tools to make things like this. Well equipped garage or some shop especially if cutting it shorter.
1 piece ok but doing 100 pieces is a little different.
And the total price does add up, $10 host, $3 MCPCB, ~$15 for emitters, lens, o-rings if they need to be added or changed, $3 driver + soldering if you want more output which it can’t dissipate though (2A is enough heat for this size of light), cables, …
Material, cutting, other work, …
$30-35 in material easily as you said + work
I like the D4 and am looking forward to using it again instead of UF C20. Triple Nichia 219, still thinking of direct drive to avoid the 0.1V drop on AMC7135s. Can always limit the output by PWM modes.
D4 has 115mm, realistically 116mm due to tailcap not screwing all the way because of the switch assembly which is very compact and uses low profile boot. But if you want it to tailstand it has to be done well and the boot not pressed out. On mine the boot goes out a little due to compressed air inside when closing the light, which goes away after some time when the air leaks, slowly. Stands fine. You can see that on FastTech that the tail does not screw all the way down.
In my setting when suing Nanjg105c, Carclo lens and O-ring, I could take away 12.5mm from the length due to more compact head assembly. So you’re looking at 103-104mm or so total length with tail clicky.
The front rim does cover the lens a little so the lens or reflector holds inside, this happens on all lights but it may be less on some or if you increase the id/diameter in front of the lens.
No idea how much you would reduce by removing the tail clicky and making it a twisty.
My guess and measurement is possibly getting to 94mm still with protected battery of 70mm.
DQG is 90mm but won’t fit protected batteries. Sure you could get smaller if you’re willing to give up some things and milometers of material that make the light strong.
Easier it may be, but I want to “try” and make it a tighter fit for there to be more surface area for heat to transfer to the body…Winter is Coming…need to keep my hands warm somehow.
@JackCY: so you need at least 3mm of spacer if you keep the lens in front of the optic? Doesnt sound like too much. And then you would chop off a part of the head, have to remove the threads because of the O-rings and thats it? Doesnt sound too complicated. Most Dremel bits (the tough ones made of steel) will remove aluminium, you could even use the round sand paper, would also work.
With the shorter no-lens head and the tailcap unscrewed to the 'off' position (off, but not far enough to be locked out totally) overall length is 3.7", or 94mm. DQG 18650 is listed as 91mm, but it also doesn't put out ~1500 lumens.
I can make this fit 70mm protected cells, too, by moving the driver forward in the pill, which won't affect the outside dimensions at all. There's plenty of space between the top of the driver and the bottom of the new forward-mounted LED shelf even with a triple stack of 7135s.
12x 7135s is probably about right for the Nichias, 14x for the XPG2s.
If my only option was to make an o-ring counterbore with handheld tools, I wouldn't bother. I'd leave the threads as-is all the way down to the cut line, use the light long enough to know everything was working as it should be, then seal it with a little clear RTV silicone on the threads. Honestly, how often do you need to disassemble the head? And when you do, that stuff peels off pretty easy and is easy to reapply.
True. Or leave the O-rings out completely, my lights never get wet. :P
I just took some measurements on my Convoy S7, seems to be possible to remove about 2cm while keeping the clicky and tailstand-ability. Would be 96mm. Too bad it will get an XML led.^^
The shorty AA MiniMag is 95mm in the off position, could be down to 88mm off if the tail cap has the button trimmed, could even put a clicky in it. Running an Efest IMR14500 it pulls 2.85A in direct drive for something in the neighborhood of 1000 lumens. Pretty slick trick it is, Thanks Dan!!!
Well, Fasttech has just updated the status on the $10 X-Power hosts to 'special order, ships in 7 days'. Is that 7 Chinese days (3 months)? Who knows! |(
2.5-3mm without glass, just the O-ring. At least on mine, I have it there now so I can hear how it rattles it’s really just a bit of spacer needed.
Yep I might use some dremel bit or use a normal drill bit or order some cheap end mill bit. That is if I cut it shorter.
S7 is the same or very similar to D4/Xiaozhi/X-Power I think, it’s just stainless steel so have fun cutting and drilling it lol. No no no, no stainless steel for me. Heavy and hard to work with. Although how deep the thread is cut on a S7 who knows. Such things may change even on the same model if not from the same factory or a different batch.
Might be because people don’t buy them much. From what I see everybody goes for Convoys for some reason, dunno why. I haven’t bought the host either and I asked them to list it J)
Would have, but got another light so I didn’t need to in the end.
7 days ain’t bad though. Probably just don’t hold it in stock or no stock currently so they have to get it from the factory that does their X-Power lights.
Good thinking with the silicone. Will it be ok to still make enough electric contact?
We have a drill stand but the garage is a total mess, but I’m looking to try get it working.
12x 7135 = 4300mA, “that’s not much” for 3 Nichias.
Current plan is to direct drive it. Got MOSFETs to mod Nanjg105c, got the layout, just need to do it.
We are already quite off topic here, so here is the Nanjg105c. board layout with SiR424DP
Obviously without the cuts and drills needed.
Oh I think the S7 is very well possible to cut down. Stainless steel is no problem. The problem is.. I dont really need it. I have 2 triple Nichia lights already and I cant afford to put triples in everything. :D
It doesn't take much silicone to seal it up, certainly not so much that it would affect the threads. Just enough to seal the two parts at the joint, an even smaller volume of sealant that the original o-ring. Just a little spread around the surface the head contacts when tightened. Let it cure completely, then peel off any excess that squeezed out. Trying to clean it off before it cures is like herding cats.
The stainless S7 would work perfect if the threads in the head were 3mm further. That’s sad. 
Might have to order a D4 or X-power just for fun.
Just finished one with Nichias, and... well, I can see the appeal of the high CRI I guess, but they just ain't very bright, are they?
Not as bright as XPG2 but decent. About a third less lumens but higher Vf, so..