My first project, lots to learn.....

I've bought a cheap ultrafire e17 to play with, it's a xm-l T6 with a aspheric (I think) lens that can be moved in/out for flood or spot. What I want to do with it is mount it on a rifle for lamping at night, I've already tried it and it's o.k. to 150yds. I'd like the spot to be slightly smaller but I can live with how it is - what I do need though is more light beyond 150yds. 200 or more would be ideal.

It uses 1x 18650 battery or 3 x AAAs

I'd like to modify this torch to suit my needs as well as possible without spending too much, I've not measured the lens or driver yet. I'm not too worried about the battery lasting for ages, I can carry spares (got some 5000mAh batteries on the way) and the torch is only on for short periods of time (30-60 seconds at the most usually) so I'm not overly concerned about heat. What would you recommend?

bit of an update; both driver and emitter are 20mm

is it possible to use an sst50 emitter (4.2v), a suitable driver (unknown) and a different battery or more than one battery?

Hello shootercf and :welcome: .

I googled the light and unfortunately, I am afraid that I have quite a few bad news for you (some good too). Let me list some things:

• There is no such thing as a 5000mAh 18650. Some cheap manufacturers/sellers exaggerate the numbers, but the best available currently is 3400mAh. And those that claim more will most likely be less than 3400mAh. You can find a lot more information in the batteries section.
• I am pretty sure that the light is not strong enough to handle the recoil.
• It might be possible to use SST50 or not, but it wouldn't give you more throw (the spot wont reach farther). You could perhaps get more light but the beam would be a lot wider, hence making throw smaller. To release the full potential of SST50, you would also need a different driver and the heat would easily become an issue.
• If you want more throw, you should use a smaller led like XP-G2. It would be overdriven but if the light is on only short periods at a time, it could very well be ok at max, too (the link I clicked claimed 2000 lumens with XM-L, which is more than twice as much as possible from that light). You could also use the original driver, so, the mod is quite cheap. You would get a bit less lumens but the beam becomes tighter and the light will throw farther.
• So, my first suggestion would be to buy a stronger flashlight (with no zoom) for shotgun use. My second suggestion is to buy an XP-G2 emitter of your choice on a 20mm board. It should give you a tighter beam with noticeably more throw.

Good luck!

Thanks esko,

im under no illusions about the batteries, as long as they're half decent; I'm not too worried.

erm, it's a rifle, not shotgun (.22/250) but I've yet to fire a shot with the light so can't comment on recoil - though it's not harsh with that calibre.

I understand your point but I have this torch now and might as well see what I can do with it before I buy any more - I'll learn something new and enjoy pottering around with things anyway.

I'll have a look at the emitter you recommended, as you've already grasped; throw seems to be key here.

would a driver that can provide more current be as good as the xp-g2? I've read that the xm-l is normally run at 1A but closer to 3A is ideal.

I have no idea why it changed to a shotgun in my reply. Anyway, for a .22, especially if it has some mass, it might be just fine.

It is hard to make comments about the driver since we don't know the current power. 3A means something like 1000 lumens (less in real life scenarios, especially for a zoomlight). The link I clicked said 2000 lumens, which is obviously wrong. More current means more lumens, but going beyond 3A means more heat and more difficult modifying (due to heat), which most likely is not worth the trouble/time/money for this light. Compared to XP-G2, you need roughly twice as much current with XM-L(2) to get the same throw.

For throw, you need brightness of the LED. If you double the light, and double the size of the LED, you end up with the same brightness and thus the same throw, just a bigger spot. The brightest LEDs right now I think are the 2nd gen CREEs, XP-E2, XP-G2, and XM-L2. All have around the same brightness at specified drive levels, but the smaller LEDs you can overdrive more easily without overheating them. Since this is a small light, long-term heating is a big issue and the smaller LEDs will give you better throw without overheating, simply because they give the same brightness at lower power levels. The tradeoff is that the spot will be smaller.

I have just mounted a Primus light onto my helmet, its working great.

i have also just bought 2 cree lights, on test this evening they worked well for half an hour.

O.k. so I've had a think and scrapped the original idea - it's still a handy torch (flashlight) but doesn't throw as far as I'd like it to.

Any suggestions what to get that would get me what I need? still needs to be relatively small and light and being able to buy a remote switch cheaply would certainly save me some work.

I wondered if this with a 2-3A driver (heat shouldn't be a problem as it'll only be on for short periods at a time - 30secs ish) would get me any closer to what I'm looking for but I'm sure you guys can come up with better suggestions (keeping to the same sort of size and not too expensive please)?

A L2x host with Ahortons aspheric kit commes to mind.