GTL Headlamp - quick review and mod - updated

Flashlight Modding and DIY Parts
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Ok, the biggest thing you can get from this post is - don't buy this headlamp unless you want to spend time modding it. The cell is crap, the beam is a TIGHT spot and the output is too low for useful spill.

I paid $16 from meritline. There are gray, 2x18650 and different emitter tints available.

The second biggest thing is, if you want a headlamp w/ crazy throw and super wide/even spill...and you don't mind cobbing it together, this is a decent host. I dare say, getting the same (modded) specs any cheaper or in a lighter weight package would take some effort...

here are some stock pics

!{width:80%}https://sphotos-b.xx.fbcdn.net/hphotos-snc7/429437_10150697308231798_1844326016_n.jpg!

!{width:80%}https://sphotos-b.xx.fbcdn.net/hphotos-ash4/432333_10150697308561798_17641257_n.jpg!

stock vs sk68 clone (li-ion) at about 2 feet - donut hole disappears at 4 feet

!{width:80%}https://sphotos-b.xx.fbcdn.net/hphotos-snc7/429437_10150697305786798_1264352320_n.jpg!

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The mods:

the short story:

xm-lt6 from trustfire Z6, 2.8a 105c driver set to h-m-l, aluminum vga heatsink

the full story:

stock driver was rivet/soldered THROUGH the base of the reflector to the emitter?!

After ripping them apart and bending up the back of the reflector, I cut off the base, then filed it exactly to the start of the reflecting surface.

Next, I wanted to be sure I could tilt the headlamp farther forward than shown in the picture with it sitting on a hat above. So, I heated the part of the housing that touched the hinged with a hot air attachment on a torch, then pushed the housing forward (I forgot to get a pick of that...basically it just put a nice even dent in the housing that you can sort of see in the second pic below).

The heatsink was next.

In order to be able to retain full swivel range, and get the heatsink to the emitter, I cut the back of the housing off and filed it (reasonably lol) flat.

After checking fit/focus and marking emitter placement, I drilled and tapped the heatsink for emitter retaining screws.

Then I hot glued the heatsink to the housing, turned it over, put a big hunk of play-doh in the middle where the emitter would go, and in the hole where the wires enter, and then slathered jb weld in there. You can smooth jb weld w/ water soaked fingers, almost like it is clay.

About 3 hours in the toaster, wrapped in aluminum foil, on very low, and it was set, so I ripped the hot glue off and cleaned out the play-doh in the sink.

Next was the circuit. I potted (one side of) a 105c w/ devcon 2 ton and alumina, jumpered it to h-m-l, replaced the stock switch w/ the one that comes in most xxxfires, connected everything w/ twists to test current, soldered it all together, insulated w/ shrink and plasti-dip, and hot glued the stuff back in.

Stock battery did 2A on high, Panasonic cgr18650ch 2.6A (should have used better wire...but it is on 'the slow boat' lol).

That's it for now.

I won't be putting this thing near my face w/ that battery. When I get a dedicated IMR, I'll install that. I might drill new holes for battery cover retaining screws, and use wing nuts on the front side, or I might just screw it back together, cut the connector off the stock charger and wire it to a dummy battery for charging w/o removing cover.

pics! sorry my beamshots suck. I did finally get a new camera, but I don't know how to take beamshot pics yet (they're worse than these cell phone pics!).

this is like 2 feet from the wall and the camera is about 5 feet - massive spill

citipower X5 2.4A, same position/distance

citipower x5 - gtl xml

same w/ cam brightness turned down - no donut past 4 feet

Despite 'appearing' dim in these shots, the spill is PLENTY bright to be useful, and the throw is so far it is ridiculous - great for a bike helmet, snowmobiling, etc

cost - host $16.99, emitter ~$9, driver $5, heatsink was scavenged, still need a safe battery. not cheap, but budget, imho.

I'm about to do some heat testing, but so far in playing around w/ it, heat isn't an issue at all.

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that is awesome, now i wanna do the same

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thanks. it is like it was MADE to do this to lol

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100 views and 1 comment

not many fans of plastic lights here

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I like this a lot! Guess there was no way to keep any heatsinking inside the lamp housing, eh? Only the reflector acted as heatsinking as stock? I wonder how hard you could drive an XM-L with a small heatsink inside there.

This interests me because I've always wanted to upgrade our company's mining cap lamps to LED technology (as the resident flashaholic I feel it is my duty). Right now our cap lamps are stored at our other office and I don't get down there too frequently. They should be very similar to something like this:

Big heavy battery on your belt with a xenon or halogen bulb in the cap lamp. These lights are expensive (link shows $432), and I think I could produce something that would blow these away. I know your light would be too cheap for this kind of "industrial" use, but it gives me ideas and tells me I need to get a good look at these lights. Hopefully we have one that is dead and just laying around.

-Garry

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If you relied on mass you could keep the heatsink inside the housing and still drive it pretty hard, but obviously that'd be much heavier.

It is VERY light as is.

It is surprisingly rugged for the price - the plastic is not as brittle as you'd expect - and now that the housing is filled w/ jb weld and has aluminum on the back, the weak point would be the hinge.

But, as I was putting the 'dent' in the housing, I was torquing that hinge pretty hard...even making it flex, and it didn't break.

Obviously no where near as rugged as something metal though...

I think you'd like this headlamp more for bike riding than a work light since it has so much throw - it could even be strapped to handlebars.

I'm sure if you modified one of those industrial ones properly it would stomp all over the stock bulb...

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Well actually I'm usually looking more for flood than throw. I like to be able to light up the whole area right in front of me. Not so much for bike riding, but things like camping, working around the backyard after dusk, etc . . . Wonder how long these are "on sale" for? (I don't browse Meritline much.) You couldn't fit a 26650 in that battery case, could you?

I keep thinking about it (personal use, not work use), but I'm probably better off just putting the money toward the a UF-H3.

-Garry

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Hell, I never even saw it. You know just using the “front page”, I miss most of the good stuff, since there’s so many posts here every day. I never think to actually go into the forums, just hit the front page and go on…

Well, I'm not a fan of plastic, since I molded the crap for 26+ years, but I can see the economics and the weight factor there. You can make something out of just about anything, if you set your mind to it.

I wouldn't put that on your head either, with that battery in it.Tongue Out

Thanks for giving us new ideas!

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there's a ton of flood/spill. but, even w/ 600 or so lumens coming otf, it is so wide that it isn't as bright as I might like riding a bike. A lot of light is wasted w/ that circular beam, imo (goes up in the sky...).

The beamshots are deceptive because that other light is also t6 at 20% more power.

if I use it on my snowmobile (if it ever snows here again?!) it will be a secondary light to a more traditional headlight type beam - so that whatever direction I look I can clearly make out distant targets.

you'd have to modify the battery box for 26650 - but it would fit 2x18650. They sell that version, too, so if you're going that route, I'd buy that one - I assume they're paralleled.

If you want to try it out instead of just buying one, and you don't mind paying the postage to send it back to me, PM me your snail mail address.

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Thanks for the offer, but I think I'll pass for now.

-Garry

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I know, right?! that's just asking to be visibly scarred for life

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Just a bit of modding required ?

Very nice instructable, dthrckt. The pics like you've turned it into a very nice, usable light - the proverbial silk purse, and whatnot...

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haha, yeah, it took awhile, but it didn't require any special tools or skills :) thanks!

oh, btw, nothing to report on heat tests. that vga sink works great - hardly gets warm.

with better wires and an IMR - so I get the full 2.8A - that will probably change some, but I have no doubt it will still run full bore, while stationary, w/o a problem.