Ultrafire F10 with MT-G2 - 2x/3x 18650 - Build thread with pics

I was looking for an easy to carry and reliable outdoor flooder with enough runtime, a kind of ‘reasonable’ MT-G2 build. A torch to check around the house and bring daylight to the vicinity.

The Ultrafire F10 has many advantages for this endeavour.

The reflector fits nicely around the LED, as the opening is wide enough. In addition the reflector base is very small, so it does not touch the LED wires. The flashlight body is beefy enough to handle some heat, the modular structure helps a lot with the build. The pill sits tight and can accomodate a 20mm LED and a buck driver.

I like its sleek and unpretentious design. Size is in the ballpark of a Maglite 2C, but more slender, more lightweight and way more powerful.

Let’s have some pictures.

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Ultrafire F10.

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XM-L T6. At least, it says so…

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Hmm, this an XM-L? :wink:

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Let’s have a look at the internals. The reflector is quite long, makes for a halfway decent spot even with an MT-G2. But make no mistake, this is a flooder.
Into the center part of the head the pill is screwed in from above and a retaining ring from below. Both share the same threading, so the position of the pill is variable. The light comes with 2 extensions, here only one is pictured.

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The reflector sits straight on the LED, surrounding the dome. Centering the LED is not that easy, as you might have noticed 2 pics up…

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As you can see, the yellow material on the substrate beside the dome is coming loose. Might be a good idea to add some kapton tape. I’m not sure whether the top side of the substrate (below the yellow layer) is part of the current path, but I suspect it.

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The pill itself is a bit thin, this is the only downside on this nice ‘host’. If I were going to the limits of this build, I’d definitely back the LED shelf up with some copper. But for my needs I just milled the shelf flat, added notches for 2 screws and tapped 2mm threads to fasten the Noctigon.

My driver is one of the ubiquitous 2x/3x-buck drivers from LCK-LED. It’s the 3A 3-mode version with the smaller inductor. Bought it some time ago from LCK via eBay. Testing gave ~2.85A on high with the MT-G2. I aimed for 2.5A, so I changed the R200/R200 to R200/R330. That made for very reasonable 2.4A for now.

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Just for the record: the 5A variant of the driver with a larger inductor does only fit into my pill with force or modding.

This driver has a plus-pole-post instead of a contact board, so I added a 22mm contact board I happened to have lying around and piggybacked the driver with bell wire on it. Unfortunately I forgot to take a picture and it’s pressed very tight now. Next time I will file a notch.

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The large retaining ring comes in handy. It secures the contact board very nicely.

One could even use a slightly larger contact board that sits on the outer rim of the pill, instead of being pressed in. The retaining ring would hold the board in place and there would be room for the 5A driver with the larger inductor. Just a thoght.

Here’s another shot that shows pill and ring. As I had mentioned, it is useful to be able to adapt the height. Placing the reflector on the LED-substrate leaves the reflector rattling sightly against the lens after full assembly. You could use a thicker o-ring, but I simply installed the pill slightly higher.

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Just a small ring of copper bell wire under the rim of the pill, and the pill sits higher. Pill countered with the retaining ring inside, and all rattle is gone.

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Result? Very nice indeed.

The MT-G2 at 2.4A already gives a lot of light. Compared with an XM-L2 at 3A it’s got less spot, but is much brighter. No surprise here, that turned out as hoped for. The heat is handled quite well, but the light, if left lying around on High, gets too hot to hold after about 10-15 min. I drained several pairs of 18650s on High and the driver survived without potting.

With this driver you even have the option for 3x 18650. Downside is, that the extensions give only 63mm, even very short for unprotected cells. 2x protected cells do fit, but I already cleared some space in the tailcap for that by exchanging the washer between switch and rubber boot for a thinner one. With 3 protected cells the tailcap would not close completely. But electrically it worked well with 3 cells, so if you gain space behind the pill or between the tube parts, you are good to go.

I can’t recommend using unprotected cells. As I said I drained several (different) pairs of cells and it was always the protection of one of the cells that kicked in. Can’t say if the driver has low voltage protection at all.

So is there still room for improvement?
Well, yes:

The light must have sat on the shelf for ages. I have never ever seen so many dry and partially shrunk o-rings before in a supposedly new flashlight. This is everything but waterproof.

One could reach for higher current, but I’d pot the driver, regardless which one is used.

This LCK driver is not my cup of tea. There’s humming in all modes, even on high, but loudest on medium. Time for a nice Zener Modded Nanjg driver. :wink:

Nice mod HQ. It will be interesting to see the run times with the different driver at the same current output. Is this your first MTG-2?

Great mod, thank you, my F10 needs something else done to it, XM-L2 T6 at ~5A needs improving.
Now all I have to do is convince the purse string holder that getting a MT-G2 is a necessity :expressionless:
To use protected cells I sacrificed a cheap 9 led light, you know the ones they sell everywhere made some rings to extend the tube just enough .

A bit closer

They fit just nice, take the O ring off first, ask how I know, note the gouge in it :slight_smile:

They are a bit rough but I have enough left over to do a good job next time.

Now what can I buy her so she lets me spend a bit :bigsmile:

Cheers David

Very creative pommie. It gets the job done.

This is a very similar light at an outstanding discount of $9 shipped:

http://www.meritline.com/showproduct.aspx?ProductID=78963&SEName=cree-t6-5-mode-white-led-flashlight

I just received it and it's branded Sipik HK70. It's a TrustFire or UltraFire X8 clone. clunky next mode driver, but still has the high quality body parts - SS bezel, heavy brass pill, heavy alum reflector that the pill screws in to, then the reflector screws in to the body. Should be an excellent MT-G2 host - I know 18sixfifty built at least one up and sold it on BLF.