Making the BEaST! Overdriven MTG2 in Convoy L2 Host!

kosPap

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I meant to make a 2000 lumens thrower for sometime now, but I waited till I could find a good combination of Host flashlight, driver and LED.
Enter intl-outdoor with an 6V MT-G2 in P0 bin (very good)
http://intl-outdoor.com/noctigon-mtg20-mcpcb-cree-mtg2-p0-5000k-6v-led-p-727.html

and 2 choices for electronics
http://intl-outdoor.com/xml-multicell-circuit-board-3a-55126v-p-361.html
http://intl-outdoor.com/xml-multicell-circuit-board-35a-ouput-55126v-p-543.html

And fasttech, with the Convoy l2 host which is a bit of a beast as flashlights go.

The parts before assembly
3e7c.jpg


Convoy L2 as a Host

xxfm.jpg


The good thing about this host is that it has a LED opening the size of the MT-G2 and accepts a 21mm wide driver.
But internal room for the electronics is limited heightwise and the screws that hold the LED protrude into the pill. So you got to file down their length.

nt4b.jpg


By and large it is a good host, especially for the price. Well machined, good enough anodization, AR coated glass, and press fit rings on the tube ends for better conductivity.

O-rings are a bit stiff and dense and not that high. Since the threading relief cuts are big enough I added silicon 26mm ones too.

I judge flashlights by the threads in the body and tailcap. In the Convoy they are anodized but thin for the size of the flashlight. I would expect a beefier design.

Did I tell you it is BIG?
dk6a.jpg


Mothership BIG?
tvqe.jpg


The Assembly in stages

Prepping the materials

d7sq.jpg

The very first thing to do was cover the Huge 68mm reflector opening in shrink wrap. It makes for a clean and safe handling of it. Then the reflector base was isolated with self-sticking vinyl, the kind you find in car banners.

The reflector screws on the body and that makes for good heat transfering and good centering. On its edge there are two opposite tool cuts for the pliers so you got to be extra careful not to let them slip….

bqxe.jpg

The LED socket

Preparing the LED

w7c7.jpg

I added silver paste on its bottom, just enough to fill any metal-to-metal voids.

edwe.jpg

The LED MCPCB screwed on.

uzed.jpg

Reflector test fit…..It is a hair off-center, do not know why.
(the red blot is the vinyl part we removed from the LED opening)

Preparing the electronics

x8fz.jpg

The driver came with a self-adhering thermal pad. But since space was limited I forego it. I positioned the wires that joined the two boards as best it could be done than filled the rest of the space with thermal glue (Fujik).
I also used some solid wiring to join the two boards tight against eachother.

wx1x.jpg

What the driver socket looks like.

mcv3.jpg

The LED wires soldered. It was a Pain in the A** cos the housing was so deep the tweezers and soldering iron were almost vertical.
I ended up soldering in 3 passes. A first join to just keep the wire in place, a second pass with extra flux to fix the wire properly and a third to "polish" the job…

18pa.jpg

End by screwing the brass retainer ring and adding a spring. While the original one was copper (?) colored I found it to be a bit weak for the calling and of too thin a wire.
I added an aftermarket thick and HARD one.

Measurements

I have a problem with them. They are too good to be true.
Either my lightbox is off or there is something fishy with the driver.

After the assembly I found out that the driver specs changed after I ordered it. It is supposed to be a 3.5A one but the new specs talk about 4.5A of output.
Practically I cannot know what I got, and I have no urge to desolder a LED wire to measure…
Reverse calculating it the driver must be feeding above 4amps to the LED

So…the numbers are.
4.2A current draw for the 18650 batteries
Lux at 1m: 48540
3350 Lumens on high!
1050 lumen on mid!

A runtime and temp test ended early cos the flashlight was scorching hot!

Min – Output – Temp C
0 – 100% - 23.7
1 - 94% - 32.7
2 - 92% - 37
3 - 91% - 39.7
6 - 87% - 51.7
9 - 81% - 58.6
12 - 80% - 62.9
15 - 77% - 67.5
18 - 75% - 69.8

I used protected Sanyo 2600s batteries. When the test stopped they measured 3.83volt and that makes for a 45% estimated capacity left.
Tempwise the battery had reached 65 C at the end of the test.
A bit latter I tried measuring the driver temp. The body temp had dropped some but the driver was cooler than it, at 45 C (at the time of measurement the body was at 54 C)
And that explains why the speced driver temp protection did not kick in during the test.

Sadly no outdoor pics are possible for now.

Across the square the light is not that good a thrower as acroos the distance the hotpsot thaws out, but it is resistance-is-futile stunning!

thanks for reading
 
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pyro1son

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This thing is insane!!! :drool:
Temps are a little worrying tho :shrug:
Cannot wait to see the beam shots for this tho!
 

papershredder

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May 31, 2013
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Protip: To apply the thermal grease, get some of that shrink wrap and pull it tight over your index finger. Then you can spread it around by hand without getting it all over you, and hand oils getting all over the part. By hand is always easier than the end of the applicator. =)

Good documented build!
 

kosPap

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interesting....
but i did not use the applicator...I just neglected adding the tool I use in the photo
I use angle cut toothpickers for pastes, glues, lubricant and flux. it makes for a chisel tip. this is how the checkering was done in order to reduce the material applied.
 

rechmp

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Jan 28, 2014
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interesting....
Dear kosPap, tell me please how you feed 6v led with 9v driver? As i understand driver have constant current stabilization, and pulling into diode as much voltage as it needed to diode (around 6.5-7v on that current).
Isn't it will be better to use 9v diode?
I want to make same l2 burner, and looking for components now. Can you advice me driver for is, because there is no more offer on IO.
Regards, rechmp.
 

jason 77

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Dear kosPap, tell me please how you feed 6v led with 9v driver? As i understand driver have constant current stabilization, and pulling into diode as much voltage as it needed to diode (around 6.5-7v on that current).
Isn't it will be better to use 9v diode?
I want to make same l2 burner, and looking for components now. Can you advice me driver for is, because there is no more offer on IO.
Regards, rechmp.

This is the Driver I used in my MTG2 flashlight project, and IO still has it for sale.

http://intl-outdoor.com/ld2c-3a-12-cell-circuit-board-p-732.html
 

kosPap

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wow! I did not expect thsi thread getting noticed.

Dear kosPap, tell me please how you feed 6v led with 9v driver? As i understand driver have constant current stabilization, and pulling into diode as much voltage as it needed to diode (around 6.5-7v on that current).
Isn't it will be better to use 9v diode?
I want to make same l2 burner, and looking for components now. Can you advice me driver for is, because there is no more offer on IO.
Regards, rechmp.

Maybe it would be, but the 9V version was not readily available. And shopping from theUS has its limitations for me.

It is my understanding hhat the driver wroks exactly as you suppose.

I wish you luck finding a driver that can output more than 3 Amps. I just checked and the original options driver options are out of stock.
Else go with Justin77's suggestion
this is exactly my understanding. What Buck drivers i have seen output the voltage the LED needs and they define curent output
 
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Fireclaw18

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Mar 16, 2011
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....

I wish you luck finding a driver that can output more than 3 Amps...

How about a Nanjg 105c with Comfychair's FET and Zener diode mods? Mountain Electronics has all the parts and will even build the driver to your specs.

The mod isn't hard. Take a 17mm nanjg 105c driver, remove all the 7135 regular chips and replace with a single FET. You can use your choice of firmware for either an electronic momentary or clicky switch. Or if you want an even fancier UI go with DrJones firmware. Just make sure whatever firmware you use has phase-correct PWM. In addition to replacing the FET, a resistor and zener diode are also added to the board so the MCU can take the extra voltage.

The result: A very small and flat 17mm driver that retains all modes while delivering near direct drive performance! The driver doesn't even get that hot. An MTG2 reportedly can draw 10 amps with this driver when running on 2x Panasonic 20r 18650 INR cells. If your light's driver compartment is too big for a 17mm driver you may need to attach it to a contact plate.

Input voltage will be the same as output voltage though. It's not a buck or boost driver, so you'll need to run it on 2 cells in series.
 
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Rod911

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I finally managed to build one of these, but in a Dipper D19 (Convoy L2 clone). I have it being run at around 5A as well and it's brighter than my S6330vn (in NW). The host plus this LED makes it a great balance of throw and flood.

As for beamshots, I'm planning to do another set with my other throwers, but in a different location.
 

Icarus

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I finally managed to build one of these, but in a Dipper D19 (Convoy L2 clone). I have it being run at around 5A as well and it's brighter than my S6330vn (in NW). The host plus this LED makes it a great balance of throw and flood.

As for beamshots, I'm planning to do another set with my other throwers, but in a different location.

Which driver did you use?
 

Rod911

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Melbourne, Australia
I resistor modded the stock driver in the D19 to get me 5A. I was supposed to use an LD-40 and resistor mod that to 5A as well, but because it hasn't arrived yet, I thought I'd give the stock driver a go, and to my surprise, it worked.

I have another D19 in the way which will be used to try and emulate Sabb's REV-Captor light at a fraction of the cost. Initial tests using a Yezl Y3 as the host was disappointing (with an MT-G2), so I am going to try for a bigger reflectored light along with driving it to 7.5A. The flood project will be using the D19 driver as well.
 
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