Courui/Big Head Torch Mod [FINISHED]

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Rod911
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Courui/Big Head Torch Mod [FINISHED]

I am managing to find some time in the wee hours of the night to mod this light. Note that, I have two of these lights and I intend one of them to use an XP-G2 driven at around 4.2A and the other one, an XM-L2 driven at around 5A and both the LEDs have already been de-domed. Both lights will have the exact same mods done to them, with the exception of the resistor mod. I have hit a stone wall at the moment because the soldering iron that I have been using does not have a fine tip. I am waiting for this soldering station to arrive, before I can start working on the driver.

Now the pics.

20mm XP-G2 R5 2B de-domed. The XM-L2 used is on a 20mm star and an U2 bin, 1A tint. No pics of the XM-L2.

The backside will be used to place the LED on it. As per the pictures, it already had these massive scratches on it.

Tried my best using 120 grit, then finally, 600 grit to get rid of as many of the scratches.

Worked on it a bit more. Got rid of all but a few of the scratches (see macro shot). Kept on using 600 grit, then finished it up with 1200 grit. I could have clean it all up, but I felt it was ok to leave it as is (sore fingers…).

I also replaced the wire used in the contact plate with 18AWG.

Before.

After.

For heatsinking, this is what I came up with. The solution was using these heatsinks from FT, I lapped all the sides (up to 800 grit) that would bond with another heatsink or onto the LED shelf itself. I stuck them to one another using my preferred method which I have been using since the days of attaching CPU heatsinks onto GPUs, and that is to use a two-mix epoxy and a small dab of Arctic Silver 5. They all seem to be stuck fast to one another. This method will again be used when I stick the whole thing onto the LED shelf. At this stage, it hasn’t been stuck on.

Orientation of the heatsink from a top-down view.

Kapton tape was used on the underside of the reflector to prevent any possible shorting.

Last but not least, the good old copper braid on the springs mod.

Before.

After.

I have also taken up janko.hrasko’s mod of making the light lockout.

That is it for now. I’ll update this post once I am able to start working on the driver.

10/01/2014 – FINISHED

Driver before any mods done to it:

Driver after mods. Mods done were to replace the existing R200 with an R120 for the XP-G2 and R100 for the XM-L2. Along with this, change the wires with 22AWG. Kept the switch wires as they were.

The inside of the driver cavity. A lot of space. The heatsink installed. Note that, I did apply a bit of Arctic Silver 5 on the shelf before screwing it in.

A slight set back with the XP-G2. It was working just fine for a minute, then after installing the reflector/head, poof. Turns out, the R120 was burnt out. Easy fix.

The XM-L2 mounted. This was the same for the XP-G2. Ended up removing the kapton tape from the underside of the reflector. Initially I found that the twisting motion simply ate up/ruined the kapton tape underneath the reflector. This was my solution.

XP-G2 centred.

XM-L2 centred.

Note that, all centring was done by eye. The reflectors were screwed right in. I did play around with moving the reflector in and out, but found that, especially with the XM-L2, that the most intense hotspot was when the reflector was all the way down. Also, only Arctic Silver 5 was used to hold it in place. Essentially relying on the pressure from the reflector to keep things where they are.

Ceiling bounce shots.

Top is a D40A-NW, bottom left is the XP-G2 and bottom right is the XM-L2.

Top is now a modded OEM Big Head K8.

Top is now a Vinh modded BTU Shocker. Also, bottom right is now XP-G2 and bottom left is XM-L2. I did the tail stand in a different part of the room.

Right now, I am doing some run time tests on high. The XM-L2, I am seeing some flickering every 5 minutes or so at the corner of my eye. I am not sure what’s causing that. 40 minutes in, and I had to put them in a bucket of water as it was getting a tad bit too warm.
edit: Stopped the test at 1hr 30 minutes when the XM-L2 dimmed. Checked inside and both lights had a good 5-10ml of water inside of each one of them. So much for the o-ring and lubing it up? The breach came from the bottom.

Also, the tailcap measurements are a bit weird. I didn’t do a before measurement. But after everything is said and done, the XP-G2 is pulling 1.10A on high and the XM-L2 is pulling 1.11A on high. They’re both quite bright, and, to the naked eye, probably around 650 lumens and 900 lumens respectively – but that’s a total guess.

My first “real” mod and I am happy with the outcome.

Album of pics here at full resolution.

Edited by: Rod911 on 01/10/2014 - 03:15
Ouchyfoot
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Good idea with the heat sinks. I’ve been thinking of picking some up from FT for some time, but I was never sure if they were copper or brass.

The underside of my COURUI emitter plate has the exact same grinder marks as yours.
comfychair
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Adding mass without adding to the contact area between the hot parts and the cold parts... sounds like a kitchen sink with a partially clogged drain to me. Making the sink bigger only delays how long it takes for it to overflow and spill all over the floor. Sad

Rod911
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Mods done. See OP for details.

leaftye
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comfychair wrote:

Adding mass without adding to the contact area between the hot parts and the cold parts... sounds like a kitchen sink with a partially clogged drain to me. Making the sink bigger only delays how long it takes for it to overflow and spill all over the floor. Sad

To me it sounds like stacking ice on the supercharger of a drag racer.  It doesn't last very long, but it doesn't need to.

The low mode should be lower.

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Very nicely done Rod911. Your efforts for a first time mod is to be commended. I’m looking forward to the night shots at which I’m sure your neighbors will help out. Wink

 

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Ouchyfoot
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How did you take your tail measurements? I’m just wondering, because 1.11A seems kind of low for XM-L2. My COURUI gave me a reading of 2.2A at the emitter in stock form.
I’d really like to know what the reading is at the emitter with a single R120 resistor. I myself get confused when trying to do resistor math. I added an R100 on top of the R200 and got 4.1A. I also got some smoke and burning smell. I ignored that and ran it for a couple days with no problem until I removed the driver and stripped the board.
I’m wondering if adding an R120 on top of the R200 would give about 3.5A.

Rod911
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Ouchyfoot wrote:
How did you take your tail measurements? I’m just wondering, because 1.11A seems kind of low for XM-L2. My COURUI gave me a reading of 2.2A at the emitter in stock form. I’d really like to know what the reading is at the emitter with a single R120 resistor. I myself get confused when trying to do resistor math. I added an R100 on top of the R200 and got 4.1A. I also got some smoke and burning smell. I ignored that and ran it for a couple days with no problem until I removed the driver and stripped the board. I’m wondering if adding an R120 on top of the R200 would give about 3.5A.

As per comfychair’s instructions . I thought it was odd as well, but, that was the reading I got. Anything on the MM I should be weary of? I continue to use the settings recommended by HKJ as well which hasn’t caused problems previously.

MRsDNF wrote:
Very nicely done Rod911. Your efforts for a first time mod is to be commended. I’m looking forward to the night shots at which I’m sure your neighbors will help out. Wink

Thanks. I have already modded the driver I am planning to use for my Convoy L2 build (Lightmalls “5A” driver – which is in fact, around 3A as measured by Ouchyfoot), along with de-domed the XM-L2 and lapped its underside. I’m only waiting on the host which you have ever so kindly tapped for me, before I am able to put it all together. I’m hoping there won’t be a problem with this one because, if I fry this emitter, I am out of U2 1A’s… and I have yet to learn how to reflow an emitter. That’d be handy because I have an XP-G2 on a Noctigon that doesn’t work and I can reuse the MCPCB again.

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leaftye wrote:

comfychair wrote:

Adding mass without adding to the contact area between the hot parts and the cold parts… sounds like a kitchen sink with a partially clogged drain to me. Making the sink bigger only delays how long it takes for it to overflow and spill all over the floor. Sad

To me it sounds like stacking ice on the supercharger of a drag racer.  It doesn’t last very long, but it doesn’t need to.

Beer
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Thanks for sharing your mod rod911. Lots of nice work you got going there.

I have to agree with comfy on the extra heatsinking. Try connect a small heatsink like that to an emitter at 4A. It gets very hot in no time.

Effectively its more like a 10-20 second buffer, and even when that buffer is working you are probably seeing zero gain. I think it makes zero sense in a light like this. If it were connected to the body in some way it would make sense because then you would make the thermal pathway to the body. 

Keep up the good work and sharing mods!  Beer

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Rod911
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With the XM-L2, the flickering annoyed me so I decided to open it up and have a look at what was going on. I saw no visible water damage, so that was a good sign. Then, I thought to myself, whilst I had it opened, I may as well make a few changes…

I removed the 22AWG wire and replaced them with 18AWG. Next, I stacked on an R120 resistor on top of the R100. I have no idea now as to what amps this is pulling, or even if it is brighter, but I can definitely feel it heat up more. Also, the AS5 looked really dry, possibly due to it mixing with water, so that was cleaned up and replaced as well. When it gets dark, I’ll do a comparison ceiling bounce test to see if there are any improvements in output.

The downside to these mods though, was that, because I am now using 18AWG wire, I found that the reflector could not go all the way in as it use to. The hotspot still looks sweet, but that maybe due to the increase in lumen output making it look brighter. All I know is that, it works, no more flicker, it’s bright and it throws really well.

comfychair
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Sense resistors shouldn't be burning up like that. Has anybody poked around at this driver to see what's what? Are they actually sense resistors, or limiting resistors (inline with the power to the LED)? Check resistance from LED+ to BAT+, and LED- to GND.

Rod911
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comfychair wrote:

Sense resistors shouldn’t be burning up like that. Has anybody poked around at this driver to see what’s what? Are they actually sense resistors, or limiting resistors (inline with the power to the LED)? Check resistance from LED+ to BAT+, and LED- to GND.


I don’t think so. I am taking the figures that others have taken as I don’t really know my way around when it comes to measuring things with a DMM other than simple tail amp checks and voltage checks with cells. So, what you have mentioned above, is way over my head.

As for the added resistor (R120), it did yield brighter results. I think it is around 1100 OTF lumens now. That number was pulled from doing a ceiling bounce test against a D40A at turbo. The XM-L2 was simply brighter.

If indeed the R200 is the only resistor we should worry about here, and if the driver originally was providing 2.8A to the LED in stock form, then the stacked R100 and R120 resistors should mathematically, say that it is providing 10.27A to the XM-L2. Highly unlikely.

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comfychair wrote:

Sense resistors shouldn’t be burning up like that. Has anybody poked around at this driver to see what’s what? Are they actually sense resistors, or limiting resistors (inline with the power to the LED)? Check resistance from LED+ to BAT+, and LED- to GND.

Don’t believe it is a sense resistor, think it is a power dissipation resistor (could be wrong :_( )

That resistor is definitely a weak spot on the driver, look at it sideways and it blows, mine blew as I was trying to take measurements, If anyone wants to do resistor mods would be worthwhile getting higher wattage ones.

Flickering is down to a less than perfect solder joint at the resistor (at least on mine). Got a bit fed up with the driver so just removed the resistor and bridged with solder wick. Have had to adjust the amps with wires and type of batteries. Got lucky with my guesses and am easily getting 4.8 amps first try. Don’t want to go higher at the moment as I am using the stock emitter and star.

So far at that output no problems even after fair usage.

The views in this post are mine, they are views and beliefs only, and not to be taken as facts.

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Sorry to dig up an old thread.. But I have one of these lights on the way and I want to change the resistor to get higher amps.. Where would I be able to find a suitable resistor that would give me around 4.5A? Fasttech has lots of value packs of SMD resistors but I don’t know what value and size I need

Rod911
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logesearle wrote:
Sorry to dig up an old thread.. But I have one of these lights on the way and I want to change the resistor to get higher amps.. Where would I be able to find a suitable resistor that would give me around 4.5A? Fasttech has lots of value packs of SMD resistors but I don’t know what value and size I need

You’d need an R120 (or 0.12R). That can be found here:

https://www.fasttech.com/p/1234403

However, I have found all of FT’s 0805 sized SMDs pretty useful. I bought two of each SMDs ranging from R100 to R220. Because they’re small, I sometimes end up losing them, so having lots of spares is great.

logesearle
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Thanks Rod, have some on the way now!

WOODY1
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Rod911 wrote:
logesearle wrote:
Sorry to dig up an old thread.. But I have one of these lights on the way and I want to change the resistor to get higher amps.. Where would I be able to find a suitable resistor that would give me around 4.5A? Fasttech has lots of value packs of SMD resistors but I don’t know what value and size I need

You’d need an R120 (or 0.12R). That can be found here:

https://www.fasttech.com/p/1234403

However, I have found all of FT’s 0805 sized SMDs pretty useful. I bought two of each SMDs ranging from R100 to R220. Because they’re small, I sometimes end up losing them, so having lots of spares is great.

Hi, i need a couple of R200, R100 and R120, has any body got a link for fasttech for these, really not sure what to order, thanks.

Rod911
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WOODY1 wrote:
Rod911 wrote:
logesearle wrote:
Sorry to dig up an old thread.. But I have one of these lights on the way and I want to change the resistor to get higher amps.. Where would I be able to find a suitable resistor that would give me around 4.5A? Fasttech has lots of value packs of SMD resistors but I don't know what value and size I need
You'd need an R120 (or 0.12R). That can be found here: https://www.fasttech.com/p/1234403 However, I have found all of FT's 0805 sized SMDs pretty useful. I bought two of each SMDs ranging from R100 to R220. Because they're small, I sometimes end up losing them, so having lots of spares is great.
Hi, i need a couple of R200, R100 and R120, has any body got a link for fasttech for these, really not sure what to order, thanks.

Use the same link as above.  In the drop-down, select 0.2R, 0.1R and 0.12R respectively to get the resistors you need.

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Rod911 wrote:
WOODY1 wrote:
Hi, i need a couple of R200, R100 and R120, has any body got a link for fasttech for these, really not sure what to order, thanks.

Use the same link as above.  In the drop-down, select 0.2R, 0.1R and 0.12R respectively to get the resistors you need.

Also see this link (and the dropdown) for the 3 different 1206 sized sense resistors FT carries (R100, R120, and R330): https://www.fasttech.com/products/1002/10007371/1615807

… yeah, the 0805 selection is much better!

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

WOODY1
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Thanks Rod911, i understand now, i will order them, and also gives me an excuse to order another light!

WOODY1
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Would you put in a R100, or just bridge it with solder for direct drive on high?