BTU Shocker Triple MT-G2 with a twist -- Aiming for >100Watt ~9000Lumens -- With external 2S power pack, handle etc...

Aha yes of course, the master of looking so sternly at a piece of copper it cringes into an elaborate heatsink. :wink:

Well considering I haven’t even finished the first one, talking of mass production is a bit early methinks. Haha :stuck_out_tongue:
But hey if someone is really serious about wanting a light like this and is realistic about how much it would cost for me to hand make them one. Then sure, I’d be up for building a couple more, why not.
Parts cost alone is over $300 last time I checked, so that should give you some idea.

Oh and Updates are there… I’m afraid you’ll have to look through the thread to see the latest stuff. I can’t update the first post anymore since the thread is so old… :~

I don’t plan on LED/MTG change or Driver change. Just the tactical handle and otterbox & rc batteries. I’ve already gotten a BTU-Shocker. So i thought it would be cheap (under 100). Also thinking of doing a shoulder mount like camcorder’s in the past. A u or clamp mount on an old shoulder pad camcorder pad.

Ah right so you’d be interested in a kit something along the lines of this?

Yeah I could see that working but it does require a modified BTU tailcap or getting a run of custom tailcaps made up. And for the whole thing to thread straight onto a stock BTU, unlike on my light, the handle rail would have to be bolted to the tailcap instead. But in theory yeah that could work fine. A plug and play battery pack kit for BTU owners. :slight_smile:

–2x 3S rc packs in parallel probably around 10,000mah (3s and much lower current requirements from stock BTU would allow for a thinner power cable)
-Main power switched by a Fet in battery carrier driven by clicky in trigger
-MCU in battery pack for automatic overcurrent/undervoltage protection cutoff etc. (still haven’t gotten around to adding this functionality to my pack either but should be relatively trivial)

But for under $100, I’m afraid not.

Quickly worked it out and the cost for just the parts in the image above is over $150!
I’m sure you could source things for a bit less but that’s what it works out for my build, big ticket items such as the battery packs alone will run you around ~60bucks.

yea that’s fine the only big problem would be finding another tailcap without buying the whole thing.

Yep definitely. I could send Ric at cnqualitygoods a mail and ask if he has any BTU tailcaps lying around unused. Maybe he can check down the back of a couch or something, who knows… :stuck_out_tongue:

Vinh modded a few as well, might be worth PMing him too

I swear I did not clean Ric out of all his left over Shocker parts.

So you’re to blame! Hah, good thing I swiped them from you just in time then! They’ll be worth their weight in gold soon enough :wink:

Did he actually say those were the last bits he had laying around?

No I'm no sure. He did not have any lenses as I broke one and he had none left. He did send me some misc o'rings and a few other parts though I guess he had kicking around.

Internet broke so couldn’t upload any progress.

It’s alive! Finally :slight_smile:
Running off the battery pack fully assembled for the first time was a really great moment.

But it’s already back in pieces, for final tweaking and assembly.
Measured 15Amp draw from a single partly charged pack and Lordi does it pump out the heat! I definitely need to spend some time maximizing the thermal path into the reflector and out to the front of the light because the BTU pill and body is completely overwhelmed by the heat these three emitters pump out. Not unexpected really and I’ll definitely have the turbo timer enabled on this light, probably set to 1.30-2min max but I’ll see how the thermal properties are when everything is fully assembled. Then I’ll find a medium/high mode power level that can allow for continuous operation and go from there for low.

Very pleased with the STAR off timer driver UI and Moonlight mode works great. I’m pleased with the output level set to 12, but I do notice a bit of the usual moon mode flickering. Wondering if the phase correct PWM leads to more stable moon modes at very low levels? Has anyone got any experience with this?

After running on high for 2 mins I also saw some output throttling/flickering even though the pill surface wasn’t above 50degs, so I need to make sure the 7135s aren’t getting too hot inside and throttling back. All told it’s a bit of a nuclear reactor this thing, especially since the battery pack doesn’t give in at all under these power requirements and just keeps feeding the juice! :open_mouth:

Well as you can see still lots of tweaking and tuning to do but it’s getting there.

Oh and it’s quite a bright Mule this thing :wink:

At 15 amps although each led is on getting 5 amps that will still be generating enough heat to use in a steel foundry. I reckon the pill could possibly be getting a lot hotter than 50 degrees in that time. I have a single MTG-2 at 9 amps on a large copper pill and copper star and that chucks a mental after a few minutes because of heat. Getting closer to being finished. Again thanks for updating.

Its alive. Its alive! :)

Some really neat looking work you have been doing. A joy to watch.

I looked into it a bit more and running the pill separately from the driver I noted that a few of the 7135s were getting too hot and started throttling back within a minute.
This was running the driver direct from a single pack without the long cable so the vF difference that the chips need to burn off was exaggerated (I drop ~0.6v across the cable at 18A so max vBatt the 7135s should ever see would be around 7.8v or rather 7.6v with sag) but it resulted in the same issues I was noting before.

Mostly the chips on the bottom of the slave boards without a direct heatsink link where hitting the limit rather quickly but all of the chips were inadequately heatsinked (-sunk? -sank? -sunked?). I underestimated how much heat these chips produce and expected a single solid solder point from the top ground ring to also sink the bottom of the driver adequately. Should have known really.

So anyway I spent the evening soldering copper tabs between the ground rings of the three slave boards top and bottom and reinforcing the connections to the copper posts. I’ll probably also pot the bottom of the boards to the aluminium assembly with fujik once I’m happy things are working well enough to be more permanently mounted.

Urgh it’s a mess tbh, don’t look too closely. It’s more flux residue than driver at this stage… :wink:
Was tempted to just start the thing from scratch and use those new Nanj 105d drivers instead. They have a great layout for this type of thing and much more generous grounding ring, not to mention I’m pretty sure the copper is thicker on those than on these crappy KD drivers…might still end up going that way if I can’t get this to work well…

It’s not a solution to the mental heat the Mt-g2s put out, actually they’ll just be running at high power for longer now…doh …but at least the driver doesn’t start going mental before it’s own heatsink has even had a chance to heat up to match the rest of the pill. After that it’s just a matter of tweaking the turbo timeout for sensible operation.

This is why I focus on making things easy to disassemble, I certainly don’t trust myself to get things right first time even with all the testing I do along the way. Generally it’s time well spent. :stuck_out_tongue:

Are you telling us Kim Kardashian succeeded?

j/k, the light looks great

Not unless she was the one working in our garden and snagging the cable with a shovel. :stuck_out_tongue:

Well think I’ve hit a bit of a speed bump here. Even with the thermal path reinforcements some of the 7135s are still getting too hot. Honestly wasn’t expecting this to be an issue, never really had any overheating issues with these chips before as long as some basic heatsink considerations where undertaken.

Especially the stack of chips on the outside of the puck, where I had to file down the solder blob and ground ring for clearance issues, are getting very toasty. Hard to get extra copper connections on there too.

Will probably have to rebuild this thing from scratch to maximize the thermal paths… :frowning:
Last thing I’ll try before going that route though is potting the whole thing in fujik…but urgh that’s really a last resort since I wouldn’t be too happy with such a messy solution…

Welcome to the MTG-2 on heat club.

Haha, let me get the hose!

Ok, let’s see if this will work. Hacked up Nanjg 105d with extra copper thermal pathways.

Basically I used one of those new layout Nanjgs and instead of stacking an extra layer top and bottom I triple stacked the top because that allowed me to solder a copper ground band all around to maximize heatsinking. I noticed before that the 7135 chips on top of the stack and only connected to the heatsink through a thin solder bridge where the ones that couldn’t dump the heat quick enough. This should no longer be the case, all 7135 ground tabs (at least on top of the board) are now solidly soldered to the copper band which in turn is soldered down to the ground ring. Finally I will solder two copper “ears” to the band which will be bolted and possibly also soldered to the copper posts on the assembly to complete the heatsink/grounding path.

I guess I just like pain… haha…but I’m not going to jump in and make three of these things before I’m absolutely sure they’ll work! :stuck_out_tongue:

Time to test this thing and see if it can dump the heat fast enough! Fingers crossed! :nerd_face:
Cheers

+1 !

Nice looking solution. I hope it works as good as it looks.