MT-G2 Mag Mod. Simple heatsink question

MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Hey again guys :wave:. So I'm doing another mag mod, this one is a 3D mag that I'm gonna put a Cree MT-G2 in. It's going to be powered by 3 18650's or possibly 3 32650's in the future. The build is relatively straight forward but I have a question about emitter height and reflector compatibility. So here is the parts list so far. (I have not ordered the parts yet, so if there is something that should be changed please let me know)

• Cree MT-G2 QO on a 16mm noctigon from Intl-Outdoor
• LD-2D 3A 2-3 Cells Circuit board for 6V LEDs from Intl-Outdoor
• home made heatsink (details below)
• 3D mag host
• Cut down mag rebel reflector
• Delrin sleeve for batteries
• Deans connector on switch to driver wires for easy disassembly

My questions are...

1. How tall do I need to make the emitter post in the heatsink to focus with the rebel reflector? Does the below height of 7mm (flush with the top of the heatsink) look good?
2. I assume it is possible to use the rebel reflector right?
3. And does anyone have experience with this driver? http://intl-outdoor.com/ld2d-3a-23-cells-circuit-board-for-6v-leds-p-865.html It looks to be a good match for my build.

My heatsink design is pretty straight forward and is in essence an upscaled H22A heatsink (which are great BTW)
I have some rough design ideas below. (again sorry about the amateur design skills)


Side view (37mm lip rests on threads of mag tube)


Bottom view of driver recess


Driver from above


Bottom view with driver (driver will be potted with artic alumina)


So this is just a rough design and is not set in stone. I was also thinking of maybe just removing the lip at the top which would allow the heatsink to be lowered and secured with a set screw. The only problem with that approach is the heatsink has to be shorter to physically be able to be lowered into the body without hitting the switch assembly.

Any and all help, comments, critiques, and recommendations are welcomed. Thanks in advance.

I will say it now, I have no experience doing modding but could you not power up the emitter on a table top and then hold the reflector over it and move it until it is focused? After getting it focused measure where the location of the led is in relation the the reflector?

First off I wish I had your amateur design skills. I read somewhere on here not long ago that most reflectors are focused when they turn yellow from the emitter. In other words when you look at the business end squarely the reflector will be yellow. I think there should be a slight ring at the base of the reflector for optimal focus. Don't quote me on that last part though. If you look at pictures of production light like nitecore sometimes they show a pic from the front and you can see how the reflector is yellow. Hope that helps.

Hey, thanks for the replies guys. Yes I can power up the emitter using a bench power supply and measure where the reflector needs to be, and that's probably what I'll end up doing. It's just that when I wrote this I didn't have the bulb or the rebel reflectors. I've since ordered all the parts for this build and have received the reflector but I'm still waiting on the rest. Also I believe you are correct about the die color being shown in the reflector when its focused light-modder. I was mainly looking for someone who has tried this setup to pass on some measurements so I would only have to machine my heatsink once instead of trial and error to get the height just right.

Thanks again for the replies guys. I'll be sure to post pics once all the parts arrive and I start assembly.

I'm a huge fan of Mag-mods like this, and I'm looking forward to seeing pics of the finished product!

Re: MT-G2 Mag Mod. Simple heatsink question FINISHED WITH PICS

Hey Guys, sorry its been so long since I've updated just been busy with work. So I've finished the light with a few tweaks on the original design. The first change is its now in a 2D mag instead of a 3D, and is being run off 2 Keeppower IMR 5200mah 26650's. The other is the heatsink which has changed dimensions from above, I removed the lip at the top and added a set screw. I also shortened it and didn't make the traditional style pedestal for the bulb. And the biggest change is I've realized that the design would have to change drastically to accommodate a rebel reflector, so that will be another project (possibly with a de-domed MT-G2 :naughty

The standard mag reflector does have artifacts if your wall hunting but is not very noticeable outdoors. I got some current and voltage readings (from the bulb) and the circuit appears to be driving the bulb to it's full potential. The host is just an old mag I've had sitting around for years, I plan on dropping everything into a dark green 2D mag in the near future. Pics to follow.

(as you can see I've got a few projects in the works right now )


Heatsink machined out of 6061 aluminum rod stock




Driver potted in with arctic alumina




Bad camera work here, trying to hold the camera and the work at the same time
Voltage at the bulb on low


Amperage on low


Voltage on medium


Amperage on medium


Voltage on high (yes that's a 6)


Amperage on high




Got a little hasty when I was threading the set screw hole and broke a tap off in the heatsink




On low






Performance wise the light turned out great and its not overly heavy, according to my math its putting out about 2260 lumens. haven't done any runtime tests but after about 5 mins on high it only gets slightly warm. And don't worry the mandatory beamshots will follow tonight or maybe tomorrow night.

Re: MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Looks good thanks for the update!

Re: MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Nice work!
Of course, being the perfect machinist that I am, I've never broken off a skinny tap in a hole.... Yeah, right!

Re: MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Beamshots?! Any updates?

Re: MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Again sorry for the delay, But the weather has cleared up and I have finally taken plenty of pictures and uploaded them to photobucket. It's already late tonight but I will post them tomorrow evening.

Re: MT-G2 Mag Mod. Simple heatsink question NOW FINISHED WITH PICS

Ok I will be comparing this light with a few others for cross reference. My camera is not great but it seems to take pretty good comparison pics. It does however make the lights seem dimmer than they really are in person.

The stump in the backyard is 70 feet away.
Control


Nitecore PD12 2015 version.


Custom XM-L2 T5 Mag mod with Rebel Reflector, Roughly 1,000 Lumens. This is one of my favorite lights even though its pretty straightforward. I doesn't look like much compared to these other monster lights though. The rebel reflector makes a huge difference over the stock one, light throws great.


Custom MT-G2 light (This Light)


Triple XM-L2 U3 light


The house in these pictures is 75 yards away.
Control


Nitecore PD12 2015 version


Custom XM-L2 T5 rebel mag


MT-G2 mag mod (this light)


This picture is just to show the top of the trees, to demonstrate how much brighter these are in person. In person you can see the tops of the trees as you can in this picture while aiming at the wall of the house, but apparently my camera doesn't do a good job picking up the spill of these lights.


Triple XM-L2 U3 mag mod


The building in these pictures is about 90 yards away

Nitcore PD12 2015 version


XM-L2 T5 rebel mag


MT-G2 mag mod (This Light)


Triple XM-L2 U3 mag mod

Great build!!

I am new to the CPF, and have a few questions about your build as would like to build something very similar.

Why the change from 3D to 2D,

What was the reason for removing the pedestal for the LED?

Have you built the rebel reflector version?

If you could go back, what would you change, tips etc.