I see the GT4 is finally getting made?
Sorry, I couldn’t resist. This is looking quite impressive so far, grin!
Funny that,
I get side tracked a lot. this build is giving me more ideas to go bigger. Quad using 4 x GT reflectors, 4 x sbt-90.2 leds, 4s4p 21700, thing is that light would be $1k for parts, haha i have the reflectors the, leds are ordered, i have found 250mm glass lens………
Should order the glass, you never know i might decide to actually build it. Aluminium billet i cant find so a lost wax casting would need to be done. Carving a dragons head with the reflectors in it mouth and nostrils out of wax will take some time so how do you do it in parts?
Then how pick it up? You could put it on your bull bar, light up a worksite 1km away, blind whole crouds of drunk people on their way home,
Just for shits and giggles some idea of what it could do.
K75 beams shots, chimney stacks are 178m high
So dont get me started until I finish this one.
Now it is starting to look like it should.
Thats come up a real treat. Any idea where the wiring is going to come through?
I was going to put it through one of the pillars but that was to much work without a mill. Then i thought of a glass tube in the centre and the aux LED in there to light up the heatsink. Eventually decided on a brass tube in the centre. This is the first one like this and wont be the last.
Wow, looking good grin 
Very impressive light! Are you adding a tripod mount or a shoulder strap? Even in AL, that’s got to add up!
As it is now the heatsink weighs 1.9kg by itself. It will have a tripod mount and also a shoulder strap but not sure how it will be done yet as I am making it up as I go.
The heatsink is proving to be a bit of work i dropped it and damaged the thread enough so it wont screw into the reflector housing so i started again.
Ready to silver soldering
I feel your pain grin.
How did you clean the edges of the fins up?
Trimmed them with the grinder, then filed and sanded them in the lathe, finally cut the burs of with a knife. The 3 pillars made it easy to straighten the fins with the knife.
My main concern is the weight and there is no way to make it lighter. I have thought of clamping a heating element to it so I can test how long it take to reach 60c. Maybe one or 2 fins could go.
I hate it when stuff like that happens! And to be clear, yes I’ve started over on more than one occasion!
I love copper, but it can be such a challenge…
I remember the amazement I felt when OL carved those reflectors and how well they came out. Now you’ve taken it to the next level of insanity. So much tenacity and sheer will power to make this beast come together. I actually cringed when I read that you dropped it!
I finally got some time to do a bit on the light tonight. The driver housing internals are done except for the battery contact and switch.
Driver retaining ring
Driver housing
Now the light is finally starting to take shape. I think I have found a way to fix the first heat sink I made by soldering more copper to it for the threads.
It is taking shape nicely Have you got more info on the lights to the left ?
One is and aspheric with 1mm2 osram, taskled h6flex, a 63mm precolimator lens and 100mm secondary. Im not sure how accurate my calcs are but it works out 2.8km throw. This is a beam shot at around 40m next to the w30 on the left.
The other is a SRK clone battery tube I made for sbt90.2 with Q8 driver and home made collar and it will be able to screw into some different lens setups.
Well I started a new heat sink but I found some big brass electrical fittings in some battery chargers I was moving (I lift the heavy fings for electricians 
) I silver soldered this on the bottom for the driver housing to screw into. The mistake cutting the thread for reflector part was fixed by cutting it down and silver soldering another piece on and recutting the thread. The soldering is very rough but is solid where it counts.
The bottom plate grew worts and there is still a lot of cleaning up to do. I used to much solder and it would have been cheaper to use bullion for solder.
The driver housing needs a switch and a cover ring for the join.
Cover plate for the reflectors then I can focus the LEDs. It is getting there
Nice comeback grin. Getting closer now.