beauty and the beast….thanks for showing off 
I inserted some 3mm screw rods in the exsisting holes of the spring board and let them stick out around 12mm as you can see on the picture. I then drilled four 5mm holes roughly at the appropriate spots at the second tube as you see on the same picture. 5mm allows some room to play and find the perfect fit. I filled the 5mm holes with epoxy and placed the tube with the screws on top of, with the screws being inside the epoxy. After it hardened they became inseparable. I suppose if i heat the pieces a lot and melt the epoxy I can separate them if needed…
The SRKs I used where the cheapest I found on aliexpress that had the smooth type tube. Were around 15-17 dollars a piece. They are I think 10 or 11x XML (they had fake XMLs so sacrificing them was not a problem).
Thank you all for the kind words.
Fantastic build!
Cool build. Would be nice to see more pictures if you have any.
Absolutely awesome build!
Wonderful work with that heatsink and active cooling. OL would be proud! :sunglasses:
How long can it run on turbo with the fan speed set to high?
Got any outdoor beamshots at turbo?
Thanks for the info. So the electrical contact for batt- is done only by the 2 tubes connected with epoxy? Since I have a somehow similar mod in my mind I wonder if over the time the pressure between the 2 tubes decreases and the contact resistance rises.
The tubes are nice, they look similar to the Q8.
Deserves a bump.
[quote=Flashy Mike]
Yes you are right, over the time it could happen. You also need to have both surfaces very smooth and gapless before gluing , and use some weight while it hardens. The current doesnt flow through epoxy and the screws but through the exposes aluminium where the 2 tubes meet.
Now if the tubes loosen with time and I lose contact, a possible solution is to drill one or more small holes exaclty between the 2 tubes(in the gap) and insert a short piece of singe core copper cable or similar conductor (with a tight fit) to reconnect the two parts.
If you find a conductive epoxy, it would be the best solution in first place…
To the other memebers asking about temps and beamshots, until now I didnt have the time to use the flashlight enough. I will try in the next days to do it, and write back.
my reaction was WTF 
same as the brand of the fan you use
There are other techniques that assure electrical contact between 2 SRK battery carriers.
They can be threaded on one side, pressed fit and pinned together with roll pins (4) of them and then epoxied.
You are right! I have done this in another 8 cell project, the last one in my signature. Its 1s8p with 2 tubes. This time I wanted to avoid the conencting ring for a smoother look. It is more practical with the ring though, as you can unscrew it if needed.
You can still roll pin, or get really fancy and use brass pins, and on the PCB side, use the 4 PCB mounting holes, drill them out for the pins, press together and epoxy. You just have to drill and tap M2.5 or M3 for the new PCB location on the one end.
Well we need a BLF Museum of Fine Flashlight Art! 
This one needs to be in it!! :heart_eyes: :+1:
Very nice :+1:
Yeah. I guess I would choose the option of screwing them together with a threaded ring, similar to Kourtinoksylos’ previous mod, but the ring should have twice the height of the tailcap to fit nicely. It’s a pity I don’t own a lathe.
very very nice !!!
I dont have a lathe either. Just cut the plate of a tailcap like this picture, then epoxy the non threaded side to the back of first tube leaving the tailcap threads free so that the second one can be screwed.
I have seen your mod earlier and like the idea but still would prefer a ring of proper size which can be screwed on both sides and allows to separate the tubes with little effort later. But if I don’t find a fitting ring i consider to use your approach too.
All done by hand, no lathe at home, not yet…….
Haha with 1300gr=2.85 pounds it needs a backpack. It is a cometitor for the BLF GT in terms of mass.
I started to make some meassurments for the effectivness of the heatsink. I need to top up the cells between every test to keep the results consistent and this takes a lot of time. First results show little difference in turbo as we are dealing with 335W of power and the heatsink i built is definately not big enough.
–41sec to reach 51C without the fan, cells top upped, retested: 50sec to reach 51C. So it makes no practical difference in turbo.
Other levels are being tested and I will update the original post.