Nice project and thanks for showing ……
Also nice to see “creativity hard at work ……”.
Cheers,
Martin
I’m here for the fun 
Welcome MB, here is some fun 
.
To check the potential of the lens, I clamped it in with a FT03-mini (harddriven SST-40 with dome) behind it. I measured the throw at 6.99 meter from the fresnel lens and got 2.16 Mcd (at 30 seconds). So the potential is there, the domeless SBT90.2 should even do a bit better, and if it doesn’t I can always go SST-40 and have the runtime and less heat.
That is fun indeed!
I admire your creativity and work! An SBT will blow it, not in the “explosive” way! You’ll soon rename your city to Amster…daaaamn :o when that beam hits the sky 
Thanks Martin, and others. The creativity was already 4 years ago, it is more of a rebuild with improvements based on what I learned back then. I like that you do not need to be a fancy flashlight manufacturer to make a superthrower, this thing will look extremely homebuilt . But I must admit that the cost of the parts add up, I’m over 100 dollar already, the led+board+heatsink+alu plate+SD2 were 92 dollar, I can’t remember the cost of the lens, but it was about 10 dollar. Maybe 8 dollar worth of plywood, and a dollar for a handle, so maybe 120 dollar. That is what I paid for the Lumintop/BLF GT a year ago so homebuilding is fun but does not really pay off :person_facepalming:
Well see it like this .... you're now or soon will be ..... the owner of (another) homebuild world exclusive ! ....
... and in "my eyes" that's basically priceless !
Also the "material cost" is probably only a fraction of what the "manual creativity" would have cost ....
... that is if "someone would have payed you to do it" ?
Cheers,
Martin
PS> Let me know when you plan to use it so I can close the curtains first ...... 
A really nice build djozz.
Hope the judges let it in.
If no….you have good chances to win the mod category.
Cool 
Modified light category?
A slightly modified SD2
Its not what you spend that matters but what SWMBO knows. 
I’m afraid that despite me not telling all there is, she still knows everything, no idea how she does that, there is no hiding from her :person_facepalming:
I did most of the wood cutting, using ruler, pencil, a jigsaw, a fretsaw, sand paper. It took much more time figuring the dimensions and how to do the focus adjusting than the actual work, and after some changes of design I had to re-make some of the panels.
It resulted in two new features:
*a small silent fan on low power (it is a 5V fan that runs on the single li-ion cell) blowing between lens and led will keep the lens and interior a bit cooler.
*it is going to be a zoomie! :sunglasses:
That’s going to be one cool zoomie.
I hope so
WIP
Running out of clamps, I need three more. Have to wait for glue to dry to free some clamps 
Most structural work is done. Everything fits and the slider that focuses the led seems to work fine. It still needs a handle and a cover for the lens. And then the cosmetic work: final touches, sanding, painting and such.
The led is still underway from China to Amsterdam, so I can not work on the electric side of the build, but it will not be before monday anyway before I have time to continue.
Nice work bench. Looks like your almost finished. 
Nice! Very retro looking and the use of plywood is very cool.
It is monday and mondays bring hours of time without people telling me what to do.
Today I made the thing work!
A few days ago I received the SBT90.2 on a chunky Noctigon from Hank, so I could do the electric stuff.
First the battery carrier was adapted. The driver board of the SD2 was cleared of components using a heat gun, then handy traces (near multiple via’s) for picking up batt+ and batt- were enlarged by scraping off some extra solder mask. Then led+ and led- wires (about 15cm of 18AWG silicon wire) were soldered on the board, so this light will be uncontrolled direct drive, with the current limited a bit by the long led wires.
Initially I bypassed the driver spring (see pic), but that limited the travel of the spring so much that the battery did not fit anymore. So I removed the spring and soldered a thin brass washer instead as batt+ contact (no picture of that).
I also glued the battery tube in the hole of the aluminium plate (with arctic alumina adhesive because that is strong glue and was at hand), so that it is fixed in place. The tail section of the battery tube was sanded a bit shorter so it does not fix/makes electric contact against the aluminium plate but against the tube as it should.
I still need to saw a bit off the head of the SD2 because it hits the lens when zooming out and thus limits the flood.
Now the spot was marked on the heatsink that is exactly centered behind the fresnel lens. I already found out that the centering is not extremely critical, a few mm off is not noticable in the beam. But still…
Then I did several attempts at drilling two 2mm holes in the heatsink to make M2.5 threads for the screws that fix the ledboard in place. But I did not get that done. Not sure what type of aluminium this is but the drills kept digging in the material and then break off in the hole 
. Had to sand everything flat again, twist the heatsink 90 degrees, mark new holes, and fail again. In the end I decided on using two existing M2.5 threaded holes in the heatsink with some creativity with a small steel plate. Behind the board is a thin layer of AS5 for best thermal contact with the heatsink.
The thick wires come from the battery, the thin wires go to the little fan, it is simply wired parallel to the led and the ledboard had a convenient extra set of solder pads to connect the fan.
The lens thusfar was fixed in place with two small pieces of tape, but that needed a bit more permanent solution if I wanted to check out the workings of the decice, for the time being that will be four little screws. I think eventually a new clean lens will be glued into the frame.
A handle was added. I planned aluminium, but found with how this thing looks, a wooden handle was better.
The device still looks very basic, I’m not sure if I can ever make it look fancy, but some cosmetic stuff is still in the planning for next monday.
But now it is ready for some testing!
On a 50E battery I got 15-something amps, a bit low. On a 30T I measured 17-something amps. Although I would have liked 20A, this is good enough for some intial throw measurements. I can still bypass the tail spring, although is is already a copper-alloy one.
The fan works, even with the lagging voltage caused by the led, it makes a faint humming sound as it spins quite slowly. With the light running for about 8 minutes on a 30T, the fan suddenly stopped, it appeared that the voltage had become too low for the fan to run. The battery at that point appeared to be 3.08V resting voltage, which is fine for recharging. So maybe the fan works as a sort of low voltage alarm, if it stops the battery needs recharging. Not sure yet if that works just as nice for a 50E battery.
After the draining of the 30T, the heatsink and aluminium plate were only hand-warm, maybe I could have got away with one size smaller heatsink.
A quick and dirty throw measurement at 5.5 meter (led focused at that distance) showed 3.9 Mcd. So a few things seem to be working! 
. The beam is way better than the beam from the 36cm fresnel thrower, that, and the SBT90.2, explains why the throw number is better than you expect when you go from 36 to 20 cm (which is a 3.2 times surface reduction).
Aiming the beam on the small square where I live is fun, but making a beamshot proves a challenge. Here is one at 70 meter, I kept the background lighting as I see it in person, but then the spot is totally overexposed. When all is finished I will try some proper beamshots.
Next week the light will be dismantled again, the interior will be sprayed black, the exterior will be sanded and maybe touched up a bit, a lens cover must be fabricated, and I have not decided on an outside colour yet.
Awesome work! :+1:
Awesome!
I love these build threads