Awesome work! 
:+1:
Awesome!
I love these build threads
Awesome! Following intently.
I’m in the design phase of what may become a 1000-1500 watt MH HID based searchlight with a 24” parabolic reflector. Horribly inefficient and messy, but I’m looking for the most visible beam possible, not max CP or max throw. I also have a cheap A4-sized fresnel and an old 250 watt halogen incandescent worklight that I’m experimenting with. It’s only 4000 bulb-lumens and a filiment length of about 100mm, so I don’t expect much. But we shall see.
You mad bastard. I mean that in the nicest possible way. 
Nice build! That box needs a few coats of paint or lacquer, as well as a name / model number and a logo! (And a groupbuy!) 
At your service 
Today was a quiet sunday in partly lockdown Amsterdam, and I could do a couple of things.
First a lens cover. The nr1 vulnerability of a plastic fresnel lens lamp is that the grooved side of the lens is on the exposed outside of the lamp, and any dirt/grease/fingerprint will be impossible to remove without damaging the surface. So a cover is essential for any moment that the lamp is not in actual use. I made the cover from polycarbonate which is tough and flexible. I used a small slat to create a groove at the underside of the lens that exactly fits the cover thickness, so that the cover can be slit in the groove while bended a bit and when it is pushed down it springs into position against the lens.
Now I removed the slider, the fan and the fresnel lens and did some cosmetic things to the box and painted it. I likely would not have done this if not because it is for a contest, which shows what a contest does to people, or just me 
Knowing well that this is a plain square plywood box, and that any attempt making it look like a slick light is quite hopeless, I still went for some detailing, and by making it bright red it might even give a slight impression of being fast and furious? Probably not 
The inside was spraypainted with a matt black paint sold as “camouflage” 
The outside received a base-paint first, and then after some slight sanding, bright red!
That is all for today. Next job will be shortening the battery tube by chopping part of the head of the SD2 off, so that a wider flood can be obtained. And changing the long 18AWG ledwires for 14AWG ones, in the hope to get the 20A sweetspot for a well-cooled SBT-90, but I can not do that yet because the 14AWG wires are still somewhere in the mail between Hobbyking and my place.
And I have a cunning plan for a fun detail…
looking at the box that looks so innocuous, one can only be amazed at what emanates from it. Scary.
Well done!
That box looks great now.
I’m looking forward to your long-distance beamshots.
The fan is because most of the light never exits the lamp and is absorped by the dark-painted wood, that is maybe 20W of heat. The fan causes a minimum of air circulation to get rid of some of it. I do not expect much heat to build up in the lens, maybe a bit in flood position when the led is closer, so the lens is cooled a bit too. The fan is parallel because that was easy, it draws maybe 100mA so it does not eat much of the current. The alternative was a dedicated battery for the fan, but it seems not needed sofar.
Your solutions using glass plates and such sound very fancy, I’m not sure if fancy is needed, it was certainly not my intention and everything works as it is.
Sweet 
Yes, a collimator could be useful for making better use of the light coming from the led, and in this design there is enough space and mounting opportunity for one.
But the original purpose of this lamp was pure throw, and every added optic will reduce that number to some extend.
If more light is needed: I placed the light engine on a slider, so that with the led moved closer to the lens, a flood beam is created, in the closest position I expect light extraction to be fairly good.
Wow! Somehow I completely missed seeing this thread when it first appeared. Great stuff, makes me want to get my hands on an aspheric lens and see what develops.
“Relax Honey! We don’t need to call the police! Its just that crazy flashlight guy on the other side, testing out his latest ISS signaling device creation. Just like the other time, we will hear all about it in a few days on the NASA channel.”
What happened to the die projection? Did you burn a part of the phosphor?!
Waiting for that to come ………… Djozz Van Helsing :smiling_imp:
Agro already noticed the fun detail, although he did not guess it right.
Are you going to project the legendary ‘bat signal’ with this flashlight? Or better a ‘BLF signal’? 
I could have a try on the bat signal, but it must be cut out of a strip of metal within a 10x10mm area 
The starfish (zeester)?