I would have to check, I don’t know exactly.
The distance from the focal point to the outer rim of the reflector is 9.4cm (this is what I mean with “maximum focal length”).
Michael drilled a hole into the center of the lens because I had further ideas on how to increase the throw. There wasn’t enough time to implement this yet and we don’t know if it will work at all. I will keep it a secret for now ;).
Yes, the LED is 3V (technically it’s almost 4V, the Black Flat has a very high Vf).
This driver is of very high quality in terms of the components used. I don’t think there is a higher quality buck driver for LED flashlights. That is one reason why it is so expensive (also because it’s sold in Germany and the guy is trying to make money with it). It has all the features I wanted (over discharge protection, “nerdy” status LEDs, possibilty of connecting thermal probe) and can go up to a last 11A. I wanted to able to upgrade the light with a better LED and be able to utilize it fully. Newer LEDs are able to take more and more current.
No, not completely. One reason is that I was lucky on multiple fronts. If someone else were to build the same exact light they would pay much more money.
Most importantly you need a large, electroformed precision parabolic reflector and a matching head with large diameter. Where are going to get that and how much will it cost?
If you ask Peakbeam Systems how much a spare head with reflector costs, you will probably fall off your chair as we like to say in Germany. I have heard that they want around 170€/$ for just the glass lens!
- you need multiple Osram Black Flat LEDs for testing, not all are good (but we had more good ones than expected)
- the driver you can replace with a cheaper one, but it needs to be a buck driver (the Convoy L6 driver, FX-30, might be the cheapest, it does 5A from 2S cells, but I don’t know how well it works with 3V LEDs). Otherwise the mtn max buck driver would be a very reasonable option.
- you need a DTP PCB for each LED (for testing)
- you need a variable constant current source for testing (lab power supply)
- you need a way to electrically isolate the batteries from the center solder pad of the LED without negatively impacting the heatsinking (we used a battery carrier which I already had)
- you need a machinist who makes all the parts
- you need to anodize the outer part of the body and gold coat the contact plates
- you need a large UCLp lens (or other ar-coated lens)
- you need somebody who has a lot of time and is skilled at building lights
You calculate youself what you would pay ;).