I do hope, and I belive we all know, this flashlight needs e good reflector…so please don’t use a low-quality reflector in this build… :person_facepalming:
In my mind we have to build this flashlight around a pretty high-end reflector…and have the china’s to make the housing for us.
The led we have chosen will do our job, that I’m sure of. :+1:
Then we will (maybe) reach our goal of +–100$ price…maybe.
But what do I know about this…
(DavidEF and the_driver, I hope we don’t need a bigger led to make up for a low-quality reflector… )
I said this based my knowledge of spotlights and the experiences from multiple modders, notably Vinz. If the parabola shape of a reflector is not accurate it is impossible to get a small light source in the optimal focus point so that the entire reflector surface is lit up uniformely (which is needed for maximal throw and efficiency). This is why HID spotlights (those with short-arc bulbs) like the Maxabeam (and even the Polarions and XeVisions) use high-precision electroformed reflectors (larger ones cost multiple hundreds of dollars). Short-Arc bulbs have very small arcs (<10mm) and in these arcs most have a very small, much more intense part of the arc. The 75W Xenon bulb of the Maxbeam for example has a 0.3mm hotspot in the arc. The reflector needs to be precise enough to be lit up completely by this small hotspot in the arc if you want maximum throw.
Now, with LEDs this is much easier because they are much larger than the hotspots in the arcs of short-arc bulbs. The XP-G2 for example has a size of 1.6mm^2 to 2mm^2 (depending on how old it is) when de-domed. The XP-L HI with 3.67mm^2 and XHP-35 HI with 5.9mm^2 are already much larger. Still though the XP-G2 (de-domed) and smaller LEDs like the XP-E2 and Osram Black Flat are much smaller than the XHP-35 HI.
Mostly problems arise when large plastic reflectors are used like the one in the Fenix TK-61. I have read a post of someone who had problems getting a de-domed XP-G2 into focus. The XP-L HI worked though.
EDIT:here is a nice example of what I wrote. There are 6 different HID spotlights which all have large reflectors of varying quality. You can ignore the size and actual brightness of each reflector. Just look at how uniformely bright each one is. The last two lights have high-quality reflectors. The Polarion (second from the right) has a electroformed reflector and the light on the right has a glass reflector.
A note regarding the Polarion: because of the position of the light in the picture, the arc was not straight. This causes part of the reflector to be darker in the picture. LED lights don’t have these problems.
EDIT2: this might be interesting for some people here - the brightness of the reflectors in the pictures shows the luminance (“surface brightness”) of the different lightsources. All of the lights except for the last one (last two pictures) have standard automotive HID bulbs. You can see that they are very similar, but the Polarion and the Vector are better because they overdrive the bulbs. The last light has a 120W Philips UHP (ultra high pressure) mercury short arc bulb used in projectors. They have an extremely high luminance. Even though it has a slightly smaller reflector than the Polarion it produces more than 5 times the Candela/Lux. Candela is the product of reflector size and luminace of the light source.
I don’t think it will be too much of a concern as long as the reflector is made out of metal and works with the XHP-35 HI. Most people will just use this configuration. You can’t expect a 150$ reflector in a 100$ light .
I do think that the reflector should be tested with the XHP-35 before planning continues. Otherwise it makes no sense to design a host specifically for this reflector.
You can have the most precision Reflector in the world, but if you put it in a POS receptacle, like a TK61or a Courui D01 being even one of the worse for example, good Luck tuning it!! So a precision engineered and manufactured receptacle is just as important to match and support this reflector. You think you got it till that last turn of the bezel and it twists or the body shifts on the loose POS threads your precision reflector is thrown off axis or cantered!! :person_facepalming:
The bigger and taller the reflector the easier it is to throw it out!
I have heard the complaints of the TN42 costing way to much ( I paid $164.00 shipped DHL ) maybe so, BUT the engineering, design, and manufacturing, machining, the precision is there. I have done numerous mods to it, taken it apart 8-9-10 times maybe, using a de-domed XHP35HD and it went back together perfect every time, and the results were and are repeatable! Try that with a TK61 for a $130.00!
Thanks, you make a very good point I forgot to mention :+1:
A precise mechanism for adjusting the focus is complicated and probably rather expensive. If the tolerances of the light are good enough there wont need to be any adjustments.
Yeah, many components & variables that must work together in harmony as well as compliment each other in order for the ‘BLF GT’ to be “all that it can be”.
Looking forward to the right combination coming together at some point for this monster light.
The ‘target price’ will be tough I think…. but time will tell. Quality & value are my main concerns… hopefully both well above average.
And of course throw is expected to be second to none…… :+1:
I know it will probably be a long time coming…. but I am ready.
Looking at the other forum today,I saw a thread about a special searchlight made by Vinz,made with 2 lenses. Sold/Expired - Mjölnir - Custom made Searchlight with Lens-System | Candle Power Flashlight Forum.
Look at the included photos please to see well the many fins which the light has,which as he says,“can stay cool even under harsh condition, thanks to a huge cooling surface (many big fins)”.
That light is much smaller (about the size of two fists) compared to the light being planned here, but is almost as powerful. It definitely needs the fins to run cool.
That light is a beauty too - if it’s the case that it is almost as powerful and much smaller, why does ours need to be so big? Just a question, not a criticism. I am guessing mainly down to our $100 budget, that combined with loads of work (2 years it took him to finalise).
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