I really like the K value for these light. They seem to make colors pretty vivid, very powerful as well.
Thanks, this is a great reference! The light in the video is 34.5mm in head diameter, which is about 1.4x your desired diameter, so with the same emitters, your hotspot will be 1.4x as wide, and 0.5x as intense. If you like how SFT70 looks in the video, then you could go with SFT40 in your smaller light, and it would still have a wider hotspot than the SFT70 in the video, without sacrificing as much intensity as using SFT70. Plus, a smaller LED sustains the same throw for longer time.
For the SFT40, I’d get the smooth reflector to maximize throw. Unlike the SFT70 it has a single-die construction and no artifacts with smooth reflector.
I tend to find that beams are wider IRL than shown in photos/video, not sure if you have the same perception.
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Base on the terms ’ tac on the title, and your plan to build the light from ground up, i wonder what sort of interface you plan to apply to the light,
As you see, hardware-wise there are light with simple single tailswitch, forward clicky/momentary action, dual tailswitch; power/momentary + mode/strobe button, triple switch; two in the tail + side switch. Klarus, Acebeam L series etc.
Regards the mode, those multi interface require multifacet coding, (should you program the mcu with your own preferences) some fellow member here have those skills (definitely not me 
).
Tac’ wise i always carry 1+ flashlight.
The tac one is Convoy s21b xhp70.2 6v5a, 21700
set to mode 11 of the 12 group; Turbo, Mid, Strobe memory off; for that 'Sun in your face sensation and 4 to 6 square meter foreground wall of light.
Or ConvoyM21b xhp70.3 hi 6v8a
The + is some edc light with ability to start on Low mode. (This is just me)
Color temperature, for tactical purpose i prefer white light.
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I agree with @QReciprocity42 , there are trade offs.
At 50yard /45meter you need thrower format like C8’s reflector size at minimum with the candela numbers to 'carry the lumens to the target.
For close quarter, 2,5cm to 3cm reflector combined with xhp50’s or xhp70’s should got the ‘intruder’ ‘covered’ 
Here some tips, get/use Convoy flashlight as your base to build your light measurements since there are many variant to choose and the pricing are 'budget friendly or
Watch Convoy flashlight video reviews
(Should you build your light simple)
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I want to be able to mount this light to a picatinny rail. I am making a handle grip that will have a single button and battery on it, maybe even the driver. It will depend on what component needs to dissipate most quickly.
Ideally, I would like to have battery, driver, and button all mounted inside/on the handle and the light connected to the picatinny rail by a wire.
I’m here trying to learn the logistics of what I need to accomplish this. The cool thing is that I have an abundant supply of scrap aluminum, the CAD and CAM skills, machines, and tools to be able to make generally whatever I want.
It’s my electronic component knowledge that I fall a bit short. I have been reading books about electronics to try to get up to speed. I can learn more in depth programming without an issue. I look at g-code and understand that the code needs a certain structure. So Those will be the biggest hurdles.
I will guarantee that this light will be robust to say the least and I will design everything around the component. I want to guarantee that everything is isolated electrically really and as waterproof as I can make it.
This is an item designed for home defense.
Here some food for thought; candela vs lumens, indoor and outdoor, tradeoffs
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If you really want robust, you can use a simple 1-mode light. Last thing you want to do is go switching modes if you “misclick” the switch. Like, you want to light up Mr Badguy, and accidentally start blinking out the battery voltage instead, etc.
I got a few custom lights like that, as well as 1-2 out-of-the-box lights like that. No issues with the light going mental because of the µC, etc. Just simple stoopit on/off.
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This is excellent advice. These lights are compatible with a wide range of LEDs, optics, and drivers, and should help the OP narrow down their preferences before committing substantial effort. Some Convoy models also can be had with a “tactical” remote switch.
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Awesome resource,
They guys at Trex arms really know their stuff. Like he mentioned in the video. High lumens will be much more effective for what I want. This light will be used in a close quarters scenario.
I’ve been looking at these flashlights and I like that they sell individual components.
I wasn’t sure if it would be worth my time to essentially just take all the components out to basically design my light around their parts. It’s looking more and more like that will be the best option.
Yeah. The difficulty with building a light from scratch is that the different parts require completely different machinery and expertise to make. It looks like your setup is very well-suited for producing the body/host of the light, but you probably could not build a reflector (due to the surface finish) or switch or driver completely from scratch. In that case it is a good option to build around Convoy parts which are cheaply and widely available/replaceable and easily modifiable.
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You can focus on ergonomics, styling, sizing and leave the hassle by using oem parts
I can build the body of the light. Anything that is a piece of metal, I will make. I have a look and design in mind. I don’t want to try to make a OP reflector or the switches or anything like that. I will just use parts off the shelf to throw into my design. That was my attention but I was going about choosing individual parts instead of finding parts that were already part of a successful package. The convoy M21 series would get me close and on the high side of my expectations.
I’ll find a flashlight that has the features I want and remake the body and extend wires to accommodate my needs.
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Do you have access to a multi axis cnc machine or just a manual mill?
I would love for someone to build me something like a zebra light sc700 but out of black zirconium
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IMHO, the best form factor is the Nitecore P23i…
Relative slim, bezel for glass breaking, tailstand, pocketable, nice looking.
I think the sweetspot is 35-40mm head, 21700, lenth of 130-140mm.
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I run two 5 axis mills.
Here is a video of a part I programmed running on my machine:
So if you can make it on a mill. I can make it on a mill.
I cant reply as much as I’d like because I’m a new member.
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I’m looking forward to seeing what you end up making
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Now I am just fighting out of stock issues.
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simultaneous 5 axis… 
Looking forward to your build 
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Alright everyone, Pioneman K35 is coming in the mail.
Everything Convoy is out of stock. Seems like even on Ali, idk whats up with that but I’m moving forward. I like the idea of the SFT70 so I’m stoked to get this flashlight home, taken apart, and a new housing designed.
I will keep this thread updated as things move forward.
I am going to keep an eye on the web and keep watch as to what comes in stock. I’d prefer to get the light up and operational and when I get an opportunity to get a light with more bells and whistles, I will and I will integrate that in.
Keep an eye out everyone.
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