I skimmed the thread, so sorry in advance for that.
- For ~40mm I’d look into using the Ledil or Khatod optics. Ledil’s Cute-3 or Cute-4 line is available to fit XM-L2 emitters. Khatod should also have compatible optics.
- XM-L2 or XP-L is what you want for this hotrod, not something else. That’s assuming that you want it to produce a “wall of light.”
- The product you pictured in Post#5 is for a very old emitter. It appears to be compatible with Luxeon-I emitters (and modern generics), this would not be acceptable.
- Does this flashlight have a large lens on the front, rather than a reflector? This could affect your build goals if you consider doing an aspheric thrower. Use search if you don’t know what that means.
- Look at lagman’s thread here to start trying to understand drivers - Understanding the difference between Linear, Buck, Boost and Direct Drive drivers
- Shop for drivers on FastTech.com, intl-outdoor.com, and MTNElectronics.com
- Research driver testing done by HKJ at lygte-info.dk
- Understand that driving 5*XM-L2 emitters at 4A each is 70W of output power before driver losses. Around 88W including driver losses. You cannot build this flashlight in such a way that it can handle that continuously. If you are determined to do so, research turbo stepdown or turbo ramp-down. You may want to look into a custom firmware such as STAR - STAR Firmware by JonnyC - Source Code and Explanation.
- In my opinion you should reduce your power level.
- You can’t run anything like what you want on 2*D cells, so you need to consider what type of battery conversion you will do. 8*AA might be a good idea, or 2*26650 or 2*18650.
- Look at these two graphs (which djozz made) of XM-L2 and XP-G2 to better understand the current-vs-voltage relationship with these things - Crash-testing a XM-L2 and a XP-G2 on copper Sinkpads