That's the most accessible for an individual, but manufacturers use vapor deposition, most likely of aluminum in this application. It might be chromium deposition though, which may explain why when it's rubbed off there's usually a copper colored layer beneath it.
You’d think chrome would make one of the best reflectors but it’s doesn’t. It’s hardness and corrosion resistance makes it superior for holding it’s shine in harsh conditions but aluminum and a few other soft metals are far more reflective.
I may be wrong but I don’t see any advantage depositing aluminum on aluminum since the surface would have to be well-polished before coating anyway. A thin layer of something more corrosion resistant makes more sense. Hardness isn’t important.
Well, maybe not peasy. Remember the average reflector does what, about 15% loss and that’s a plated one. Polishing will leave tons of microscopic scratches. Check it with a 15x loop after and see. I imagine it will loose 20-25%. I’m not knocking what you are doing. It is an awesome test and one that I haven’t seen hardly anyone willing to try. I applaude your efforts and look forward to the result.
I wouldn't think it would be superior, except for those people that can't keep their fingers out of their reflectors, although aluminum coatings can have a polymer coating (used in automotive reflectors) that reduces efficiency by ~5-10%, but it's still better than chromium. The advantage should be a more uniform surface. You can polish an aluminum reflector, but you can't polish away the imperfections in the material. Some more expensive billet aluminum is formed under a vacuum to improve its quality, but there are still imperfections that occasionally make it unsuitable for an engine, not to mention a reflector. There's a whole lot about this that I don't know though. Everytime I start looking into this, I also look at economical rigs and lose interest when concluding that there's no budget way of doing this and there doesn't even seem to be shops that will do small orders.
I have tried to make my own reflectors before. The reflector finish turned out good but trying to get all the proper angles and curves in the reflector is way over my head. With each led type requires a different shaped reflector. The one I made turned out to be quite floody, it did have a large hot spot that was only slightly brighter than the spill. Would have made a great close up light I guess. I kind of like to have both, a decent hotspot that will throw a little and decent spill to light up the surrounding area. Looking forward to seeing some beam shots. Great job with making the cutter. Excellent work.
I just checked out 2 reflectors, one crappy and one good (XinTD V3). Both seem to have the same construction. With my fingernail, I can rub off the thin reflective material fairly easy. Below that is a relatively thicker, yellowish “plastic” layer bonded to the aluminum.
If that's really plastic, it might be the same stuff they use in automotive reflectors to smooth things out. I have a book that describes how those are made. I'll look it up later. It still won't help us unless we can find someone that will do micro orders.
What is your ID at the top? Do you think it’s better configured for an XM-L, XPG, or would it work well with the MT-G2? Let’s go with an XM-L in the HD2010. Flexibility there. Make the outer diameter whatever you wish, length (top to bottom) is 38-39mm or 1.5 inches. A 5/16” opening (8.5ish mm.) works well. The OD of the current reflector is 58mm but it wouldn’t matter if there were empty space between the reflector and head, the lens would press it down onto the star/centering ring anyway. As long as it fits between the contacts of a 20mm board at the bottom we’re good, and even then if it were wider I can use insulators for that as well.
My HD2010 is now pulling 6.07A and making 1421 lumens OTF at 30 sec. Lux calculates to 222Kcd for 942M throw. Wonder what your reflector would do here?