A few microscopic scratches might just smooth out the beam profile a little .
My question is , how will you seal it against oxidation ?
Great work! I’d love to test it for you! I can do beamshots! 
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.
Nice one Jack! Couldn’t let that go without a compliment! 3 tiered prose, well done! 
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.
Definitely not superior for reflectors but for the harsh conditions where chrome is commonly used nothing comes close.
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.
Ok. What dimensions do you want for height and diameter? How do you want the bottom profiled?
You could try spraying the inside with epoxy paint to get a smooth surface and then use this kit:
http://www.classicstencils.com/Mirror-Solutions—Bottle-Silvering-Kit-50-bottle-kit-30ml_p_67.html
well, if you can make your own tool for making reflector i’m pretty sure that you have more than one plan for polishing it
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?
I’m game if you are!
That looks elegant!
DBCstm, I'm going to make a second one since I drilled the first one too deep. Height will be the only problem. This is an inch high. I'll have to make it taller than the parabolic portion and bevel the remaining material to get to 1.5 inches. Not a big deal.
Here its what I'll make unless you say differently:
OD = 58MM
Hole for LED = 5/16"
Total height = 1.5"
Small shoulder on bottom to clear contacts = 1mm.
I will bevel the remaining height from where the parabolic ends at some angle...30' 45 or whatever you think you want. I'm not going to ask for this back so ask for what you want in case you might want to put it in a light. I can even put a clear powder coat on it.
Buck
To better fit your reflector, we’ll use the Raysoon F13. It’s reflector is 1 1/32” tall. 1 11/32” inside the reflective area at the top, total diameter at top is 1 7/16 with a lip (5/64” thick if you care to duplicate it), 1 3/8” behind the lip (this 1 3/8” fit’s inside the head, the lip portion fits on top and presses into the lens, you could leave it an overall 1 3/8” diameter and not worry about the lip). 9/32” opening for the emitter with a 17/32” shoulder. This should be pretty close to what you’ve got, save a lot of work.
This light uses a 26650 cell, is hosting an XM-L2 T6 3C emitter and is driven at 5A for 1080 OTF lumens on a Powerizer cell. It’s got a fairly large hot spot with the now customary shoulder at the emitter in the reflector. I’m hoping a straight parabolic curve without that shoulder will give a better, tighter hot spot. I will run lux tests and get the current reflectors numbers on kcd and throw for comparison, as well as get some preliminary beamshots worked out for side by side style results.
I don’t know about a powder coat, seems to me that would be counter-productive. I have had excellent polishing results using Mother’s Billet Metal Polish, so if it’s raw aluminum I can always polish it.
This is really fantastic! I really appreciate it Buck, will do everything within my powers to document it to it’s fullest extent.
The baked Raysoon F13
Pardon me for interrupting, but wouldn’t you want the paraboloid to extend to the edges of the head? What would the bevel do?
I’d be interested in a relatively deeper P60 reflector, cut for XM-L, as well as a relatively shallower one for the same drop-in…
No, I’m not asking. I know what tooling that would require & can’t afford to fund it.
But you seem to be in a position to illustrate the beam differences in scaling your paraboloid to fit a certain size lens, but taking a different “cut”.
EDIT: I found a picture which illustrates (if you cut both lines at the x axis line) what I’m trying to say:
But you probably already know all that, & have worked on it already…
I’ll go back to reading now…
Dim
I have always used Mothers Mag & Aluminum Polish for great results. Probably Close to the same stuff DBCstm is using. Makes for quick work when the piece is chucked up in the lathe spinning at 1200 rpm.
DBC, I'll work on it tomorrow and let you know how it goes. I still have a little bit of honing to do on the bit yet.
Dimbo, I do want the parabola to extend to the top of the head but my reflector was only designed to be 1" in height. The light he previously mentioned needed 1.5 inches in height. The extra half inch would have to be occupied by something and in this case I would just machine some of that spacer at some angle.
I have thought of doing different both deeper and shallower reflectors. This one is at y = .875x^2. Believe it or not I just graphed it on an online graphing tool and liked it's shape for a one inch(height) reflector. I could make the equation whatever I want times the x^2 and machine it. I will likely do so if this experiment pans out well enough. It is quite a bit of work though. Especially if I ruin every other one I make 
. If I get that far, I will probably solicit recommendations from you guys.
I don’t know what you could sell em for, but that HD2010 reflector has about 25 orders looking for it as we speak. Ryan started looking for it as did Bill, I have asked Calvin at IS into the search, which is proving elusive.
It would be nice to have a rough cut bit and a finishing bit, so you would’nt have to do the roughing out with a finely honed bit. Just sayin…
Thank you very much for giving me this opportunity, I really do appreciate it!
007, is the Mag and Aluminum polish in a squeeze bottle? The Billet Metal polish is a paste in a can.
Billet Metal Polish is designed as the next step after Mag and Aluminum Polish