elmers glue might work, I’d just be worried that it might lift some of the reflector finish with it. Give it a go and perhaps try diluting it a bit with water too.
I imagine they make reflectors the way they do as it’s a super cheap automated process and probably a bit more optically efficient than even the most highly polished aluminium.
The plating is pretty tough on these, it just doesn't survive when the AL base metal gets close to melting point and gets a little soggy (gee, I wonder why? lol). From the smoke and color change when I used the torch to help bubble up the areas of plating not lifted by the grinding, I think there's a thin layer of clearcoat over the top.
If I try the Elmer's I won't try to peel it off, I'll let it soak and dissolve it away in hot-but-not-boiling water. Won't be enough to damage the plating or clearcoat.
I think I read somewhere that silver is the most reflective metal. I’m guessing that is what they vaporize and adhere to reflectors. I imagine the vaporization process is to use as little expensive silver as possible. This is all guesses here. Maybe you could adhere silver gilding or something to the reflector and then polish it. I think I saw somewhere that someone tried it, but their result was so so. Maybe they didn’t know how to polish it correctly. I just searched a bit, but gave up.
Thanks for this.
Yeah, what kind of witchcraft is this, anyway? I tried it (blue pool cue chalk - don't ask) on a nearly-new freshly cleaned file, it's smoother than the first time I used it.
Hrm. Not P60 reflectors, but I wonder if I can squeeze some compatible dimensions out of these?
37x32mm, that OD will likely come down to ~35mm, maybe less, once the threads are milled off. Figuring out if the OD will fit in the SRK head while keeping the centers compatible with emitter spacing on 20mm stars would involve math, which makes my head hurt too much. I'd rather just cut one up and then take measurements. (and if they won't fit with 20mm spacing, who says they have to be on conventional stars?)
Keep in mind, P60 reflectors are generally only like 18mm deep from the front face to the emitter surface (typical quoted dimensions of '26.5x22mm' or whatever includes the threads at the base for the pill). These are 32mm, though that includes a useless ring at the base, but looks to be only about 1-1.5mm, don't know yet how much will have to be trimmed off the base to get the emitter opening large enough for the MT-G2. Like I said... cut first, then measure. I have 4 of these (reflectors) on the way, the spare will be the guinea pig to figure out the dimensions & emitter focus for the three to be used.
Oh my gosh comfychair. That looks frikkin awesome! Man, I don’t want to be on the receiving end of that light. Might get instantly blinded and cooked.
My thought on that reflector is that you will have challenges with not getting shorts when trying to get the emitters high enough into the reflector. Maybe those stepped C8 reflectors from Lightmalls. I have one. I will check and get back to you. You don’t need OP. The emitter puts out a ton of flood and the beam is smooth, smooth, smooth.
EDIT: Just looked at the following reflector. It looks like it would work great if you increase the opening about 1mm all the way around. You need a 8.9mm opening. It would rest on the emitters pcb and give you tons of room for wiring.
This one looks even more interesting, but I don’t have one to messure:
re: emitter positioning; Well I've cut up several P60 reflectors to test with. One has had the base filed down until the opening is big enough for the entire MT-G2 package to pass through, and one where it's just big enough to fit over the dome only, and sits on the corners of the substrate. The smaller opening works way better than the one that sits all the way down, but still isn't great - it goes yellow right in the middle of the hotspot. Raising it up off the substrate by about .030" makes the yellow go away and gives a much tighter spot.
bad = left, better = right
I think the 42mm C8 stuff is a no-go, those would need flats cut on the outer edge too to fit the 52mm hole. The triple P60 at the top of the page leaves 2-2.5mm slack to the ID of the SRK head with the 20mm stars touching at the middle, so it can go bigger OD than the P60, but not by that much.
Good info. You made me just go try to adjust the focus on my MTG2 spotlight again. I get the same result. The beam seems to come into focus best with the top of the emitter a little below the reflector’s interior. Will you have enough room to solder to the pads at the . 03 lift level?
So the numbers break down like this...
Absolute max ID of the SRK head at the very top is 52.5mm.
With 3 20mm stars butting together, spacing center-to-center of the LEDs is 20mm, so center of each LED is 10mm out from dead center.
Half 52.5mm is 26.25mm, less the 10mm out to the LED. Half the reflector needs to fit in that remaining space of 16.25mm.
Assuming I can shave the SST50 reflectors down to a new OD of 35mm, that's still a tight fit as half 35 is 17.5mm. The 41mm C8, I don't think I could get it down to less than 39mm, which leaves 19.5mm to fit in a 16.25mm hole.
The only way around that is to shorten the reflector from the top, which will reduce the top OD cause of the taper. Actually, they would need that top cut anyway as even with the head bored out to drop the LED mounting base/heatsink down as far as possible, all the way to where it interferes with the switch hole, that height from there to the underside of the lens is only 27mm, and from that dimension you still have to subtract the thickness of the LED and/or star.
edit: Yes, I can cut notches in the flat base of the reflectors, they don't need full contact all the way across to still keep everything fit together tight. There's a lot of meat around the base that doesn't need to be there.
I just want to thank you for post 34 above. It helped me identify a problem I didn’t realize I had in my MTG2 build.
You have really taken on an ambitious build. It has challenges in spades. Please keep up the good work and postings. It’s refreshing to see someone who thinks and then actually works outside the “box”.
Yeah I haven't figured out yet what causes the MT to be so different than the smaller dies in what it 'likes' in regards to focus/reflector positioning. The rules of thumb you learned with the XML definitely do not apply with this one. Not a large enough sample size to say for sure, but with both the S1100 reflector and the dinky P60s, the MT isn't happy unless it's sitting lower than where you'd expect it to be.
I guess the base of the reflector in a ZY-T08 must be just thick enough. I didn’t have to space it away from the emitter at all, and no yelly belly hotspot 
My UF-T90 was a pain to align. I have to make a spacer for these emitters so I can get the reflector centered. Luckily, they are very forgiving and do not create a nasty deformed hotspot when slightly off-center.
Well good news and bad news. It's no longer gold, but somehow the driver ended up dead. Or, one-third of the driver is dead, the section for LED3. I removed all the junk I'd added to it, cleaned everything, looked it over a hundred times with magnification and good lighting, I don't see anything. I guess I will use this driver as a contact plate for the MT-G2 version, and the driver from the other light in this one.
The aluminum plate in the first pic is 1/4" thick, with a step cut on the bottom to set the internal spacing. When the bezel is screwed down tight, it's right at .005" shy of being fully seated against the head, has to be that way as the stars and reflector just sit there loose until the lens clamps it all together for good thermal contact.
I still need to machine off the lanyard loops that got all bent up in the War Against Loctite. Final finish will be just buffed with wet green scotchbrite, as I hate polished aluminum. Like this, if (no, when) it gets scratched or banged up, I just hit it with the scotchbrite again and it's like it was never there. Plus it looks a bit like titanium and titanium is just sexy.
that’s a beautiful finish, nice job!
given how finickity the MT-G2s are proving with the smaller reflectors (no huge surprise really, considering it’s size), why not mix’n’match? You could wire 2 XM-Ls in series and then in parallel with one MT-G2 - if you can pump in 5A (I know, I know), each string would get 2.5A, which would be a ton of light and relatively efficient. Not exactly a simple option, but might be worth thinking about.
Abso-freaking-lutely amazing job you did with the miters in the reflector array, Comfy!! 8)
I've often thought of doing what you did but never tried because I would frustrate myself trying to get it as good as you did and would probably not succeed anyway. Kudos!
Damn shame about the chrome coming off but using the heat like you did left it no choice but to jump off the reflector like a scalded cat. If you had a band saw you could make the initial rough cuts pretty safely without destroying the chrome then come in with the hand file to do the fine tuning needed.
Again, great job! Once you have them polished up I can't wait to see what Lux reading you get from the entire upgrades you've made to that light. ;)
That looks sweet
That looks so good comfychair. Bad luck about the driver. Whats next?
Yay! So much easier...
Uh... crap.
Just so you guys don't get the impression I'm some kind of infallible wizard, this is what happens when the angles are wrong. The three are touching at the outer corners with a gap at the center points - the angle between the two cuts is too shallow. It can still be saved, but changing the angle on all six facets (and altering them all by the same amount) after they're all cut this far is really not fun.
You are a better man then me. I would be quite happy with that little of a gap and just go with it.