Be careful man. The wife could be reading LOL.
Just think. First you ask her to throw things at you at high velocity and now you are talking about attempting to change physics. She's going to take the meds away! LOL
It’s your god given right to be stubborn wight. Right or wrong everyone else has it too so what can you do? Being the prick that I am, I just had to do a math check though.
Area of a shelf is pi*r^2 minus emitter hole or 3.14*15.85^2 - 3.14*10^2 or 3.14*(15.85^2-10^2) or 475mm^2.
Area of shelf plus emitter pad area is 789mm^2.
Area of 5.6mm high rim is 2pi*r*h or 6.28*15.85*5.6 or 557mm^2
Area of 2mm lip is 126mm.
Other than to agree with wight about the difficulty in getting both bottom surfaces to mate at the same time I do tend to also agree that the emitter area does seem to add significantly more contact surface area to the host. Whether that additional contact area is needed is left as an exercise for the reader. Me, I’m just throwing marbles on the dance floor. 
If the best place to mate the heat-sink is the emitter hole (where the MCPCB would usually sit), then it doesn’t make any sense to not use that area. Add to that the math showing how much added contact you are getting by mating both the hole and the shelf. As for the possibility of not getting one or the other mated due to differing height, well let’s think about this. If the protrusion on the heat-sink is machined ~0.5mm too long, you don’t get a mate between the heat-sink and the shelf. Put some thermal paste on the shelf and forget about it. That would be better than having the protrusion too short and using some thermal compound at the most critical point for best heat transfer to the fins. As for leaving out the protrusion entirely, I think I’ll just leave this here:
(Emphasis mine)
Sure enough, I was mistakenly using D instead of R. (!) The figuring works out similarly either way: you’re getting more contact area from the big shelf than the little one, and the big one appears to be at a known, non-variable height whereas the little shelf - not so much.
I agree with RBD and anyone else who’s posted it: yes, if we could implement a heatsink which adequately interfaced with both shelves [eg no bridging a gap with TIM, this is not adequate] that would reduce thermal resistance a lot. I don’t think that the reduction would be significant, despite being a lot.
IF the 20mm shelf was at a known height I’d recommend interfacing with that rather than the 31.7mm shelf. (I’d establish a loose fit on the 20mm diameter cylinder, tight fit on the 31.7. I’d do a rough face on the 31.7mm surface and a perfect face on the 20mm surface.)
Wish we could do a pour, but then machining a new head altogether would probably be the way to go. lol
Maybe that’s what nitro should be working on instead of just an insert? Or, maybe have all three options?
A few different choices here. I don’t think milling an entire head from copper is a viable one. A simple 5.6 x 31.7 disc is easiest. Adding a 2 x 20 post adds some unknown to the capabilities and looks cool sitting on a desk. If the cost stays reasonable then I’ll get one but if not then I’ll just ghetto some scrap aluminum. It’s a bit unreasonable to ask Nitro to come up with more than one option but once he settles on one there’s no reason someone couldn’t produce another.
Well, in all fairness, a few things changed on the X6 for the Group Buy…the tail cap is not interchangeable for example. So they’re two different lights. We run into that a lot don’t we?
The target here is for the Group Buy Special Edition light. Looked at solely in that regard, and with over a thousand of them out there, then it makes sense to spec the heat sink to that specific set of measurements.
Man oh Man spent close to $300 on metal, so i hope u guys are ready for these, once i get the sample in few days ill be off to the machinist to have them made
im considering doing a run for the X6 SE and some for the NON X6 if the current design dont work out (on both) so this way these will sell and everyone is happy ? and i dont want to get stuck with $300 of wasted material :(
Dale made one of these work so it might not be a bad idea to follow his lead on this.
So do u guys want this done or not ? if so just post so i can cancel my order on the material
Are you having trouble understanding the two posts you quoted? [Both DBCstm and Stittville Ed are suggesting that you stick with your original plan make a heatsink shaped like DBCstm’s drawing.]
Most posters seem to be in favor of you sticking with that plan. In my opinion the worst case scenario (other than a run of undersized parts) isn’t that bad: it’s simply a higher than necessary cost and the requirement of sanding or filing to get good acceptable fitment.
Stick to the plan and start making chips!!!
Oh that's good to hear because i really want to see these turn out for everyone
Nitro, did you give the machinist an X6 to use as a baseline in order to ensure the diagram leads to his part fitting the light? Or is he going to make the part off the diagram alone?
I gave him my BLF X6 :( but it will be a perfect fit for that host,like i said here or to u dale i can send out the heatsink to the members who would like to try it out ? just pay the member who has it the postage necessary and they can send it to them then back to me when done....
Thumbs up.
Hmmm, so second batch is a different one…I wonder if the WW batch is also different 
I may have to cancel my interest, or at least put it on hold knowing that they could have changed it all yet again, unless you are getting a WW in to measure too?
B42, to my knowledge there’s only one time the light underwent a change…from stock to the BLF Special Edition. With the thicker copper MAXToch star they Might have cut the emitter shelf a little deeper, I don’t know this for sure but it’s been suggested. It’s not undergoing any changes throughout this Group Buy To My Knowledge.
I'm in no rush,i got my machine guy,i have LOTS of copper and aluminum coming and i got u guys to back me up on any mistakes :) maybe ill contact the supplier and see if they kept records of any changes on the host ??