Can HOOP make DTP copper boards, even mere prototypes? I would think that takes a quite specialised production process, with discontinued dielectric layer, solder mask and raised copper core.
I can think of a # of advantage of 1 "super size" MCPCB:
- more copper (
) - aligning the LED's is locked in to the reflector (nice feature)
- wiring could be done much easier/better, using one set instead of 4 sets
- on-board traces of the LED+ and LED- are wider, bigger
- it will be XP, not XM footprints for the LED's - more diversity of choices (XPL, XP-G2/3, Nichia, etc.)
- if you want to change to XM, no problem - use you own 4 pieces of MCPCB's in place of the big XP one
- Did I mention more copper? ohhh, ok. I do like lots of copper... Can you imagine if it was 2.0 or 3.0 mm thick? Wow...
I've done a few of multi-emitter XM-L2 mods and the wiring is a total pain, and very time consuming. This single piece makes the wiring as easy as a single LED.
With all that said, I always thought of it as a "nice to have", but if cost is nuts, then punt. If the height stays the same as stock copper DTP's (~1.60 mm), then not much changes, just have to account for the wiring thru holes.
About the reflector, maybe I missed this, but we are still targeting XPL neutrals, so I'm not sure what direction ThorFire is goin - XM size holes or XP size holes? If XP, then there's no current 4X reflector out there I know of designed for XP sizes. If XM, then we would need centering pieces to adapt accordingly.
Here’s some reasoning:
“an off-the-shelf reflector” Does it exist? What do those SRK clone builders use? We have not asked questions nor made proposals which reflector they are going to use, we just offered a solution for the use of thick ledwires, none of the SRK (clone) flashlights that I have ever seen have a solution for this (anyone?), they all use very thin led wires to make them fit in the space allowed by the thickness of the led centering rings (so 1 or so mm). And with thin (24+ AWG) ledwires there will not be a Q8.
The wish for a central screw was abandoned because it allows twisting of the reflector-ledboard-shelf assembly during assembly, potentialy shearing leds and/or ledwires (it will happen as we all know), two screws (as is not uncommon, my 9x SRK clone is made with two screws, very handy) solves that, and on top of that allows the ledwires entering in the middle which then allows the cavity in the reflector that fit the thick wires.
The way this proposed large MCPCB is sandwiched between reflector and shelf allows modders to use 4 separate led boards just as well.
It is all up to Thorfire, their first technical drawing they sent to us had such a large quad ledboard, but there was so much unclear about the drawings that I do not think it was really well thought out already, I actually think they just copied the internals from a standard SRK clone they had.
Such a big copper DTP quad is a new to be designed part, but I do not see why we would not try to achieve it: If they are not able/wanting to make it we will hear it soon enough, then we will see how we go on from there.
Assembling and wiring 4 separate ledboards will be more challenging than just one, from that point of view I can imagine Thorfire wanting a quad board as well
Not sure why you think it will be for XM-footprint leds, the idea was XP-L, so an XP-footprint board is what we try to get.
I see Tom gave some reasoning too, less puzzled now Sharpie?
for the big copper mcpcb its easy to get supplier in china i can give you a few brochures and contacts for it if needed. but i think thorfire sure know where and how to get them
I’ve never voiced this anywhere (cause I don’t know enough to know anything about it) but I’ve often wondered the same thing. I don’t think there’s room to fit the two sets of contacts “on top” of each other for use in single-emitter boards, but with a multi-emitter setup like this, can’t the XM-sized pads be set 45 degrees out from the XP-sized pads? You’d need two sets of screwholes for mounting but it seems like that should be pretty simple to do.
But like I said, I don’t know.
Like the idea
But there is a big trace in the way.
So the places to flow the LEDs must be able to accept both
How would LEDs flow onto this?
In my drawing there’s a +inner ring and a -outer ring, if the 4 existing pads shift a bit to the side you can squeeze in an extra 4 sets of led pads. Looks a bit messy but it is doable.
There’s a whole set of clever idea’s (mainly from Sharpie) to make the Q8 multi-multi-multi versatile, but the thing is: we are not making it, we have to persuade a chinese manufacturer that what we propose is going to sell. Not just to the 30 or so (?) SRK modders in the world, but to general flashlight lovers. And to communicate these exotic idea’s is hard, I think. Communicating any idea is hard actually.
But keep the idea’s coming, who knows what we can get done! 
That too Djozz!
And looking at my sketch, the XML/XHP leds would have significant less contact to the raised part of the DTP star.
So modders would use individual stars on XHPs anyway
So this seems not a viable idea.
Opting the XPL footprint makes it modfriendly with a wide array of LEDs to be reflowed.
The reflector is screwed with a hole through the ledboard AND integrated shelf
Remove the ledboard and XHP / XML stars can be used.
I thought so as well when I first saw the design. It would be nice but I’m a bit wary of shorts with all the unused exposed pads. I don’t know if they’re justified worries or not. For that matter, the suggested reflector design with the 3mm gap in the center for the wires also seems risky. Unless I understand this wrong, we’d be a small solder blob away from a short to the reflector there. Unless it’s going to be plastic, I’d make the gap more like 5-7mm.
Please don’t make it plastic.
Without the gap, which is the normal case in SRK’s, shorting to the reflector is even closer to the solder blobs 
If it ever comes to this design, we will ask Thorfire for an insulation disk inside the gap, or simply some Kapton tape.
Don’t worry, I’m not advocating that 
djozz’s solution of insulating disk/tape sounds good. Probably could do the same for the extra LED pads if there’s a need.
Yes plastic reflector is not an option
That sounds great. Because the idea of The Miller would not work. You will get a short on the XM-LEDs because the + and - pads will have contact to the terminal pad of the led.
With 8 Pads (4 XM pads and 4 XP pads) on the copper MCPCB we should have 2 Sets of holes to screw the Reflector and we have to get enough place for the led wires for the 45° rotating copper MCPCB. With the big whole in the middle of the reflector it sholdn’t be a problem.
The holes could be placed at the outer end of the reflector and mcpcb if there is not enough place for them between the LED pads.
These holes can not be on the outside because the screws start at the underside of the ledboard shelf, the cavity is only about half as wide as the mcpcb, and then also there must be room for the screw heads. So you end up about as near to the center of the mcpcb as I have drawed them.
When time allows I will give drawing a 4xXP+4xXM board a try, just to see if it would work. But no guarantee whatsoever that this will be proposed to Thorfire!
Mark me down for 1.
I hope we can eventually source these MCPCBs.
Yes me too MG
Will update OP later.
Joined just to chime in. Please put me down for one!