The KaiDomain KDLitker / KDLIGHT 20mm MCPCBs have a goofy footprint.
Be advised that in a typical flashlight, hold down screws will not be compatible, or it may be difficult to get wires to feed through the heatsink without modifying something.
Edit: (6/1/23)
KaiDomain has released some new 20mm stars with standard 60 degree notches. 
I just put one of these in a C8+ and it worked on the second try but its a little wonky. It’s just off no matter what. I did get it to screw down but its kind of just slightly on top of and squishing the wires. Not perfectly flat. My temporary solution was to just give it a big pillow of thermal compound. I’ll have to fix it before I use it longer than a few seconds at a time probably. I also don’t like how close the screws are the soldering pad. I’m new to emitter swaps so maybe that’s normal but it’s feels like they should be spaced further apart
I’ve used several KD 20mm MCPCBs and the easiest fix for me, was to trim the MCPCB with a good pair of diagonal cutters.
Edit: You also need to watch that the screws don’t contact the Solder.
Cool ya that’s exactly what I need to do.
Dumb question but what actually happens if the screws contact the solder?
Short circuit to battery negative (body of the light)
These are just a few ideas:
Mark the area where the solder is, take out the screw and file that part of the screw without getting to the screw cross, this way the contacts will be further apart.
Another way is to put the screws in a dremel just for ease and while turning put the file until you get almost to the x of screwing.
Or look for flat screws by under smaller data that mount are, or look like wood cone head are not good for flat accessories.
Even if it does not make contact it is very close I would file those screws anything could happen a simple metal spot in the air would short the flashlight body.
Or use insulating washers that can withstand a lot of temperature depending on the model and is the same width as the head of the screws.
They are only ideas do not take it to bad.
Thank you.
I did try grinding that side of the screw down the other day, it does help but you can’t grind off that much. I cut the sides off the board like shown above today and that really helped with getting the board to sit better. That’s definitely a must. Cutters were sketchy so I used a sharp utility knife with the board on a block of wood. Went smoothly.
The light works fine but I think I’m going to use some kapton tape like a washer around the screw just for some extra insurance. Kapton tape because it doesn’t have to lay flat like a washer it can cover the solder blob better.
It’s true I didn’t think of that!
Besides, it can withstand 300°C or more.
The washers I have are deformed are not hard, it is a rare material fiberglass or something more flexible I do not know where they are if I see them, I send photo.
But I see very little space to leave it uninsulated.
There are small sizes of non-conductive nylon/plastic machine screws available.
Various chemical and heat resistances
Oh ya look at that. Plastic machine screws. What will they think of next.
Btw what are you guys using for hosts/drivers for these no-name chinese LEDs? I ordered 1 of each last week. As bare emitters tho, i’m going to put them all on convoy boards. I was gonna try convoy’s 8a buck in an m21b for the smaller 3535 ones. Is convoys 12a fet any good? Not sure what I’m gonna do for the bigger ones. I keep coming back to the soda can and L-size convoy hosts and his sbt90 drivers. What else is out there that I’m overlooking?
The MTN drivers are nice but idk what host I’d use
I have those I bought for RC helicopters and now I use them for my electronic circuits as spacers for the metal case and they are not very strong.
They do their job but you can’t tighten them too much.
Maybe there are higher quality ones mine were Nylon RC ones.
I noticed that it is the head of a Convoy C8+.
How is it?
Too big?
Compared to an S21A with SST40.
I guess buying a Convoy C8+ SST40 if I have a S21A SST40 would be having the same thing.
You who have it is it worth the C8+ if you already have a S21A with the same led?
The truth is that if I buy it, I would have one more model and one more flashlight at home, in the end I will have a collection 
I see that by having a larger head you can put the led and driver you want.
Thank you.
I don’t know how that plate would have looked before with the previous one.
But I would have drilled new holes in the pill (I think that’s what the copper threaded part is called) so the wires come out just right.
And also the led pcb would be complete plus base to dissipate the heat.
I don’t know how the old one was nor do I know what the C8+ looks like.
But I would have accommodated the copper pill to the led and not the led to the pill.
I don’t know if I have explained myself I use a translator.
In my picture I’m using a SFN55.2 in a Convoy M21B, Convoy 22mm 12A FET driver and a Convoy OP reflector with 10mm hole.
It gets pretty warm at 100% but it eventually steps down to a tolerable level.
In my opinion the Beam is very nice, way better than expected actually.
I have some beamshots if you’re interested.
Edit: I’ve also installed a SFN55.2 in a S21A with a MTN20DDM and I put 4 SFQ35 in a D4K
I think if I did it all over again, I’d mask off about a 1/3 of the Positive and Negative pads with Kapton tape before soldering the leads on.
The pads are HUGE and that would give me plenty of screw clearance.
No idea how well that would work in practice but the pads are huge there’s definitely space if you can make it.
That’s ok, think I have a general idea. Just wasn’t sure if the 12a driver was any good. Ill see it myself soon anyways, it’s already ordered lol. No turning back.
What’s the d4k look like though?
The c8+ is a bigger reflector, way bigger than the s21, for more throw but it only holds a tiny 17mm driver and a 20mm mcpcb. You can put a bigger driver in the s21a. 20mm I think? No copper pill in the c8+ either.
I wouldn’t buy a c8+ with the sst40. It’s good with the cslnm1 emitters though. They can’t handle a lot of current anyways. Or a 519a dedomed would be good too.
Post with beamshot here:
https://www.reddit.com/r/flashlight/comments/10s3jue/nld_d4k_with_sfq35/?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=share_button
Thank you for your help!
This is what you can expect from basically any plastic…tensile strength is not going to be good. I would sooner use thermal epoxy than trust a nylon (or even better plastic) screw for clamping force.
Nylon screws totally work btw. Touching the positive and I don’t care
Smallest size I could find at the hardware store was M3, the convoy screws are m2.5.
Got 50 for <$1 shipped from Ali. Idk how they’ll hold up but I can get them to the point where I feel I’d be about to strip a steel screw. Enough to start to push into the copper. Good enough for me
