The ones I got from FT are the same way. Can we trust KD’s pictures?
I got a 10 pack in my last KD order. I’ll have to look at them tommorow if I remember.
What’s the best way to ensure ground between the copper pill and ground ring on the driver?
In what light?
Either pressure from a retaining ring or soldering the driver in.
May I know if the the new one is really worse than the old one (the one with 8 points)? Is it the new one doesn’t fit the LED/reflector well?
I have the last piece of the 8-pointed one left, and now thinking should I order some more.
Just checked the 10 pack from KD order and they are round. 
All I could find on AliX. I hope it’s something Richard could use.
I got some centering rings yesterday from Randar. I still have to try them out but one of the centering rings I got are for that 6.8mm Nichia UV that just happens to fit on a MKR/XHP70 Sinkpad. Since the XHP70 is 7mm, it shouldn’t be hard to make it work with a XHP70. I haven’t found a XHP70 centering ring anywhere.
Going to place a battery order soon. Is the 30Q the high discharge cell of choice now?
I'm thinking, yes. As far as I know, no official posted tests, though I was begging HKJ to review these new top end cells. I got a pair on the way from MtnE.
Richard said vinh liked them, but I think it's between the 30Q and the LG HG2's. I've done further tests on the HG2's I have (one pair), and they test slightly lower than the 25R's, HE2's, ad HE4's now. in 2-3 DD lights. There's variations in lights/driver/led's of course, and not sure what went on. My first tests of the HG2's showed them superior to the 2500 mAh high amp cells on one DD light.
The Sanyo GA's are the latest/greatest for high capacity and moderate low resistance - along the same lines as the Pana PD/PF/BD's but higher capacity.
My gut is saying slightly lower than the top rated 2500's for both the 30Q's and HG2's, but the extra capacity should get you more time at high amps. It sure is getting more interesting... 
I would love if HKJ could keep up - he gets somewhat distracted with the named labels that send him cells to test/post, so can't blame him. He's got $1,000's of dollars tied up in test equipment for sure, and the time it takes is crazy as well, and I don't think he gets any money for these efforts, just maybe a handful of free cells.
I’m sure most of what’s sold to individuals like us is ‘odd lots’ — leftovers from big business or military orders, or batches made by ‘accidentally’ leaving a production line running after an order was filled. Or, sometimes, the leavings and rejects from a competent quality control filter, of course.
There’s a lot of good stuff (and bad and worse) that you only see for a little while and may never see again.
We forget how huge China is, I think, and how fast it’s been changing. There aren’t many things produced consistently over a long time — it’s all one batch, “good enough for now” stuff.
ok so small rant.
i purchaced 4x 16mm xhp70 sinkpad. and spent hours trying to get them to not short out. it seems like they have been milled to far for the traces and all you have to do is put some solder on the ± pads and they connect with the copper. there needs to be a small gap between the pads and the edge of the mcpcb. really not cool. Anyhow i did manage to get all 4 sorted by using solder wick and scraping the edges with a blade.
Anyway i have put my light together with 4X xhp70 and 2s2p samsung 30q all worked tine but i fried the FET in the driver maybe it couldn’t handle regulating power down with so much power. now my hands smell like melted electronics.
HELP…
I'm sorry to hear about the frustrating experience--I think we've all been there before. Yes, they are difficult to solder. The pads are right against the edge, but there is really no way to do it otherwise. It is a compromise of having a 20mm MCPCB machined down to 16mm. I recommend using some flux and being careful to heat only from the inside edge of the pad. This should minimize the chance of bridging.
4xXHP may be too much for a single FET driver, in fact I'm pretty sure it will be. 2x XHP70 with good cells is probably pushing it. That's a lot of watts passing through it.
How long did it work for? I'm wondering if the FET wasn't damaged by a short circuit somewhere. I would suspect the 4xXHP70s to melt the FET off the board eventually, but not fry it right away.
> to ensure ground between the copper pill and ground ring on the driver?
Someone a while back suggested this for aluminum pills,
and I’ve found it helps a lot:
Take a tiny little bit of copper wire
Heat it to soften it, hammer it flat, then bend it so it fits over the edge of the driver, contacting the ground rings on both sides.
Solder one end onto the ground ring on the inside-toward-the-LED
wrap it around the edge of the board (the insulating/fiberglass stuff that will mostly contact the pill when pressed in)
solder the other end onto the ground ring on the outside-toward-the-spring
Made thin, when you press the driver into place, it will make sure your driver is grounded to the pill.
You can put a dab of solder over that to bridge to the pill, but so far I haven’t needed to do that.
The driver worked for maybe a minute on and off. It may have been effected by some shorts as I was having some issues with that. The piggybacked driver was squashed up against the heat sink. I will need to order a SRK FET driver that is set up for huge wattage and that will sort out most of the problems.
I've done several MCPCB's sanded/filed down the same way, all the way into the pads. What I usually do is angle file the edge of the PCMCB's at the pads, so I create a little gap on the edge. I don't think I ever had a problem soldering the +/- pads then, but, things can go wrong for sure. I go really careful with tinning the pads though, and keep the wire from going near the edge. Then I carefully inspect it with a high powered magnifier, and of course continuity test.
Living on the edge... Sometimes Richard accomodates us a little too much .
Just checking. Do you have an ETA on the convoy S2+ 18350 hosts and nichia 219B triples?
I see the MTN-MAXlp HP driver is available. My problem with these buck drivers has been finding a 2x18650 host to make use of these. Does anyone have a suggestion?
For example the Rocher LS01
See this thread for host details.
It needs the 22mm version of the buck driver.
Probably about 1 week on both.
Sounds like a solution in search of a problem! 
They work great in the UF-1405. That's been my main test bench.
Got the pair of Samsung 30Q's in, Thanks Richard!
Wow! They appear to be legit top contenders. I got excellent results in a 3 different DD FET driver based lights I tested them in. Don't have the detail results with me, but I got it recorded. In 1-2 lights, they were the highest amps results I've gotten, and I got a ton of variety of low resistance cells tested against: HG2, SAM 25R, HE2, HE4, AWT, VCT5, EFEST 26650 3500, EFEST 35A 18650, etc.