I occasionally wondered if the 17mm goal could be achieved by stacking a mode board on a buck board. I’m really curious about this.
You don't need to do that. It is enough to just move the inductor up above, either on a secondary board or a toroidal inductor.
Thanks RMM. My type of driver meaning it runs of more than one cell making better use of the true capacity of a battery at maximum output. I feel all fuzzy and warm now. Thanks for making me feel like that. You are a real champion. 
Richard, do you have an idea when the BLF 20 mm fet driver will be back in stock?
Good work! This buck driver is an interesting development 
I really enjoy seeing your intuition producing these kind of advancements, you call it sloooowwww motion 
i would call it fast enough
I was a little bit worried that driver development would grind to a halt when wight “went to lunch” ;), but then i remembered that i was you who realized that i was possible to fit an 7135 on an single sided 17mm driver and made that possible & then you released the single sided 10mm attiny13a-mmu driver and now a couple of days later this new buck driver.
And if i am understanding things right, a 6-8A 17mm buck driver has also not done before.
I will possibly list some this weekend if I can get all of the outstanding orders finished before then. I am trying to keep the volume under control until the new baby comes because when that happens I probably won't work for a few days.
I had my flashlight tester (my 3 year old) testing the 22mm buck driver in a light over the weekend and it passed with flying colors. I had it set at about 5.2A running off of two 18650s and it is running great. Low voltage protection works, and after several sets of batteries everything is running strong (including LVP).
Heat doesn't seem to be as much of an issue as I thought it would be once the driver is installed in a light. The driver will overheat after about 60-90 seconds on high out in the open air, but I measured the temperature a bit with a thermocouple and it seemed like the heat was getting out to the ground ring like it was supposed to, so once it is installed with a good thermal connection to the pill it works great. I think that pills where the driver is soldered in or where there is a retaining ring it will work great. I'm not sure how much less heat transfer to expect from a press-fit pill, but I think that it will also be sufficient because to get a good electrical connection there has to be at least decent contact.
Will make some more layout tweaks, test again, then release.
My plan going forward with the 17mm driver is to have two versions: one that is good for 3A or so that is very low profile, with a small SMD inductor. This is intended to fit in P60s and lights with a very shallow pill; the other will be able to use either an SMD inductor on a piggyback board or a toroidal inductor and be good for around 6A, but will obviously need some more pill depth. Again, no ETA on these drivers. I will be sharing these on Oshpark when they are ready and reasonably tested.
That’s really excting. Will these be user-flashable?
Yes. They all use the attiny13a, although some of them will use the MMU variant which is a bit more difficult to flash. I will use the SOIC version wherever possible, since it is easier to flash and cheaper.
awesome.
again, no hurry, but I’m really excited for this one.
Fixed that for you. 
You’re assuming he sleeps now!
One more question Richard: Will the new bucks be compatible with all major FW’s? I assume yes since its the 13a. I want to use star dual-switch.
no you will need at least 3-4 days of nothing but baby time if not a week. I better get a kit order in before that happens lol
Some buck drivers I have used in the past have had less current output at the led with a higher voltage led. For example with the old style XML-2 the led had 5 amps but with a 6 volt MTG-2 it would only get 3.7 amps. Other drivers made no difference. They just delivered 5 amps regardless of the voltage of the led. Have you tested yours with a 6 volt led. Thanks and sorry if this sounds confusing.
I’m not planning on getting any buck drivers soon, but I’d be interested in the answer to this as well. I didn’t know this happened with buck drivers.
I should point out it was different model drivers gave different results. One model gave 5 amps another model and brand only gave 3.7 amps. I assumed the drivers only delivering 3.7 amps were set at a maximum wattage output if thats possible.
In my testing it is almost exactly the same, provided there is enough overhead and the parts are run within specifications.
Same firmware, same pinouts, same operating frequency.
However, none of the current smaller drivers are going to work well with momentary setup without locking out power source, since the constant drain will kill your batteries in a hurry.
Cool cool. I have the zy-t13 in mind. Clicky in the tail for power, and an e-switch just for modes.