Narsil is up to about 80% of 8K used for code space, so only an 85 will do.
Yeah, I didn’t figure you would be fitting it on a 25 anytime soon lol. I have a few on hand, just not enough to really mess around with it. This is why I like stocking up on little things ahead of time.
One thing when picking a board size, the 17mm will not fit the 85 without taking up half the stinking board, so you will have to bend the pins as you know. The 20mm+ versions have the full sized 209mil pads so it would be simpler to fit the 85.
It will be not very funny when bridged pads will short cut 4S high current cells:
I am not sure what you mean? How would it short the cells as long as you insert them into the correct tube? The cells would have to be inserted from the tail, the battery tube would need to be glued into place and springs installed onto the driver pads.
You would not be able to screw the battery tube on like normal, there is no way to allow that in a 4s/2s setup.
The driver simply makes the conversion easier, it is still very much a DIY project. Now in the Q8 it is possible we could have the tailcap designed to allow for easy battery insertion, in fact this is something to consider.
We could change the design quite easily to have the batteries always inserted from the tail. There is really no reason that they have to be inserted into the battery tube and screwed into place. This would also solve the issue of wearing down the contact ring and needing button top batteries at the same time.
Something to think about actually.
Im not sure you are right.
If we want to use various of different cells, we need to use springs.
If we have springs from driver side, and glue tube to the head, so cells are fixed and then screw tail with tail pcb, you will short cut 2 from 4 cells in 4S config and the only way to avoid this is tail pcb that can slide around incide tail (Klarus G30 and etc.)
If we have springs from tail side, and use fixed tail pcb (insulated from host) and cells that inserts from head side, we have same problem with some extra solutions.
If both - and + pads are on head side, we can use some extra part that is made from plastics and inside it - pad goes to host, + goes to driver and all extra space are insulated to prevent unforeseen short-cuts.
If both pads are on tail side, we can use same plastic insulator for intermediate cell connections and connect negative to host through tail pcb, positive should goes to tail pcb center with should be connected to some solid rod which should goes through center hole between cells to the driver.
All posted describes 4S connection and I think this solutions are much better that tail switch and big bada boom if it is on when you screwing the tail.
I am not totally sure what you were describing but I am also into a pile of buck drive data sheets and can’t really focus on it at the moment.
I was talking about the conversion that many have done to the SRK over the years where the battery tube stays fixed meaning it can not short at the front of the light.
The tailcap is then modified to allow the PCB to spin as you screw the tailcap into place.
Just like the Klarus G30 now that I look it up, that would seem to be the simplest option. Anyone can do it, particularly if the Q8 already had the screw hole machined into the tail cap and PCB.
K, just ordered the 17's and 22's, 3 each, 17's in 2 oz. copper. 
For $6 shipped, not much of a risk.
Curious how the 2oz version holds up, I forgot to change one of mine to that sadly.
Mine are supposed to be made on the 29th, curious when yours get done.
Last time I ordered I got them in like 5 days! lol.
Sometimes they upgrade to the express service, simply because they got room on an express panel our small boards fill in to. It's happened to me several times. The17's are nice in the thin size. I really don't think it makes much of a difference for us having the heavier copper, because typically the batt+ is connected direct from the spring w/bypass to the LED, and the other critical power path is batt- (grnd) to the FET input. When I piggyback a driver in, I make sure I got a nice wire connected from a good grnd point on the contact board straight to a FET input pin. I also sometimes will wire a jumper from the grnd ring to the FET, all depends.
I figured that was the case, these little boards would fit into lots of small areas.
I put in an order today as well. Scheduled for the 29th
Hi, I am new here (if you couldn’t tell from my post count!) I want to build the 17mm version of this driver, I am having trouble locating and selecting the correct items, I looked up the fet found choices on mouser but the size etc still gives me a list of values I need like gate voltage etc. Same with the resistors .10 and $1 ones in the same 603 size, not sure which to order! Thanks!
I know your feeling! I can say for resistors, I usually narrow down the options using these filters:
0603 package(or 0805, 1206 depending)
In stock
Cut tape
1% accuracy
Then I sort by price and choose the cheapest resistor that has the highest temperature range. At the low prices the temps are usually the same, but sometimes there is a low temp version in there and I usually stay away from those.
The price is usually .10 for one, but buy 10 for .25. Something like that.
Edit: I use a similar method for choosing other components, but yes, there are some basic values that you need to know. For fet, you need to know the size or package you want. Look for single n-channel fet ,best temperature range and for a low resistance.
There are a lot of things that go into choosing a FET in particular. The SIR800DP(?) is regarded as the best (and also expensive). You can search the forum to find discussions on a couple model #’s that suit our purposes as well.
Ditto the above, I just got my parts order for the drivers in today. After I build a few and make sure everything works I will try to make a shopping cart with everything you need.
I follow lightriders selections for narrowing down the selection to the parts that are at least the type I am looking for.
Thank you guys, I look forward to the cart. The last few builds I did I used MTN17DDm-NUV but this looks like DRJONES-H17F with Bistro, that seems like the best of both worlds. I wanted to try a 1+7+FET but I didn’t want to give up Bistro.
Just got in the 22mm's today. Look'n good/!See they are labeled 26 mm 
Hope to have a chance to reflow one tonight, we'll see.
LOL, opps. I will put that on the to fix list.
I am hoping to reflow one tomorrow.
My 2oz 17 and 22mm boards arrived today. Boards look great, but boy are those pads tiny. I knew they would be tiny, but didn’t realize how tiny they would be. I’ll see what 0805 parts I can get away with and then order the rest. Probably, won’t get around to it for a couple days at least.
LOL, yeah I knew the entire board would be tiny but seeing it in person really drives the point home. Dealing with it in software at 10” diameter, you forget how small it will end up.
I looked over the boards and they look good to me, a few minor things I will correct just because they annoy me (26mm printed on the 22mm, the FET resistors not perfect lined up ect).
Only thing that I noticed that was not how I wanted it was the copper pour not going all the way to the edge of the board. I know oshpark says in the specs that they won’t do that but PD seems to get them to do it on the tripledowns?
These should still work, just remember to solder them in place and/or add a soluder blob to make the ground contact.
PD, how do you get OSHpark to take the copper all the way to the edge of the board?