“The ledboard its clamped equally evently. This is the work of the Big center screw.
Neither deformation will occur with any of two desings.”
That would be correct if the center screw fixes against the shelf, but instead it is fixed against the ledboard so it does not clamp down the board.
“The reflector is in a fixed position in the two desings, because this is the work of the big center screw.”
The center screw allows rotation of the reflector over the ledboard, in many of run1 of Q8’s you can see the leds slightly off-centered all in the direction of the rotation, this probably happened when closing the bezel. The run2 design change makes that rotation impossible.
I think the batch 2 screw re-design in the head has more to gain, less to lose from batch 1. Totally disagree with the "BIG FAIL". I've worked on about 10 batch 1's, about 6 or so batch 2's, and from direct experience, I can center the LED's better in a batch 2, get real nice even compression of the MCPCB on the shelf, and overall batch 2's seem to perform slightly better in terms of output and holding output, with all the same driver and tail mods.
I've had many struggles centering a batch 1 LED's on the center reflector screw - the 2 long screws now eliminate those struggles. Of course I replace all 3 screws with brass ones, so that helps as well, but also replaced batch 1's with brass screws.
Thanks Dale. I appreciate that. I will sit down at some point and go through the documentation and see what I can do. I don’t want to get rid of ramping. For me that is one of the slickest parts of the light.
The Miller - One item you might suggest to the builder is to make the black feed wire as long as the other wires attaching to the bottom of the processor board. That short wire really limits access to the processor board.
Ordered 15 brass screws but got closer to 30 (bag says 15). Poor fellow (or lady) must have gotten tired of counting and just started tossing them in a bag. Most screws well made, very few with imperfections.
If I understand correctly, the first batch had longer wires. The second batch seems to be a bit random about how long the wires are, so some are long enough to flash the driver without soldering, and others aren’t. (edit: Tom checked several and found the wire length to be pretty consistent, just barely long enough for reflashing)
I would definitely not mind if “wires long enough for easy reflashing” was a design requirement… but I recognize that longer wires reduce maximum brightness and can potentially increase electrical noise on the driver. So there are good reasons for shorter wires. And I’m, uh, a bit more reflash-happy than most people, so what I want isn’t typical. But still, I love when I can mess with the code without having to otherwise mod a light.
It seems I got lucky my results are pretty normal for batch 2… wires just the right length, reliable and balanced switch LEDs, screws made of metal instead of butter, generally no significant issues. I had some AR coating to remove, but that’s resolved now too, thanks to an entire day worth of abrasive scrubbing and harsh chemical treatments.
My code changes only took a short time though, so I haven’t opened up my Q8 in a while. There isn’t much left for me to optimize.
Of course, my needs aren’t really emergency-related. I’m more interested in it as an entertainment device than as an emergency tool. It’s fun to close the door, turn off the lights, and take a shower with a modded Q8 running in lightning storm mode. Maybe I’ll finally add a candle flicker mode too. That might be nice for a bath.
I've re-programmed several batch 2's with the stock wires in place and didn't have any problems. My preferred length for replacement wires is 48 mm though - I seem to need the extra length, might have to do with how I strip/solder the ends. But Yes - the shorter the better. There's no good reason to go over 48 mm. I haven't seen any randomness with the wire lengths, least in the few pieces I've worked on.
Weird though you see the black wire shorter than the red - sure it's not how you have the driver positioned?
Group buy coupons have expired, but the M4D M4X code works as of today, and it's a pretty good deal, for $46.50 here: https://m4dm4x.com/blf-q8-arrived/
Im going to heat up my sauna tonight, put a red plastic cup over the Q8 and put in low-ish mode.
Also, i just noticed the flat part of the tube lines up perfectly with the flat part of the head.
I am surprised how little i have to un-screw the tube before the light doesnt work. Maybe 2-3mm movement and green light goes off.
Does that mean the batteries are “just” long enough to make contact?
Would be cool to see the candle light mode on video in a dark room
yep, and even without the screws in place (who needs those), the battery springs keep the driver pushed up and it still works reliably, actually because of the battery contact.
The battery tube is, basically, a retaining ring for the driver. The driver gets BAT- by having the battery tube screwed down against its outer ring. Loosen the tube and it breaks contact, even if the batteries are still firmly pushing against the BAT+ ring.
Indeed. But in the Q8 the contact between the tube and the driver is also rather ephemeral. After a little adjustment mine is contacting OK all the way around the edge of the driver, but that’s not saying much, barely half a mm, and the driver PCB surface is showing signs of wear already after a week, despite polishing the end of the tube.
I think I am going to have to come up with a mod. to fix this, if I want it still to work this time next year.
Meanwhile I am not cranking the tube down hard, nor loosening it for lockout, the less wear and tear the better I think.
