Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

No. When it loses power to the driver for any reason it reverts to start up when power is reconnected.

Oh that’s disappointing, would a large knock be enough then?

Interesting. That hadn’t really occurred to me, but I always got impatient waiting for the confirmation blinks on lockout so I made it do two very quick flashes instead of four slow ones. Kinda regretting not doing the same to the D4 firmware, and moving its lockout to four clicks, because six plus four is slow enough that I’d usually rather unscrew the tailcap instead. But four plus two-quick seems okay.

Yes, a jolt, not necessarily much, will re-set the torch. Try it yourself, even a small slap on the base.

Switch LEDs will blink.

It will be back into I think lowest level of ramping, not sure what happens if it was set in modes. Nor other “soft” settings.

Mechanical lockout can work if no conductive grit in the threads. Mine, as delivered, had swarf there. After careful cleaning with old toothbrush and solvent it doesn’t, and the remaining anodisation is insulating.

Mechanical lockout is the same as momentary cell disconnection. Certain things are only remembered in battery-backed memory and will re-set to defaults. Others are stored in non-volatile memory, and will persist.

> Mechanical lockout is the same as momentary cell disconnection.

Yeah, no problem for me as I haven’t changed any of the defaults.

I know, booooring …

Worth noting though for any subsequent hardware design, carefully decide what is reasonable to erase by mechanically locking out the light.

Or just changing the batteries…

Most things seem to stick, but I don’t think it is yet documented. Other basic stuff does not.

The amount of acceleration required to cause a power disconnect depends on battery type and, apparently, luck (on a per-light basis). On mine, even with short cells, a “bump” means hitting the back end of the light against a hard surface with enough force that my neighbors can hear it.

The saved-vs-not-saved settings were carefully decided on, and are documented in the code:

/**************************************************************************************
* SaveConfig - save the current mode with config settings
* ==========
*  Central method for writing (with wear leveling)
*
*  config1 - 1st byte of stored configuration settings:
*   bits 0-2: mode index (0..7), for clicky mode switching
*   bits 3-6: selected mode set (0..11)
*   bit 7:    ramping mode
*
*  config2 - 2nd byte of stored configuration settings:
*   bit    0: mode ordering, 1=hi to lo, 0=lo to hi
*   bit    1: mode memory for the e-switch - 1=enabled, 0=disabled
*   bit  2-4: moonlight level, 1-7 enabled on the PWM value of 1-7, 0=disabled
*   bits 5-7: stepdown: 0=disabled, 1=thermal, 2=60s, 3=90s, 4=2min, 5=3min, 6=5min, 7=7min
*
*  config3 - 3rd byte of stored configuration settings:
*   bit    0: 1: Do OFF time mode memory on power switching (tailswitch), 0: disabled
*   bit    1: On Board LED support - 1=enabled, 0=disabled
*   bit    2: Locator LED feature (ON when light is OFF) - 1=enabled, 0=disabled
*   bit    3: BVLD LED Only - 1=BVLD only w/onboard LED, 0=both primary and onboard LED's are used
*   bit    4: 1: moonlight mode - 1=enabled, 0=disabled
*   bit  5-6: blinky mode config: 1=strobe only, 2=all blinkies, 0=disable
*
**************************************************************************************/

The mechanical lockout will fail over time with the wearing of the threads but can be restored. The driver ground ring sits on an anodised so electrically insulated shelf that is unlikely ever to wear, so the only electrical contact from driver ground to the body is via the screws. You can break that contact forever by cutting away the brass of the ground ring (perhaps needed at both sides) in a small circle around the screws, or by using plastic screws.

As has been discussed a couple of times before (not complaining, these discussion threads are long) conduction through the threads is not the primary ground route and is easy to stop. Conduction through the threads requires conduction from the driver to the head case, which means through the screws. Simply removing the screws or replacing them with a dab of glue or adding plastic washers to them fixes that. The main thing that unscrewing the tube does is not disconnecting the the tube from the head, it's disconnecting the tube from the driver itself. The screws really aren't needed at all actually. They just keep the driver from flopping around a little when the tube is off. Do use a properly fitting screw driver and preferable a rubber band to remove the screws. Don't let the screwdriver turn without turning the screw.

I kind of wonder if people with more bump trouble than average are using non-sufficiently button-top-ish cells. There are some flat top cells that will barely work, but the guard ring is about even with the positive terminal. Some pressure compresses the guard ring and gets a connection, but that could require some pressure and be less reliable during moments when pressure is reduced.

I just got my Q8 toke ages to come but finally got it and i am happy, i almost buy any BLF special made light even if i have similar

I will make the spring bypass mod, Another thing should i change the wires from the Driver to the led bored with a thicker one for better current or the stock wires is good enough ? i am hoping for 6A per led

You can prevent a bump from breaking contact by lengthening the battery. If you add a magnet to the negative side it causes the spring to compress more creating more tension. No more bump turn off.

I was running my v1 Q8 with one flat top 30Q until my button top set arrived. With the flat top the wrap got a little scratched and it was too easy to reset, just a medium bump against the heel of my hand. With 4 button tops I would have to hurt myself or hit a solid object quite hard, very acceptable spring tension.

perhaps a solution for those who have insufficient tension is to insert a silicone blob inside the cone of one or more springs?

Yes, I’ve bought a few different BLF lights, and they’re all amazing. Okay, there’s always a minor nitpick here and there, but overall they’re way better than most production lights. Especially when you consider the leading features and attention to details like the user interface, tint, and heatsinks.

Most production lights are designed for mass market appeal. BLF lights are designed for the user.

Recently got to stretch the legs of my Q8’s on hunting trip to Texas. While the weight of these is just too much to justify carrying over long distances, I used them with great success in and around the ranch, and always had one in the 4-wheeler just in case an excuse came up to use them. The ability to effectively light up several acres at once was great for critter-searching on the quick.

Now a couple of my buddies want one. I told them I only paid $40, but I see BG and AliEx have them for $60… is this the going rate now that the group buy is over?

-Sam

samnavy
look here
Cupon from M4DM4X
https://m4dm4x.com/blf-q8-arrived/

I guess you would still be looking at $70 to $80 once you buy batteries and a charger.

More than that. A decent charger such as the Lii-500 and four decent cells will be $50ish all combined. It’s very much worth it though.

From what I have seen recently:-

Q8 $45-$50 with discount
Lii500 $18-$23
4x30Q $16-$22

All together $79-$95 depending on what discounts you manage to grab, Black Friday is just around the corner.
Biggest potential saving on that ($10) would be opting for a ±$7 on discount Lii non-LCD 4 bay charger (I got one for $5 recently), half speed and no analysis. If you are lucky with discounts you would come in just under $70.
Worth the extra for a Lii500 though.

I agree, worth the extra.