Hi The Miller, I’m #329, would you please put me down for another unit? Thank you very much.
Team Q-8, you guys are doing an outstanding job on this! Thanks for all of the patience, and hard work.
It sounds to me as though all that can be done with this light is pretty much done (including the 6 points yet to be done/checked on).
Time to drop the hammer on it?
It should be a pretty good light for $40. (how’s that for understatement?) It looks as though TF is getting a good design out of it too.
Sorry, this is a relatively old post - meant to answer it. Yes, of course! The classic, best SRK around has always been the SupFire M6, and it has one, with a nice hefty raised contact ring. It's bigger brother - the SupFire L1 has one too (I have two L1's 
). I've had and modded other lights besides SRK's that had a similar setup with a ring type of cell contact. The challenge for using a retaining ring is clearances - clearance for the cells on the outer edge, and a good contact surface. Most, maybe all, designs with a retaining ring have a raised contact surface, like we are using in the Q8. In fact the better mods and modders (TA, etc.) of SRK's are using a contact surface ring because of the where and tear of 4 batteries rubbing the driver will do. I find brass to be the best, some use copper.
There's a new SRK out from UltraFire, the real UltraFire, that's supposed to be a "good quality" SRK - haven't seen or heard any details on it though, so not sure what setup it has. Some on BLF have it, but again, don't recall seeing any details posted. I know it was posted it has a built-in shelf though, and they got models ranging from 3X to 9X LED's.
@PBWilson
The Supfire M6 is exactly the light i have in mind!
I love the look (but i also love the appearance of the Q8) and they did not use flathead screws for the driver (this is the main reason why i dropped out the Q8). They use a retaining ring and it is working perfectly fine! If i could get a Proto1 Q8 with a Driver that follows the specs i def. would prefer the Q8!
Now i will probably buy a M6 and put in a TA46 Driver. A bit more pricy but i know that everything will hold up and i do not have any weak spots.
I really hope and pray that nobody will have any problems with the Q8! ! ! ! But i am curious to see if some of the 1000+ lights will have problems with cracks in the PCB around the flatheads.
If TF absolutely want to use srews to hold down the driver, one good option i can think of is, to make the inner brass ring bigger (higher) to get enough clearence to use normal screws. This way there would be much less tension on the driver!
hhhmmm, when those cells die, I'd be 95, modding, or dozing, away...
One more thing on the polarity protection - if you use the Samsung 30Q button top cells like the ones I have, they have that extra thick transparent wrapper over the pink wrapper, making it even safer. No way could the battery "-" end make contact with the brass ring on the driver side if you insert them in backwards, so polarity protection is already there. Other protected cells have the thicker wrapper too.
Is there something I'm not seeing or understanding here? The stock GA flat top cells, and flat top SONY's have thin wrappers, but probably still could not make contact on the "-" end to a flat surface, like the "+" contact ring is.
Put me on the list for one of these if not too late.
Thanks.
The inexpensive SRK that I bought and mentioned a a few pages back has, what is in my opinion, a huge flaw.
It has 3 modes. Hi, med, and strobe. At normal room temp’s on hi mode the outer shell reaches 135°F in 3 minutes. In med’ it does the same in 10 minutes. It has no low mode. So to use this light, unless it’s raining, snowing, or cold out, it will either self destruct in a short time, or 2 are needed to let one cool off while using the other. Lack of a low mode is a huge mistake IMO. BTW, I have no idea what it’s true output is, but it drains the 4 cells pretty fast.
Now I understand why there was such a concern over the Q8 heating up. I don’t remember what the solution was concerning heat protection on the Q8, but for me the solution is still me handling the light and figuring out when it starts to get hot. My hand always informs me long before the light gets too hot.
Due to the nature of a SRK this is a characteristic of the design isn’t it? There’s just no mass there to soak heat up, and very few fins to help get rid of it.
Just curious, has anyone done any long “burns” to find out what output allows continuous running without over heating? I used 130-135°F as my cut off knowing that internally it would be quite a bit hotter. I don’t know what would be considered an acceptable temperature. But with the ramping (the Q8 has output ramping correct? I think I read something about that back a ways.) would it be impossible to know the output level?
The answer isn’t a deal breaker for me; again, I’m just curious. I know that at some output level the Q8 will run continuously without overheating but I would expect that to happen at some point above moonlight mode.
True. There has also been the concept of a "good host" too though and it's obvious from retail that it's not 4 people on BLF interested in that concept.. Anyway, there will be stars of all kinds.
Funny because I've modded a COURUI D01 by adding screws to hold down the driver... I think you are way too worried bout the possibility of cracking the PCB of the driver. Sure I've modded M6's to get about 5,000 lumens, but you will be limited by the 3 LED reflector and 3 separate LED boards, and of course it's designed for XM size LED's. Anything can be done for a price and/or parts/labor.
Here's some of the comparative points of Q8 vs. M6 for modding purposes:
- LED's - Q8: 4X of XP size w/low profile design, M6: 3X of XM size
- Cooling fins - Q8: 10 slots fully wrapping, M6: 5 slots only partial
- shelf - Q8: ~5 mm thick, M6: not sure, can't find it posted but probably thinner than 5 mm
- Threads - Q8: square threads, M6: sharp pointed (Q8 has a big advantage here)
- Driver - Q8: secured by screws and slightly larger than std SRK's, M6: secured by retaining ring, std size
- LEGO issues: both have their problems. For battery tube inter-changing, the square threads of the Q8 is pretty unique for SRK style lights in the lower price ranges. An M6 battery tube will screw into a Q8 head, but that's with two different thread cuts - probably not a good idea. For the M6, I tried 4 different clone SRK tubes in the head of the M6 - none of them could thread on fully.
- Switch - Q8: waterproof rubber design w/built-in green LED's, M6: standard aluminum
- Overall length - Q8: 133 mm, M6 143.4 (Q8 is 10 mm shorter)
- Weight - Q8: 393.3g, M6: 431g (Q8 is 38g lighter)
Of course for both in stock form, there's no comparison. Q8's advantages:
- more advanced UI (ramping, configurable mode sets, configurable moon mode level, turbo timeout, etc.)
- much higher power in a better NW tint (most want NW vs. CW, not all)
- more efficiency out of higher bin, later tech CREE LED's, and much better efficiency at low output levels (better driver design)
- smaller, lighter, but a better thermal design
- square threads - superior lasting, less wear & tear, easier to engage
- waterproof switch design w/built-in green LED's programmable features for the LED's
- it's cheaper at this point
@Tom E
I really hope that you prove me wrong!!!
But i see a big difference between you tightening the screws carefully down by hand and some cheap TF worker with a electric tool in the production run under time pressure. Of course many people would not even see if there are cracks because they glued the polarity protection plastic ring on top of the srews.
Damn why do they have to change it? I really like this project!!! Has TF given a explanation why they want to use the ugly srew and glue solution instead of a retaining ring that is working perfectly in so many lights? If it is only a cost thing, how much could it cost/light to pay for the extra time the worker would need to assemble the retaining ring instead of the srews + the differece of the costs /ring compared with the costs for the srews ? ’I think 50cents/light max probably less! So if only 10 of 1000 have a problem with cracking and they have to send out a new light to these people the cost would be the same.
Tom E is too modest concerning Q8 vs. M6 et al.
……wasn’t even on the fence before the UI came along (already having two Meteors, which I would pay 40 bucks each to have Narsil implanted.)
The way I see it, you get free flashlights with the ramping/configureable interface.
Hhhmmm, have you seen a PCB actually crack from this kind of abuse? I'm seriously wondering. I literally have a stack of SRK OSHPark outdated/obsolete drivers I could experiment on, but it would be my drilled holes, not from fabrication.. The ground rings on each side, though thin, would add some sturdiness there. Also we are only seeing prototype boards in the two units I have here, so they might do a better job on those thru holes in production.
Generally what I'm familiar with seeing is thru rules for screw mounts being fully plated inside and fully around the edges. But those holes are for flat head screws, not pan head, like they use.
Also the cracks would have to be pretty long to effect anything. One is a distance away from the LED- pad, the other is somewhat closer to the LED and switch pads, but the surface traces would have to get damaged somehow from the cracks.
I have the ULTRAFIRE U-4L2 4 (4 x XML-2”s model).
Yes it has a driver retaining ring & a raised contact ring.
3,300 lumens on start with 30Q”s in a stock light.
It is a really nice light & probably the best stock “SRK” type light out there at the moment.
The Q8 though will of course blow it away :+1:
TOD:
If damage occurs from not careful assembly they know when doing the turn on test and will repair there and then. Also if that happens we can be sure the worker doing the damage will be notified and change his methods (if they are not using a tool with torque settings).
So this is not a concern IMHO.
Tom has addressed it, we have explained several times how tight of a budget we want it for and it is explained why this method is cheaper.
I get you want all to say what a smart decision it is to go for a M6 instead of a Q8 and for some modding plans this might be true, especially if the things the Q8 has going over the M6 aren’t things you think are important.
I think this is about as close to confirmation you did the right thing you will get 
For me better threads, higher lumens, better tint, infinite cooler and better UI, better waterproofing, lighted switch for the same price (well with shipping and taxes a RMM stock M6 would cost me the same as 2 * Q8 but they can probably be bought in China with free shipping) would be a no brainer if I was not involved in it and just looked at it from the sidelines. But that is just me
As you are aware I have that same light b_h. Are your 30Q’s button top or did you solder blob them?
I have used GA’s in mine with no problems.
Why was the ring dropped in favor of the screws anyway ??? :person_facepalming:
Was it a possible safety issue that battery might contact the retaining ring and short??
It seems using screws saves cost and manufacturing time.
Interesting about that ultrafire SRK is that its design, a bit of extra electronics and price all seems like they have been following this thread wouldn’t you say?
Ok… I understand that. :+1:
Maybe, I’m not sure how new this UF model is.
Ian may know or can find out from “”, who told him some great info about them.
They are a great light. Well built and very nice! !
ToyKeeper Wrote:Those who mod still take things further, always pushing the bleeding edge, but it’s nice to have projects like this where the rest of the crowd can get something nice instead of the usual overpriced/underperforming items one can buy retail.
Thank you TK. While I do extensive work on truck and motorcycle engines and chassis, I just don’t have the knowledge to mod flashlights and would rather those with the skills design and build them instead. I’ll be in line with cash in hand!!
:+1: … Welcome to BLF BT100! 
Thank you teacher! Could I be added to the list for a Q8, thanks.