The thing is that solder boobs do the job quite well, are softer than the contacts, so will not damage the contacts, and are simple to refresh if they do wear. Copper washers or balls or magnets all need to either be soldered on anyway or rely on glue or some other mechanical means to keep them in place.
So why complicate things? Tom’s testing appears to show that simple solder boobs marginally outperform even commercial button tops.
The respect we (ought to) have for our cells probably plays a big role in the not being all that happy to solder on them.
For me for sure
I am happy with the 30Q BT I bought and to be honest even on Panasonic protected cells the Q8 is very bright
But I am no solder-whizz like others, maybe if I was I’d blob them too 
Just solder boobed 8 VTC6's. I call it "ST" (Solder Top) vs "FT" (Flat Top) or "BT" (Button Top). I bypassed the springs in the round #3 proto with 22 AWG wire.
Pretty much all the spring issues go away when you bypass them - they stiffen slightly but might still disengage on a good bump. I also gave the stock ones a little stretching so they sit at 11 mm now. There's no risk of over heating the springs with the bypass.
From the best I could figure, there's 73.6 mm of space for the cell and spring. VTC6's are about 65 mm dead on, and the solder adds about 0.8 - 1.0 mm. So in theory, a 10 mm spring would have to compress 2.4 mm, or with a 11 mm spring, 3.4 mm.
10 mm spring: 63.6 mm of space for the cell, a 66 mm cell compresses 66 - 63.6 = 2.4
11 mm spring: 62.6 mm of space for the cell, a 66 mm cell compresses 66 - 62.6 = 3.4
I measured a 30Q BT at 66.75 mm, so you would get 0.75 mm more compression. The issue is the range 1 spring needs to support, figure shortest cell is a GA FT at 65.3 and I got 2 protected cells at 69.7 and 70 mm each. So the one spring has to support a variance of close to 5 mm. On many (most) lights, this variance is easier supported by two springs, one at the driver, one at the tail.
So with my newly wired up tail PCB, rigged with an 18 AWG loop for a clamp meter, and also cut down the 18 AWG LED wires and soldered/shrink tubed them to 16 AWG wires, and on a new set of VTC6 ST's:
at 4.20V: 21.2A at the tail, lumens: 6,800 @start, 6,375 @ 30 secs, throw: 66 kcd (514 meters)
I'm thinking that if we had a 13 mm spring, might be better to stay with a relative soft spring, so the 70 mm cells aren't a problem threading up. I dunno - maybe these guys doing the design of the lights understand all this well, but certainly there's an optimum zone the light should be designed for. If we picked a cell range of 66 mm to 70 mm, a 12 mm spring would give you 4.4 mm compression on the shortest, and 8.4 mm compression on the longest. Now 8.4 mm is a lot of compression and force, specially x 4 for 4 cells. A soft 12 mm springs could handle that, but a stiff spring might be hard.
I’m so proud. :cry:
Lol
Quick pictorial run through of the tail mods Removed the springs:
Cut traces and added solder pads (scraped off solder mask) to isolate the connection down to one wire:
Made up jumpers to connect the 4 screws for contact to the tube, spring side:
Drilled out center holes for the bypass wires:
Re-mounted the bigger springs (tossing the small ones):
Bypass wires all prepped. Little long but will be clipped after soldered on top:
Bypasses installed, soldered on bottom of the PCB:
18 AWG meter loop installed. Notice the solder blobs for the bypass wires:
Don't think they are necessary, but added 20 AWG teflon coated jumpers for lowering resistance:
This is the conversion of the stock 18 AWG to 16 AWG wires. They overlap and are soldered together. The theory is it reduces resistance, if my understanding is correct (?). They are little longer than the stock wires to allow easier re-programming, access, etc.:
As DEL reported, the shelf is pretty well machined, and think it's better without the anodizing. All I did here was use 2000 GRIT paper to sand smooth/shiny the back of the MCPCB, then used Arctic MX-4:
Shelf thickness: 4.7 mm
MCPCB: 38.04 mm x 2.00 mm
Definitely don't want to re-solder the LED wire connections on this MCPCB with all the bubbling around those pads.
Nice work Tom! :+1:
Thanks! What I like about this built-in loop is that you know the amps measurement is as real as can be - nothing changed between amps, lumens, throw, or actual usage. I've done several of these now, but the heavy gauge wire has been taking a beating. With this slightly modified method, I think there's less wear and tear on the loop wire. 18 AWG barely fits, otherwise I might have gone with 16 AWG, since it's carrying the full 20+ amps.
please sign me up for 3 of these.
Welcome to BLF!
Three , sure will update list later!
Nice work Tom!
So professional!
A flash sale at GB for the Pana batteries. Correction, that’s for flat top batteries. Guess that’s not needed.
Can anyone tell how it works when you signed up for more then one Q8?
when available, do you have to buy the amount you’ve given up for? Or is it possible to split orders?
Still thinking about buying more then 1
you can sign up anytime for as many as you like whenever you like. when they are available you will be a pm with instructions to buy. you are not locked in but if you decide to buy after the GB ends they will most likely be more, a lot more!
I do not see why the Q8 should sell for a lot more. The main difference with a regular SRK clone is that more thinking went into where the metal is and where not, and of course in the firmware, but a lot of that thinking is done for free by BLF members. A number of details also are better than your regular clone(leds, ledboard, driver) and that will add a bit to the costs.
So if a current SRK clone can be sold for 25 dollar, the Q8, in production costs + normal profit, should not neccessarily be more than $50 (don’t kill me if I’m completely wrong).
What I worry more about is that the specs may change after the group buy, to cut costs.
I’d hope they would take the BLF logo off the light, at the point when/if they degrade its specs to cheapen its production cost.
Or, sigh, when their suppliers start supplying quality-faded components, as often seems to be the explanation for a fade.
Just ask to be put on the list
Just order what you have asked for
The exact ways (probably several limited use codes) will be in the PM
I expect the logo will change as soon as the group buy is done. I don’t see why they would want to sell the light without their own logo on it. Although in the case of the BLF A6, it is still sold as both A6 and Astrolux S1 so I guess anything could happen.
Agreed, but I think that is beyond our control. Of the various brands, Thorfire does seem to maintain it’s product quality and integrity better than most of it’s direct competition. Plus if they’re turning a good profit on the after-GB public sales (which I think they will) that will help them stay the course.
Lessening this light would just put them back in with the other SRK clones which is where they started and there’s no point or extra profit in that. I think that Thorfire is smart enough to see this and to keep on taking advantage of the excellent development work they got for free
Phil
I hope there are some way i could get BG to mark the value as 10 dollars, if they dont then in the end when i receive the parcel at my door the Q8 will cost me 80 dollars if not more.
I am also contemplating getting a #2 light as it is after all been a while ( that’s a month or 2 ) since i last enjoyed the pleasure of giving and by doing so making happy, and both of those feelings make me happy and i dont really get that a lot any more with my financial and physical situation.
When ordering add note with value to be declared, this I talked to Swi about and should be done…
AFAIK Thorfire listens the first S70 had a white/clear side switch booth, the second run grey and they changed it back to white/clear when people complained the cell indicator LEDs could not be seen as easy.
And funny thing is of course that the Thorfire logo is on the Q8 but jot the name.
I am curious too to see what is going to happen and at what price it will be listed.
Cant Thorfire sell Q8 directly on there website ? And we can buy from them directly.
http://www.thorfiredirect.com/
Why it has to be through Bangood ?