I did this for the 16X XHP50 light shown above:
Replaced stripped stock screws as well. At 37K lumens with 2S3P, there's lots of amps going thru this.
So until i get my hands on a XM size ledboard my Q8 is nearly ready.
- 20AWG Spring bypass + thickening the traces and installing a 16AWG loop for measuring the Amps.
- 16AWG ledboard wires
- 2,2k switchled resistor + 2x0603 UV LEDs´s
whats left is changing the srews when they arrive.
Sorry for the shaky pictures (new meds have sideeffects)
What is this light?
The bare 22AWG fits into the via (hole) in the center of the spring pad and gets better contact to the traces on both sides of the PCB. Desoldering wick may not be the way to go on This Lights design.
Best is what Tom E did above. Drilling the hole larger to use a wire as close as possible to the screw contact hole and the traces on that PCB he modded there is anemic compared to the Q8 board. My wire was long enough to lay into the soldered traces and follow to a screw hole. But I didn’t feel it would make enough of a difference with stock driver and emitters.
Here at FT: https://www.fasttech.com/products/4173002
$60 w/BLF discount. Big moddable light but typical budget clone stuff all the way. It's far from ideal. I had a custom alum plate/heatsink made for it, but could not permanently mount it because only way to access the driver is from the top (reflector) side. Inherent modder design flaw, but I used thermal grease to do the best I could with it. SRK size drivers fit perfect.
What I really, really like is the 2S3P battery configuration. 2S4P is little too big to hold comfortably (GT) and 2S of 26650's is not enough power.
OK, thanks. Perspective doesn’t give this battery tube justice, it really looks smaller. 
Pro Tool to open camera lenses
I don’t know if these thing is small enough for the switch ring
https://www.amazon.com/Neewer-Professional-Stainless-Spanner-Opening/dp/B00J5F6ZI2
Ohh, some update on this. ThorFire told us the contaminant in the screw holes for the tail PCB mounting is sand blasting remnants. This is consistent in what I've found as well - fine particles, but not metal.
Also fyi, I actually got in 9 pieces total of Q8's. 3 picked up Saturday at the post office, 1 came Tuesday (Expedited via DHL), and 5 were delivered yesterday (USPS). I felt a little bad bout gobbling up 9 in the first 500, but 7 are spoken for, leaving hoping to keep 2. I thought this would be a nice sample size to look at production/QC issues as well, all together, all in one batch.
So good news:
- All are in great shape - no scratches, dings, fingerprints, mis-aligned LED's (except for what's known...)
- All units work, all units have working SW LED's. Of the 9, two have noticeable brightness differences
- the heads seem consistent: drivers and LED's - great consistent tint unit to unit, seems to be equal performance (not all tested yet)
- most lights came with threads pre-lubed. One or two lights were either close to bone dry or were bone dry. I'm gonna Nyogel them all!
Not so good:
- some of them have stripped out screw heads, but can be loosened, just not re-used easily. One light had all 4 screw heads on the tail PCB stripped
- some inconsistent lumens output measurements, one had a noticeable mild flicker - could not see it but could measure it - weird
- swapping parts and such, seems like the lower performing units have lower performing tail/battery tubes - suspect the screw contact to the tube, which really corroborates vwpieces findings. I've seen case of best to worse at like 12%. Also seems like harder tightening can bump up a low reading, but over tightening the tube to the head results in higher wear on the driver ground ring, where the tube contacts it. There is very little surface area of contact being made - you can see the contact marks after a couple/few times of loosening/tightening. We were concerned about this, but I don't see evidence they attempted to beef up that ground ring - not sure if they were going to do anything or not. A brass retaining ring would have done the job better, I believe.
Any idea how to get the positive contact ring of the original driver so I can reuse it?
I know heat is the answer, but i’d like to be able to reuse the original driver if the custom one would fail or not suit me.
On the Q8 prototype I got it off using a hot and powerfull solder iron (Antex 80W). Perhaps a hot air gun would work as well.
I did this on the very first proto - the driver ended up being junk, but survived in tact after removing the ring. Think I used my hot air station to get it off without harming the driver - it was simply soldered down - this one should be the same. I also made up my own brass rings though - easy to do from stock brass rounds I buy off of Etsy, just drilled out a center hole basically - did this once or twice to add to OSHPark SRK boards.
If I had to remove this ring I would try it on a cooktop.
Dam i noticed djozz Luxeon V test a few minutes ago. To bad that it has a new footprint. A quad dtp copperboard with Luxeon V leds @ 5700k would be nice (and dam hot after a few seconds @35A+)
Thanks, just upgraded to induction in the kitchen, so i’ll have to try it on the campingstove :-).
Copied over from the main Q8 thread:
Plyoman wrote:
Yes yes yes, me too, please let us buy extra switch boards for the peace of mind, as soldering bitty bits is scary.
Or convince TF to sell a batch to somebody with the chops to change out LEDs who can mod them, and sell them.
And tell ThorFire that people are nuts for different colors, and they could sell the Q8 with switch LEDs with all different colored buttons and some people would go crazy to buy every possible variation. $$PROFIT$$.
Think he said he'd attempt this mod to a Q8? Wow, seems like a challenge enough to get one LED seated right, but 4? Yikes!
Yea, a dedicated MCPCB design would be real nice... 4 16 mm MCPCB's at 2.0 mm thick should be a simple drop-in mod.
The driver screws have a biger impact on the Total Amps that the Q8 draws than i thought. I was checking some things and removed the driver to open up the screw holes a bit so that the screws fit nice. After that i put all back together and measured the Amps. I got ~15A. Not good. So unscrew the driver checked for dirt or something that was preventing a good contact. But nothing. This time i used panhead screws so that i can put a bit more preassure on the driver to be sure to make good contact and what said the meter? 21.8A (the cam was to slow picture shows only 21.6A)
I think i will remove the anodisation under the driver (where it makes contact with the outer ring from the driver) when my new thinheadscrews arrive. Maybe there is a little bit left for optimisation.
And :+1: for mod ledboards in XM and in Luxeon V size!
And it would be nice to be able to buy a clean switchboard. Maybe with pads for 3x0805 size leds and each with a (if space is to small) 0603 size resistors.
^
I imagine the driver has more contact with the tube when it is sits properly. Like the idea about removing the anno on the driver seating ledge.
I think my integrating tube is reading a bit high. With tail springs bypassed to the mounting holes (So basically bottom of cells connected to bottom of the battery tube via wire), I measured 7K lumens at startup using fairly new fully charged 30Q's flat tops, no solder blob. I would expect less output due to voltage sag. I only used 22 gauge wire because I had a scrap of it needing to be used and I figured the dual springs will already move current nicely.
Even if the measurement is high, this light clearly delivers the goods, both in the tube and outside. Next time I measure, will try to measure current at the same time.
I didn't measure out 30 seconds, but the output drop was slow and steady. So it appeared the drop was due to the cells discharging and not due to thermal sag.
Oh, swapped in one of those RBG slow flash emitters and a 56K resistor in the switch. I also swapped out the other green emitter for one of my green smd's for good measure. Has a nice effect.
I have built an M6 using a new battery tube made by MRsDNF for this purpose, it utilizes a TK61/TK75 battery carrier with an adapter to allow contact with the brass ring. This makes 2S2P really easy, and of course would allow a 4S carrier just as well. This particular M6 built with 3 70.2 emitters is making 13,558 lumens.
I don’t see why doing similar with the Q8 would be all that difficult, and with 4 emitters the total output should be better. Even easy to use 4 XHP-35’s if desired. I would use Richards driver for the 12V emitter, probably Richards driver for a 2S2P as well.
In my own M6, using a single 17mm FET with TK’s ramping firmware, I’m seeing 28.74A to 3 of the new SST-40s for 8866 lumens. This one has a large Omten clicky installed in the tail for cut-off, took 2 18ga loops to get the light to work with these SST-40’s due to the high amp draw.
The carrier modified M6 is manxbuggy1’s, pics here show the set-up
The way this was made by Steve, the adapter sat loosely inside and would fall out when removing the carrier. Manxbuggy1 had some issues with this so I made a retaining ring to cover it that is captured by the battery tube, it no longer can fall out and gets securely pressed onto the driver by simply screwing the battery tube down on it. I also modified the carrier with spring bypasses but did not remove the original brass supply lines (rods) as I have done previously. In this case I opted to not use 18ga Turnigy wires to replace these brass rods. Output is sufficient without radical overheating of the M6 head. Pretty confident the Q8 would fare well done similarly.