electrical conductivity of copper is 100,silver 106,iron 17.
Yikes :person_facepalming: Actually steel is listedd as “3-15”, even the zinc is only 27!
What material are the battery contacts though?
Pure nickel
I have 3-channel PWM working in the bistro-tripledown firmware, and the ramp calculator supports 3+ channels. However, the third channel runs at 31 kHz and I don’t know how to slow it down. And, as you noted, it would eat a pin currently being used for other purposes.
It can make the mid-high modes more efficient, but it’s a pretty big tradeoff due to the added driver cost and complexity, and probably eliminates the indicator light. It also tends to put a second elbow in the ramp and makes the driver even less friendly to changes in the number or type of emitters.
Usually get them at the Parker/Exotic store- we have one in our plant. But you can get them online too.They are actually copper hydraulic sealing rings (crush washers) - they come in various sizes and thickness. I use them for making driver adapters, 26650 battery tube spacers, heat sinking drivers and contact rings for SRK/M6 builds. Shouldn’t be a problem to get in China.
I started a new thread for a possible driver upgrade/option for the Q8 that would allow for a pretty easy 4S cell conversion and the use of XHP35’s in place of the XP-L’s.
There is the possibility of up to 10k lumens with XHP35’s based on the fact that Acebeam gets 2600 lumens out of an XHP35 HI in lower bins then we can get now in the K70.
If anyone is interested here is the new thread: The Texas Buck driver series, Q8 / Skyray King 2S/4S buck driver RELEASED!
Also got some discussion going on in this thread about a possible Q8 driver with 3 channels and a bank of 7135’s to allow for a regulated low and medium mode, which is honestly all you will need most of the time with a light like this IMHO. Would also net you more lumens and less heat in all but the highest modes as well.
Ooops, Yes - that's an old post of mine. Since then, learned much 
.
The size of the copper washer in Roche M170 is 20mm x 29.9mm x 1.1mm
The most similar at Uxcell a14122500ux0519 (22mm x 30mm x 1mm)
Here are some links… https://www.amazon.com/uxcell®-30mmx38mmx1-5mm-Copper-Washer-Sealing/dp/B00W97KNTK/ref=sr_1_52?s=industrial&ie=UTF8&qid=1471302091&sr=1-52&keywords=copper+washers Amazon.com https://www.amazon.com/20pcs-Flat-Copper-Washer-22mmx27mmx1-5mm/dp/B00WW53JKY/ref=sr_1_14?s=industrial&ie=UTF8&qid=1471301898&sr=1-14&keywords=copper+washers
TA, NICE!
Say now that we are on the topic of a washer…BISMUTH!
This conducts heat 50 times worse then copper
Argh no it is has a high resistance
But bismuth bronze has a high conditivity, it loses the advantage of low heat conductivity
BUT the bismuth n the bronze acts as a libricant thus a disc made of this would have the advantage of not waring down.
I really enjoy this idea.
By the way we still havent see tail pcb shape/design. 4S convertion requires insulated tail pcb with battery pads connected in pairs.
Search thread tail PCB is spoken about and designs are posted.
The battery tube and tail are Thorfire design and our design is not emailed yet.
First we have the housing ledboard reflector and driver to tackle.
Here you go
Copper ‘rings’ are used as sealing washers (sometimes called crush washers or banjo washers) to attach hydraulic and oil lines, and come in a variety of sizes.
Copper oxidation shouldn’t be an issue. Wipe with steel wool and you’re good as new. Or tin the whole ring or disc with solder before installing. I doubt oxidation has a serious enough electrical effect to matter though it may be measurable in a lab. All houses have copper connecting to various metals through pressure-type connections with no problem except when connecting with aluminum. Would be an easy mod.
Phil
This was posted in another thread and I think it is worth quoting here for others to consider since the discussion of contact rings is the currently active one.
The more I think about this the more sense it makes. We were going on the priceable that since all the other SRK lights do it this way, we should to but this light is supposed to be the best design and frankly I think there has to be a better option then screwing the batteries to the contact plate.
This inherently wears things down, using springs like a normal light has no wear and tear except on the threads.
What really made me think it over though is when I was letting someone use a light yesterday and they wanted to look at the batteries. So next thing I knew they have the tailcap off and were asking where the batteries were. The fact is people expect to remove the tailcap and have the batteries looking at them.
It would not be that hard to design a tailcap for this, not much harder then getting a contact ring installed on the driver anyways.
Going with the classic floating PCB on the tailcap with pins to line it up is proven to work, just a matter of beefing it up some with proper engineering. Or I am sure someone could come up with another idea as well.
I do not suggest to make real changes in this project. I just asking questions and I suppose that changes that will make modding more sumple and less expensive should be made when it is possible and when they do not influence on project cost.
It doesn’t hurt to see what people think about the idea, better to voice a question now when changes can still be made then to wait until after the design is finished.
I have no vested interest in it, the tailcap conversion is simple enough to do myself.
Although I would really like to see the tailcap machined with the necessary screw hole drilled and tapped and the addition of a hole in the PCB would be nice as well so that all we have to do is add a screw and washer, cut the traces and add alignment pins to the PCB to convert to 4S cells.
This should be super easy to do, just a screw hole, a bit of clearance and some extra meat around said screw hole to hold it steady.
Well as long as tail is not emailed to or discussed with Thorfire debating it is great and in the spirit of the project.
However please realise we are now looking at using a Thorfire tube and tail of a not yet introduced light so that means 1 we cannot share it and 2 not changing it would be cheaper for them to make and save lots of time to get our designs worked out since communication is slow.
There is no need in sharing CAD files or smth like that.
Just add several main measurements to the first message:
-LEDs PCB dimentions (and what is the reason in making pcb pocket in shelf when it is more simple to screw it down with 3 or more screws)
-Distance from leds pcb place to the glass lens
-Driver size is 46mm, how much place under driver rim? Can be posted in dependent with shelf thickness, like 20mm minus actual shelf thickness
-Tail PCB size and shape
I think this information will be enough to realize different modding ways and prospects.
As long as the design would allow for the self-modding to allow the batteries to be inserted from the rear, it is not a big deal for me. This is a place where if it cuts down on cost significant;y then we can spend that “savings” elsewhere.
Modding a normal SRK tailcap is not that hard, just not that run to line up the hole in the dead center, a hole in the center added would be great and make it far simpler, even just a small dimple to line up a drill bit.
A much better change for modders IMO would be to reconsider the MCPCB design that allowed for both XP and XM sized LED’s at 45 degree offsetts. Thus allow for you to use either by simply rotating the reflector by 45 degrees vs the MCPCB.
Lining up multiple MCPCB’s is never fun and it would suck to throw away such a nice MCPCB like this im converting to XM sized LED’s.