Supbeam K50 V2 Mod Thread

From all the modding information and my own experiment I’ve came out a general (unscientific) “conclusion” - we need to make the LED sit into the reflector as much as possible to get the maximum throw, and I’ve seen lux improvement on my modded T08 after I have grinded the reflector base a bit. I know this concept is not applicable to each and every cases out there but it’s just a wild idea.

Yeah I’ve always thought that the LED should be inside the reflector as much as possible, but Vinh wrote that in the K50, the LED should be pushed away from the reflector and I think SelfBuilt commented on the same thing on Vinh’s TK61vn review.

The TK61 performs best with the substrate below the opening in the reflector. Maybe 3mm? I worked hard on filing the back off the plastic reflector to get the emitter higher into the opening. BUZZZZ! Wrong answer! So I created a spacer out of a copper disc, topped with Kapton tape then also topped with a 3M insulation disc. So yeah, this particular reflector works best with the emitter backed off, not pushed in.

I think I’m going to create a test bench for finding the focus in a reflector using the tiny 10mm SinkPAD, if I cut it down to barely larger than the XM-L2 itself I’ll be able to test focus first, then duplicate that in light.

The hit and miss method is a PITA.

Here is a rig I sometimes use to play with focus. It's just a scrap piece of 4" (I think) square aluminum (from the scrap bin at Metal Supermarkets) with an aluminum plate (also from the scrap bin) and copper sheet for a pill. A 4" (I think) PVC pipe has just enough resistance to keep it in what ever spot you slide it to. It works great.

I’ll take it! :stuck_out_tongue:

Have to find a mart and see what I can do….

I bridged a sense resistor on a TN31 and without putting on heavy wires it was fine. I’m guessing if I had put super heavy wires on I would have been in trouble.

On TN31's, I measured as low as 5.5A to the LED with bridged resistors and maybe 22 AWG, but I measured 6.2A to the LED with 20 AWG I believe, and I think 18 AWG is used to get the 6.5A to the LED.

Thanks Tom. That’s great info right there. Something to keep in mind for sure.

I replaced the resistors with solder on my TN31 and used 18awg wires. Works perfectly.

Ohhh - ok, those results were on different lights, so not a controlled comparison. Also O-L mentioned this and I believe it - the Teflon coated wire with less strands performs better, so believe he said 20 AWG Teflon is as good or better than 18 AWG silicon wire, something like that. I am still very confident that the wire thickness is the difference of why my fully modded TN31's in the past were under-achieving, compared to others (vinh), which I later found out was using heavier gauge wires. 6.5A on a TN31/K40 is about the max. The K50 sounds like it max's out higher for sure. After working on Fenix lights, I'm a total believer in heaviest possible wire - their LED wires are the largest I've ever seen - believe it's 16 AWG (smaller than 14, larger than 18), and for them, weight does matter, so they didn't mind adding weight in the wires.

The strand count does matter. I have been using Bell wire on lights that I need to keep the wires really small for profile reasons. Lights where putting in heavy wire would set the reflector too high. It’s a single strand of heavy wire with very thin plastic coating. I have even used the wire that is used for installing cable TV. It’s a single strand of very heavy wire. I used it on multi-emitter lights. I pulled it out of the cable wire and then coated it myself with non-conductive glue.

I was taught in my electronics classes that electrons flowed around the outside of the wire/ wires. So in theory a cable/wire with 30 strands would conduct/flow better than a wire with one strand of the same diameter because the one with more strands has more surface area compared to single strand. Of course this is only theory.

Doesn’t the skin effect only apply to very high frequency AC current?

The buck driver does switch on and off very fast but the replacement wires to the LED only carries DC.

High current DC wiring tends towards more smaller strands. I don't buy that junk about single conductor wire being better for DC. I think people 'discovering' some benefit with single conductor wire over stranded wire are missing some other signifcant factor and then misidentifying the cause.

My classes dealt only with automotive electronic systems so it was DC voltage but I was not the teacher nor did I question them about it. But nowadays I work with engineers so I can ask one at work and see what they say about it ( of course they might not be correct either but they have that degree and will NOT hesitate to tell you so)

I haven't done direct tests to compare wires (strand counts) - sounds like it would possibly be easy to do. I know O-L mentioned it and I thought there was other agreement/confirmation. Hope 18sixfifty can report if he noticed differences - I assume he meant less strands were better? Not sure...

Another factor in the wire debate is the quality of the wire itself. There’s a lot of cheap wire out there. The Teflon wire is generally a very high quality silver coated oxygen free copper wire. So is it the strand count, or just the overall quality of the wire? I think it’s the higher quality of the wire that’s making the difference.

+1 ouchy, similar to what comfy said, could be other factors -- well all I do know is 20 or 18 AWG seems better than 22 AWG, least it's been my experience Smile.

Would measuring the resistance with a DMM and crocodile clips help with the process of figuring this out? Just throwing a thought out there if anyone is going to test them all.

It’s going to be very difficult because we’re talking miliohms and most meters can’t accurately measure many levels between 1.0Ohm and 0.0Ohm.

I like what djozz is doing, pushing a high current across the switch and then measuring the voltage drop. Much more accurate than the DMM method. switchtesting , (june13th2015:additional test by MRsDNF in post#44)