Q8 modding

I deeply hope we haven’t found another potential design flaw, I have seen this earlier in cheap SRK clones. Bad contact between battery tube and driver board. Last time I simple beefed up the trace with solder, since I didn’t have anything better at hand that time. Worked out better than expected but of course a brass or copper ring would be far better.

Hank is onto it…. and yes, a good finish on the end of the battery tube will allow for the most contact while protecting the trace. A rough end on the tube will be an abrasive to that trace, while also providing the peaks and valleys that will undermine a solid ground contact. And that 1/3 contact, all the current flows through there so if you can get the driver to seat firmly on the head’s shelf then the battery tube should also fit squarely onto the driver contact ring and provide the optimum ground path.

That’s the biggest trick to getting the most out of a light, making all contact points optimized to cut resistance everywhere possible, or at least in my experience. I’ve even gone so far as to solder thin copper discs on top of the springs so they make a large contact to the negative end of the cell. The little things, added up, yield the biggest gains.

Designers need to keep a thorough list of all the possible bad designs that have been used in the past on any similar product.
There has probably been a financial reason for every corner that’s ever been cut — watch out for those choices to happen again.

Does anyone build driver PCBs with a solid copper ring instead of a trace around the edge of the board?

When all that’s done, stick an UCLp in place of the glass lens and measure output again. :smiley: I remember seeing a 17Kcd gain in an Maxtoch SN6x-2s by simply replacing the lens with an UCLp.

Seems the good drivers have thicker copper pours for the traces, like 3oz, or the same as the new Noctigons. If they’d wear out it’d take a lifetime of regular use I’m pretty sure.

A suggestion for those who have some conductive lubricant like Nyogel — wipe the driver board contact ring and the end of the battery tube clean of the lube that’s on them now.
I wiped off a lot of dark discoloration, presumably metal powder.

Then —
Run a thumbnail along the bare metal surface of the end of the battery tube to feel for any rough spots.

I found one little ding on that metal face, a tiny notch with a raised edge and a missing chip of anodizing just outward from that. I cleaned up that rough spot (rubbed it with a bit of hardwood til I could no longer feel the raised edge).

Figured that was likely abrading the contact ring.

Added dabs of Nyogel to the bare metal surfaces.

Figured I don’t know if the lubricant supplied on the flashlight is electrically conductive or not. Has anyone a way to check that?

When I was a kid my Dad owned a Lumber Yard. I remember the finer grades of lumber had to be slid into bins by hand… I used that manual labor time to let my mind wander and focus on issues. For me, modding lights is a hobby, a manual labor where my mind can be free and I tend to work a light as a matter of habit more than giving it deep thought, the learned things that time has shown after hundreds of mods. So, with health issues in mind, I mod for the escape with the ever elusive maximum in mind as a target goal. It’s not electrical engineering or deep science, it’s pure fun, by design, to escape the serious issues that cause me mental anguish and physical pain. In the end, it matters not one whit to me if TA or Jerommel or TomTom or whoever is actually “right” or not, I’m all about results. For the most part, the 140+ lights I’m surrounded by are the provenance to that way of thinking. (And the hole in my bank records.)

How about lightly tinning the ground contact ring near the FET? That’s where you’ll want contact first as otherwise the current has to go around the driver through a trace of unknown resistance. And a bit of relatively soft solder with good tightening of the tube should mean a good contact after a little wear. At least that’s my theory :slight_smile:

I did this with a SRK mod (but the whole trace not only a part) and it worked out ok - but it is not beautiful. And after some usage you may have to reheat the solder since it gets flattened by the tube.

I will check the wear on the outer ground contact ring in the near future more often. And if its get to much i will put solder on it or put a brass ring on it if i can make one (making it by hand without proper machinery will be a challenge)! A driver retaining ring would solve the “problem” clean and would also look good. But my “first aid approche” will be to polish the tubes contact surface to reduce the wear.

Would the wear and tear be reduced on this ground ring if the effort was made to only “snug” the battery tube instead of cranking it down tight? Just a thought…

We discussed this wear&tear on the ground ring before, when TF first introduced us to the nightmare of removing the brass retaining ring for the driver. It's barely hitting the outer edge.

I see now what you guys are talking about with the screws pulling the driver up, resulting in poor contact -- this is why I drilled out the screw holes and am using low profile button head screws now. Believe I posted pics of this earlier. The wear is still an issue - we asked TF to use a thicker layer trace there, but doesn't look like they did. Dunno bout the follow-up on this, or if it was dropped. Think DEL, Miller, or djozz could recall better than I can.

What I would like is spare driver boards, so I can update my old SRK clones. Pretty please.

Only on BLF, I may have to ship my 2, when they get here, to Texas as some of this is getting over my skill level but certainly is really interesting. Meteor mod is an amazing idea as are all of the others as well.

Who needs a tail PCB at-all ? Just whack in a copper disc with springs soldered straight onto it.

But the tube and head probably have no continuity, the threads are anodised etc. Easy to test for, can you lock out the torch by loosening the head ?

I hear ya T18, that triple triple/quad insert is appealing enough that I might just have to put my 4-jaw chuck on the lathe and learn how to do offset bore. Been meaning to do that anyway, but always seems to be something in the way… (pain, mostly)

That’s the sort of thing I use, but my cunning trick is to wedge a suitable metal rod between the jaws, which I pull towards the handle to lock the jaws open whilst I twist. Difficult to explain, but dead easy once you grasp the idea. First two fingers pull the bar towards the handles, rest of hand twists.

I’ve been saying the same for some time, but it doesn’t seem to have sunk in either.

I don’t think so, they are anodised ?