Q8 modding

Are there real issues here or is it “if this is done like this we gain that so that is what I’ll do next”?
Sorry, lots of new posts, got a PM about this thread , trying to read up I see things like “corners cut” and Tom saying “oh gosh” which is not a good sign.

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I don't think this is a real issue. It's just the driver mounting screw holes being too tight and sometimes not letting the driver sit properly. I would think most lights will work fine the way they are, but one may want to check it if they are using good cells and the light is underperforming. All that needs to be done to fix it is remove the 2 screws, open the holes just a smidgen, then rescrew the driver down flat.

EDIT: This post is the same thing.

EDIT2: OTH, it would be a good idea to make the manufacturer aware of the issue. If they have the 2000 drivers loose, it will just take a few seconds per driver to ream out the holes to a slightly larger diameter.

Yes Thorfire is planning on using better screws.

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That might fix it if the screws have a narrower diameter across the threads.

Do you recall the discussions we had way back about the wear&tear on the driver ground ring from the battery tube? Think someone said it's not much of an issue, but we wanted ThorFire to make than ground ring a thicker trace than standard. The Q8's I'm testing a lot on are showing wear, but who knows - might take 1,000's on loosens/tightens to fail - I really don't know, but I recall we discussed this in depth, after TF got rid of the brass retaining ring from the first prototype.

I don’t think that Thorfire tickened the ground trace for us.

But this is only an issue once it is an issue, as you say it may take many years to wear through the ground ring or it may be sooner than that.

At least for folks who can use a solder iron a fix is easy once the ground ring is worn away: some solder blobs or soldering a copper wire around the edge will buy you another hundred years.

I just realized that my plan to swap out the existing 2 green LEDs with pink and blue may not work with the purchase I made. I measured the LED voltage and it’s currently at 2.17v when the batteries are full. It looks like the pink can be swapped in since it works between 2-2.6v but the blue requires 3.1-3.3v to function. Any ideas?

https://www.aliexpress.com/item/Free-Shipping-100pcs-SMD-SMT-Super-Bright-Surface-Mount-0603-1608-Light-Emitting-Diode-LED-Diode/32368361712.html
https://www.aliexpress.com/item/5-colors-x20pcs-100pcs-SMD-0603-led-Super-Bright-Red-Green-Blue-Yellow-White-Water-Clear/32383494488.html

The Miller, I think there is only one significant issue coming up here, and some other discussions about how to improve a few things:

1) The holes in the driver for the screws are too small, so the M3 screws, that were a surprise to see in production, (last prototype had M2.5 screws) have to bite into the driver PCB to be fitted, cutting their own threads.

This means that there is a chance the driver won’t be clamped solidly against the head (unless the screws were cranked down hard enough to strip the “self tapped” threads that they had cut into the driver PCB).

Knock-on from this is that the battery tube may not give a good contact all around the driver ground ring. We are seeing witness marks on the ring indicating only partial contact.

That’s why some of us are drilling out the holes slightly larger, to clear the M3 screw threads completely, i.e. at least a 3mm drill. Even then, I think some are seeing only partial witness marks, suggesting incomplete contact, which may, or may not, become an issue, TBD.

Personally I don’t think it is anything to worry about.

My own suspicion is that the drivers might have been drilled for M2.5 screws, and whoever changed that to M3 forgot to update the drilling drawing for the driver.

So if Thorfire are going to fit improved screws (M3 thin panheads ?), please could they also re-drill the driver boards to the proper clearance.

Given that they have 1500 near-completed torches held waiting for new switch LED boards, I assume that the drivers are as-is, the heads are already tapped for M3 screws, so please could they use the waiting time to re-drill the driver PCBs, so when the better screws are fitted, everything is just-so.

It might also be that the bare end of the battery tube is not cut precisely square. If so, this would be a trickier thing to fix.

2) Then we have a secondary concern, that the thin plating on the driver ground ring (was asked to be a heavier pour, 3oz ?), combined with a rough finish to the end of the tube, may lead to a wear problem, long term ?

Best we can suggest for now is to smooth the end of the tube, maybe apply some conductive lube, and file off any nicks and gouges, to minimise any such wear.

3) Then we are having a debate about whether there is a second current path from the battery tube to the metal of the head, and if so, whether there could be further improvement by making sure this current path gets through to the reverse side of the driver PCB. It’s a pretty academic debate at the moment (but I think that Flashy Mike and I have it correct :wink: )

But it is easy for me to pontificate, since I am on the backorder list, so frankly could be talking out of my ar**e

That’s my summary, I’m sure others will chip in where I have got this wrong. I haven’t been following closely today since I have been travelling all day (5 hours driving, 7 hours on 3 trains (thank you Virgin Trains, your WiFi is excellent), then a taxi, and I’ve only just got home and am knackered.

Edit:

I forgot a fourth one: there is a lot of room for improvement at the tail end. Large gains are being reported with mods, bypasses etc, but it also seems that the threads in the battery tube for the screws holding the tail PCB have got anodising in them, and sandblast residue. This is not good for this critical current path. If the threads were masked during anodisation, or tapped post-anodise, that would be a good thing. Meanwhile some are running a tap through them to remove the anodise, and cleaning out trapped sandblast residue.

The voltage you are measuring is simply the Vf of the original LEDs. If you put in a different LED then the series resistor would compensate. If you had no LED fitted at-all, you would measure full battery voltage across the LED pads.

At the very low current levels used here you probably don’t need anything like as much voltage as you might think for the LEDs to light up just fine. If not, a slight reduction in the series resistor value might be all that is needed to get them glowing again. It is really just “suck it and see” (AKA modding).

Djozz has suggested that blue ones dim a bit when battery voltage drops at lower charge levels.

If you plan on fitting one blue, one pink, well it’s anybody’s guess, because they may not be be well matched, using the original one-resistor switch PCB. Or if you are lucky, with the particular LEDs that you bought it might work just fine. Even if so, it might not work for someone else, with different LEDs.

Nobody can assure you that it will work well, you are on your own here, which is part of the fun.

If Thorfire do change it so each LED has it’s own resistor, that would be the ideal platform for this mod.

Looks like I’m getting contact all the way around. Green area didn’t show on one camera view, so I rotated for different perspective.

The driver retaining screws tapping their way through the driver holes is certainly not a good thing. Anytime one wants put two pieces of anything together with screws, the hole through which the screw passes has to be larger so that pressure can be applied by the screw head.

In this case, screwing tighter will only get the two piece as close as they where when the screw was first inserted. They kind of froze in that configuration… and if not enough pressure was applied at that precise moment then it will stay so unless the screw rips it own thread in the driver board - as Tom Tom explained.

Sorry if i’m kind of repeating what has been said earlier but there seem to be some confusion as to what the issue is on that point. AFAIU it’s not a matter of grounding the driver to the head but rather having it sit flat on the shelve so that the battery tube can make good contact. TF using other screws (with a flat thin head?) will not help - a larger hole will.

My Q8 is only making contact on one side, and slightly on the opposite side where you can see the battery tube starting to dig in. Only maybe 6 openings.

Does that not look a bit “edgy” to you ?

I.e. the contact seems to be right on the outer edge of the driver. I’d be happier to see the witness marks solidly in the middle of the driver ground ring ? Except that there are those screw heads in the way.

Nevertheless, it looks like plenty of contact area.

Difficult to judge at a distance.

Oh crap. That’s not good.

I'm using 1/8" drill bit to drill out the driver holes a little bigger. It's working well so far, but also replacing the flatheads with button tops.

I did find definite glue substance at the screw holes on the spring/tail PCB on one Q8. Why on one Q8, and nothing on others - no idea. Cleaned it off with 600 GRIT - that seemed to work well, in thin strips, folded, using the thumb nail to get in there. They do a not job of keeping the aluminum surface clear of anodizing, then put a layer of glue on it - I don't get it. Also had one badly stripped out tail PCB screw. Had to use a cutting wheel on the rotary to cut a slot in the head, then slowly worked it out with a flat-bladed screwdriver.

Yep, that’s what I saw on mine — except one of the screws was in line with the middle and the contact mark skipped that part of the ground ring, like the PCB was pulled slightly down along the radius where the screw happened to be.

Bother!

Jtm94, zooming in on yours I see contact from 2:45 thru 11:00 (clockdial reference), continuous.

Tom Tom, It does run out at the very edge,
A.)the battery tube is only 0.057” thick
B.) The driver board leaves a small gap between outter perimeter and head body. You can site straight down the threads and see the gap.

Is the wear on that ground ring as bad as it looks in the picture? It looks like it already went through the copper layer in places.

And what happened to the + ring? Did it shrink along the way to make room for the screws? I don’t remember the early prototypes (without brass) wearing on the very edge of the ring like that. It’s probably not an actual problem like the ground ring but it looks really stupid.

Fixed it,

Don’t think so, I scratched a small area pretty hard with a drill bit, the brass is thicker than it looks, I believe. Did not pierce thru.

I wasn’t hallucinating. :+1:
I swear I saw another post with glue on the tail PCB screws. Paged all the way back to my Q8 arrival post, scanned it over and no joy finding it. 45min I quit. I am glad you found glue for my own sanity.