That’s an unfortunate problem with these 7135 drivers. I think I read that djozz reamed out the center of the retaining ring some for it to fit. With the qlite 8x7135 driver the 7135 chips extend right out to the edge of the PCB so there’s no way to use a retaining ring, but with your driver above it looks like the chips are not as close to the edge so reaming the retaining ring might work.
If you don’t want to ream out the ring you should solder the driver to the pill at 2-3 spots around the edge. You want a good connection to the pill both for electrical connection and for heat transfer from the 7135 chips. Soldering to the pill is a bit of a pain; you have to heat up the whole pill very hot in order to get a good solder connection.
I used to solder the driver to the pill but it’s a pain to do and an even greater pain when you want to remove the driver. What I started doing was soldering 2 thin wire stranded to the edges of the driver and then press-fitting the driver into the pill. With a little fitting you can get a tight press-fit with a good electrical connection.
I know there are two different kind of 7135 based drivers in an S2(+).
What I call the old Nanjg AK47 or 105C based drivers, and the new Convoy drivers in the OP.
For the first kind I grind out the under side of the retaining ring with a 20mm sferical tool.
Maybe a bit hard to see, but the left ring is original and the right ring is grinded out.
Normally the threads of the retaining ring are not able to reach past the 7135 blocks.
But the grinded out ring is “cupping” the 7135’s and does reach the threads of the pill.
I’m not quite sure but AFAIK the 7135’s on the new driver are placed more to the center.
And thus don’t interfere with the retaining ring. If they do, grind the ring.
The 7135’s are not in harm: the retaining ring only pushes the driver gently in the seat of the pill.
The pressure of the S2(+) tube goes past/around the retaining ring and directly on the pill.
Yeah those are great tips. I have a set of grinding rocks too. Plus shaving the 7135 should work out. Ohhhh!! I just had and Einstein moment. How about using some kinda tiny circlip! Super fast and easy to remove too. :-)
1/ you have to have a groove inside the pill. That only works fine with 1 size thickness of driver. A retaining ring can be fine-tuned with more precision towards dimensions and pressure.
2/ IF you are able to find a circlip that fits INSIDE a pill, chances are nihill that the inner diameter of it is wide enough to keep free of the 7135s.
With one or maybe a few exceptions, like a piston pen snap ring, or something like this:
Incoming unrelated comment here. But I just wanna say man, it’s been a while since I see a black Convoy S2+
It has always been grey or colored or white but rarely a black S2+ was featured
Thanks for sharing pics
In my opinion, 7135s never were a proper solution for a linear driver in a flashlight. Cheap and available, sure, but they don't really deal well with PWM, required to make them output less than full blast, and PWM sucks in a light source anyway.
I’ve done that several times. Use a marker to color the bit that interferes, then a flat file to notch the lip on the ring. Works fine. There are pictures of that I’ve posted, lost somewhere in the old BLF posts.
EDIT: Aha, bless you SB for your wonderful forum tools.
Looks awkward but, as I see it, a combination of retaining ring filing until the holes are at the verge or very slightly swallowed, plus driver modification like Lightbringer suggested (filing down the 7135 corners plus capacitor relocation if needed) would result in a very clean, nice looking solution.