Jerommel's Hand Job 2018 - 6th annual BLF / Old Lumen Scratch Made Light Contest

Great start :star: looking good :+1:

Interesting!

Well, i bought 2 of those 20700’s almost a year ago now, but i haven’t got anything to use them in…
And then i found that, with a little persuasion, it can fit inside a 22mm diameter copper pipe when you remove the wrapper.
Triple board and optic also fit snugly in this size tube.

Great start to your build :+1:

I have a couple of those charging circuits for my build - Interesting to see how you cut them down like that.

Cool :+1:

Looks interesting! Pretty compact indeed.

Nice :wink:

Very nice with a couple of cool new concepts! :+1: :+1:

Thanks for the encouraging comments!

I could have used the Convoy S9 e-switch driver with USB charging port, but i didn’t like the idea of parasitic drain, so i used a reverse clicky set up in stead.
This takes up more space though, and it will be a bit more of a challenge to sort out the switch button.

And that will be the next part of the build:
Holes for the USB port, charging LED light and switch button.
Also have to widen the copper tube a tad to get the assembly in without too much force.
Lining the lot up properly will be a bit of a challenge too…

Very cool, very nice, Jerommel. :+1:

Looking great, Jerommel! Very cool setup so far, I like how you’ve got everything stacked tight and epoxied in place (JB Weld?). Interesting how you’ve trimmed down the charging circuit. Are the eliminated bits just for over/under voltage protection?

The battery does not have its vent holes anymore btw, whatever the implication is of that.

Pipe Bomb! :smiling_imp:

Yeah, maybe i’ll send it to some globalists… :smiley: :partying_face:

But it’s true, it’s gonna have a harder time venting.
I decided it was not that important.

Nice work Jeroen. Looking forward seeing the end result.

:smiley: :+1:

Well, let’s hope not that it will end like that… ^

I will update this evening / night with pics.
Had a bit of a set back, but that’s what you get when you build hastily and without proper planning up front…

Me too ! :beer:

Pics from yesterday and today with (quite a lot of) text:

So, the copper tube was too narrow to get the battery in, or rather, to get it out again.
I originally planned to hammer the tube over the internal assembly (battery, charger PCB, switch and driver), but this didn’t seem wise, so after looking for anything to ream the tube out, this was the only thing i could use:

Subtle tool…
This SDS drill is just over 20mm across the chisel point, and i used some household scrubbing fluid along with it.
This did the job, but the outside of the tube got a little wider too, and not evenly, so…

…the outside had to be sanded back to (near) perfection.

Drilled the switch button hole too.

Also drastically enlarged the centre hole in the shelf, because…

…this is how close the driver board will be to the shelf, so i needed to make some room for the slightly thick wires (22 AWG)…
This doesn’t look beneficial for the thermal path from LED’s to the shelf, but i figured it would still be good enough.
The LEDs are mounted on a DTP copper LED board, and although it’s a thin LED board, i think it will still conduct the heat pretty well to the shelf.
…but i did enlarge that hole more than necessary…
O well…

Switch button hole.

The tube is not 1 mm too long, as it turns out…

Not yet sure how to finish the tail.

Size comparison with 2 compact 18650 lights:

(Yes, the DQG is empty…)

_
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And then, i noticed some problems in my plan…

It was the lack of a plan, i guess…

The USB port sat pretty deep, so it could only be charged with a long micro USB plug, and then it still didn’t go in far enough to snap in place…

The charging indicator LEDs didn’t line up nicely either with the side (at 90° of the USB port / switch.

Conclusion: the charger board should move a little towards the wall of the tube to solve these things.
But i used epoxy… No way i can move it…

Additionally, trying some switch boots, the switch was sitting a bit deeper than i would have liked.

And another problem with the switch itself occurred !?
Probably too much heat when soldering, but it had some problems every 8 clicks (full rotation of the inner parts every 8 clicks, or, i think it’s 8, could be 12 too…)
It could be traces of super glue too that crept in too…
Injecting WD40 with a syringe did help, and possibly it will improve further with use.

SOLUTION:
I have plenty of those charging boards (ordered 10 of them at the time).
I have another 20700.
I have a bunch of small Omtens.
I have another LD25 driver.
…so i make another assembly… :person_facepalming:

That’s a lot better.
It cost me a PCB trace though (that’s why the 1st attempt ended up so deep), so i had to lead the + to the indicator LEDs with a wire (yellow).

The switch has to be glued on top of the the charger IC again, but both go more towards the outside.
Need something on the back of the switch to glue it to the charger IC.

A bit of cotton from a cotton tip swab drenched with super glue will do.

Driver on top etcetera, and compared to the first assembly:

Goals met for now.
Bit of a waste of parts on the first assembly though…
No idea what to do with it or the parts it consists of…
All epoxied…
O well, who cares. :beer:

CONTINUED HERE

That is Prototype #1. :wink: Seeing far enough ahead to avoid all part fitment issues can be quite difficult, especially when working with such a compact size. Good going though!!