CRX Rotary - 6th Annual BLF/ Old Lumens Contest Winner

I recommend Bi57Sn43 solder for magnets, makes things much easier. :slight_smile: But watch out for fakes.

An absolute wonder!!!

Thanks very much for the comments, much appreciated :beer:

Yeah heat will destroy the magnetism, even a seconds contact with the iron will affect it so you have to be fast, Neo fast… :laughing:
Not the first time I’ve had to replace a soldered Neodymium magnet because I applied too much heat, plus the damn things will jump onto & stick to your iron tip until they kill themselves and fall off :person_facepalming:

I solder as fast as I can, wetting the surrounding area first and dragging the solder to the magnet. It helps to have the magnet stuck to something else too, to wick away heat, like a piece of thin copper sheet then more magnets on top.

I think type N lose part of their magnetisation permanently at a temperature of around 60-80°C, though there are different types and a lower melting point solder would help too as mentioned but I only use silver solder with added cadmium :stuck_out_tongue:

Sometimes, I wonder myself :smiley:

:person_facepalming:

Thanks for the explanation

Neo wasn’t just fast. He could see the source code of our world and change it to his will. I think this build easily proves that CRX really is the Chosen One. Where’s Agent Smith? :cowboy_hat_face:

:smiley:

Re. soldering magnets - I’ve heard that having a big magnet with a thin piece of silicone rubber on top helps.

The idea is that you take the small magnet you’re soldering and lay it on the big magnet with the silicone rubber in between, then solder. As the small magnet cools, the field of the big one remagnetises it. The silicone rubber stops the heat reaching the big magnet to demagnetise it.

Anyone know if that works?

Oh man…. That could explain some things… :open_mouth:

:+1: :beer:

That is an interesting idea, might be worth further investigation. :+1:

Core body midsections soldered together & lighted rotary switch installed.

I cut the inner core copper tube to accomodate an 18350 cell, applied solder paste with toothpicks & made neat with cottonbuds, held positioned parts with grips and used dual jetflame lighter to flow switch board surround in place.

Same technique with the mid section spacer and front o-ring stop.

The slim 1mm gaps are where the rubber o-rings will sit, one for the head unit water resistance and one for keeping the rotary tail smooth in action.

Solid copper wire poked through vias, bent in place and soldered. Copper disc added to centre of ring magnet with JB weld, rebuilt switch temporarily for fitment and magnet strength test.

Modified a little and soldered the bottom contact board into the battery tube with copper pins drilled through the tube into the board, soldered and filed flat.

Top contact board with traces etched in using the same methods as before, resistors & 1206 green LEDs installed.
Each LED has it's own 1206 2kΩ resistor fed by a 1k bleeder resistor bridging the positive contact on the pill to the copper body core.

Soldered top contact disc into rotating copper shell end piece, this unit is now held onto the main body with M4 brass nuts securing to the 4mm brass bolt in the bottom contact board.

The rotating copper shell unit will be fixed to the finished outer flashlight body tail section.

Quick test: :THUMBS-UP:

I installed a temporary XP-G2 emitter along with the old reflector just to get things up & running to check the operation.

The tail LEDs work as most lighted switch setups do, remaining lit until a mode is selected by rotating the end tube section.

What can I say? Superb!!! Amazing!!! Excellent!!!

CRX: the MacGyver of copper

Looks amazeballs :+1:

+1

Great build mate, can’t wait to see the finished product :+1:

Making the momentary switch button & copper retaining rings.

I cut three pieces of copper tube, two from 22mm diameter and one from 10mm diameter & filed flat.

The larger pieces are for the front bezel and switch retaining ring, the smaller for the tail switch button.

Cut & filed round a 20mm disc from FR4 board, marked three slot positions, drilled and filed out with small diamond files.

Removed some copper from the outer disc and a 1mm copper wire circle soldered to the back of the cover with slightly less diameter than the Fr4 board to avoid unintentional contact to the flashlight body.

10mm copper tube piece soldered to front and diffusion film cut out to stick underneath.


Chemically antiqued copper facing, diffusion film disc put in place and UV setting glue applied.

Showing 20mm x 2.5mm copper switch retaining ring.

Using titanium sheet, I marked & cut out a piece, filed round to 8mm diameter and fixed to the centre of the 10mm x 8mm copper tube with JB weld.

And polished.

Acrylic diffuser disc made to sit on top of LEDs and spring fitted.

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Since the brass bolt is connected directly to the battery negative it seemed logical to fit a spring here and have a momentary on switch connection.

I also made a temporary brass casing from 25mm x 22mm brass tube and inserted the copper retaining rings, though they are not fixed in place.

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The outer casing, reflector and LED are still temporary but this gives an idea of the finished form.

Test of momentary tail switch button :THUMBS-UP:

Still waiting on some parts to arrive but we're getting there :-) :THUMBS-UP:

All that “temporary” stuff and it’s still a functional light :laughing:

Yeah, I’m still waiting on the LED, reflector, glass and they sent the wrong tube for the outer shell but I got not patience and need to see it working :smiley:

Amazing number of hand made pieces. All nice