Preparing the outer & inner core copper tubes to fit together.             

I started off with two hours of fun, freehand filing some copper tube to reduce the diameter of the smaller tube as I want them friction fitted together.

The larger 21.96mm OD x 20.40mm ID copper tube is a cutting of plumbers pipe.
The smaller 21.22mm OD x 18.98mm ID tube, a comrade sent to me last year.

This tube needs to be reduced in diameter to fit inside the other.

Tube measurements prior to work:

Outer tube - Outer Diameter - 21.96mm
Outer tube - Inner Diameter - 20.40mm
Inner tube - Outer Diameter - 21.22mm

I filed evenly around the inner core tube using a hand file to reduce the diameter by about 0.84mm.

Pro Tip: Do not use left hand as filing guide    Inner tube filed down, sanded, light polish and a comparison to an unworked tube.

Tube measurements after work:

Outer tube - Inner Diameter - 20.40mm
Inner tube - Outer Diameter - 20.38mm
Inner tube - Inner Diameter - 18.98mmNow we have two copper tubes fitting nicely together.

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MRsDNF wrote:

That file was a real Bastard.

Making the copper pill.

Filed down a scrap piece of 20mm copper bar and brass ring to 18.92mm.

Parts soldered together.

Soldered the parts together with some copper sheet insert and copper wire using a dual flame jet lighter with the parts placed on a ceramic tile with solder paste in the joints.Cleaned up with wire wool, sandpaper then metal polish.  

First a scrub all round with coarse wire wool then a rub on some 800 grit sandpaper, keeping the face flat down to finally a polish on some old newspaper with a dab of liquid polish on it.

Cleaned up.Showing the pill inside the inner core tube.

This will eventually be cut to shape and fixed in place. Showing preliminary core flashlight parts.

This is an old reflector used for checking fitment only.Pill inside inner core inside outer core with MCPCB & reflector in rough positions.

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It’s really only a quick three stages I do for shining the metal after filing – sandpaper, wire wool
then liquid polish on newspaper.
I’m not too fond of polishing, I’m more of a filing hacking & sawing kinda guy yi know

MRsDNF wrote:

Where do you get your copper from?

Well the plumbers don’t as they probably wonder where their scrap pieces disappear to… unless they have a suspicion the spark on the job has a copper cutting fettish or something

Making the mechanical rotary tail switch.

Copper washer.

Using a scrap piece of 0.3mm copper sheet I drilled a 4mm hole and filed the outer edge into rough shape with the file before switching to the finer stone then a quick polish.

Sprung brass switch contacts & enclosure supports.

I used an old brass Zippo flint stopper to make a switch contact.

Filed the brass rod down a little, sanded and soldered to a silver coated spring from an old clicky switch.

Cut two contact enclosures from 3mm x 0.5mm brass tube and filed down to 5mm length then neatened up with the fine stone & sandpaper.

Two sprung pieces, only one is for making the circuit, the other is made to balance the switch disc, is non conductive and also showing a 5mm x 4mm brass tube to be filed down to 3.8mm length for the central pillar support.

Some switch pieces.

Rotary switch contact boards.

Using the FR4 copper board again, I drilled, cut & filed an 18.92mm diameter disc with a 4mm centre hole.

Using the first as a template I sanded down the second using an M4 brass bolt & nut holding them together.

Now we have two equal contact discs

I marked six points on one as well as I could freehand.

Further marked, kapton tape applied to both sides then I cut out the tape roughly where marked with a scalpel blade.

I used ferric chloride to dissolve away the copper that was not covered with the tape, this takes a few minutes.

Pieces removed from the acid bath, cleaned and tape removed from boards to leave copper contact points hopefully where I want them.

A little more tidying up and ready for test assembly. It is not OSH Park quality but it is all hand made  Order of how the parts go together. The brass contact enclosures will be soldered in place to the disc later.The steel washer is temporary to hold the contacts in place and will not be used when everything is soldered.

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