Piece display PCB

[Tony]

For this you will need the entire contents of BAG 4 plus the M5 nuts and bolts from BAG 1, solder from BAG 5 and copper wire.

Remove the surface mounted components from their tapes. Only one of each type of part is used so there is no risk of mixing up different values or types.

You will have:
Dual diode packs - these are small rectangular 3-legged black plastic blocks. 3 are needed for each board.
Single diodes - Copper-orange glass cylinders with a black band marking one end. These are polarised and must face the same way as on the example baord. One is needed for each board.
Capacitors - Beige rectangular ceramic blocks. Seven of these are used on each board.

Separate the foil cpacitors into another pile, these are cream plastic blocks with 2 wires and '10n' marked on them and the 'D' connectors into another pile. Put these piles of components to one side until the coil winding is done.

[Tony]

Assembling the coil former:

You will need one PCB, one 1.5mm thick spacer and one 0.8mm thick base:



Use a polish block or fine emery paper to clean the surface of the copper PCB and check for any copper whiskers that may cause shorts.

Assemble these pieces on a 5mm bolt in this order and hand tighten the nut:



At this stage it's worth running a few drops of superglue into the groove to hold the pieces together.

Make sure the notches formed by the 2 holes drilled into the edge of the PCB are clear, then feed the copper wire from the top of the PCB through one notch into the groove formed between the PCB and the baseplate.

Wind 46 turns of wire into the groove then feed the wire back through the second notch to the PCB top.



Fix the coil turns in place with varnish or superglue and wait for it to set/harden.

Trim the wire ends as shown, scrape off the insulation and solder them to the PCB.



Repeat 32 times.

[Tony]

PCB assembly:

Place a spot of solder here for the glass diode:



Pick up the diode and solder in place. Once the solder has hardened solder the other end. Make sure it's this way round:



Place solder spots as shown for the capacitors:



Solder the capacitors onto these spots and solder the other ends. These can go either way round:



Place solder spots as shown for the diode packs:



Solder these in place. They can only fit one way round as long as you make sure the side with markings is facing up.



Trim the leads of one 10n capacitor to about 5mm long and bend outwards slightly. Place it in the cutout as shown:



Solder it in place. That's the PCB completed except for the pins, the position of these will depend on the letter you want to display.



Repeat again 32 times

You should now have 33 base PCB/coil assemblies ready for pins.

[Tony]

Display socket pins:

Take one of the 15-pin 'D' sockets and cut open one rivet:



Open up the socket housing and remove the pins.



Cut the excess pin off just below the centre bulge.



Solder 2 or 3 of the pins to the PCB as required - I used 2 and it held the display but yo may want to use 3 for extra stability:

[Tony]

Pin positions for various pieces:

minion: 16x



King (IN-7) and Knight (IN-7A): 6x



Alfiere: 4x



Vizier: 2x



Tower (IN-7A): 4x



Now form a solder bridge between the cathode pin and the ground loop: