How to build a 8x8x8 led cube (English version)

Step 2 Let us build the real cube (second part)

Once the 8 layers have been made, we are going to connect them together.
Place the led layer on the plywood board, one layer at each time. Bend the anodic terminals (+) as shown in the picture. Bending the terminals is necessary to solder all the anodic terminal on the column with a straight wire, without the need of wire bending to overcome the led.

SEE FIG. 05.1, 05.2 and 05.3

Once all the led layers are ready, cut an electric wire into 64 pieces 20 cm long. Take the insulation plastic off these wire pieces and make them as straight as possible (surely you do not want to build the Pisa cube!). The more straight the wire the more squared will be the cube. The led layers must be spaced 1.5 cm in vertical.

SEE FIG. 06

Place the top layer on the plywood board with the leds corresponding to the holes. Solder all the previously prepared 64 wires to the anodic terminals of the leds. After finished this layer, insert from the top the next layer and continue soldering the terminals.

Important tips:
To obtain an even spacing between the layers, prepare 4 small wood pieces 1.5 cm thick. You will insert them between the layers and they will help in holding the layer in place during soldering.

After soldering each layer, always test all the leds. If you discover some bad leds at the end of the project, it will be very hard to replace them. It is far better to spend some time in preliminary tests than completely unmounting the cube to fix a single led. You will need some patience for this tests, but, as the cube building goes on, the structure will become more and more steady.

SEE FIG. 07.1 and 07.2

SEE FIG. 08

SEE FIG. 09

Once all the layers have been connected, you have to bring all the cathodic terminals to the cube bottom. Remember that at this step the cube is up-side down. So, bend at 90° all the terminals of a layer and solder them to the wires, as already done for the columns.
Now remove the plywood board and drill 8 small holes on it to let the cathodic wires pass through. Place the board over the cube, where the column wires (anodic contacts) go out vertically. Let these wires pass through the 64 holes. You can use the 1.5 cm wood pieces to hold the board over the led cube. Cut a prototype board into 64 squares of 3 x 3 holes. These boards will serve to fix the terminals of columns and layers to the plywood board.

SEE FIG. 10

Fill the holes of the plywood board with hot glue. For each hole, fill in the glue and then insert the prototype board square at the right place, with column wire in the central hole. When the glue is cold and solid, the wires will be steadily fixed in place.
Remark: 8 prototype board squares will host both a layer wire (cathodic) and column wire (anodic). After all the 64 board square have been fixed, solder all the wires to the prototype boards and cut the exceeding wires. In this way the connection with the control cables will be easy.

SEE FIG. 11.1, 11.2 and 11.3

At this moment, the cube is almost finished. It only remains to solder the control wires to the led terminals. However, this step will be carried out later, after defining the connections between the led terminals and the pins of control circuit.

Comments

[randomness72.5]

What are the three wires going across each LED layer for? Are they the ground wires, and if so what are they connected to?

['earl]

Those are just brace wires. they only serve the purpose of supporting the frame of the cube. They dont connect to anything. they are just soldered to each leg. Thats it.