Building Brick (The Great Circular Wall)

These instructables explain step by step how to make a mould and the building brick.

Have fun!

Materials:

• Plastic granules;
• Aluminium block 120x120x240mm;
• Aluminium block 100x100x85mm;

Bolts:

• 25x M6x20 socket countersunk head;
• 15x M6x30 socket countersunk head;
• 8x M6x40 socket countersunk head;

Machines/devices:

• Milling machine (manual or CNC);
• Drilling machine;
• Band saw;
• Oven;
• Extruder;

Download all STL files

The parts can be made in different ways. The easiest way is to have everything made on a CNC milling machine. Another option is to mill each part yourself on a conventional milling machine.

The mould consists of 3 main parts: the bottom, the cover, and zijplaat.

The bottom:

• 1x Bodemplaat;
• 2x Bak kort;
• 1x Bak lang;
• 2x Vierkant blok;
• 4x M6x20 socket countersunk head;
• 15x M6x30 socket countersunk head;

The cover:

• 1x Deksel mal;
• 2x Staaf;
• 2x Deelblok;
• 2x Deelblok mirror;
• 15x M6x30 socket countersunk head;
• 8x M6x40 socket countersunk head;

Zijplaat

(Total assembly: 21x M6x20 socket countersunk head)

The weight of the quantity of plastic that goes into the block can be calculated using the following formula: m=ρ×V

The volume (V) of the block is 527.17 cm^3.

The density (ρ) is different for each type of plastic.

Below are a few examples of densities of different plastics:

• PETG: ρ=1,250 g/cm^3
• HDPE: ρ=0,955 g/cm^3
• PP: ρ=0,902 g/cm^3
• PS: ρ=1,045 g/cm^3

Preparation:

1. Coat the inside of the mould completely with petroleum jelly before the mould goes into the oven;
2. Heat the mould half an hour in the oven at 230°C;
3. Let the extruder heat up for half an hour at about 240°C;
4. Connect the mould to the extruder;
5. Make sure that the part ''bak lang'' with the air holes is at the top;

1. Fill the extruder with the weighed quantity of plastic;
2. Switch on the extruder;
3. Make sure that the mould remains warm during extrusion, for example by using a hot air gun;
4. Extruding is finished as soon as the plastic comes out of the air holes in the 'bak lang';

1. After the plastic has been extruded into the mould, it must cool down slowly. 
2. Remove the mould from the extruder and leave it to cool in a room at about 22°C for about 2 hours.
3. The slow cooling ensures that the plastic block does not shrink extremely.

1. Loosen the bolts connecting the cover to the bottom;
2. The cover will not immediately come off the base. This can be made easy by screwing four M8 bolts into the lid;
3. The cover will now slowly be pushed away from the base;
4. Finally, remove the plastic block from the lid;

The plastic block has some edges and thin layers that can easily be removed with a peeler.

Your first plastic block is now ready!!!!!