Building Brick (The Great Circular Wall)

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

Have fun!

Supplies

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;

Step 1: Download STL Files

Download all STL files

Step 2: Producing Parts

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.

Step 3: Assemble the Parts

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)

Step 4: Weighing the Quantity of Plastic

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

Step 5: Preparation

Preparation:

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

Step 6: Extruding

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

Step 7: Cooling Down

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

Step 8: Open the Mould

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