Filament0.1 is a school project that has been started two years ago. The purpose is to create coils of material for a 3d printer by recycling scraps.
Filament0.1 works with an alluminum extrusion chamber and the material (PLA, PET or other kind of plastic for 3d printer), melted with a resitance putted around the extrusion chamber, go throughout that thanks to a helical drill bit. The rotary motion is given by a motor for windshield wipers obtained from a car. At the end of the chamber there is an extrude with a hole of 1.6 mm.
The entire devce works with a computer power supply and the resistance is controlled by a thermocouple and a PID controller allow us to regulate the maximum temperature according to the material that we are melting (each material melt at a different temperature, in our case the PLA melts around 190-200°C).
Step 1: Material
First of all you need some materials and some machines:
- Laser cut, to create the box where the entire device is putted in;
- A 3D printer, to print a funnel, where you put the crushed scrap material;
- Alluminum bar, you will shape this bar using a lathe;
- An helical drill bit;
- Power supply;
- Switches, to set some parameters (like speed, sense of rotation);
- A resistance;
- A thermocouple, to detect the temperature of the resistance;
- A PID controller;
- Connecting cable, to connect the electrical part to the power supply;
A gearmotor (24V DC);
- Mechanical tools, to create, assemble and modify the device (like screwdriver, cutter).
- Status solid relay;
- Pixnor speed regulator;
- Crushed plastic (PLA in our case, in the last photo).
Step 2: How to Prepare the Material
First of all, you have to shape the alluminum bar: drill it inside (our hole is 14 mm large, because our drill bit has a diameter of 14 mm), here the helical drill bit will push the melted material. Around the shaped bar you will put the resistance: since the alluminum is known as superconductor, taht chamber will melt the material like a owen. The resistance is normally on/off, so we can't set the temperature directly. So we need to use a Status solid relay, wich is connected to the PID controller. That allow us to modulate the ignition and we can defet the thermal inertia (we can power on and power off the resitance according to the temperature we need).
That drill bit is connected to the motor for windshield wipers that always rotate at the same speed: it is necessary to have an homogeneus filament.
Between the motor and the estrusion chamber, you have to put a hopper for the raw material: at the base of the hopper, we have a sort of cavity, where the drill bit passes and mince and carry on the pieces of plastic, throughout our hot chamber.
At the end the melted plastic will pass through the extruder and we will have the finish product.
Step 3: Wirings
As we told before, we have a power supply that feed our device.
We also have a PID controller that needs to be wired with the temocouple. In the first photo you can see the datasheet of the model we have used.
In the second photo you can see the connection scheme of the gearmotor.
We have used a power supply 220V AC / 3.3-5-12-24V DC. You have to connect the phase to the PID's switch by one side. On the other side we go into the status solid relay (AC OUTPUT) that goes to the second plug of the PID controller. The second AC OUTPUT plug is connected to the phase of the resistance.
The neutral is connected to the first plug of the PID controller, that is connected to the neutral of the resistance.
Then the Ground is directly connected to the resistance's ground.
The status soldi relay is supply by the fourth and the fifth plug of the PID controller (connected to the DC imput of the relay).
The ninth and the tenth plug of the PID controller is connected to the thermocouple.
The generalcable of the power supply is connected to a switch that allow us to power on the supply whenever we want, that switch is in the end connected to the ground.
Then we have a switch for the fan that is connected to its negative and it's alimented by the positive (+12) of the supply. This alimented also the Pixnor speed regulator (that is also connected to the negative of the power supply, -12)
The speed regulator is controlled by a switch and allow us to regulate the speed of the motor.
You can see the conecting scheme in the third photo.
Step 4: PID Controller
We said that we have a thermoucouple connected to a PID controller.
The PID controller ,in practical terms, automatically applies accurate and responsive correction to a control function.
So we set our maximum working temperature (as we already said, 200°C), than when we switch on the power supply, the resistance will start heating and it will maintain the working temperature that we set.
Step 5: How Does It Work?
Filament0.1 is composed of a hopper (blue) in which the crushed material or the pellet is deposited, at the base of the tank there is the helical drill bit which performs the function of a worm screw with the task of pushing the PLA into the chamber, before, and to the extruder, after.
The worm screw is started by a 24V powered geared motor.
Under the extruder, we have printed a funnel (yellow) and the fun conveys the air into it to cool down the temperature of the extruded filament.
You can modify and cut the box or you can print all the objects as you prefer.
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