24 Jan How to make good filament with Felfil Evo: basic steps
Felfil Evo allows you to extrude filament for your 3D printer starting from industrial pellet or shredded plastic waste. The extrusion is a relatively simple process: anyway, to improve the quality of the filament and especially to get a consistent diameter, it is advised to follow some basic steps and to test different settings.
Getting ready for the extrusion
Regarding the preliminary operations, first you need to dry up the material (with rare exceptions). Most of the materials, in fact, are hygroscopic, ie they tend to absorb water; the amount of moisture absorbed will affect the good result of the process. For this reason the material must be prepared before extrusion (the PLA, for example, is one of those that most needs to be dried).
The second step is much simpler, and implies to correctly place Felfil Evo on the edge of a table (more information is available in the manual), with the nozzle facing the edge. In this way the filament can fall freely to the ground without encountering obstacles.
Find the correct parameters
At this point, once the material has been inserted into the tank, Felfil Evo can be switched on. The parameters to be set on the machine are two: the operating temperature and the engine speed. Both determine the success of the extrusion and vary from material to material.
The first setting required is the temperature, which, as mentioned, depends on the material that will be extruded (you can follow our table to get a starting point). Once the set temperature is reached, the interface allows to select the motor speed. The suggestion is to start with a mean speed value of 6-7rpm; the rpm value represents the number of revolutions that the screw performs in one minute, and consequently the pressure to which the material being extruded is subjected. This pressure depends, apart from the rpm, on the set temperature. During the extrusion it is possible to constantly monitor on the display the temperature, the motor speed and the absorption, indicated with the letter A.
Monitor the extrusion
Once these parameters have been set, the chamber will begin to fill and after a few minutes the filament will start to appear from the nozzle. The extruded filament tends to wind on the floor. After the first two spirals, measure the filament with a caliber: if the dimension of the thread is too thick, slightly raise the temperature, while if it is too thin, decrease it slightly. This operation must be repeated until the diameter of the filament meets your needs, always considering a gap of a few hundredths of tolerance (even industrial filaments have a bit of deviation).
The absorption control is passive (it is not possible to change the value directly), and indicates the current absorbed by the motor and therefore the effort that the machine is making. You act on this value by changing speed and temperature: in general, the more you raise the temperature, the more the absorption decreases, the faster the speed is raised and the more the absorption increases. The absorption value can vary from 0.3A up to 1.8A, once this value is exceeded Felfil Evo will enter the “protection mode” mode, to avoid damage to the machine; therefore, if the absorption value continues to increase and approaches the threshold, it is better to intervene by increasing the temperature by a few degrees or by decreasing the speed.
If the material in the tank should end, you can add more without interrupting the activity.
For more details, you can watch the video on our YouTube channel!
Have a good extrusion!