3devo Extruder
Extrude recycled PLA 2.95mm
Preparation
Add 10% fresh PLA granulate to the regrind
Close doors and windows to avoid air draft.
Add cutters next to the extruder
Start up the extruder and the Windows computer. Connect them with a USB cable.
Start up 'DevoVision' on the computer. Click on the toolbar on the right (for services?): Show hidden icons > DevoVision ('3d' logo). If this icon isn't present, click the DevoVision app in the toolbar first. (It will notify you that the service should be started instead). Test this for clearer instructions.
On DevoVision, connect to the com port and give a name for the log file (use 'year month day - number' for example). Now the extruder needs to be restarted (press the button on the LCD screen).
On the extruder, go to:
Startup
Start extrusion (automatic): The machine warms up and starts extruding.
Wait for the material to become thick enough to be put in between the puller wheel. This might take half an hour or so
Click 'Spooling' and follow the instructions.
Filament width specifications
±0,1mm deviation is in spec (± means both + and -)
Bad: < 2.75mm
In spec: 2.75mm
In spec: 2.85mm
In spec: 2.95mm
Bad: < 2.95mm
Switching materials
let hopper run enpty for approximately 15 - 20 sec
add little batches of material each time
when the extrusion is pure, add more of the material
Shutting down
PLA, HDPE & DevoClean-mid-temp can stay in extruder after shutting down. All other materials need to be flushed out (with purge material, PLA or HDPE)
Dry filament
Hydrate filament
When the filament is too brittle
Boil water in a large pot.
Place a test piece of filament into the boiling water with tongs for 6 seconds.
Allow the filament to dry completely (we recommend at least 24 hours). Do not dry the filament in direct sunlight.
Test the re-hydrated filament with your 3D printer.
If filament sizzles when printing, we recommend re-running the process, but only re-hydrate the filament for 2-3 seconds
If the filament is still too brittle, run the process but re-hydrate for 10-12 seconds.
Submerge the entire spool in boiling water for the same amount of time which worked for the test piece.
Allow the spool to dry for at least 24 hours.
Your filament roll is now hydrated and ready to use again.
Info summarised from here
Getting consistent extrusion width
Extrusion width is difficult to control. It depends on many factors and there's no simple setting to make it work.
This is a simple methodology to get you started.
Enter dimensions of spool into the settings panel
Make a stable environment
Set initial parameters
All heaters: 10% above the melting temperature (see datasheet of the material)
Extruder speed: 5rpm. This is a good starting value. Common values are between 3.5 and 6rpm.
Fan: 50%. Changes to the cooling have a big impact on the filament.
Apply the settings
-
Start extrusion.
Check for unmelted particles (too cold)
If filament is too viscous, lower the temperature
If there are bubbles, the filament needs drying
Set all heaters to the same temperature. Find out ideal temperature iteratively
When sweet spot is found, set up the temperature profile
Increasing shape: All heaters heat up to increasing temperatures. This causes more compression in the screw due to material being more solid at the beginning.
Bell shape: the first 3 heaters increase the temperature. The last heater has a lower temperature.
It's yet unclear to me how to determine a profile, or why it's necessary instead of using all heaters at the same temperature.
If you are dealing with filament deviation, the first temperatures to experiment with are the temperatures of heater 1 and 4. Also make sure that the material will be fully melted when entering the metering zone of the extruder.
check if your granulate is pure. Contaminants (a pellet of a different polymer for example) might partially block the flow.
Purge the machine with DevoClean might make the extrusion more consistent.
Feed material regularly. Avoid big changes in hopper loading.
Cooling:
Extruder RPM:
output rate of the material
If the extruder speed is inconsistent, so will the material output rate. It will be very difficult for the puller mechanism to maintain a consistent filament thickness when the extrusion rate is inconsistent.
Extruder speed inconsistency can be caused by different things:
Reducing the Extruder speed gives the puller mechanism more time to react, which results in more stable extrusion
Winder mechanism:
Source of info
Recycling plastic
keep waste plastic waste away from moisture, UV light, dust or grease
sort different polymers. Only work with 1 kind at a time
shred
dry (if the polymer is hygroscopic)
extrude
print
Source:
Powder based pigments / fillers
The Pigment Dunaliella Salina comes in a range of particle sizes. When mixing with PLA pellets, shake the batch well, then repetitively move the pot back and for on a table so the large particles sink down and the fine ones stick to the pellets on top. The fine powder colours the PLA darker orange and the filament has almost no speckles. Filament batches from further down the mixture are more yellow with more speckles. Make sure to only very lightly coat the PLA pellets with pigment powder. Too much powder and the extrusion won't be consistent.
Troubleshooting
The diameter never settles and is way too big and then too small.
The filament feels rather stiff when handling.
Sometimes blobs of pure pigment appear, throwing off the diameter sensor.
If this happens with fillers (Plastic pellets with added non-plastic parts, for example Algae powder pigments), reduce the amount of powder added to the PLA pellets. I used 25g of Dunaliella Salina for 750g PLA. But this was too concentrated. For every 100g coated PLA pellets, I added 120g clean PLA pellets. Then I mixed them for a few minutes thoroughly with a spoon. The extruded filament is dimensionally stable and feels much more supple when handling.