One of the first things you’ll want to do with a new 3D printer is learn how to change the filament. This step-by-step guide shows you how to change filament spools without damaging or clogging your extruder nozzle.
These instructions will work for most FDM printers, from Creality Ender 3 to Voxelab Aquila S2 and Anycubic Kobra. That said, it’s always good to read your 3D printer manual, especially if you’re new to 3D printing or using a model you’ve never used before.
How to change the filament of your 3D printer
There are several common reasons for changing filaments.
- You have reached the end of the filament on the spool.
- You want to use a different type of filament.
- You want to change the filament in the middle of the print to achieve an effect.
- The current filament is damaged.
Whatever the reason you want to change filaments, the steps are essentially the same.
1. Turn on your printer
Make sure your printer is turned on. The nozzle has to be hot to change the filament. If not, you may not be able to purge the old filament and you may not be able to load the new filament all the way to the nozzle tip.
2. Set the desired hot end temperature
You need to know the recommended printing temperature range for the filament already loaded in the printer (if applicable) Y the recommended temperature for the filament you want to charge. Preheat the hot end to the higher of those two temperatures. This will prevent extrusion problems later on.
This is why. While you are loading new filament, there can be two different types of filament in the nozzle at the same time: some of the old filament and the new filament you are loading. The nozzle temperature must be high enough to melt both types. Otherwise, you could end up with a clogged nozzle.
For example, imagine you are printing with PETG and want to switch to PLA filament. Because PETG melts at a higher temperature, if you were to set the temperature for PLA, the PETG may not fully melt and may not fully purge during filament change. This is the most common mistake people make when changing filaments.
3. Remove the old filament
Some printers will have a menu option on the printer’s LCD screen to unload existing filament. On other printers, this might be a completely manual process. See your printer documentation. If it’s automatic, use that option and follow the instructions on the screen.
When manually removing the old filament, if the nozzle is too close to the base of the printer for you to get your fingers under, locate the printer nozzle. move axis and raise the z-axis about 50 mm.
Next, disable the stepper motors. That’s usually in the control settings. Alternatively, you can send a g-code command, m18.
Some Bowden tube printers, like the Ender 3 Pro, have a manual extrusion lever to release the filament from the stepper motor. Very gently pull the filament until it is completely separated from the printer. Be careful not to pull too hard. You could break the filament.
If there is a lot of resistance, double check the temperature of the hot end; make sure the stepper motors are off, and if you have a Bowden extruder, make sure to use the manual lever on the extruder if necessary.
After removing the filament, consider blowing some compressed air on the extruder gear to remove any plastic flakes that have built up.
4. Prepare and load the new filament
Inspect the new filament. Make sure there are no folds, weak spots, or punctured areas. You want the filament to look and feel flawless. Fingertips are very sensitive, so run your fingers along a few feet of the filament to see if you can feel any flaws. If it does, cut off that part of the filament and discard it.
While inspecting the filament, make sure it doesn’t unwind from the spool. You don’t want the filament to cross or tangle.
To prepare the new filament, use wire snips or a razor blade to cut the filament at a 45-degree angle. It should feel sharp at the tip. This ensures that it slides easily into the printer. Place the filament spool on the spool holder before continuing.
If your printer has a menu option to load filament, find it and follow the on-screen instructions. If it doesn’t and it’s a Bowden printer, make sure to use the manual release while feeding the new filament through the Bowden tube.
If your printer has a filament run out detector, make sure you feed the filament through it. Push the filament until the purge is complete and see the melted filament come out of the nozzle. Confirm that the color matches the color of the new filament you are loading.
After changing filament, make sure your hot end temperature is set to the recommended temperature for your newly loaded filament. If you loaded it manually, once it has reached the target temperature, push in some more filament. If the hot end temperature is set higher than the filament you are loading, you will want to load the new filament quickly and adjust the hot end temperature right away so the filament doesn’t get too hot.
Remove any filament that has been extruded. Make sure the nozzle is clean and ready to go.
What to do if you run out of filament in the middle of a print
If you have a filament run out detector, your printer will alert you that it has run out of filament. Follow the steps above to remove the old filament and load the new filament.
In general, you want to load a new spool of filament before the existing filament runs out completely. If the filament is so short that it moves past the extruder gear, you may need to disassemble the hot end to remove it. In our opinion, a filament runout sensor is a must. If your printer doesn’t have one, consider adding one.
If you replace the filament with the same type, you can leave the hot end temperature as it is. Otherwise, follow the instructions above.
If your printer does not have a settings menu option to change filament, you can send a m600 ga code the printer. This will pause the print and move the print head out of the way so it doesn’t touch the print. You can now load the new filament as described above. Sends the m602 g-code to resume printing.
To fix any other issues, check out our troubleshooting tips for failed 3D filament prints.
