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How To Change Filament During 3D Printing (6 Steps)

Changing filament back and forth can come with many issues, including filament getting stuck, difficulty replacing the filament, and bad print after replacement.

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If you’re using a 3D printer that can only print one filament at a time and wondering how you’ll go about changing the filament, then you’re in the right place. Unfortunately, changing filament back and forth can come with many issues, including filament getting stuck, difficulty replacing the filament, and bad print after replacement. 

Here’s how to change the filament during 3D printing in 6 steps:

  1. Turn your 3D printer on.
  2. Choose the right temperature setting.
  3. Remove the old filament.
  4. Clip off the end of the filament.
  5. Install the new filament.
  6. Purge the nozzle.

Changing the filament on a 3D printer like Ender 3 is pretty straightforward. However, you need to learn how to do it properly and efficiently, especially if the filament has snapped midway or you need to switch filaments. Read on to learn more.

1. Turn Your 3D Printer On

Unless you were mid-printing and only needed to switch filaments, you should first power on your printer before changing the filament. 

A 3D printer like the Ender 3 comes with a small LCD screen to see the menu and settings. You’ll know it’s on once the screen lights up and you can see the menu.

2. Choose the Right Temperature Setting

From the menu on the screen, go to control settings, choose Temperature, and then heat Nozzle. Use the LCD knob to set the nozzle temperature to 200°F (93.3°C) for PLA filament or the recommended Temperature for any other type of filament. Ideally, you want a temperature that can quickly melt the filament inside the extruder and make it easy to come out.

You can tell the extruder is heating up on the LCD screen because the temperature increases. 

Make sure the heatbed doesn’t heat up too. You only want the nozzle to heat up at this point because you are not printing. Thankfully, the controls for the two are separate unless you confuse them.

3. Remove the Old Filament

Once the nozzle reaches the correct temperature, it’s time to remove the current filament from the extruder.

Tightly squeeze the lever and let it push the filament out. The extruder is designed to hold onto the filament, so you have to pull the filament from the nozzle gently.

Be careful as you do this because both the filament and the nozzle are very hot at this point. If you’re experiencing any resistance when you pull the filament, don’t force it out. Pulling too hard can damage the nozzle and the entire mechanism, forcing you to buy another one.

4. Clip Off the End of the Filament

Push the filament through the extruder’s hot end until melted filament oozes out from the nozzle. This ensures easy extraction of the filament.

After that, push down the coupling to release the hot filament from the hot end and gently unplug it. If the temperature setting was right, this process shouldn’t give you any issues.

Clip off the blob-like end of your filament, so it has a sharp end. Then, unclamp the filament and slowly wind it back onto the spool holder.

Secure the loose ends of the filament through the hole of the spool holder or simply bind it with a filament clip or tape. This ensures that the filament remains in stellar condition if you want to use it in the future.

Once that’s done, put aside the current spool.

5. Install the New Filament

Now that you’ve removed the old filament, you have a clear way to load a new one.

Take your new filament out and cut a sharp angle at the end to make it easier to enter the extruder. Ideally, you should use scissors to cut a 45° angle.

Again, you have to preheat the hot end based on the temperature guidelines of your new filament.

Feed the filament into the extruder. Please note that the filament won’t be straight since it’s coming from a circular spool. You have to bend a small section (10cm or 3.94in will be enough) at the end of the strand to make it straight.

To feed the strand, squeeze the extruder arm lever and place the filament between the idler pulley and the toothed extruder gear.

With the lever still pressed, push the filament through using your hand gently. Alternatively, you can use the extruder knob and rotate it counterclockwise to draw in the filament.

Push the filament until you start to feel a firm resistance, which clearly indicates that it has reached the nozzle.

You’ll also notice you have done it because the filament will start oozing out of the nozzle.

Secure the coupling to ensure the filament doesn’t get out by accident.

multiple color filaments

6. Purge the Nozzle

Congratulations, your new filter is now inside the nozzle. But before you start using it, you have to purge the old filament out of the nozzle to ensure your print model is perfect.

Please note that as you change from a higher temperature material like PETG to a lower temperature material like PLA, you should set the nozzle temperature to a high value until you are done purging.

To purge manually, you only need to force down about 3-4cm (1.18-1.57in) of filament through the hot end, and it’ll flush out the old filament. Flexible materials can take longer than that, but 5cm (1.97in) is always sufficient. You can then cut off the excess filament from the nozzle with some tweezers and start afresh.

However, some 3D printers like the Ender 3 printers have features in their software to help make purging as easy and as quick as possible. Here are the steps for this procedure:

  1. Touch the LCD knob to open the settings menu and then scroll to Move Axis > 1mm (0.04in) > Extruder.
  2. Scroll again to move the extruder axis 15 to 20mm (0.59 to 0.79in). The extruder will feed the material through the nozzle and purge the old filament.
  3. You can do this more than once to ensure the old filament is completely out of the nozzle.
  4. The nozzle is 100% purged when you see the new color or filament flow out of the nozzle.
  5. Cooldown the hot end.
3d printer nozzle

How To Change Filament Mid-Print on a 3D Printer

There are a myriad of reasons why you may want to change the filament midway. For example, the filament you were using may be running out, or you want to switch to a different material or color. 

Whatever the reason is, changing the filament mid-print is a simple process that can go on seamlessly if you know what you are doing.

There are two ways you can do this:

Manual Switching

Changing the filament manually is easy, but there are some preparations you need to make first. For example, you may want to employ the G-code script to display the current filament layer on your printer’s screen. This will make it easy to monitor your printer and see if it’s ready for the switch.

  1. If you’re using the Ender 3 printer, for example, open the printer and click “Extensions.”
  2. Select “Post Processing” from the drop-down menu.
  3. Click “Modify G-Code” and wait for a box to pop up.
  4. Select “Add a script.”
  5. Choose the “Display Filename and Layer on LCD.”
  6. Ensure the “Initial Layer Number” is 0.

The second part is preparing when to switch the filament. Follow these steps:

  1. Choose your slicer settings or profile on your Ender 3.
  2. Slice the model and click “Preview.”
  3. Activate “Layer View” for the view type option.
  4. Move the layer slider on the right side to find where you want to switch filaments.
  5. Identify the layer number and write it down somewhere.

And now to the switching part.

When your printer displays the layer numbers and knows when to change the filament, it’s time to start printing. 

A crucial point as you do all this is checking the nozzle temperature. Remember that if you’re changing filaments of different materials, you must set the nozzle temperature to the higher of the two materials during purging. 

Keep an eye on the process to see when you’re getting to the layer you want to make the switch at. Once you get there, follow this process to switch the filament:

  1. Pause the printer. Since you were already printing, you only need to hit pause so the printer can stop for a while and allow you to switch filaments. Be careful not to press STOP, as this will stop all printing, and you’ll have to redo everything. Once you hit PAUSE, the z-axis of the 3D printer raises a little bit, allowing you to move it aside to the home position where you can swap out filaments.
  2. Reheat. Set the bed and nozzle temperature to the values you were using unless the material you’re switching to requires a higher print temperature. The heated nozzle will make it easy to remove the old filament, while the heated bed ensures the print doesn’t lose adhesion to the plate.
  3. Slowly remove the filament from the extruder and load the new filament, as we’ve already discussed above. You must also push a little filament out to purge the old one.
  4. Once the next layer is extruded without any traces of the old filament, you can continue printing.

G-Code Assisted Switching

The G-Code-assisted method is a more automated option if you don’t have a lot of time on your hands. You have to add the Filament Change G-Code command to your slicer to start.

  1. Go to Extensions on your printer.
  2. Select Post Processing from the drop-down menu.
  3. Click Modify G-CODE, and a box will show up.
  4. Select Add a Script.
  5. Chose the Filament Change option
  6. From there, go change the filament switch G-code sequence settings on the pop-up screen and pick the layer you want. If you want multiple filament switches in one model, you can add more than one filament change command with this process.

The filament change script you just activated is a helpful assistant that makes it easier to change the filament. If you did it right, the printer will pause at the exact layer height you specified, retract the filament and remove as much as it can and then move the print head to another location.

Here, the nozzle will stop heating, but the bed will retain its Temperature to ensure adhesion. When you’re ready to switch, click the printer’s control knob, and the nozzle will heat up again.

After that, follow the steps to insert a new filament, purge the extruder, and resume printing.

The advantage of the G-Code-assisted method is that you don’t have to remove the filament or pause the printing manually. This makes it less likely that you’ll mess up and ensures a smooth process. 

Using any other 3D printer besides the Creality Ender 3 may not be furnished with the M600 command function that enables the above script. However, you’ll still be able to switch the filaments manually, as shown above.

How To Mitigate Challenges of Changing Filament Mid-Print

The mere fact that you can switch filaments mid-print is awesome, but it comes with a handful of challenges. 

For example, you can accidentally touch the print head and move it slightly while removing or inserting the filament. There will be a slight offset between the first print and the second one when this happens, which isn’t pretty.

The print head can also be shifted upwards or downwards, making the result different. 

To avoid these printhead movements, make sure you don’t move or even touch the print head or any other printer component when inserting and removing filaments.

The Temperature of the hotbed or the nozzle going down while you are switching is also another issue that could cause problems. A cold bed will cause your print to warp or completely detach from the glass bed.

To avoid this problem, make the switch as fast as you can without bumping the print head. It’s also important to increase the nozzle temperature by 5°C when changing from one material to another.

Final Thoughts

There you have it. You have successfully changed filaments in your 3D printing. 

If you did it mid-print, you can continue with the project at hand and see it to the end. If you’re getting ready to start a new project, good luck with the new creation, and we hope it’s a beautiful one. 

Lastly, don’t forget to check that the settings for the new filament are correct before hitting print again.

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.