Manual Filament Change G-Code Patcher

The Easy Way to Multi-Color 3D Print Without an AMS

🛠️ No AMS? No Problem!

Create multi-color prints by injecting manual pauses directly into the G-Code. Supports swapping between layers and mid-layer color changes.

How to use: Upload a G-code file that was created with multiple filaments, then download the patched file.

Need help preparing the file? | Already applied the patch?

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Drag & drop your .gcode file here, or click to browse

Download Patched G-code

Note: While it is very unlikely, we are not responsible for any damage that may occur from using gcode generated by this tool.

📦 What Next? Transferring to Printer

Once you've patched your G-code, you're ready to get it to your printer and handle the manual filament changes. Follow these steps:

Choose one of the following methods to transfer your patched G-code file to your printer:

Option 1: SD Card

Insert your SD card into your computer.
Navigate to the models folder.
Copy the -patched.gcode file into that folder.
Safely eject the SD card and insert it into your printer.
Select the file on the printer and start printing.

Option 2: Bambu Studio v1

Open Bambu Studio v1 (note: v2 cloud upload currently doesn't support the patch).
Drag your -patched.gcode into the prepare window.
Review the preview to confirm it looks correct.
Click Send to Printer to begin the print.

Once your print starts, the printer will pause at specific points for you to swap filaments. Here's how to handle it:

🧰 Performing the Manual Filament Change on Your Printer

The printer will pause automatically at the designated layer and display a message, likely stating "Printing was paused by the user". DO NOT press 'Resume Printing' on this screen!
Instead of resuming, locate and press the 'X' button (or 'Cancel' / 'Back' depending on your printer's UI) to exit this prompt.
Navigate to the 'Filament' section on your printer's screen.
Perform the manual filament change following your printer's usual procedure. This typically involves unloading the old filament, loading the new filament, and purging any old material until the new color is clean.
Once the filament change is complete, return to the main print screen on your printer.
Finally, press 'Resume' to continue your print. The printer will seamlessly pick up where it left off with the new filament!

Resuming print after manual color change

❓ How to Prepare Your G-code for Multi-Filament Prints

If you're looking to print with multiple colors or materials on a single-extruder printer (without an AMS), you'll need to prepare your G-code correctly in your slicer. Here's a general guide, focusing on Bambu Studio:

Step 1: Open Your Model & Add Filaments

Start by opening your 3D model (e.g., an STL or 3MF file) in Bambu Studio.
Add at least one additional filament to your project. This will typically give you two or more filament slots to work with. For example, if you're printing in two colors, you'll need two distinct filament profiles.

Step 2: Assign Colors to Objects/Parts

If your model consists of multiple separate objects, select each object and assign it a different color (filament) from the available slots.
If your model is a single object with different parts you want to color, use the "Paint" tool or "Split to Parts" function in Bambu Studio to separate the sections and assign colors accordingly.

Step 3: Configure Print Settings

Select your desired print settings such (layer height, infill, supports, etc.) as you normally would for your printer and chosen filaments.
Crucial: Disable "Prime Tower". This setting is typically found under the "Others" tab in your print settings. A prime tower purges filament to a separate structure, which isn't necessary and can cause issues with manual pauses.

Step 4: Slice and Export G-code

Once all settings are configured and colors are assigned, proceed to "Slice Plate". This will generate the G-code for your print.
After slicing, export the G-code file. In Bambu Studio, this is usually done via File -> Export -> Export G-Code.... Save the file to your computer.
This exported G-code file is what you will upload to our tool for patching. Our tool will automatically insert pauses before each filament change.

How our tool works: Our tool reads your uploaded G-code file and automatically identifies where your slicer has instructed a filament change. It then replaces those instructions with a special command (M400 U1) that tells your 3D printer to pause the print and wait for you to manually change the filament. This way, you get perfectly timed pauses for multi-color or multi-material prints, even without a fancy AMS system!

Frequently Asked Questions

Does this work with Bambu Lab A1, P1P, or P1S?

Yes. This patcher is specifically designed to inject the M400 U1 pause command, which is the native pause command used by Bambu Lab printers to trigger a manual filament change.

Can I print multiple colors in the same layer?

That's exactly why this tool was made! While this tool also injects pauses between layers, it was originally created to add mid-layer pauses since Bambu Studio doesn't let you.

Can I do multi-color printing without an AMS?

Absolutely. This tool allows "AMS-less" multi-color printing. You simply swap the spool manually when the printer pauses and beeps.

Is this safe for my printer?

The tool only injects a standard pause command into the G-code. It does not alter movement speeds or heater temperatures. However, always monitor your first few prints when using modified G-code.