If you’re a 3D printing enthusiast using Bambu Studio with a Bambu Lab printer, you’ve probably come across situations where inserting custom G-code can make your prints more efficient, safer, or simply better tailored to your workflow. Whether you want to add a nozzle clean routine, fine-tune temperature changes, or send custom commands for your printer’s bed leveling sequence, understanding how to properly implement custom G-code in Bambu Studio is essential. In this guide, we’ll walk you through a comprehensive, structured approach to integrating custom G-code into your projects using Bambu Studio’s interface.
TL;DR
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Adding custom G-code in Bambu Studio allows users to modify their printing processes by inserting specific instructions at different points in the print cycle. Bambu Studio offers several areas where G-code customization is available, such as the start and end of prints or between tool changes. This capability enables advanced control over printer behavior, but requires careful syntax and awareness of printer-specific commands. This article provides a step-by-step breakdown of how to implement and test custom G-code securely and efficiently.
Why Use Custom G-Code?
G-code is the language that 3D printers understand to perform actions such as moving the print head, extruding filament, adjusting temperatures, or triggering sensors. While default profiles in Bambu Studio are optimized for general use, custom G-code lets you:
- Improve print reliability by cleaning the nozzle before printing
- Customize thermal settings to suit specific materials
- Incorporate supplementary steps like bed leveling or homing axes
- Control accessories such as lights, fans, or other modifications
Understanding Where G-Code Can Be Inserted in Bambu Studio
Bambu Studio provides several key insertion points for custom G-code. Knowing when and where to integrate your commands greatly influences their effectiveness.
1. Start G-Code
This section runs before the actual printing begins—ideal for pre-heats, nozzle wipes, or setting up special configurations.
2. End G-Code
This is executed after the print completes—useful for cooling down, moving the bed for easy removal, or turning off accessories.
3. Tool Change G-Code
For multi-material or multi-color prints, this code runs each time the printer switches extruders or tools.
4. Layer Change G-Code (Advanced)
This integrates commands per layer, allowing detailed control over dynamic parameters like speed, fan, or lighting.
Image not found in postmetaHow to Add Custom G-Code in Bambu Studio
Follow these steps to safely and effectively integrate custom G-code into your printing process:
Step 1: Launch Bambu Studio
Open the Bambu Studio application on your desktop. Ensure it is up to date to access the latest features and bug fixes.
Step 2: Open a Print Profile
Click on the print profile menu near the top-right corner. You can either edit an existing profile or duplicate it to create a custom version.
Step 3: Navigate to Custom G-Code Fields
In the left-hand menu, go to Filament Settings or Printer Settings, depending on your target. Scroll down or open tabs related to Start G-code or End G-code.
Step 4: Insert Your Custom Code
Click inside the text box and type or paste your G-code commands. Some examples include:
G28— Home all axesG1 Z0.2 F3000— Move nozzle to 0.2mm height at specific speedM104 S200— Set nozzle temperatureM140 S60— Set bed temperature
Step 5: Save the Profile
Click “Save” or “Apply” to ensure your custom settings are retained. Consider giving the modified profile a unique name to avoid confusion with defaults.
Important Considerations
Incorrect G-code can result in failed prints or even damaged equipment. It’s important to test your changes using smaller prints first. Keep these tips in mind:
- Validate G-code: Use online checkers or dry-run simulations (some slicers or firmware support this)
- Avoid redundant commands: Some printers already include bed heating or auto-homing by default
- Monitor printer during initial use: Watch for unexpected behaviors to improve safety
Advanced Customization Techniques
Conditional G-Code
Some firmware variations support conditional logic within G-code, such as running commands only if certain temperatures or sensor readings are met. However, Bambu Lab printers have a proprietary flavor of G-code, so always check firmware documentation for compatibility.
Pausing and Resuming Prints
You can insert pause commands like:
M25 ; Pause print
M24 ; Resume print
This is useful for adding hardware inserts, magnets, or changing filaments mid-print.
Custom Commands for Bambu Lab Printers
Bambu Lab printers support additional special commands such as:
M990— Prevent job start until manually resumedM997— Load specific system settings profiles
Always refer to Bambu Lab’s documentation or community forums for updated command syntax and availability.
Testing Your Custom G-Code
Before committing to a large or high-stakes print, use these testing methods:
1. Use a Test Cube
Print a small 20x20x20mm calibration cube to validate start and end G-code changes.
2. Monitor Console (If Available)
Some printer interfaces allow real-time console output where you can see G-code execution line-by-line. This helps in debugging issues effectively.
3. Use Simulation Tools
Preview your G-code using online simulators or within Bambu Studio’s layer preview. This lets you visually spot anomalies such as unnecessary head movements or paused operations.
Common Use Cases for Custom G-Code
Not sure what to use custom G-code for? Here are some common use cases for inspiration:
- Nozzle priming: Create a priming line to ensure consistent extrusion at the beginning.
- Nozzle wiping: Add a nozzle cleaning movement over a brush or silicone pad.
- Custom bed cooling: Insert delays or commands to keep the bed hot until print removal.
- Print queue management: Adjust how the printer signals job completion for automated queues.
Troubleshooting Common Issues
If your print is not behaving as expected after adding custom G-code, consider the following:
- Print doesn’t start: Invalid syntax or incompatible commands like missing parameters in M104 or M140.
- Nozzle crashes into bed: Incorrect Z-values added in Start G-code without referencing the actual mesh leveling system.
- Printer ignores custom code: Bambu Lab firmware may override or ignore specific commands for safety. Consult printer logs or support.
Conclusion
Adding custom G-code in Bambu Studio provides a powerful way to control and optimize your 3D printing workflow. While this customization offers flexibility and enhanced performance, it demands precision and understanding of both the printer and the slicing environment. By following best practices and carefully testing changes, you can unlock advanced capabilities and tailor each print to your specific needs.
If you’re ready to elevate your 3D printing projects, explore the custom G-code options in Bambu Studio and take full control of your machine’s behavior. But always remember—with great power comes great responsibility. Double-check commands, and test wisely.
