Turn your Bambu Lab 3D printer into a pen plotter completely free, no subscriptions, no accounts, no uploads. Everything runs locally in your browser.

The included test file uses the boat drawing shown in the preview image a detailed line-art illustration that works great as a first plot to verify your setup. When using the tool please consider using the included print profile test model. This helps me out and helps supporting this project with since i could not upload the Bambuplot file directly on Makerworld.

⚠ Read this first  this is a tinkerer's project

This tool is made for people who enjoy experimenting, troubleshooting, and figuring things out. It is not a plug-and-play product. It will probably not work perfectly on the first try, and that is completely normal. Getting a pen plotter working on a 3D printer requires patience: dialing in the Z height, finding the right pen, getting the paper flat, tuning the feed rates, and sometimes just accepting that the first few attempts are learning runs.

I do not cover any damages to your printer, pen holder, bed, or any other part of your setup. Using this tool is entirely at your own risk. Sending custom G-code to a 3D printer always carries a risk of unexpected movement, crashes, or damage if settings are wrong. Always supervise the printer, always do a dry run first with the Z height raised so the pen cannot touch anything, and never leave it running unattended especially not on a first test.

If you are not comfortable with that, this project is probably not for you yet but if you enjoy the process of making something work from scratch, welcome aboard.

What is BambuPlot?

BambuPlot is a single HTML file you download and open in your browser. It lets you design drawings and convert them into G-code that your Bambu Lab printer can execute with a pen instead of a nozzle. No internet connection is required after download — it runs 100% on your computer.

Supported printers all current Bambu Lab models:

A custom bed size option is also available for any other setup.

What you can draw:

• Text three modes: single-stroke plotter font (looks like real handwriting), your own custom handwriting (draw each letter yourself, up to 5 versions per letter for variety so repeating letters never look identical), or filled outline using any of 13 fonts
• Shapes square, circle, triangle, star, line, with optional hatch fill
• Freehand draw directly on the bed preview with your mouse or stylus
• Images drop any photo or logo, adjust the threshold and line density, and convert it to plotted lines
• 3MF import drop a Bambu Lab .3mf file and BambuPlot extracts the 3D geometry and renders the top-down footprint as plottable paths, in either vector outline or hatch-fill mode

What you need

• A Bambu Lab printer or anything else that takes gcode 
• A pen holder that mounts on your toolhead (search MakerWorld or Printables for your specific model many free designs exist)
• A ballpoint pen that fits your holder
• Paper to draw on, attached to the bed (see bed preparation below)
• A way to get pure gcode on your printer (USB stick/microsd)

Bed preparation protecting your print surface

This is important. The pen tip will press directly down onto whatever is on your bed. Printing on bare paper placed directly on a softer printing bed can cause damage, especially with a stiff pen or too much Z pressure.

My recommendation: place an old flat PEI sheet (Like mine from my old ender 3 v2), a thin sheet of plastic such as a folder cover or binder sheet, or any similarly flat, smooth piece of thin plastic underneath the paper. This gives the paper a firm, even surface to rest on and takes any wear from the pen instead of your actual print bed. An old or scratched PEI sheet you no longer use for printing is perfect for this.

Attaching the paper: I use small magnets placed along the edges to hold the paper flat and in position they are quick to place, leave no residue, and hold very reliably. Other options that work fine include masking tape or binder clips on the edges. Whatever you use, make sure the paper is completely flat with no bubbles or lifted corners, as any unevenness will cause the pen pressure to vary across the drawing.

How to download and open BambuPlot

Go to :[https://joep648.github.io/BambuPlot/bambuplot-v1.0.1.html](https://joep648.github.io/BambuPlot/bambuplot-v1.0.1.html) to use it online.

or

1. Download the bambuplot.html file from:[https://github.com/Joep648/BambuPlot/tree/main](https://github.com/Joep648/BambuPlot/tree/main)
2. Open it with any modern browser (Firefox recommended for best performance Chrome and Edge work fine too, but Firefox handles large designs more smoothly)
3. That is it no installation, no internet needed after that

Step-by-step: from design to plot

Step 1 Select your printer

In the top bar, choose your printer model from the dropdown. The bed preview updates to the correct size. This ensures your G-code coordinates match your actual print surface.

Step 2 Add content to the bed

Use the tabs on the left panel:

• Text tab type your text, choose a style (single-stroke is best for plotting), adjust letter spacing and line spacing, then click Add text to bed
• Shapes tab pick a shape and click Add shape to bed. Enable Filled to get hatch-fill lines inside the shape
• Image tab click the drop zone or drag an image in. Adjust the threshold slider until the preview looks like clean black lines on white, then click Convert & add to bed. High-contrast line art like the included boat image gives the best results
• 3MF tab drag a .3mf file onto the drop zone. Choose Vector outline for a clean single-stroke contour of the model, or Top-down silhouette for a hatch-filled footprint

• Freehand in the Shapes tab, click Draw directly on bed and sketch with your mouse

  

Step 3 Position and size your content

Once an item appears on the bed preview:

• Drag the body of the item to move it
• Drag a corner handle to scale it the line density automatically recalculates to stay consistent at the new size
• Drag the white circle above the item to rotate it
• Use the Layers tab to show/hide, duplicate, or delete items

Step 4  Configure pen settings

Go to the Pen tab and set:

These values are starting points every pen holder and pen combination is different. Adjust Z draw until the pen just barely touches the paper with light pressure.

Step 5  Generate and download the G-code

Click Generate G-code in the right panel. The code appears in the preview (large designs only show the first few thousand lines the full file is always in the download). Click the ⭳ button to download the .gcode file.

Step 6  Send to the printer and plot

My personal workflow:

1. Home the printer manually via the touchscreen or Bambu Studio
2. After homing, clip the pen holder onto the toolhead with the pen inserted
3. Place your protective plastic sheet on the bed, lay the paper on top, and secure it with magnets, tape, or clips
4. Start the file with in bambuplot Home all axes (G28) at start option turned off
5. Always do a dry run first: temporarily raise the Z draw value by 5–10 mm so the pen stays off the paper, and watch the full motion to confirm the design lands in the right place before doing a real plot

Alternative workflow using the dwell option: The Dwell after homing checkbox in the Pen tab inserts a G4 S30 command (a timed pause) after the G28 home command, giving you time to clip the pen on before plotting starts. This feature is experimental and untested I have not personally used it this way. Bambu printers do not support the standard M0 unconditional pause command, so a timed dwell is used as a workaround. If you try it, set the duration long enough to comfortably attach the pen holder (60 seconds or more).

Tips for best results

• Use the right paper  smooth, slightly heavier paper works best. Thin paper can wrinkle from pen pressure
• Ballpoint pens are the most reliable. Felt-tips can bleed on paper and dry out if the pen sits in one spot for too long
• Start with a short test  plot a small shape first to calibrate your Z height before committing to a full design
• Line density matters  lower density (higher number on the slider) = fewer lines = faster plot and less ink bleed. Higher density looks more solid but takes much longer to plot
• The settle time setting (default 120 ms) adds a brief pause after every pen up/down move. This is the main fix for random stray lines on the paper if you see faint marks between strokes, increase it to 150–250 ms
• Mirror X or Y if your plot comes out flipped  

Saving your settings

In the Pen tab, click Save profile + handwriting to file to save all your pen settings, printer choice, and your custom drawn handwriting alphabet to a single .json file. Load it again any time even on a different device with the load button.

Questions, problems, and ideas for future versions

If something does not work, you have a question about the setup, or you just want to share your results feel free to leave a comment on this MakerWorld page or send me a message directly through MakerWorld. I am happy to help where I can, though keep in mind this is a hobby project and responses may not always be instant.

If you have ideas for features you would like to see in a future version, I would love to hear them. BambuPlot is actively being worked on and new features get added regularly. Things on the radar include better SVG import, more letter styles, and improved multi-layer support. If there is something specific you need for your use case, suggest it in the comments  the best ideas from the community are what shape where this goes next.

BambuPlot is a fan-made tool and is not affiliated with Bambu Lab. Pen holder designs are not included search MakerWorld or Printables for a mount that fits your specific printer model. Always run a dry pass before plotting on good paper. Use at your own risk.