The first 3 words print at 10% speed. Micro-adjust Y position and Z depth to sit exactly on the paper lines.
Select character to draw
Each block shows the status of its drawn variants (V1, V2, V3).
Uppercase
Lowercase
Numbers & symbols
Greek & math symbols
Add / open custom character
// No G-code generated yet. Click "Generate & Print" or "G-code only" in the left panel.
Mounting & calibration guide
How to reliably convert your Anycubic FDM printer into a handwriting plotter without damaging the heatbed.
OctoPrint alert: “Invalid mesh / Failed to enable Bed Leveling”
If your print stops immediately with an emergency stop command (M112) stating Failed to enable Bed Leveling, your Kobra Neo's internal memory (EEPROM) does not currently hold a valid bed mesh.
To resolve it:
- Instant bypass (recommended): uncheck Enable bed mesh (M420 S1) in Machine → Pen & motion, then re-generate the G-code. This skips the leveling check so your plot proceeds immediately.
- Precision plotting option: run “Auto Bed Leveling” from the printer's LCD and save/store settings to EEPROM afterwards. This gives the printer a valid mesh so it can execute
M420 S1without crashing.
1. Hardware pen setup
- Spring-loaded mount: highly recommended. If the Z-axis drops slightly too much, a solid mount can bend the pen or dent your bed. A spring-loaded mount absorbs height differences.
- Zip-tie / tape hack: mount the pen to the side of your extruder housing with zip ties or electrical tape. Make sure the pen tip hangs 10–15 mm lower than the nozzle to avoid hotend collisions.
2. Securing the paper
- Clean your magnetic PEI bed so tape adheres well.
- Center your lined paper on the bed. A4 is 297 mm long, so let the extra overflow front and back. Make sure the paper doesn't catch on the printer frame during Y-axis moves!
- Tape all four edges tightly with masking tape or blue painter's tape. Keep it completely flat.
3. Zeroing the Z-axis (crucial step)
To print correctly, the printer must know exactly where the pen tip touches the paper surface.
- Ensure the pen is mounted securely.
- From the printer's control screen, home all axes (
G28). Keep your hand on the power switch in case the pen hits the bed! - Slowly lower the Z-axis manually to
Z = 0.0. - Adjust the pen mount physically (or use the babystepping / Z-offset menu) until the pen tip just touches the paper with a tiny bit of pressure.
- The
Z=0.2pen-down height in Machine → Pen & motion represents this contact point.
Aligning with notebook lines perfectly
No notebook paper is perfectly straight when taped down. Use Calibrate → Alignment checks → Line alignment G-code first. It draws single straight lines matching the top and bottom lines of your text block. Watch where the pen draws, adjust the paper, and repeat until it follows your paper lines.
How to save the pen tip
A rigid mount is risky: if Z drops slightly too low, the tip will bend, break or tear the paper. Follow these safety tips:
- Use a gravity slider or spring-loaded pen mount: the gold standard. Build or print a mount where the pen is loose inside a vertical slide, held down only by gravity (a couple of washers/nuts for weight) or a light spring. When Z lowers, the pen makes gentle contact and slides up instead of crushing the tip.
- Babystepping during USB printing (OctoPrint): Marlin disables LCD tuning menus during host USB prints on some firmware. Use Machine → Live Z-offset: those buttons inject Marlin
M290commands to raise/lower the pen by 0.05 mm on the fly. - Dry-run alignment first: always run Calibrate → Alignment checks → 10 s dry-run check before printing. The pen stays safely raised while moving so you can check the path lines up.
- Emergency: the red Lift pen & pause button in the top bar is always available — it pauses the job and lifts Z by 30 mm.
FDM bed leveling & screw calculator
Keep your heatbed flat. Enter probe deviation values and get the exact screw rotation needed at each corner.
Step 1 · Calibrate thread pitch
Turn one bed screw exactly 360° clockwise (+) and record the probe difference below.
Step 2 · Current variations
Enter your printer's bed-mesh probe values (mm) at the four bed screw positions.