Delta-Bed-Calibration-Tool

This tool is archived, refer to github.com/coelacant1/OpenDACT

A tool for calibrating the bed of delta-style 3D printers, achieving an accuracy of ±0.015 mm (or better) in under five minutes.

Overview

This program corrects key parameters in a delta printer’s firmware (via EEPROM) to achieve a level, accurate print surface without physically adjusting endstops or shimming the bed. Tested from an initial ±2 mm error down to ±0.015 mm.

Key parameters calibrated:

• Alpha Rotation
• Delta Radius
• XYZ Offset
• Horizontal Radius
• Diagonal Rod Length

Benefits

• Tolerates Non-Square Towers: It will still calibrate even if tower angles aren’t perfect.
• No Endstop Tweaks: You won’t need to touch or adjust endstops.
• Warps & Slants: Corrects for warped or slanted beds, including warped borosilicate plates.
• Minimal Physical Adjustments: All changes occur in software (EEPROM), saving time and hassle.

How It Works

1. XYZ Offset

   • Identifies the most extreme tower offset and applies a compensation.
   • Ensures all towers are brought closer to zero, enabling accurate diagonal rod calibration.

2. Horizontal Radius

   • Averages bed height at each tower (and “virtual” towers) to balance measurements around zero.
   • Adjusts individual tower heights and the global horizontal radius parameter to flatten the bed.

3. Alpha Rotation

   • Fine-tunes alignment of opposing (virtual) towers by rotating their reference angles (α).
   • Balances the measured height on opposite towers to ensure uniformity.

4. Diagonal Rod

   • Changing rod length shifts the height at each tower differently.
   • This is counter-corrected by subsequent adjustments (e.g., horizontal radius) until all towers converge near zero.

By iterating these steps, you can theoretically achieve extremely tight tolerances—even if the bed is mechanically warped.

Usage

1. Input Current Settings: Enter your existing EEPROM parameters into the program.
2. Run Calibration: Click “Calibrate” to generate new, corrected values.
3. Update EEPROM: Copy the new values back into your firmware EEPROM.
4. (Optional) Repeat: For ultra-precise prints, run additional iterations.

Future Plans

• Improve the HTML interface or create a desktop app.
• Add carriage offset calibration.
• Further refine accuracy and automation.

Disclaimer

Use this program at your own risk. The author assumes no liability for any issues arising from its use.