3D Printing Build Plate Control for Micrometre Z-Axis Precision

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Solution Overview

Problem

Current 3D printing technologies, particularly in SLA and LED-LCD systems, face challenges in achieving high precision and repeatability along the Z-axis, especially for microfluidic applications, where micrometre-level accuracy and smooth surface quality are critical for reducing friction and enhancing fluid control.

Innovation Solution

A computer-implemented method for controlling the movement of a build plate along the Z-axis using a distance sensor and a PID controller to adjust motor speed based on real-time position feedback, combined with stepper motors and piezo-electric actuators for precise movement, ensuring smooth transitions and avoiding oscillations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional SLA printers use laser scanning to print layer by layer, then the printing process can be completed, but the printing speed is relatively slow

Engineering Contradiction:
Improveprinting speedVSAvoidtime required to scan entire surface
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical laser scanning system with a digital light projection system (DLP or MSLA). Instead of using a moving laser to scan each point sequentially, the entire layer pattern is projected simultaneously onto the resin surface using digital micromirror devices (DMD) or LCD screens, achieving parallel processing and dramatically improving printing speed

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements periodic layer deposition cycles where each layer is cured in a single projection step followed by systematic build plate movement. This periodic action optimizes the printing process by maintaining consistent layer thickness and curing quality while maximizing throughput through automated, rhythmic operation cycles

Inventive Principle:
Principle #19Periodic action

2Manufacturing precision

If 3D printing systems use standard motor control for build plate movement, then the system is simple to operate, but the precision along the Z-axis is insufficient for micrometre-level requirements

Engineering Contradiction:
ImproveZ-axis position precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements a closed-loop feedback control system for build plate positioning. Distance sensors continuously measure the actual position of the build plate relative to the resin surface, and this feedback is used by a PID controller to adjust motor commands in real-time, ensuring micrometre-level precision while maintaining system stability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic speed adjustment of the build plate motor based on real-time position feedback. The system varies motor speed during different phases of layer deposition and build plate movement, optimizing both precision during critical positioning moments and overall printing efficiency during transit phases

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If the build plate moves at constant speed, then the control system is simple, but abrupt movements cause oscillations and reduce surface quality

Engineering Contradiction:
Improvesurface qualityVSAvoidspeed control mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic speed profiling for the build plate motor, where speed is continuously adjusted based on position feedback and operational phase. During critical positioning and layer deposition moments, speed is reduced to minimize vibrations and ensure precision, while during transit between layers, speed is increased to maintain productivity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies acceleration and deceleration ramping before and after critical positioning events. The control system pre-reduces speed before layer deposition begins and gradually decelerates before stopping at target positions, preventing abrupt movements that would cause oscillations and surface defects

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances layer thickness precision to micrometre levels, improving the accuracy and stability of 3D printing systems, particularly in LED-LCD systems, by reducing abrupt movements and ensuring smooth surface roughness.

Implementation Method 1

data is received representing a distance to the build plate acquired by a distance sensor of the 3D printing system

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Implementation Method 2

combined with stepper motors and piezo-electric actuators for precise movement

Methodology Applied
Scientific EffectPiezo-electric effect: Piezoelectric Effect

Implementation Method 3

stereolithography (SLA) is an additive manufacturing process in which an ultraviolet laser focusses on a vat of photopolymer resin, which solidifies

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP4610027A1Method for controlling a 3D printing system and 3D printing system
Publication Date: 2025.09.03 UNIV LIEGE
  • EP4610027A1 patent drawingFigure 1
  • EP4610027A1 patent drawingFigure 2
  • EP4610027A1 patent drawingFigure 3

AI summary

Computer-implemented method for controlling a movement of a build plate of a 3D printing system along a substantially vertical Z-axis, and a 3D printing system comprising a build plate configured to move along a substantially vertical Z-axis and a motor configured to drive said build plate.