3D Printer Ejector Head Shift Compensation for Build Registration
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Solution Overview
Problem
Three-dimensional object printers face challenges in maintaining precise registration in the cross-process and process directions over the entire height of build levels, leading to cumulative errors and misalignment issues, particularly in low-end printers with lower quality components and in high-end printers during setup and operation.
Innovation Solution
A method for operating a 3D object printer that involves measuring distance components of material drops from fiducial references at multiple build levels, calculating differentials, and determining incremental shifts for the ejector head to compensate for misregistration, allowing for accurate alignment and reduced setup time and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If painstaking and time-consuming setup procedures are followed to ensure proper alignment of printer components, then manufacturing precision is improved, but loss of time and device complexity increase
Solution Approach 1:
The system performs preliminary measurement actions by placing gauge blocks at different build levels and measuring the positions of material drops relative to fiducial markers. This preliminary data collection enables the calculation of drift characteristics before actual printing, allowing the system to pre-determine correction values that will be applied during operation, thereby reducing the need for time-consuming manual setup procedures
Solution Approach 2:
The system implements a feedback mechanism where the measured positions of material drops are compared against expected positions, drift differentials are calculated, and correction values are determined and applied to subsequent printing operations. This closed-loop feedback system automatically adjusts for misregistration errors, eliminating the need for manual realignment procedures and significantly reducing setup time while maintaining high precision
2Manufacturing precision
If painstaking and time-consuming setup procedures are followed to ensure proper alignment of printer components, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The system performs self-diagnosis and self-correction by automatically measuring drift through gauge blocks and fiducial markers, calculating correction values, and applying them to compensate for misregistration. This self-service capability eliminates the need for complex manual setup procedures and expert intervention, simplifying the overall system while maintaining high precision through automated error detection and correction
Solution Approach 2:
The system replaces complex mechanical alignment procedures with an automated measurement and calculation system. Instead of manually adjusting components to achieve proper alignment, the system uses sensors to measure actual positions, calculates drift differentials, and applies computational corrections to the printing process, substituting mechanical complexity with automated sensing and data processing
3Ease of manufacture
If components are not properly aligned during manufacturing and setup, then device complexity and setup time are reduced, but manufacturing precision deteriorates due to cumulative error
Solution Approach 1:
The system converts the harmful effect of component misalignment and cumulative drift into beneficial information by measuring the actual drift characteristics using gauge blocks and fiducial markers. The measured drift differentials are used to calculate correction values that compensate for the misalignment, effectively transforming the manufacturing tolerance issue into a correctable parameter that improves overall precision without requiring stricter manufacturing tolerances
4Manufacturing precision
If error compensation mechanisms are integrated into existing printers, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The error compensation mechanism is designed as a universal system that can be integrated into both new and existing printers. The gauge blocks, fiducial markers, and measurement procedures can be applied to any 3D printing system, and the correction methodology works across different printer architectures. This universal approach allows existing printers to gain precision improvement capabilities without requiring complete system redesign, thereby limiting the increase in device complexity
Data Source
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AI summary
A three-dimensional object printer comprises a platen (120), a gantry (130) positioned above the platen, an ejector head (140) positioned on the gantry, a sensor (146), and a controller. The controller is configured to operate the ejector (142) to eject at least one drop of material toward the platen at an upper build level (112) and determine process and cross-process differentials between a fiducial and the at least one drop of material deposited on the upper build surface. The controller is also configured to determine an ejector head shift in a process direction and a cross-process direction associated with each of the plurality of build levels based at least in part on the determined process and cross-process differentials and a number of build levels between the base build level and the upper build level.