CMM Base Plate Design for Accuracy and Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional portable coordinate measuring machines face challenges in achieving high accuracy due to thermal and load-induced warping, resulting in reduced performance compared to non-portable machines, and are often bulky and heavy when attempting to improve accuracy.
Innovation Solution
A novel portable coordinate measuring machine design featuring a simplified, lightweight base plate with a cavity housing the main printed circuit board, paired with shoulderless shafts and housings fabricated using precise grinding and honing processes, and structural elements made from materials with matching thermal expansion coefficients to minimize deformation and enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional portable coordinate measuring machines use traditional multi-piece mounting arrangements for the main printed circuit board, then the device provides adequate functionality, but the device becomes bulky and heavier
Solution Approach 1:
The patent merges multiple separate components (mounting plates, housings, and circuit board supports) into a single integrated base plate structure. This consolidation eliminates the need for multiple separate mounting pieces while providing all necessary mounting functions, thereby reducing overall device weight and bulk without compromising measurement accuracy.
Solution Approach 2:
The base plate is designed to perform multiple functions simultaneously: it serves as the mounting surface for the main printed circuit board, provides structural support for the articulated arm, and acts as the reference frame for measurements. This multi-functionality eliminates the need for separate components, reducing weight while maintaining measurement precision.
2Device complexity
If conventional portable coordinate measuring machines use traditional multi-piece mounting arrangements, then assembly is straightforward, but the device becomes more complex and bulkier
Solution Approach 1:
The patent combines multiple mounting plates and support structures into a single integrated base plate, reducing the number of parts from multiple separate components to one unified structure. This integration simplifies the overall device complexity while minimizing the volume occupied by mounting structures.
3Measurement precision
If the distance between the base plate and the adjacent joint is increased, then assembly and maintenance become easier, but flexing and deformation increase, reducing measurement accuracy
Solution Approach 1:
The base plate incorporates locally optimized features such as recessed areas and precise mounting locations that allow technicians to access and work on components in confined spaces. The design provides just enough clearance for essential assembly and maintenance tasks while keeping the overall distance minimal to prevent flexing and maintain measurement accuracy.
4Measurement precision
If structural elements are made from materials with matching thermal expansion coefficients, then measurement accuracy is improved by minimizing deformation, but material selection becomes more restricted and potentially more expensive
Solution Approach 1:
The patent specifies precise material parameters (thermal expansion coefficients) for structural elements to match between the base plate and adjacent joints. This parameter matching minimizes differential thermal expansion and contraction, reducing deformation and improving measurement accuracy while maintaining manufacturing feasibility through careful material specification.
Data Source
AI summary
A coordinate measurement machine (CMM) includes a manually-positionable articulated arm having first and second ends. The articulated arm includes a plurality of arm segments and a plurality of rotary joints, and an electrical circuit including a main printed circuit board and a plurality of encoder printed circuit boards. The electrical circuit has at least some portions disposed within the plurality of arm segments. The first end includes a connector configured to connect to a measurement probe. The second end includes a base plate for mounting the CMM. The base plate has a cavity with a bottom opening. The main printed circuit board is disposed horizontally within the cavity.