Abstract
In this research, a needle bar was studied to approach the techniques and manufactures of this product by learning via the expert. Although the fixed of the pins on the brass bar is the only one step to make a needle bar, the fixed method is so complicate. It requires the fineness and high skill from manufacturer. The soldering process was used for fixed pins and brass bar together. However, the effect of heat transfer from soldering process on brass bar revealed the curve of specimen. The hitting technique was used to modify the curve. This technique is very useful. The curved of needle bar was improved and became too straight. By measuring the distance of the needle. With the microscope camera.
