Terms to represent the degree of accuracy that is difficult to signify by value
Many terms are used in the specification of the PCB prototyping machine. Here, I would like to describe the true meaning in selecting your system. The resolution and the processing accuracy. It is misleading to regard that the better resolution of the machine is the better finishes of the processing.
• The limit of resolution
The limit of resolution means the value of the minimum step of the command signal regulating the X, Y, Z axis of the machine. It does not mean the processing accuracy. In order to realize the processing the PCB of great precision, it is much more difficult to mitigate the backlash on each axis of the machine and to produce machines with utmost care and attention to the degree of orthogonality or flatness of the table, than to increase the limit of resolution.
• What is the accuracy of the machine
The following factors dominate the accuracy of the finished products by prototyping machines.
- Accuracy in the repeated milling operation
- Accuracy in tool positioning
- Degree of machine vibration during operation
- Degree of the spindle run-out
- Accuracy of a milling tool and the degree of the tool wear
The processing accuracy is influenced by the worst value of the above five factors. Hence, it is delusive to state that the overall accuracy is good enough by tackling up the partial factor (Resolution)
Without the balance of the whole factors, it cannot be reflected upon the processing accuracy. One value is not sufficient. Maximum drilling speed and the maximum processing stroke.
In the specification of MITS, we state the number of the maximal drilling rotation in condition of fluctuating the maximal processing stroke. Therefore, as the processing stroke become larger, the number of the rotation become smaller for its moving distance turn out to be far.
We offer the wide variety of the machines, including the 3-axes regulating processing machine. We can configure the travel distance of the fluctuation very precisely, therefore the rotation speed of the drilling noted in the specification increases.
Control Method of the Z Axis.
Solenoid Control Solenoid control is advantageous in increasing the number of up and own when short strokes. But is disadvantageous to adjust the down speed in long stroke. Additionally, solenoid control deteriorates with time. In that case, burrs can be generated after the processing.
MITS PCB Prototyping machine employs the control scheme by the motor. The motor control enables the stable processing without deterioration whereas the number of up and down will be smaller compared with the solenoid method.