The spindle part is one of the important parts of CNC milling machine. It drives the cutter to complete the cutting. Its accuracy, vibration resistance and thermal deformation have a direct impact on the machining quality. The main shaft of CNC milling machine is a hollow shaft, the front end of which is a taper hole, which is matched with the toolholder. The automatic clamping mechanism of the cutter is installed inside and at the back end for the tool clamping.
In other words, the coordinates of the three angles of the cutting tool, i.e. the three angles of the cutting tool and the axis of the cutting tool, i.e. the coordinates of the cutting tool and the three axes of the cutting tool, i.e. the coordinates of the three angles between the laser cutting tool and the main axis, y and Z, are determined. According to these position parameters, you can determine the initial position of the tool, which is a general positioning.
If extended, the above-mentioned position parameters are variable in the process of machining, which can also be understood as continuous repositioning.
Internal positioning: generally select the mounting hole, plug-in hole, or some holes without metallization as the internal positioning hole. The relative position should be on the diagonal as far as possible, and the hole with large diameter should be selected. On the premise of ensuring the PCB positioning, the less the number of pins, the better. In addition, the cutting point and machining sequence should match the positioning method. If the cutting point and processing sequence are well selected, the frame will maintain greater strength. If the cutting point is not selected properly, the frame will deform and the PCB will be rejected.
External positioning: a special positioning hole is set outside the printed circuit board figure, that is, external positioning. The cnc machining accuracy of external positioning method is about ± 0.15mm. When the length of printed circuit board is greater than 300 mm, three locating pins should be set to prevent frame deformation.