The height of the grinding needle needs to be ground for both the top needle and the embedded needle. First, use a color pen and caliper to draw an approximate height on the needle, leaving some margin, and then manually cut it with a cutting piece. Grinding the height requires the use of self-made fixtures, such as most mold rooms, which are specifically used for grinding the height of the needle. The shape may be slightly different, but the function is the same. It is recommended to prepare a higher one for grinding the top needle and a shorter one for grinding the embedded needle. There are various specifications of V-shaped grooves cut on it, which can be used for positioning when clamping the needle. When using it, it can be lying down or vertical, that is, it can be ground at the bottom of the grinding wheel or on the side of the grinding wheel. Pay attention to burning the knife, as the heat dissipation performance of the needle is not good. If you don't pay attention, even though it has been worn down to the number, the height will be reduced, and if it is worn too hard, it may deform.

2. There are usually only a few types of rubber grinding positions, such as grinding steps, slopes, R-joint slopes, etc. The following are several ways to grind rubber positions:

① Self made fixture grinding position, as shown in the picture: In addition to the fixture mentioned above, a self-made fixture is also needed, which is somewhat similar to side repair. Inside, a conical thin needle is locked with a screw, and the height can be adjusted. When grinding the needle, it is used to press against the center position of the needle, so consistency can be maintained when grinding multiple needles. Because plastic molds often grind needles, making this fixture can improve a lot of efficiency.

② The method of directly grinding the glue position with a magnetic table is also commonly used. You need to make a meson and attack a tooth yourself. When using it, clamp the cup head of the needle to facilitate manual rotation of the needle during grinding. In addition, two stoppers are needed, and the thickness of the stoppers is determined by the diameter of the needle. The thickness only needs to be slightly higher than the radius. Before grinding, the side stoppers need to be leveled with a calibration gauge. In addition, whether it is a detailed or rough magnetic table, it is impossible for every part to have the same magnetic properties. This is due to the structure of the magnetic table. Therefore, when directly grinding the needle on the magnetic table, it is necessary to use the needle to test several parts and choose the parts with stronger magnetic properties, which will have a much better effect.

③ The tool of punch molding machine and needle grinder has been introduced in the previous article. Here is a brief explanation. When using it, a slight adjustment can grind circular needles. However, if it is the grinding position, it is necessary to compare the table so that the rotation center of the tool is at the same height as the center of the needle.

④ Attention should be paid to the vise. It can be found that there is also a V-shaped groove on the vise, so the vise can also be used to grind the height of the needle. If grinding the rubber position, attention should be paid to the strength. When clamping the needle, it should not be too loose or too tight, so that it can rotate and be used to grind the rubber position with low accuracy. Similarly, any tool with a right angle and V-shaped groove can be used to grind needles within a certain range.