Method for machining inner holes in rapid prototyping of hand boards

There are many methods for machining inner holes, including drilling, reaming, mirror drilling, grinding, pulling, grinding, grinding, and rolling. Below are two common methods for drilling and expanding holes.

For drilling, the Fried Dough Twists drill has the following process characteristics due to its long length, small core diameter, poor rigidity, and the influence of the transverse edge.

1. The drill bit is prone to shaking;

2. The aperture is easily enlarged;

3. The surface quality of the hole is poor;

4. When drilling, the axial force is large;

Compared with the Fried Dough Twists drill, the reamer has the following characteristics.

1. Good rigidity; Due to the small back cutting amount and less chips, the chip holding groove of the reaming drill is shallow and narrow, and the diameter of the drill core is larger, which increases the rigidity of the working part of the reaming drill.

2. Good guidance; The reaming drill has 3-4 teeth, and the number of edges around the tool increases, resulting in a relatively enhanced guiding effect.

3. The chip conditions are good; Expanding drill without cross cutting edge for cutting, cutting is light and fast, can use larger feed rate, high productivity, and has fewer chips, smooth chip removal, and is not easy to scratch the machined surface.

Therefore, compared with drilling, drilling has higher machining accuracy, lower surface roughness values, and can to some extent correct the axis error of drilling. The machine tool suitable for drilling is the same as drilling.