1, on the dimensional accuracy
The degree of coincidence between the actual size of the part and the size of the part after the hand model is processed. The dimensional accuracy is controlled using dimensional tolerances. The dimensional tolerance is the allowable variation in the size of the part during machining. In the case of the same basic size, the smaller the dimensional tolerance, the higher the dimensional accuracy.
2, shape accuracy
The actual geometry of the surface of the component after machining by the prototype model factory matches the ideal geometric shape. The items that evaluate the shape accuracy include six items such as straightness, flatness, roundness, cylindricity, and line profile. The shape accuracy is controlled by the shape tolerance. Each shape tolerance is divided into 12 accuracy grades except the roundness and the cylindricity are divided into 13 precision grades. Level 1 is the highest, and Level 12 is the lowest.
3, position accuracy
Differences in the actual positional accuracy between the relevant parts of the parts after processing by the hand board model manufacturer. The items for assessing the positional accuracy include eight items such as parallelism, verticality, inclination, concentricity, symmetry, position, round runout, and full runout. Positional accuracy is controlled by positional tolerances, and positional tolerances for each item are also divided into 12 accuracy levels.
4, the tool: prototype model factory processing machine used by the knife is generally tungsten steel knife, this knife is generally used several times, the knife will wear, so that there are errors in the knife.
5, artificial knife: If there is a knife, there will be no problem in the knife. However, in order to save costs, many small-sized hand-saw makers will choose to have no counter-tools when selecting machines. They can only use manual countermeasures, so personnel have tolerances. In order to ensure the precision of the prototype model, the extension dimension model is equipped with a tool setting device on many CNC devices, which can not only accurately align the tool, but also greatly improve work efficiency.
All in all, the hand-to-plate factory's tolerances are about 0.1mm combined in terms of machine itself, tool wear, and manual tool setting. If the part requires multifaceted machining, the risk is doubled and the tolerance will be doubled.