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Why is machining center machine tool low precision?

One important reason may be because you have not made a foundation.
Our company made the following explanations because of the low precision of the machine tool caused by the lack of foundation:
Why do you want to be a foundation? Because the cement floor not only bears the weight of the body, but also the machine tool produces a very large cutting force when processing, the cutting force will be transmitted to the concrete floor through the body, so that the cement floor also plays a role in guiding the chipping force. In addition, due to the body mechanism of the vertical machining center, its weight is not uniform, the back end of the body will be heavier, and we need to check the level regularly. Therefore, we recommend that the customer do the foundation to overcome these problems.
There is also the reason for the principle of thermal expansion and contraction. Even if the machine tool is not used, it will have a shrinkage change of 1-2 cm on the concrete floor, or even more. Our requirements for machine tool level can't be measured in centimeters, but in silk or road. So we can imagine that this is why we will have a "warning sign of regular maintenance catalogue" behind the machine tool, asking customers to regularly. Calibration level.
If the level changes frequently, especially if the amount of change is large, and the time of the horizontal change is long, in addition to affecting the accuracy of the product, the impact on the machine body is also very large, so it is recommended that the customer do the foundation. In particular, some large equipment and equipment with uneven center of gravity must be grounded.
If the customer really does not want to make the foundation, our company can only recommend the customer to calibrate regularly. The short-term level change does not have much impact on the machine body, but the long-term level change will have a very big impact on the machine body.
Just like our CNC guide rail grinding machine, even if the foundation is made, but because our company has extremely high precision requirements for the products processed by the grinding machine, we will still check and calibrate the grinding machine once a month regularly. The processing precision of the product can guarantee the service life of the grinding machine.
Some people will have doubts: Why do some customers do not have a foundation and use it without problems? This is determined by the customer's accuracy requirements and finish requirements for the products being processed. Our company will find that when the machine tool is in the plane of processing, there is no good trace of the knife, or there are traces at the position of the quadrant when milling, or the hole size is different when the pupil is in the hole. The problem to be solved is the level of calibration, and it will be found that most of them are caused by large changes in levels. However, when some customers do not have high precision on the machine tool, they will neglect the slight change of the precision and smoothness of the machine tool. Until the long-term horizontal change causes damage to the machine body, it is found that the machine tool has a problem, and then the level is calibrated.
Therefore, our company advises customers to do the basics. There is no harm to the machine tool. It not only can extend the life of the machine, but also prevent the machine from vibrating when the customer performs heavy-duty cutting. It can greatly increase the amount of the tool and extend the use of the tool. life. When the customer does not have the foundation, we recommend that the customer conduct regular level calibration and ask our staff to communicate with customers carefully and patiently.
If our company finds that the level is very good at the customer's site after the sale, but the change of the workbench becomes a distortion change, especially in the first three months of the machine tool use, we can think that the workbench is not aging, it should be caused by the release of internal stress. Irregular changes. This kind of problem will be, but it is not common. Because the deformation of cast iron is caused by three main problems: the first is the design structure of the body, the second is the ratio of the material, and the third is the heat treatment process of the material. Why is it not common? Because my driver's body structure has been produced for more than 10 years, and it is constantly optimized and is already a mature product. Everyone knows that the casting manufacturer for our company is also more than 10 years old, and our heat treatment process is 580° annealing, then the roughing leaves the machining allowance, and the second time the low temperature tempering, high temperature 380 ° low temperature 150 ° 72 hours of aging treatment, through high and low temperature matching, to imitate the principle of natural aging. At present, this process is relatively advanced, especially in foreign countries. It has been found to be relatively stable after so many years of use.
Therefore, please rest assured that once there is a problem with the workbench change, we will not evade the problem first, and the second will not evade the problem, and we will not actively evade it. There are two solutions currently used: the first is on-site processing, horizontal recalibration, which is very effective for short time changes; for customers with long time changes, there is no immediate effect, and the calibration level will slowly It will take a long time to change again, because the anti-seismic effect of cast iron has a certain waywardness. The second is that the amount of change is very large, and it affects the use of customers. Customers are more anxious and can only take the approach of changing the workbench.

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