4 FACTORS TO TAKE INTO CONSIDERATION WHEN BUYING YOUR CNC MACHINE
A machine center is a great investment for your success, but the question remains: which machine center is perfect for your production?
Machine centers are known for their high precision, high reliability, high efficiency, and the ability to machining complex workpieces.
However, if the selection is not thought of thoroughly, you will not be able to exert its due benefits, and with the high cost of the machining centers now a days, you really want to guaranty your ROI (return of investment).
When wanting to select a CNC machine, you should start with you product and based on you can select:
- The model.
- The CNC system.
- The machine tool accuracy.
- The main feature specification.
Start with the selection of the model and the selection of the CNC system, and then select the machine precision and main specifications.
In this article, we will illustrate these four aspects and help you understand what to look for when choosing your CNC machine.
As we said before, start with your product. Study your product and the process of its production. Then, with the premise of meeting the processing requirements, choose the simplest equipment required for the job, which guarantees both the lower risk and price.
Also, try to choose an economical CNC machine center.
For example: In the processing of mold parts, CNC milling machines and machining centers of the same specifications can meet the basic processing requirements, but the price difference between the two machine tools is huge, almost double the price. Therefore, in the mold processing, only the process of changing the tool very frequently selects the machining center.
CNC system selection
When selecting a CNC machining center, know that the same machine can be equipped with different CNC systems. Depending on these systems, the performance can vary and directly affect the pricing of the machine.
Now a days, the types and specifications of CNC systems are extremely huge. Every company has a range of products in a variety of specifications.
When choosing your CNC system, you should look for:
- The performance versus price
- The ease of use and maintenance
- The system’s service life.
Therefore, you cannot pursue high-level, new systems based on reputation only. It should be based on the main performance of the machine, the system performance and price.
There are 20 to 30 precision inspection items for CNC machining centers, but the most characteristic to look for are:
- Single-axis positioning accuracy
- Single-axis repeat positioning accuracy
- Roundness of the test piece produced by simultaneous machining of above two-axis.
The positioning accuracy and repeat positioning accuracy reflect the precision of each moving part of the axis. The single-axis positioning accuracy refers to the error range when positioning at any point within the stroke of the shaft, which reflects the machining accuracy of the machine tool. The repeat positioning accuracy reflects the positioning stability of the axis at any positioning point in the stroke, which is an indicator to measure if the shaft can work stably and reliably.
For those machines with higher positioning accuracy, you must also pay attention to whether the feed servo system adopts semi-closed loop or full closed loop mode, and to the accuracy and stability of the detecting components.
If the machine tool adopts a semi-closed-loop servo drive mode, the accuracy stability is affected by external factors.
Main specification selection of CNC machines
You should select the main feature specifications of the CNC machining center according to the determined range of typical workpiece machining dimensions. The main specifications of the CNC machining center are the stroke range of several CNC axes and the spindle motor power. The three basic linear coordinate (X, Y, Z) strokes of the machine tool reflect the machining space allowed by the machine. The two coordinates X and Z in the lathe reflect the size of the allowable rotor. As a rule, the contour size of the machined part should be within the machining space of the machine tool. You must take in consideration the space required to install the clamp and select a work surface that is slightly larger than a typical workpiece takes into. Also, the size of the work surface basically determines the size of the processing space.
The main motor power of the CNC machining center can also have different configurations on the same type of machine which reflects on the cutting rigidity and spindle high-speed performance.
The spindle motor power reflects the cutting efficiency of the machine tool and reflects the cutting rigidity and the overall rigidity of the machine tool from the other side.
Also, when there is a large amount of low-speed machining on a typical workpiece, the low-speed output torque of the machine must be checked.
In brief, with a big investment like purchasing a CNC machine, you should take all factors into account and take an experts opinion before making any step.
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