5 tips on buying a machining center！

#UniversalMillingMachine #VerticalMillingMachine

Wanting to buy a machining center, we have to consider from several aspects in order to buy suitable for our needs processing center.

TIP 1.What kind of parts are suitable for machining centers?

1. In general, a workpiece needs to be processed with a lot of tools.

2. Locate cumbersome workpieces. For example, there is a certain position of the hole from the precision requirements of the porous processing, the use of high precision machine positioning characteristics, it is easy to implement.

3. Repetitive production of the workpiece for processing a single small batch production. Small batch refers to the 1-100 pieces, each batch of small, but need to repeat the production. In addition, even if the workpiece shape size is different, but it is similar to the workpiece, easy to achieve group processing (GT) process parts. Box type, plate parts in the horizontal machining center on the use of rotary table, the box parts for multi-faceted processing, such as the spindle box, the pump body, the valve body, internal combustion engine block.

If even the top of a fixture in the processing, you can use pentahedral processing center. Vertical machining center for processing box cover cylinder head, flat cam and so on. Longmen processing center for processing large boxes, plate parts, such as diesel locomotive cylinder, processing center column, bed, printing wall machine and so on. Valve body, internal combustion engine block and so on. If even the top of a fixture in the processing, you can use pentahedral processing center. Vertical machining center for processing box cover cylinder head, flat cam and so on.

TIP 2. How to choose the machine tool specifications (model)

1. According to the size of the workpiece to determine the size of the corresponding machine to determine the size of the table and the three linear coordinate system travel. The size of the table should ensure that the workpiece can be successfully mounted on the workpiece, the processing size must be in the coordinate travel, in addition to consider the tool space and the coordinates of the interference area restrictions.

2. Machining accuracy of the machining center. The accuracy of the machining center is classified as ordinary type and precision type. The precision machine tool can not be used for roughing the parts (recommended). It will damage the accuracy of the machine, open the proposed use of ordinary machine tools, if the open rough small, then there is no problem, precision machine parts mainly for finishing parts.

3. The main precision items are as follows:

Machining Center Main Accuracy Item Normal (mm) Precision (mm)

Linear positioning accuracy ± 0.01 / full ± 0.005 / full

Repeat positioning accuracy ± 0.006 ± 0.002

Milling round precision 0.03-0.04 0.015

TIP 3.Tool library capacity selection

Machining center manufacturers of the same specifications of the machine, usually have 2-3 different capacity of the knife library, such as horizontal machining center knife library capacity of 30,60,80, vertical processing center 16,24, 32 the capacity of the magazine. When the user is selected, the required quantity can be determined based on the process analysis results of the workpiece. The capacity of the knife library is usually determined by the number of tools required for a part in a single clamping, since the other parts are machined , Need to re-arrange the tool, otherwise the tool management is complex and prone to error. From the statistical point of view of vertical processing center selection of 20 knife around the knife library, horizontal machining center is selected 40 knife around the knife is appropriate. Of course, according to the actual needs of the final to determine.

TIP 4.Machine function and accessories

When selecting a machining center, in addition to the basic functions and basic parts, there are functions to provide users with their own requirements.

Select the function, select the attachment (optional attachment). With the development of numerical control technology, the choice of more and more content, its structure.

Into the proportion of the price in the host is also growing, so it is not clear that the purpose of a large number of optional accessories is not economical, the so-called "Ready to order ",the guiding ideology is essentially a waste, so the selection should be a comprehensive analysis, but also appropriate consideration of long-term factors.

Function mainly for the numerical control system, the kind of price increase is not much, but the use of many convenient features, should be properly configured

Complete, and can be more than one machine common accessory, you can consider a multi-purpose machine, but must consider the interface is common.

TIP 5. How many machine tools are needed to meet our production requirements

According to the selected workpiece, and then analyze the process route, in this process route selected to be processed in the processing center of the process, the work of these operations to estimate the time. According to the current process parameters, the cutting time of each process is estimated, and the auxiliary time is usually 10% -20% of the cutting time.

With a single process time is not difficult to calculate the annual output. 300 working days a year, the machine operating rate by 75% -85%, if the meter

The results of the output can not reach the target value, but the same, modify the process parameters; if the gap is large, should consider increasing the number of machine tools.

In the next article, we will talk about the processing center of the inspection, commissioning, acceptance, operation points.Thank you for your reading!