Advantages and Disadvantages of Hard Guide and Linear Guide in Machining Centers

Advantages and Disadvantages of Hard Guide and Linear Guide in Machining Centers

We have two types of cnc machining centers, one with linear guideway,another with hard guideway. Generally, if you use cnc machining center to make a product, you will purchase linear. If you use cnc machining center to machining mold, you will purchase hard. The accuracy of the linear guideway is higher than hard guideway, but the hard guideay is more durable.


Characteristics of Hard Guide in Machining Center


It has low friction, excellent response, high precision, smooth movement, high load capacity, long travel life, and are very easy to install correctly.



1.Different material.

It is easy to mix up the sand, porosity and porosity. If these defects exist on the guide surface, it will have a very negative impact on the service life of the guide rail and the accuracy of the machine.



2.Difficult to process.

This type of guide rail is generally connected with the main components of the machine such as the base, column, work table, sliding saddle, etc. So when we processing the machining,it can difficult to control some problems, such as shape tolerance, rough over-demand, aging treatment. As a result, the processing quality of the parts cannot meet the assembly requirements.



3.Difficult to assembly.

“Assembly” means that it must be equipped and adjusted. The process of adjust is a process of combining technology and physical strength. A general worker can not finish this. It is necessary for the assembly workers who are relatively skilled in the technology and have a good grasp of the overall accuracy of the machine tool to complete.



4.Short service life.

Under the same maintenance and use conditions, the service life of the common hard guide is less than the linear, which has a great relationship with their movement. The hard guide is operated by sliding friction, and the linear rail is rolling friction. From the frictional force, the friction of the hard rail is far greater than the friction of the rail, especially when the lubrication is insufficient. In the case of the hard track, the friction is even worse.



5.High maintenance cost.

The maintenance of the hard guide is far greater than the linear guide in terms of difficulty and maintenance cost. If the scraping amount is insufficient, it may involve disassembling the large parts of the machine tool and doing new things. Quenching and machining, even more likely to recast the large part, and the wire gauge can be replaced by the corresponding line rail, which will not greatly affect the use of the related large parts.



6.Low running speed.

Because of the excessive movement of the hard guide and the frictional force it bears, it is usually not able to withstand excessively fast running speeds. This is contrary to the current processing concept. In particular, many factory workers do not have the corresponding maintenance knowledge of machine tools. They only know how to use machine tools, but they often ignore the maintenance of machine tools. The maintenance of machine tool tracks is the most important. Once the track lubrication is insufficient, it can cause rail burns or wear and tear, which are fatal to the accuracy of the machine.

Characteristics of Linear Guide in Machining Center


1.Easy to assemble.

Because the accuracy of the machine tool determines the accuracy of the transmission mechanism to a large extent. The transmission mechanism is generally composed of a wire rail and a lead screw, that is, the accuracy of the wire rail and the screw itself determines the accuracy of the machine tool. The wire rail and the screw rod are generally in the form of standard parts. You only need to select the corresponding precision provided by the manufacturer, and generally there will be no big problem.



2.Wide choice.

Whether it is from the structure of the line rail or the accuracy level, the lubrication method or the bearing capacity, the processing method to the running speed, etc. are all optional. You can configure the type of rail you need according to the specific conditions of the machine you are designing.



3.Fast running speed.

Many machine tools run extremely fast, especially at idle speeds, which is largely due to the merits of the line. Because of the rolling friction operation mode and high-precision machining, the accuracy and stability of the machine tool at high speed are guaranteed, and the machining efficiency and machining accuracy are greatly improved.


4.High precision.

Because the linear is a standard commodity, both the material and the processing method have entered a benign and controllable range. Therefore, in many machine tools in the field of finishing, most of them use high-precision wire rails as machine guides, which also greatly guarantees the machining accuracy of the machine.



5.Long service life.

Because the rails operate in rolling friction, the balls in the slider drive the movement of the feed member by rolling on the rails. This rolling friction is subject to much less friction than the hard rail. Therefore, whether it is transmission efficiency or service life, the rails are much more ideal than hard rails.



6.Low maintenance cost.

Whether it is from the cost of maintenance or the convenience of maintenance, the rail has more advantages. As a standard part, the replacement of the rail is the same as replacing a screw. Of course, there are some adjustments in accuracy, but it is too convenient compare to the hard track.



7.Fast delivery time.

The delivery time of linear guid is 30 days. The same hard track does not have such a good time to control. If the action is relatively large, for example, to recast, the cycle may be several More than a month is uncertain.



1.Low load capacity.

Nowadays, many large-scale factory railroads have greatly improved their carrying capacity through some structural design. Of course, it is relatively small compare to the hard-bearing carrying capacity.



2.Low resistance to vibration.

But I still want to emphasize that this weakness is relative to the hard guide. In fact, the smoothness of many line rails is also very good. As long as the equipment you design is not too special, it is generally able to meet the needs.



3.Pay special attention to the protection of the rails during transportation and assembly.

As a standard part, its unique structural features make it in an embarrassing situation that is more susceptible to damage. Exposure to water or other solvents during transportation and assembly is prone to rust and corrosion, resulting in loss of precision.



Hope our explanation can help you better choose cnc machining center.

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