Yearly Archive September 16, 2020

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CNC machining spindle failure

Any equipment and machinery in the production process will have some fault problems, so our CNC processing is the same, but generally lead to the failure of the main shaft, so we can first find the problem from the spindle, the spindle system according to the transmission system can be divided into variable speed gear main drive spindle, through the belt drive main transmission spindle The main shaft is driven by two motors and the main shaft is integrated by motor and spindle. So, let’s learn about the common faults of CNC machining?

  1. Overload.

Fault causes: excessive cutting amount, frequent positive and negative rotation, spindle motor failure, spindle drive device failure.

  1. The spindle does not rotate

Fault causes: spindle drive device failure, CNC device can not output speed signal, spindle motor fault, spindle drive device fault, drive belt fracture.

  1. Spindle speed deviation from command value

Fault causes: motor overload, problems with spindle speed command output from CNC system, fault of speed measuring device or disconnection of speed feedback signal.

  1. Abnormal noise and vibration of spindle

Fault cause: it usually occurs in the process of deceleration, and the spindle drive device has problems, such as the regeneration circuit fault in AC drive.

The above points are the common faults of CNC machining spindle, and the above editor also talked about the solution. Today, I will talk about it here. If you want to know more information, please visit our website for detailed consultation.

Causes of under casting of die castings

In the process of production, there will be a lot of faults, but some of them are unavoidable, so we should prepare some methods to deal with them when we are working. So, under casting of die castings is also a common problem. What are the causes of under casting of die castings?

  1. The filling condition is poor, and there is irregular condensed metal in the under cast part;

When the pressure is insufficient, the metal in the active front solidifies too early, resulting in under casting at the corner, deep concave, thin wall (even thinner than the average wall thickness) and cylindrical hole wall. The results show that the mold temperature is too low, the alloy pouring temperature is too low, and the location of the inner gate is not good, resulting in large moving resistance.

  1. It is difficult to set up the part of overflow system because of gas obstruction and lubrication on the surface of under cast part, which makes it difficult to set up an overflow system. When molten metal moves, turbulent flow is violent and gas entrapment occurs.
  2. There is residue in the cavity of plastic mold

The amount of coating or spraying method is improper, resulting in local coating deposition.

When filling, the metal will run into the metal when filling. After the casting is pulled out, it can not be brought out completely and the flake is clamped on the gap. When the sheet metal (the thickness of the metal sheet is the size of the gap) is more convex on the surrounding mold surface, the height of the projection will be changed into the wall thickness of the casting under the condition of closing the mold, so that the future casting will have a groove penetrating (for the wall thickness). This penetrating groove is a special form of under casting. This kind of under cast phenomenon often occurs in the case of deep cavity composed of mosaic.

These are the reasons for the under casting of die castings

The principle of CNC machining error

What are the principles of CNC machining error of mechanical parts? Let’s have a brief understanding:

  1. Processing deviation

The reason deviation of CNC machining is due to the selection of the approximate machining activity method or the similar tool appearance. Because of the deviation in the machining principle, it is called the machining principle deviation. The reason deviation should be within the promise line.

  1. Geometric deviation of machine tool

The manufacturing deviation, installation deviation and wear in use of machine tools directly affect the machining accuracy of the workpiece. Among them, it is mainly the spindle rotation, the linear movement of the guide rail and the deviation of the transmission chain of the machine tool.

  1. Manufacturing deviation and wear of cutting tools

CNC machining tool manufacturing deviation, installation deviation and wear in use, all affect the machining accuracy of the workpiece. In the process of cutting, the cutting edge, cutting face, workpiece and chip have a sharp conflict, which makes the tool wear. When the tool wear reaches a certain value, the surface roughness of the workpiece increases, and the chip color and form change, and appear to be vibration. Tool wear will directly affect the cutting rate, machining quality and cost.

The above is the principle of CNC machining error of mechanical parts, hope to help you.

Attention to CNC surface machining method

We usually know that when we buy clothes, the most important thing is good-looking, followed by quality. Because only attract our eyes, so that customers have the desire to see. It is the same in our industrial industry, but we should pay attention to the quality, because our industry pays attention to the practical aspect. So let’s find out what factors should be considered when choosing the CNC surface processing method?

  1. Any CNC machining method can obtain a considerable range of machining accuracy and surface roughness, but only in a narrow range is economic, the range of machining accuracy is economic. Therefore, when selecting the processing method, we should choose the corresponding processing method which can obtain the economic machining accuracy.
  2. The material properties of CNC parts should be considered.
  3. The structure shape and size of CNC parts should be considered.
  4. Productivity and economic requirements should be considered. In mass production, advanced technology with high efficiency should be adopted. Even can fundamentally change the manufacturing method of the blank, can reduce the amount of mechanical processing labor.
  5. The existing equipment and technical conditions of the factory or workshop should be considered. When selecting the processing method, the existing equipment should be fully utilized, the potential of the enterprise should be tapped, and the enthusiasm and creativity of the workers should be brought into play. However, it is also necessary to continuously improve the existing processing methods and equipment, adopt new technologies and improve the technological level.

The above points are the factors that we can’t ignore when we choose the CNC surface processing method. We must pay attention to them. Today, we will talk about it first. If you want to know more information, please visit our website for details

How to improve the finish of NC lathe

How to improve the machining finish of CNC lathe? Let’s have a simple understanding:

  1. If the position of large-scale CNC lathe is uneven, it will cause a sensation and affect the brightness of workpiece processing. Therefore, to ensure the stability of large-scale CNC lathe processing, we can better improve the brightness of large-scale CNC lathe processing.
  2. Although the spindle is prevented from vibration at high speed, it will greatly affect the brightness of the workpiece.
  3. Despite the choice of high quality coolant.
  4. Although choose sharp and wear-resistant tools.
  5. The chip removal groove should be opened well, even if the chip is not smooth, which may cause the workpiece scratch and affect the brightness of the workpiece.
  6. Match the spindle speed and feed speed of the lathe.

The above is to improve the CNC lathe processing finish method, hope to help you

Hardware processing precautions

We all know that no matter what the equipment is, there are many matters needing attention in the operation. The purpose of this is to better ensure our work effect, reduce the occurrence of faults and ensure the quality of products. These matters needing attention are basically easy to ignore in our daily work, but sometimes they cause us some troubles. So the following with the small make-up to understand the hardware processing in the operation must pay attention to what matters?

1、 All employees should check whether their clothes meet the work requirements before entering the work. During operation, it is necessary to concentrate on the operation, and it is strictly prohibited to chat and cooperate with each other. The operator should not operate under the state of irritability and fatigue, so as to avoid accidents and ensure the safety of operation.

2、 Before the machine works, check whether the moving part is filled with lubricating oil, and then start and check whether the clutch and brake are normal, and run the machine tool at idle speed for 1-3 minutes. It is strictly forbidden to operate in case of mechanical failure.

3、 When replacing the mold, the power supply should be turned off first, and the moving Department of the punch should stop running before the mold can be installed and debugged. After installation and adjustment, manually move the flywheel for two times to check whether the upper and lower dies are symmetrical and reasonable, whether the screws are firm, and whether the blank holder ring is in a reasonable position.

4、 Only when all other personnel leave the mechanical working area and take away the sundries on the worktable, can the power supply be started to start the machine.

5、 After the machine is started, one person will transport materials and operate the machine. Other people are not allowed to press the electric building or step on the pedal switch board, nor can they put their hands into the mechanical working area or touch the moving parts of the machine with their hands.

6、 When off duty, the power supply should be turned off and the finished products, leftovers and sundries should be sorted out to ensure the clean and safe working environment.

The above six points are the hardware processing in the operation of the need to pay attention to the matter, although it is some very small matters, when we have achieved the effect is very good, so today’s small editor to talk about here, want to know more information, welcome to visit our website for detailed understanding.

Price calculation of hardware parts processing

Friends who have not contacted this line may not know. When we go to understand the market price, we find that the quotations of many businesses are different. If you don’t know your profession, you don’t know why, so you may have a big head when you make a choice. But as long as we know how to calculate the price of hardware parts processing, we will know how to choose.

  1. First look at your drawings and technical requirements
  2. There are differences in materials and labor in different places, and there is a big price difference in some places
  3. General parts are calculated according to material cost + processing cost + profit. The processing cost depends on the process. The price of different processing equipment is of course different. Some are calculated according to working hours (turning time, grinding time, etc.), and some are calculated according to working procedures (such as how much is a folding plate for a knife, how much is a common drill hole, etc.)
  4. There is also a problem of quantity. A large quantity is certainly cheap. If it is a single piece, even if it is a small piece and the materials are not retailed, you should calculate the price of the whole board! For example, if you say 0.3, the manufacturer does not use it frequently. If you only buy one or two pieces of materials, if you only buy one board at a time (such as 1220 * 2440), you will be wrongly spent on the material cost.
  5. If the parts processing factory can solve the problems of the processing factory itself, of course, there is no problem. If the processing factory itself has some processes to be outsourced, the price will be correspondingly increased. If you are outsourcing, it means that you have been outsourced twice! So you should find the right one to find what they can do and what they are good at

Causes and solutions of CNC machining accuracy

What are the causes and solutions of CNC machining accuracy

  1. The workpiece size is accurate and the surface brightness is poor

Obstacles: the tool tip is damaged and not sharp; the machine tool resonates and is instable; the machine tool crawls; and the processing technology is not good.

Treatment plan: if the tool is not sharp after being worn or damaged, it is necessary to grind the tool from the beginning or select a better tool to set it from the beginning; if the machine tool resonates or is instable, adjust the level and lay the basic, unchanged and stable; Due to the creeping of the machine, due to the wear of the carriage guide rail and the wear or looseness of the lead screw ball, the machine tool should pay attention to the maintenance, clean the iron wire after going to work, and quickly add smooth oil to reduce the conflict; select the appropriate cooling liquid for workpiece processing, even if it can meet the processing requirements of other processes, select a higher spindle speed.

  1. The taper of workpiece is large and small

Obstacles: the level of the machine tool is not adjusted well, one high and one low, resulting in instable placement; when turning the long shaft, the raw material of merit is hard, and the cutting tool is deep, forming the phenomenon of giving way to the cutter; the difference between the tailstock thimble and the spindle.

Treatment plan: adjust the levelness of the machine tool with a level gauge, lay a solid foundation, keep the machine tool unchanged and increase its toughness; select the correct process and appropriate cutting feed rate to prevent the tool from being forced to yield to the cutter; adjust the tailstock.

  1. The driver phase light is normal, but the size of the workpiece processed is large or small

Obstacles: long term high-speed operation of the machine tool carriage results in the wear of the screw rod and bearing; the repeated positioning accuracy of the tool carrier has errors in long-term use; the carriage can accurately return to the starting point of processing each time, but the processing workpiece size still changes. This phenomenon is usually formed by the spindle, the high-speed rotation of the spindle makes the bearing wear very important, forming the processing size change.

Processing plan: use the dial indicator to lean against the bottom of the tool rest, and compile a constant cycle program through the system to check the repeated positioning accuracy of the carriage, adjust the screw rod clearance, and replace the bearing; use the dial indicator to check the repeated positioning accuracy of the tool rest, adjust the machinery or replace the tool carrier; Use the dial indicator to check whether the workpiece is returned to the starting point of the program accurately. If it is possible, check the spindle and replace the bearing.

  1. The difference between the size of the workpiece and the essential size is several millimeters, or there is a great change in a certain axial direction

Obstacles: the speed of rapid positioning is too fast, and the drive and motor can not respond; after long-term conflict and consumption, the mechanical drag screw rod and bearing are too tight and stuck; the tool carrier is too loose and can not be locked tightly; the compiled program error, the head and tail are not taken care of or the cutter compensation is not canceled; the electronic gear ratio or step angle configuration of the system is wrong.

Treatment plan: if the positioning speed is too fast, the go speed should be adjusted appropriately, and the driver and motor can work normally under the rated operating frequency by cutting with slowing down and time; if the drag plate and screw rod crane bearing are too tight and stuck after the machine tool is worn, it must be adjusted from the beginning; If the tool holder is too loose after tool change, it is necessary to check whether the tool holder reversing time is satisfied, whether the worm gear inside the tool holder is worn, whether the clearance is too large, whether the installation is too loose, etc.; if it is caused by the program, it is necessary to correct the program, comply with the requirements of the workpiece drawing, select the correct processing technology, and write the accurate program according to the instructions in the footnotes; If it is found that the size error is too large, the test system parameters are correctly configured, the unique is whether the parameters such as electronic gear and step angle are damaged, which can be measured by dial indicator.

  1. The effect of arc processing is not dream, and the size is not in place

Obstacle causes: resonance caused by repeated vibration frequency; processing technology; parameter configuration bifurcation, too large feed speed, resulting in out of step in arc machining; loose or tight lead screw caused by large gap; wear of synchronous belt.

Treatment plan: find out the parts with resonance, change its frequency and prevent resonance; study the processing technology of workpiece raw materials and correctly program; as for stepping motor, the processing speed f cannot be too large; whether the machine tool is installed stably and stably, whether the carriage is too tight after wearing, the gap is increased or the tool holder is loose; replace the synchronous belt.

The above is the cause of poor CNC machining accuracy and solutions, hope to help you

Is the finer the machining accuracy, the better?

How did this come about? Xiaobian doesn’t know, but when we operate, no matter how, or according to their own needs, because with others will not necessarily meet their own requirements, so we have to choose according to their own father’s needs, so we can do it for ourselves. Then we will discuss whether the precision of machining is the finer the better?

  1. Profilometer and roughness meter are not the same product. The main function of profilometer is to measure the contour shape of part surface.

For example: groove depth, groove width, chamfering (including chamfering position, chamfering size, angle, etc.), straightness of cylindrical surface lines and other parameters. In a word, profilometer reflects the macro contour of parts.

  1. The function of the roughness meter is to measure the surface processing quality of the grinding / finishing turning process of the part surface. Generally speaking, it means that the surface of the part is processed to be smooth (the old national standard of roughness is called cleanliness), that is, the roughness reflects the micro situation of the machined surface of the part.

In general, the processing of ordinary machine tools is about 3.2, and the high-speed machine can achieve a finish of 1.6. For more information, please visit our website

Common faults of machine tools

It is also normal to have faults in the process of processing. In addition, there are many failures of machine tools, and the reasons are very diverse. Therefore, it is difficult for many users to find out the cause of the fault when they deal with it. Sometimes it is a problem of parts, sometimes it is a problem of assembly, maybe there is a problem of design, so we want to find the reason Is to spend the mind, then we will learn about Dongguan machining machine tool common fault what?

① Wear failure

It refers to the failure caused by normal wear and tear that has been expected and inevitable in design.

② Misuse failure

It is a failure caused by improper use or improper use.

③ Congenital failure

It is a fault caused by improper design or improper design.

In addition to the cause of the fault, there is a nature of the fault.

The nature of the fault is divided into the following two types.

① Intermittent fault

Some parts need not to be repaired for a short time.

② Permanent failure

Some of the functions are damaged and parts need to be replaced before they can continue to work.

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