Machinery industry – Page 86 – CNC Machining & Turning, Milling, Metal parts

The application of ultrasonic technology in the food industry

The application of ultrasonic technology in food field is divided into two main categories according to energy intensity: low intensity ultrasonic technology and high intensity ultrasonic technology.
The energy of low intensity ultrasound is generally less than 1W/ square centimeter, so when the ultrasonic wave passes through the system, it will not destroy the medium. Low intensity ultrasound is usually applied to food analysis and detection, providing food composition, texture and rheological properties data.
The intensity of high intensity ultrasound is usually 10-100W/ square centimeters, which is sufficient to cause physical cracking and accelerate some chemical reactions. High intensity ultrasonic technology has been successfully applied in promoting emulsification, cracking cell walls and dispersing polycondensation. The energy difference between high intensity ultrasound and low intensity ultrasonic technology is quite different. There are obvious differences in the development of the two generator.

First, the application principle of ultrasonic technology
The widely used pulse technology includes typical measuring devices, such as measuring chamber, ultrasonic generator and timer.
The pulse generator produces an appropriate frequency and amplitude of the electronic pulse, the electronic pulse transmits the probe into the ultrasonic pulse through the ultrasonic wave, and the ultrasonic pulse will spread to the distance end of the sample room and then return from this place. Then the ultrasonic transmission probe is used as an ultrasonic receiver to restore the ultrasonic pulse into an electronic pulse, and the pulse signal will be displayed on the timer. Because the ultrasonic wave is partly absorbed and partly reflected back, the timer will display a series of different intensity signals. The 3 ultrasonic parameters, such as sound velocity, attenuation coefficient and sound impedance, can be measured by the returned signal. Each return signal is more than two times the distance of the sample chamber length (d) than its previous signal. By measuring the interval between two successive echoes (T), the sound velocity can be calculated: C=2d/t. The attenuation coefficient can be calculated from the amplitudes of two consecutive echoes. The sound impedance can be calculated by determining the ratio of wave number reflected by the ultrasonic wave from the surface of the medium to the number of incident waves. By measuring the ultrasonic parameters of the medium system, the various properties of the food system can be analyzed and tested.
The application of high intensity ultrasonic technology is mainly based on the mechanism of ultrasonic action, namely thermal action, cavitation and mechanical mass transfer.
Thermal action refers to the phenomenon that when the ultrasonic wave propagating in the medium, its energy is continuously absorbed by the medium and the temperature of the medium rises.
Cavitation means that the average distance of molecules in the liquid varies with the vibration of the molecule when the ultrasonic wave is propagated in the medium, and when it exceeds the critical molecular distance that maintains the action of the liquid, it forms cavitation. Ultrasonic cavitation is divided into two types: steady state cavitation (sound intensity <10W/ square centimeter) and transient cavitation (sound intensity >10W/ square centimeter).
Mechanical mass transfer means that when ultrasonic waves propagate in the medium, the particles can enter the vibration state and accelerate the mass transfer of the solution.

Two, application of low intensity ultrasonic technology
The application of low intensity ultrasound technology in food field began in 1940s, but this technology has only recently attracted the attention of researchers. The application of ultrasonic analysis and measurement technology in the food industry is mainly based on several main characteristic parameters (sound velocity, attenuation coefficient and sound impedance) of the measurable ultrasonic wave, which can reflect the physical properties of the food system, such as composition, texture and rheology. The relationship can be established by two ways. One is to establish the proportional relationship between the characteristic parameters of the ultrasonic wave and the physical parameters of the food and draw a correction curve. The other is to describe the nature of the food system qualitatively by describing the characteristics of the ultrasonic wave through the medium.
1. Determine the thickness of the medium
Ultrasonic equipment can accurately measure the thickness of the medium. In comparison with other technologies, when the thickness of the medium is measured by ultrasonic, the instrument is close to one end of the sample to be inspected. Therefore, it is more convenient to use ultrasonic to measure the thickness when the thickness of the sample is difficult to be detected with traditional technology. The technology has been applied to the determination of the thickness of chocolate coating, the thickness of the meat, the thickness of the liquid layer and the thickness of the eggshell in the candy.
2, detection of foreign substances in food
Impurities such as metal chips, glass fragments and sawdust often occur during food processing. Traditional optical inspection technology can not be applied to optical opaque systems. In this case, the use of ultrasonic detection technology is very fast and convenient. The measurement principle is that an ultrasonic pulse is introduced into the sample. The pulse will be reflected from all the surfaces of the medium. The acoustic impedance of the impurities and the components of the product are distinctly different, and the characteristics of the ultrasonic wave are obviously different, so the impurities can be detected.
3, measurement of flow rate
In many food processing operations, it is very important to control the flow rate of food materials. Researchers have developed a series of flow meters for measuring the flow of food materials through the pipes, such as the flow rate meter. The range of the ultrasonic flowmeter is very large, from several millimeters to tens of meters per second. These ultrasonic flowmeters usually measure the average velocity of materials. A more sophisticated flowmeter recently developed can be used to determine the cross section state parameters of fluid flowing through the pipeline. Many ultrasonic flowmeters are used to accurately measure the flow rate of different components in fluids, rather than the flow velocity of a single fluid.
4. Determination of the composition of food

What are the advantages of the laser cutting machine?

Under normal circumstances, the plane plan can be truly lifelike only when it is processed by high technology. Laser cutting machine is an indispensable tool in modern social life. Unlike the traditional cutting technology, laser cutting machine has a fast cutting speed and improves work efficiency. For custom patterns, there is no limitation, and it is automatic in the process of typesetting, and has the effect of saving materials. The incision is smoother, and the cost of processing is relatively low during processing. This cutting method is a very excellent process. There is no scratch for the cutting of the product. At the same time, there is little distortion in the needle for the plate. At the same time, it has a characteristic that it has a narrow gap in the process of cutting.
The laser cutting machine saves parts of the mold, so it is an economical and economical cutting method. No matter what material is cut, it has no effect on the material. It uses invisible beams. How about the price of this product? As a matter of fact, the overall price is more affordable. For the buyer, it is hoped to buy more meaningful goods at a lower price, so the method and skill should be paid attention to in the process of choosing.
First of all, the information of these laser cutting machines needs to be carefully mastered, and the basic information can be understood through the related channels on the Internet. Through these information, the related manufacturers are compared. Only in the contrast, it is possible to buy the real benefit laser cutting machine.
The laser cutting machine has been constantly improved so far. This kind of product brings great contribution to the demand person. It has advanced technology and high efficiency in the process of cutting all kinds of materials. It meets the requirements of these needs. They can finally get their business through this kind of light cutting machine. In the end, the value of its own is realized.

Sheet metal stamping process and precision progressive die design

1. What is the function of drawing sill (drawbead) in panel dies?
The role of a deep drawing sill is as follows:
1, increase the feeding resistance, make the drawing surface withstand enough tensile stress, improve the rigidity of the drawing parts and reduce the defects such as the concave, distortion, relaxation and ripple caused by the rebound.
2, adjust the flow of material, make the flow resistance of each part uniform in the process of drawing, or the amount of material flowing into the mold is suitable for the needs of all parts of the work piece, so as to prevent the phenomenon of “many wrinkles and few cracks”.
3. Expand the adjusting range of the blank holder force. On the double dynamic press, the adjustment of the four angles of the outer slider can only adjust the edge force roughly, and can not completely control the feed volume in all places just in line with the needs of the workpiece, so it also needs to rely on the edge surface and the deep drawing reinforcement to control the pressure of all parts.
4. When there is a deep drawing reinforcement, it is possible to reduce the requirements for the machining roughness of the edge surface, which reduces the manufacturing difficulty of the drawing die of the large covering parts; at the same time. Due to the existence of drawbead, the gap between upper and lower blank faces is increased, the wear of the blank holder is reduced, and the service life of the die is improved.
5, correct the unevenness of the material and eliminate the possibility of slippage. Because when the material flows through the drawbead and then flows into the concave die, it is equivalent to roller leveling.
2. What is the role of process cuts in large panels?
When some deep local protuberances or drums are needed to be stamped in the middle part of the panel, the partial rupture of the workpiece is often caused by the failure of the material to be supplemented from the outer part of the blank. At this time, the appropriate position of the local protuberance deformation zone can be considered to break out the process incision or process hole, so that the easily ruptured area can get the material from the interior of the deformation zone.
3. How to cut the cutting process?
There are two kinds of punching methods for the art cut.
1. Blanking out this method is applied to the occasion where the local forming depth is relatively shallow.
2. Cutting out this is a common method in the process of drawing, which can make full use of the plasticity of the material, that is to use the radial extension of the material at the beginning of drawing, and then cut out the process cut. Using the tangential extension of the material, a greater forming depth can be obtained. When the process holes are cut out in the drawing process, the tearing process is often used, and the material is not completely separated. The waste of the cut can be removed in the subsequent trimming process. Otherwise, it will produce difficulties in removing waste from the die.
4. What is the principle of the layout of the process?
1, the incision should be adapted to the contour of the local protrusion so as to make the material flow reasonably.
2, there should be enough edge between the incisions so that the punch can be tensioned to ensure that the forming is clear and the ripples are avoided, so that the good edge quality of the flanging edge can be obtained after the repair.
3. The cut part (opening) of the incision should be on the edge of the adjacent protrusion or the area liable to rupture.
4, the number of incisions should ensure that the deformation of the material in all parts of the projection tends to be uniform. Otherwise, it is not necessary to prevent the formation of the grain. The original design is only about two technological cuts, and the crack is still produced in the middle. Then the intermediate incision (the dotted line) is added to the original.
5, which stamping process must be used with precision progressive die?
In large quantities of stamping production, multi position precision progressive die must be used for small and medium sized punching parts with high accuracy. For larger stamping parts, it is suitable for stamping of multi station transmission dies.
6. What are the requirements for vulnerable parts in Precision Moulds?
The precision die structure is complex, the manufacturing technology requirements are high, and the cost is relatively high. In order to ensure that the whole die has a high life span, especially after the die parts are damaged or worn, the replacement is quick, convenient and reliable. Therefore, the important parts of the die are interchangeable. The die parts have interchangeable die, which can be called interchangeable punching dies.
7. What is the significance of the layout design of the precision progressive die?
Answer: reasonable layout design can make the mold work coordinate and coordinate, can greatly improve the utilization of material, manufacturing precision, productivity and die life, and can also reduce the difficulty of mould manufacturing. Therefore, layout design is the most important comprehensive technical problem in the design of precision progressive die. It is necessary to make a comprehensive analysis and judgment of the stamping direction, the number of deformation, the corresponding deformation degree and the possibility of the die structure and the processing craft, so that the layout can be reasonable.
8. What is the carrier?
When progressive dies work, objects carrying blanks to various workstations for punching and forming are called carriers. The part of the connection between the carrier and the blank is called the lap edge, and the part connected with the blank is called the lap. When working, in the dynamic processing, the carrier is always kept in stable position accurately, so the carrier must have a certain intensity.
9. What are the requirements for the precision progressive die for the die seat?
M precision progressive die requires high strength, good rigidity and high precision. Therefore, the structural steel is usually used as the mold base, and its thickness is thicker than that of the standard mold base. The upper die base is thickened 5 to 10mm, and the lower die base is thickened 10~15mm.
10. What are the types of the die structure?
The commonly used type of die structure is integral. Three pieces of collage and chunk, in ordinary flushing

How to set up a window product?

1. What is a window product?
Alibaba China station provides an incentive service for high quality sellers. Reasonable use of window location will greatly increase your marketing autonomy and enhance product exposure opportunities.
2. What’s the advantage of the window product to me?
Sellers can independently decide which products to push, and which products are given priority exposure (including website search and store search) when sorting search results.
3, what products can be recommended as window products?
The quality of information products reached 4 or above, and the support of Alipay online transactions in the sale of products.
4. Who can use the function of the window product?
At present, all integrity members can use window display products.
5. Is the window product effective in the whole industry?
Yes, the whole industry can be used.
6. How to get the window position?
More online transactions and focus on service quality, provide more customer protection, you can get window award. See the rules of “window position calculation” for specific rules.
7. How to set up a window?
First step: please log in [my Ali] [management supply product] – window products. The window page will show the number of your current window.

The second step: click on the [recommended product] in the window product settings, select the items you want to recommend to the window location. – click [recommendation].

If you need to revoke the merchandise that has been recommended to the window, click on the recommended product, choose the product that needs to be revoked, click [cancel the recommendation].

Third step: the product information quality reaches 4 stars or more can be recommended. If the product can not be found in the window setting, click [to perfect the product], find the goods to be optimized, view the optimization suggestion, when the product optimization standard is reached, the commodity will enter the list of recommended goods.

Technical characteristics and production mode of high speed precision stamping parts

Technical features of 1. high speed precision stamping parts

High speed precision stamping parts have many kinds, large production volume, high precision and complex shape. The main types of high-speed precision stamping parts have the following technical characteristics.

Stator and rotor core is an important part of the motor. Its quality directly affects the technical performance of the motor. The traditional manufacturing process of stator and rotor core is to make the core by stamping the fixed and rotor flakes (scattered pieces) by the general punch die, through the flush, rivet riveting, buckle and argon soldering. For the rotor of AC motor, the chute should be twisted manually. The step motor requires that the magnetic and thickness direction of the stator and rotor is uniform, and the stator core and the rotor of the rotor are required to rotate a certain angle respectively, such as the efficiency is low, and the precision is difficult to meet the technical requirements. With the continuous development of industrial production technology, high speed stamping multi position progressive die has been widely used in the fields of motor and electrical technology, such as the fixed and rotor core of various micro motors, and the shape of mountain, U and small transformer core. Among them, the stator and rotor core can also be provided with a torsion stacking groove, and a large angle rotary stacking rivet structure between the punching pieces. Compared with the ordinary die, the multi position progressive die has the advantages of high stamping precision, high production efficiency, long service life, good consistency of dimension precision of stamping iron core, easy to realize automation, suitable for mass production and so on. It is the direction of precision die development in micromotor industry.

Electronic stamping parts have the largest variety and the most complex structure. The general precision requirements of the electronic stamping parts are high. At the same time, the precision and uniformity of the stamping material, smooth surface, no spots, no scars, no abrasions, no surface cracks are required. The yield strength of the material is uniform, no obvious direction, high uniform elongation, and low working hardening.

The fin of heat exchanger refers to the heat transfer metal sheet in the heat exchange device, which increases the heat exchanger surface area of the heat exchanger and improves the heat transfer efficiency. The heat exchanger fin has an annual output of hundreds of millions, and its material is usually 0.08~0.20mm thick aluminum foil. Therefore, high speed progressive die must be used.

Semiconductor lead frame is the carrier of semiconductor chip, playing the interface role between semiconductor device and printed circuit board (PCB). Its outstanding characteristics are: surface quality, shape accuracy, shape and position accuracy, accumulation error, appearance characteristics and so on. It is the highest among all stamping parts. In particular, the shape of its lead is basically like a crab’s long and thin cantilever, which is different from the conventional stamping process.

There are a wide variety of electrical connectors and widely applied fields. The stamping parts included are various in form and generally have the following characteristics.

(1) high reliability, due to the electrical signal connection between subsystems, it is required to maintain reliability under harsh conditions, such as impact, vibration, stress relaxation, environmental corrosion and so on. Electroplating is usually used to ensure corrosion resistance.
(2) high precision, conventional civil product connector stamping parts, general blanking precision within + 0.03mm, bending precision within + 0.05mm, and high grade blanking precision required + 0.01mm, bending within + 0.02mm.

The micro stamping parts include micro drawing, incremental forming, micro punching and micro bending. Compared with the traditional stamping process, although the process is the same, the micro stamping is not a simple reduction of the traditional stamping shape.

With the size reduction of forming parts, micro stamping has the following characteristics.

1) its surface area and volume ratio increase, thus affecting the temperature condition.
2) the smaller the part size, the greater the adhesive force and the surface tension between the die and mold.
3) the effect of grain size is very significant, and is no longer regarded as homogenous homogeneous continuum, just like traditional forming.
4) when the width of the product is equal to the thickness of the plate, the high strain rate will affect the plastic and microstructure of the material, especially the size of grain and the size of the typical workpiece.
5) the smaller the size of the parts, the smaller the proportion of the closed lubrication area to the total lubrication area, and the harder the lubricant stored on the workpiece surface.

Metal stamping parts are widely used in many areas we know well, including some electronic devices, auto parts, decorative materials, instruments and meters. The hardware stamping parts have the characteristics of thin, uniform, light, small and strong.

2. production mode of high speed precision stamping parts

High speed precision stamping parts use high speed precision press production line and multi position cemented carbide progressive die as the main technological means to implement mass production, including blanking, drawing, bending, flanging and riveting. The material is mostly coil material, which is automatically discharged by the automatic discharge rack, which is usually leveled by leveling machine. The leveling material is automatically fed by a high-speed press auxiliary feeder. In order to improve stamping performance, the surface of the material needs to be dipped or pressed. The selection of stamping oil requires the assessment of the needs of the subsequent process. The parts are usually automatically wrapped by the reel reel, and the paper or plastic film is added to the parts, or conveyed directly to the collector by the conveyor belt. Some stamping parts need post-processing, such as cleaning, electroplating and so on. The vast majority of high-speed precision stamping parts are produced by single machine automation, and individual complex parts adopt multi machine automatic production line.

Metal hose is not suitable for liquid sulfur delivery pipeline

Liquid sulfur is transported to the wharf by ship and then pumped into the storage tank in the installation area. To overcome the fluctuation of the river and the sloshing of the barge, a metal hose is selected for the liquid sulfur pipeline between the dock Zhanqiao and the riverbank.
The liquid sulphur is shipped to the dock and then pumped into the storage tank of the installation area. In order to overcome the fluctuation of the river and the barge of the pontoon, the metal hose is selected for the liquid sulfur transportation pipeline between the pier Zhanqiao and the river bank. The metal hose soon cracked due to liquid sulfur leakage. To this end. The causes of breakage were analyzed, and communication with suppliers and manufacturers was made, and suggestions for improvement were put forward.
The design parameters of the metal hose are: the jacket is accompanied by the tube DN125, the outer tube DN200, the length is 10 m, the material is 304 stainless steel, the wall thickness is 0.8 mln, and the design pressure is 1 MPa. The operation conditions are as follows: the liquid sulfur intermittent transportation, the internal liquid sulfur working pressure is 0.6 MPa, the temperature is 135 oC, the outer layer steam pressure is 0.5 MPa, the temperature is 140 degrees Celsius.
It is found that the leakage position is on the first wave peak of the bellows of the inner hose close to the pipe joint, and the crack is distributed in the circumference, and the opening of the inner surface of the crack is larger than the outer surface. It is inferred that the crack extends from the inside to the outside.
The liquid sulfur itself has a certain acidity. In the process of loading and unloading, liquid sulfur is unavoidable to contain a small amount of water and oxygen, and oxidize to a certain acidity. Therefore, the acidity of liquid sulfur is further increased; on the other hand, the solid solution treatment is improper in the production and processing of the metal hose material, the carbide is not fully dissolved and the material itself has carbide precipitation, which greatly reduces the 30 4 the corrosion resistance of stainless steel itself, in acidic conditions, first appeared micro electrochemical reaction at these locations, resulting in corrosion.
The fracture area of the metal hose is located on the upper side of the first peak. Because the hose is too long, the curvature of the fracture is too large and the stress concentration is concentrated. In addition, the interstitial fluid is used during the operation. When it is not transported, the steam is stopped and the liquid is solidified in the hose, so that the hose is turned into a rigid tube and can not absorb the stress generated by the displacement of the barge. Under the combined action of the above two stresses, the metal hose is cracked by stress corrosion.

Stamping process characteristics of precision metal stamping parts

A stamping part is a sheet metal part, which is a part that can be processed by means of stamping, bending, drawing and so on. A general definition is a part with constant thickness during the process. Corresponding is the casting parts, forging parts, mechanical parts and so on, for example, the iron shell outside the car is the sheet metal parts, and some of the stainless steel cabinet is also sheet metal. Stamping is a car repair technology, that is, to repair the metal shell deformation part of the car, such as the body shell has been hit a pit, can be restored to the original sample by sheet metal.

The basic equipment of the stamping factory generally includes the shearing machine, CNC punch press / laser, plasma, water jet cutting machine / composite machine, bending machine and all kinds of auxiliary equipment, such as the opening machine, the leveling machine, the deburring machine, the spot welding machine and so on.

Usually, the most important three steps for stamping parts factories are scissors, punching / cutting and folding.

Stamping parts are sometimes made to make gold. Generally, some metal sheets are made by hand or die punching to produce plastic deformation, forming the desired shape and size, and further forming more complex parts by welding or a small amount of mechanical processing, such as the chimneys commonly used in the family, the iron skin furnace, and the shell of the car. Plate gold.

The processing of stamping parts is called sheet metal processing. For example, making use of plate to make chimneys, iron buckets, oil tank oil pot, ventilation pipe, big head of elbow, Tianyuan place, funnel shape and so on. The main working procedure is cutting, bending and buckle edge, bending forming, welding, riveting and so on. It needs certain geometric knowledge.

The modern sheet metal process includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, sheet metal bending, die forging, water jet cutting, precision welding and so on.

The main reasons for permanent failure of hardware accessories in advance?

2018/5/24 19:48:26 Viewers:5

Generally speaking, the hardware parts we make will be designed and made according to the actual situation, but after a period of time, the mold will be wrong or permanently invalid. Today, the question is answered by the small editor.
Undefined 1) the material problem of the main working parts of the mould and improper material selection. The material has bad performance and no wear resistance; the die steel has not been refined, and has a large number of smelting defects; the convex and concave die, the forging process of the forging blank is not perfect, and the remains have the hidden trouble of heat treatment.
2) the problem of die structure design, and the structure of stamping die is unreasonable. The slender punch has no design reinforcement device, the discharge port is not smooth, there is a pile up, the unloading force is over, the ambassador mold is subjected to alternating load increasing and so on.
3) the molding process is not perfect, mainly manifested in the poor quality of the convex and concave die forging billets, and the heat treatment technology and technology have problems, resulting in the imperfection of the convex and concave die, the soft point and the uneven hardness. Sometimes there are micro cracks and even cracks. The grinding and polishing are not in place, and the surface roughness is too large.
4) no lubrication or lubrication, but the effect is not good.
Article label: hardware accessories D buckle dog buckle box

Working principle of sludge treatment equipment

The high humidity sludge is sent directly into the roller crushing dryer by the feed spiral, and the copy plate on the inner wall of the roller is repeatedly copied and dropped. After the crushing device is scattered, the material is in full contact with the high temperature medium under the negative pressure to complete the heat and mass transfer process. Because of the inclination of the roller and the effect of the introduction of the air, the material is slowly moved from the feed end, and it is discharged by the helix of the material after drying. The tail gas is discharged through the dust collector and discharged into the atmosphere.
The sludge treatment equipment adopts a flow drying process, especially for the rapid drying of the high wet sludge which needs to be preserved. For example, the treatment of fresh chicken manure can be used to dry, sterilize, deodorize and preserve nutrition at a time. The machine is equipped with a high-speed rotary crushing device, which increases the contact area of the sludge and the drying medium, and a certain inside of the equipment. Some unique designs make the sludge not easy to adhere to the operation board and cylinder wall. The whole machine has good thermal insulation and sealing performance, and its thermal efficiency is much higher than that of the ordinary roller dryer.
The sludge treatment equipment is compact in structure, easy to install and debug, and occupies small area. The roller and crushing device all adopt stepless speed regulation, which can meet the drying requirements of different materials. The machine can be used with the heat source of different fuel (such as coal, heavy oil and natural gas).

What are the safety precautions to operate punching machines?

In small and medium-sized enterprises, punching machine is one of the most used small machine tools. In the operation of punching machine, we must strictly follow the operation process, avoid irregular operation, not only affect the efficiency of machine tools, but also affect the normal operation of safety production. Today, Tai’an Shuo Yuan machine, a stainless steel punching machine, summarizes the safety matters of punching machine in operation.
First, the workers in the operation of the punching machine must not have the glove with a thread, because the punching machine is a high speed equipment, the wire of the glove is easily entangled into the equipment, causes harm to the human body, and other counties and ropes are not put in the operation area and the worktable. Secondly, in the process of operation, such as adjusting speed, stroke, clamping tool, workpiece and wiping equipment must be carried out in the state of parking. In loading and unloading bits, a special key must be used and the hand hammer can not be used to prevent the deformation of the central axis.
In order to improve the life of the punching machine, pay attention to the maintenance of the equipment, after the end of the work after the end of the power outage, use the rag cleaning, regular maintenance of the key parts, if there are abnormal, timely inspection of failure and timely maintenance, the operation of the equipment under the failure, the closure of the machine tool, clean the machine tool, clean the workplace, Before opening the equipment, check whether all parts of the drilling machine are normal.