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There are many machine tools in the workshop, but the lathe number 10 needs the best maintenance because it is so old. Everyone is aware that some cylindrical workpieces are cut using a lathe or turning machine. We must regularly check the air pressure and waterline pressure gauges. Next, warm up the spindle for at least five minutes at a low speed. Chip filter needs to be cleaned as well. The following tasks only need to be completed once per week: checking all filters, checking coolant levels, checking oil or grease levels, and topping off the oil. Oil should be changed every six months, and the drive belt and spindle bearing should be inspected. We need to carry out all these maintenance work to keep the machines working in the best condition, avoiding risks during work.

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Plastic injection moulding may occur some types of problem such as short shot and void. First of all, short shot is phenomenon in which the mould cavity cannot be completely filled by molten plastic, resulting in a portion where there is no plastic. It can be of two reasons. The first, there is not enough plastic in the shot. Second, the plastic pressure loss in the mould is too high. To solve this problem, we need check the shots continuously and use plastic with high melting capability. Therefore, increase fill speed, plastic and mould temperature. Addition, increase gate size and runner. The next problem, void is phenomenon when pocket of air is trapped within or close to the surface of an injection moulded prototype. It is caused by plastic shrinkage and plastic volume changes when plastic is heated or cooled. To attack this problem, first we should increase the injection pressure to force more material into the mould and reduce shrinkage. Second, we had better reduce wall thickness. Finally, we ought to increase gate size and locate it at the thick part of the moulding.

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As you can see in the figure, this is the process of plastic moulding process. There are 6 steps in this process. First, we remove the polymer pellets from the hopper to the cylinder. Sencond, an electric motor turns the screw in the extrusion moulder. Third, the cord polymer pellets move along the cylinder. Next, heaters warm the polymer pellets to turn them into a liquid. Then, the warm, soft molten polymer moves along the cylinder. Finally, the machine pushes the molten polymer out into the mould.

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As far as I know, plastic is a synthetic material made from a wide range of organic polymers. There are seven types of plastic. First, plastic code number one is PE/PET stand for polyehylene. Second, plastic code number 2 is HDPE stand for High-Desity polyehylene. The third plastic type is PVC stand for Polyvynyl chloride.

The next type of plastic is LDPE stand for Low Desity Polyethylene. Then, plastic code number five is PP stand for polypropylene. More over, PS is the sixth type of plastic and PS stand for polystyrene. Finally, if plastic cannot be identified in six types above then it will be included in group number 7. PET is the most common type of plastic. It holds the number one because of its widespread utility. It mostly used for food and drink packaging purposes due to its oxygen prevention. Also, PET bottles are the most widely recycled plastic in the world.

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As far as I know, plastic is a synthetic material made from a wide range of organic polymers such as polyethylene, PVC, nylon. Nowdays, a lot of product are made of plastic including food containers, machine components and bottles because plastic is versatile, safe and lightweight. As I said earlier, Plastic has lot of properties. First, Plastic is versatile because it can be shaped easily into wide range of forms. Next, plastic is durable. It has a long life compared to many other products and retain their shape and strength. Then, Plastic is cost-efficient because it is formed into final useful form quickly and inexpensively. Finally, Plastic is safe. It can be used in food wrapping and medical applications. Using plastic brings us great number of benefit.

First of all, one important advantage of plastic is that they are pretty convenient to use. For instance, if you go to supermarket, you will likely use shopping plastic bags to carry home the things you just bought since it is simply the most convenient way. Moreover, Plastic is cheap. Compared to other packaging materials, plastic is also quite cheap. Further more, plastic is durable. Plastic is also quite durable and resistant to all kinds of adverse outside factors. For example, plastic is quite resistant to heavy rain, storms and so on. However, using too much plastic everyday, people may face with different problems. First, plastic hurts the environment. It leads to sorts of pollution and especially poor countries will suffer the most since they are often flooded with plastic waste from all over the world. So, we should reduce plastic waste. Second, Plastic is not biodegradable. Finally, Recycling of plastic may not possible. Some plastic items cannot be recycled and will therefore be either have to burned or disposed into landfills. 100 years ago manufacturers could produce modern synthetic plastic but we couldn’t mould plastic into complex shapes. Nowdays, manufacturers can mould plastic into variety of complex shapes. At present, it is possible to replace components in engine with plastics and Plastic can be used to help designers reduce weight in aircraft. In the future, it will save money and increase efficiency by using smart plastic. Soon it will be possible to use eco-friendly bioplastics in a wide range of applications in electronics, automotive and other fields. In the near future, we will able to make plastics from any kinds of plant materials.

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The check valve is made of cast iron

First step is casting. In this step hot liquid of cast iron is poured into a container and then cooled to make the correct shape

The cast iron is then turned on a lathe to remove ecessive parts

Next, holes are made using a drill

After drilling process, the next step is painting. The surface is covered by paint

The final step, product is checked carefully.

This is when we make sure that the part is made properly.

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CAD (Computer Aided Design) is the use of computer software to design and document a product’s design process. Manual drafting or hand drafting is the practice of creating drawings by hand with pencil or ink on a media such as paper or polyester film using drafting instruments and equipment. Modeling with CAD systems offers a number of advantages over traditional drafting methods that use rulers, squares, and compasses. Designs can be altered without erasing and redrawing. CAD is much faster and more accurate than manual drawing, designs can be quickly modified. Computer software can provide a three-dimensional drawing easily. Therefore, engineering designers can see how mechanical components may fit together. When the design is ready, the CAD system can generate the detailed drawings needed to start product manufacturing.

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SolidWork is one of the most used programs in professional setting across the globe. As I know, over two million engineers and designers at more than 165,000 companies were using SolidWorks. SolidWorks is CAD program developed by Dassault Systèmes. It was first released in 1997. There are 3 main functions of SW, they are sketch out ideas, expriment with features and dimensions and produce models and detailed drawings. About advantages, it has three ones. First, it is easy and intuitive to use from the beginning. Next, SW is easy to use for 3D modeling. And finally, it is quick and easy to create parts, add them to assemblies and create drawing. Besides, SW has some disavantages. SW contain some unnecessary features for the common user so it spends a lot of computer space. Moreover, open different versions hardly. The old version can’t open file of newer version. And It is very expensive.  For students, they offer a Student Version for $150.

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Gear is a rotating circular component of machine with teeth, which mesh with another toothed part to transmit torque. Gears devices can change the speed, torque and direction of a power source. There are five main types of gear, they are spur gear, helical gear, bevel gear, worm and worm gears and rack and pinion.

Spur gears the simplest types of gears with teeth projecting towards or away from the centre. Spur gears are used in low-speed applications and in situations where noise control is not a problem. They tend to be noisy at high speed.

Helical gears are similar to spur gears except that their teeth are cut in a spiral shape. Helical gears are used in high-speed applications, large power transmission, or where noise control is important.

Some helical gears have just one continous tooth. They are called worms. A worm pairs worm gear, which help reduce speed.

Rack and pinion gears comprise a circular gear engaging a linenear gear, which operate to convert rotatinal motion to linear motion.

Bevel gear have a conical form and can be used to transmit rotational power through shaft at an angle, typically 90 degress to each other.

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Drives have two types, they are belt drive and chain drvie. Belt drive is used to transmit motion and power from one shaft to another by means of friction between belt and pulleys. Chain drive is use for transmitting motion and power between successive chain with sprocket special toothed wheels. Belt drive is made of plastic or rubber. Unlike Belt drive, chain drive is made of metal with a number of link. Belt drive reduces noise and vibration during operation. Chain drive is different from belt drive because it causes these problems. Slippage occurs in belt drive while it doesn’t in chain drive. Belt drive has low efficiency due to frictional loss. Chain drive is different belt drive as it has high one. Belt tension of belt drive is affected by asmospheric condition and temperature. Unlike belt drive, this problem is doesn’t happen in chain drive. Belt drive requires minimum maintenance except for re-tension while chain drive requires frequent lubrications. Belt drive is used in flour mills, coolant pumps, lubricantion pump, AC, CAM shaft and lathe machine. Chain drive is used in bicycle, motorcycles, argricutural and textile machinery and material handling equipment.

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Good morning ladies and gentlemen, I am here to day to write about how to make an effective presentation. As you know, the basic structure of a presentation has three parts. They are introduction, body and conclusion. Let’s now move on to what should you do before the presentation. You should be prepared and organized. You had better know your audience. You ought to choose a presentation style. I advise you to practice and internalize. This brings me to my next point, which is what should you do during the presentation. It is important to use gestures and body language to express ideas. You should make an eye contact, look at audience and do not look at the floor and ceiling. Remember to use personal stories or experiences as examples. Finally, it is what should you do after presentation. You should thank the audience after they ask you question and try to answer the audience question. To summarize, you need to remember the basic structure of a presentation and somethings you should do before, during and after presentation.

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Bearing has two main types. They are rolling contact bearings and journal bearings. Rolling contact bearings use roller to support loads. They have an inner race, outer race and rollers. There are 4 main types of rolling contact bearings including ball bearings, straight roller bearings, tapered roller bearings and thrust roller bearings. First, Ball bearings use spherical rollers. They support radial and axial motion. Next, Straight roller bearings use cylindrical rollers. They are support radial motion. Then, Tapered roller bearings use conical rollers. They support radial forces and moderate thrust forces. Finally, Thrust roller bearings use barrel-shaped rollers. They support thrust motion. Addition, Journal bearings have no rolling parts and they have lubricated sleeve. Load-carrying capacity is high.

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Couplings have 2 main functions. They are used for transmiting power from one shaft to another and disconnecting to maintanace easily. There are two primary types of couplings. They are rigid couplings and flexible couplings. Sleeve-style couplings are the most common rigid couplings. Beam couplings are the most typical of flexible couplings. Beam couplings are used when there is an offset. Flexible couplings transmit power without perfect alignment. These can accommodate several degrees of shaft offset. Flexible couplings help reduce noise and unwanted vibrations. These need to be used when two shaft are aligned perfectly. Sleeve-style couplings are used to hold shaft in perfect alignment. Beam couplings are cut in a spiral shape. Sleeve-style couplings are used to maximize performance and efficiency