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The presentation often consists of 3 main parts: introduction, body, conclusion. Before the presentation, it is important to prepare a lot of things. You should search the information for the topic, divide the tasks among team members and practice speaking many times. In the introduction, you should greet the audience and give the overall objective and structure of your speech, so it is easy for audience to follow. During the presentation, focus on the main points and try to give examples or pictures to illustrate your ideas. Choose images over words. Making eye contact or interactions with the audience. Do not use many words on the slide , do not read from the slide, avoid fancy footwork because it may show your inconfidence. After the presentation, you should have a question and answer section. Finally, consolidate the presentation and remember to give references and thank the audience for listening.

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There are 2 primary types of couplings that I know . Coupling transmit power from one shaft to another. The input shaft connects to the power source. The ouput shaft connects to the destination. Rigid couplings align the shafts with each other. Perfect alignment reduces wear on the machine. Rigid couplings maximize performance and efficiency. Sleeve-style couplings are the most common rigid couplings. Sometimes the shafts do not meet perfectly. Flexible couplings transmit power without perfect alignment. Beam couplings are cut in a spiral shape. These can accommodate several degrees of shaft offset. Flexible couplings help reduce noise anh unwanted vibrations.

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There are two main types of bearings that I know: Journal Bearings and Rolling contact bearings. Journal bearings have no rolling parts. The shaft rotates inside a lubricated sleeve instead. The load-carrying capacity is high. Different from journal bearings, rolling contact bearings use rollers to support loads. They have an inner and outer race and accommodate different types of force and motion. The load-carrying capacity is low-medium. In rolling contact bearings, there are 4 main types of bearings: Ball bearings, straight roller bearings, tapered roller bearings, and thrust roller bearings. Ball bearings use spherical rollers to support axial and radial motion while straight roller bearings use cylindrical to support the radial motion. Besides, tapered roller bearings are for supporting radial forces and moderate thrust forces using conical rollers, and thrust roller bearings serve to support thrust motion using barrel-shaped rollers. Actually, bearings are very important for supporting shafts because they help bear weight and direct motion. In addition, they also prevent shafts from moving in undesired directions. Without bearings, shafts might move uncontrollably, preventing useful work from being performed.

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Gears play such an important part in machines that they have become the symbol for machinery. Firstly,The simplest type of gear is spur gear. Its teeth may project toward or awy from the center beside spur gears are easy to install,cheap,the most common and simplest gears. Spur gears are used for transmitting motion along parallel axes rather than for changing direction. Secondly,Angled helical gears mesh more smoothly than spur gears. Its teeth are cut in a spiral shape and reduce noise and vibration. It is used for transmiting components and reducing speed. Finally, bevel gear is gears meet each other at an angle. It is usually 90 degree and the function of it is to transmit components and transmit power at angle

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I would like to compare two types of drives which are chain drives and belt drives. In terms of similarities, both chains and belts are for moving objects by attaching frames to them. In terms of differences, chains are different from belts in many ways. First, chain drives are often made of metal while belt drives are made of rubber and plastic. Besides, chain drives have small dimensions; and they are often narrower than belt drives. Therefore, belt drive can slip and stretch easily, but chain drives can’t. Chain drives can wear out faster than belts because they need frequent lubrication. Last but not least, chain drives have high heat resistance while that of belt drives is low, about –35 to 85°C.

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I would like to compare two types of drives which are chain drives and belt drives. In terms of similarities, both chains and belts are for moving objects by attaching frames to them. In terms of differences, chains are different from belts in many ways. First, chain drives are often made of metal while belt drives are made of rubber and plastic. Besides, chain drives have small dimensions; and they are often narrower than belt drives. Therefore, belt drive can slip and stretch easily, but chain drives can’t. Chain drives can wear out faster than belts because they need frequent lubrication. Last but not least, chain drives have high heat resistance while that of belt drives is low, about –35 to 85°C.

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Today I will introduce about Autocad 2018.It’s developed by Autodesk corporation and it was used to build the 2d and 3d model. But I do not recommend 3d design in cad because there are still many limitations. Went through many versions, autocad gradually improved and brought stability as well as many new features to users. Talk a little about why I choose this version and not the 2020-2021 version because the 2018 version is considered a stable version, suitable for even weak computers. Advantages of autocad can be mentioned: the accuracy is much more optimized than when drawing by hand. Detect errors quickly and make corrections right on the drawing. Send drawing files quickly. Besides the advantages, there are still some disadvantages: User training takes a long time and is expensive; Large CAD maintenance and upgrade costs. Until now, autocad supports 3 formats: DWG, DXF and DWF (a format developed by Autodesk)

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https://drive.google.com/file/d/1FFRnuEQzPbmKzjCCeEFQR43LRnrgNk5k/view?usp=sharing

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I did some research on current CAD options. I recommend a program called Think Creator 3.0. It supports both PDES and IGES. It also has the capability to create exploded views of machinery and parts. This would help us explain assembly much more easily. We could show clients early design ideas with B-rep and CSG. The program’s excellent photorealistic rendering will provide an accurate sense of the final product. The program makes it easy to turn designs into models. We could easily generate detailed manifold models and non-manifold models. I know Think Creator 3.0 is expensive to purchase, but it will save money overall.

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The check valve is made of cast iron.the first step is casting. This step means that hot liquid material is poured into a container and cooled to make the correct shape. In the next step, after materials are turned on a machine called a lathe, part of the materials is remaved to make the correct shape. Next, holes are made using a drill. After the drilling proccess, the next step is painting process. In this step, a surface is covered with paint. Next, pieces of materials are joined together using a nut and a bolt. The final step, a product is checked carefully.

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As I know, There are 7 types of plastic with different uses and features including: PET, HDPE, PVC, LDPE, PP, PS, and OTHER PLASTIC.

- The first one is PET. Its code is number 1. It is strong and recycable. We use PET to make/ produce/ manufacture food and drink packaging.

- The second one is HPDE. It is hard, resistant to heat, recyclable. We use HDPE to make procery bags, milk jugs, recycling bins, agricultural pipe, playground epuipment, lids, and shampoo bottles

Finally is PVC. It is lightness, durability, and easiness of process ability, hardly recylable. We use PVC to make building and construction industry to produce door and window profiles and pipes with rigid PVC. And use flexible PVC to plumbing, writing, and electrical cable insulation and flooring.

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This is a manufacturing process for producing parts by injecting molten material into a mould. In the first step, the mould opens and the cold, hard, solid plastic shaped is ejected. Next, the screw stops rotating and then a ram in front of the screw moves straight forward. And after that, small pieces (or pellets) of plastic are fed from the hopper into a cylinder. Then the soft, warm plastic is pushed towards a nozzle by the ram. The next step, he pellets are pushed along the cylinder by a rotating screw, and heated. Inside the cavity, the plastic is cooled by the mould, and becomes hard. Inside the cavity, the plastic is cooled by the mould, and becomes hard. The soft plastic is injected through the nozzle into a shaped cavity between the two halves of a mould.

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During the process of plastic injection moulding, there may be have some uexpected problems. There are some problems and the solutions of these. Voids are a somewhat common defective occurrence in injection molding applications. They present as “air pockets” in transparent molding but can also be present in colored or opaque molding applications. they can be caused by either machine (process), mold, or material issues. The solutions is increase the shot volume, injection pressure, reduce melt temperature and clean the mold. Sink marks are a phenomenon in which the mold cavity cannot be completely filled. It is caused when the internal stress is too high or the surface rigidity is too low. We can increase the injection pressure to force more material into the mould and reduce shrinkage, Reduce the injection temperature of the material and the mould. Flash, It means that excess plastic is present on the mold parting or ejector part. Causes:  Insufficient clamping force, The mold has defects .   We need Clean the mold surface Check the size of the exhaust port Increase the injection time and reduce the injection speed Reduce the barrel temperature, nozzle temperature, the injection pressure and pressure

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As far as I know, plastic is a synthetic material….. Nowadays, many products are made of plastic such as food containers and machine parts. Plastic is versatile, lightweight, durable and some kinds of plastic are safe. Plastic brings us a great number of benefits. The first pro is that convenient, lightweight and cheap. Next, it is durable and resistant to all kinds of adverse outside factors (heavy rain, storms). Finaly, it is reusable. However, using too much plastic every day, people may face with different problems. First of all, It can hurt the environment. Moreover, it isn't biodegradable. Furthermore, it isn't recycled. In the past, we couldn’t mould plastic into complex shapes. 100 years ago, manufacturers could produce modern synthetic plastics. At present, it is possible to replace components in engines with plastics. Nowadays, manufacturers can mould plastics into a variety of complex shapes. In the future, it will save money and increase efficiency by using smart plastic coatings on manufacturing components. Soon it will be possible to use eco-friendly bioplastics in a wide range of applications in electronics, telecommunications, aerospace, automotive and other fields.

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This is a lathe. It can be used in a large variety of operations such as turning, taperedturning, shoulderturning, facing, thread,cutting, parting, chamfering, knurling, drilling, boring, counter boring, countersinking, and reaming operation. And you need some kinds of maintenance work and their schedule for it. The lathe need to be cleaned daily to avoid interruptions and control the line of motion of fliuds.Not only that, you need to inspect oil weekly to help the machine operate smoothly. You need to renew coolant twice a year to prevent damage, keep engine at the correct operating temperature, help it warm up. Ideally, maintenance is carried out to keep equipment and systems running efficiently during at least its usual life cycle. As such, practical functioning of equipment is a function based on time.

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https://drive.google.com/file/d/1TMBW1OQqRV3ipNSVRAZgeLgwwlXOLZYy/view?usp=share_link

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https://drive.google.com/file/d/1TRftJaa2Klscr_5LzOvsTSgoqLp0xpzI/view?usp=share_link

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https://drive.google.com/file/d/1HspDgYvN4ECmFrq5RtjH40XcfiNGqwmH/view?usp=sharing

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https://drive.google.com/file/d/1U9ecu5sxwhObXIMQaOK4m0Vn1vjcl1vf/view?usp=share_link