https://padlet.com/lecongtuyen2412002/pro Được tạo ra với sự run sợ en-us 2022-03-07 03:37:43 UTC 2023-11-09 03:13:49 UTC hello@padlet.com https://padlet.net/icons/png/1f60f.png lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2300701344 Good morning, ladies and gentlemen, what i want to do this today is writing a paragraph about what a person should do in a presentation. The basic structure of a presentation is three parts: introducsion, body and conclusion. I will be about what we should do before the presentation, you should know your audience, you should choose the right presentation style, you should outline what you want to present and write down the your presentation. During the presentation, You should turn off your phone before giving a presentation. You should make eye contact with your audience. You should use fewer words instead of more pictures on the slide. You shouldn't read from the newspaper. You shouldn't put your hand in your pocket. You should not use too many different animations. You should not look at the floor or ceiling. After the presentation, you should thank the audience after they ask you are question. You should try to answer their question. If you don't have an answer, you can email it later.]]> 2022-09-17 03:08:04 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2300701344 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2300702663 https://youtu.be/y9Kdr1SMtCc]]> 2022-09-17 03:11:36 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2300702663 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2306487561 The functions of couplings are for connecting shafts together to transmit power and disconnecting shafts for maintenance easily. There are two primary types of couplings: Rigid coupling and flexible coupling. Rigid couplings serve to align the shafts with each other. Perfect alignment reduces wear on the machine. Sleeve-style couplings are the most common rigid coupling. sleeve-style couplings can be you to maximize performance and efficiency of the machine and reduce wear on machine. The function of flexible couplings is to allow for slight misalignment. Flexible couplings transmit power without perfect alignment. Flexible couplings help reduce noise and unwanted vibrations rotating. Beam couplings is a common kind of flexible couplings. it is cut in a spiral shape.

]]> 2022-09-21 09:10:36 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2306487561 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2306488262 https://www.youtube.com/watch?v=Ee39f4A3ELU&t=27s]]> 2022-09-21 09:11:11 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2306488262 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2306811378 https://www.youtube.com/watch?v=rFYcYNenCe8]]> 2022-09-21 13:10:51 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2306811378 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2306811988 The bearing makes many of the machines we use every day possible. Without bearings, we would be constantly replacing parts that wore out from friction. There are two primary types of the bearings: rolling contact bearing  and journal bearing. A journal bearing has no rolling parts. The shaft rotates inside a lubricated sleeve instead. Rolling contact bearing use rollers to support loads. there are three main part : rollers, inner race, outer race. An inner race of a ball bearing rotates with the shaft. Outer race of ball bearing remains stable relative to the shaft. There are  four primary types of rolling contact bearings: ball bearing, straight roller bearing, tapered roller bearing and thust bearing. Ball bearings use spharical roller. they supports radial and axial motion. Straight roller bearings use cylindrical rollers. they support radial motion. Tapered roller bearing  use conical roller to support radial forces and modente thoust forces. Thrust roller bearings use barrel-shaped rollers to support thrust motion.]]> 2022-09-21 13:11:08 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2306811988 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2322371204 Gear is a rotating circular component of machine with teeth, which mesh with another toothed part to transmit torque. Gear is used to transmit power and motion between machines components. it is used for changing the speed, torque and direction of a power source. there are five types of gear: spur gears, helical gears, bevel gears, worm and worm gears and rack and pinion gears. Spur gears have teeth projecting towards or away from the centre. they are used in low-speed applications. They tend to be noisy at high speed. Helical gears have their teeth cut in a spiral shape. They are used in high-speed applications, large power transmission and noise control. Bevel gears have a conical form and can be used to transmit rotational power through shafts at and angle, normally 90 degress. Worm hás just one continous tooth and pairs with a worm gear. Worm and worm gears is used to reduce speed. Rack and pinion gears comprise a circular gear( the pinion) engaging a linear gear( the rack), which operate to convert rotational pinion into linear motion.]]> 2022-10-02 03:22:29 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2322371204 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2322371303 There are two types of drives are Belt drive and Chain drive. 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 used to transmit motion and successive chain with sproket special toothed wheels. Belt drive is made of rubber, plastic,... Unlike Belt drive, Chain drive is made of metal with a number of links. Belt drive can reduce noise and vibration during operation, Chain drive different from Belt drive because it is can cause noise and vibration. Slippage occurs in Belt drive while it doesn't in Chain drive. Belt drive has low efficiency due to frictional loss unlike Belt drive, Chain drive has high efficiency (usually above 95%). The tension of Belt drive is affected by atmospheric condition and temperature unlike belt drive, Chain drive is not. Belt drive requires minimum maintenance exept for belt  retention. Chain drive is different from Belt drive because it is requires reqular lubrication. While Belt drive is applied in flour mills, coolant pump, CAM shafts, lathe machines and lots of other machines, Chain drive is used in bicycle, motorcycles, agricultural and textile machinery.]]> 2022-10-02 03:22:47 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2322371303 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2322371431 https://www.youtube.com/watch?v=fmoCTVsjeqk]]> 2022-10-02 03:23:12 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2322371431 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2322371572 https://youtu.be/xQj9SV5A6co]]> 2022-10-02 03:23:37 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2322371572 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2341604805 From my point of view, there are some difference between CAD and manual drafting. Computer-aided design is widely used in computer-aided devices for engineers, architects and other design professionals, while manual drafting is Drafting is the process of drawing designs and diagrams for industries like engineering and manufacturing. CAD enables the development, modification, and optimization of the design process. The biggest advantage of CAD over manual drafting is that it can be easily edited and leaves no trace. this is also a weakness when editing manually you can't edit it easily. Moreover, using cad will save you a lot of money compared to manual drafting]]> 2022-10-16 02:04:32 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2341604805 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2341604897 NX was released for the first time in 1973. it was simple, useful and powerful software. it was used in aerospace, automotive companies, mechanical companies. NX helps create drawings 2-D or 3-D models. It is used to edit data, link data from various sources. It allows to collect multiple design elements into a single feature. There aree lots of pros of using NX to design. First, NX is fast and flexible. Second, NX  creates a very high level of control. Third, NX reduces the companies mistakes and maximize productivity. Finaly, NX tracks your product through every phase os the production cycle easily. However, use may cope with some problems. The disadvantages of this software is lack ease of use and it is required professional training before using it. While Siemens NX is focused more on the layout of icons and it isn’t able to handle super complex parts or assemblies

]]> 2022-10-16 02:04:52 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2341604897 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2341919746 https://youtu.be/PvwBeHIXLO0]]> 2022-10-16 14:58:41 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2341919746 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2341920205 https://youtu.be/_XbXV7zlIp8]]> 2022-10-16 14:59:10 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2341920205 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358737438 The check valve is made of cast iron. First, it is casting process people pour hot liquid cast iron into a container and cooled to make the correct shape. The cast iron is then turned on the lathe to remove excessive parts. Next, holes are made using a drill as you can see on the screen. After drilling, the surface is painted to make it look great, the next step is punching holes. The final step is inspection. In this step, the product is checked carefully. This is when we make sure that the part is made properly]]> 2022-10-27 08:48:09 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358737438 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358738433 https://youtube.com/shorts/LoI1vDss26c?feature=share]]> 2022-10-27 08:48:57 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358738433 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358752463 Plastic is synthetic material that use polymers as a main ingredient. Plastic is able to be moulded or shaped to any form. The properties of plastic are versatile, lightweight, durable, cost-efficient. 100 years ago, manufacturers could produce modern synthetic plastic. In the past, we couldn't mould plastic into complex shapes. Nowadays, manufacturers can plastic into a variety of complex shapes. At present, It is possiable to replace components in engines with plastic. Plastic be used in manufacturing to help designer reduce weight in aircraft. In the future, we will save money and increase efficiency by using smart plastic coatings on manufacturing components. Soon, it will be possible to use eco-friendly bioplastic in a wide range of applications in electronics, automotive and other fields. In the near future, we will be able to make plastic from any kind of plant materials. Using plastic brings us many benifits: it is reusable, lightweight, durable and resistant to all kinds of adverse outside factors. however,  people face with some problem: using lots of plastic hurt the environment, plastic isn't biodegradable and recycled.]]> 2022-10-27 09:00:45 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358752463 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358752848 Plastic is synthetic material that use polymers as a main ingredient. Plastic is able to be moulded or shaped to any form. there are seven type of plastic and their code is 1 PET, 2 HDPE, 3 PVC, 4 LDPE, 5 PP, 6 PS and 7 other plastic. HDPE is the most common type of plastic. it is relatively hard and resistant to inpact and can be subjected to high temperatures. also,it is one of the most easily recyclable plastic polymers. It is not only used for grocery bags, milk bottles, recycling bins, but also for playground equipment, lids. ]]> 2022-10-27 09:01:10 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358752848 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358753191 https://www.youtube.com/watch?v=yJaxc-q_qjM]]> 2022-10-27 09:01:28 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358753191 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2358753471 https://www.youtube.com/watch?v=kgIYOXetqH0]]> 2022-10-27 09:01:44 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2358753471 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2361803617 https://youtu.be/5TH9H6xmFNQ]]> 2022-10-30 01:47:29 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2361803617 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2376465703 You can see from the diagram in figure 1, this is the plastic molding process. There are 6 step in this process. The first, pellets of plastic a fed from the hopper into a cylinder. Then, pellets are push along the cylinder by a rotating screw and heated. Next, screw stops rotating and then a ram in front of the screw moves straight forward. Next, soft warm plastic is pushed toward a nozzle by the ram. Next, soft plastic is injected through the nozzle into a shaped cavity between the two halves of a mould. Finally, plastic is cool in the mould and becomes hard inside the cavity]]> 2022-11-09 09:08:00 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2376465703 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2376470085 Some typical problems of the plastic moulding process are short shot and void. Short shot can be two reasons:    the first there are not enough plastic in the shot and the second the plastic presure loss in the mould is too high. We are going to solve short shot as follows: the first, we should check the shots continuously and use plastic with hight melting capbility. then, we had better increase fill speed, plastic and mould temperature.   Moreover, we need to increase gate size and runner. Void problem can be of two reasons: it is caused by plastic shrinkage and plastic volume changes when plastic is heated or cooled. We are going to solve void  as follows: First, i think we should reduce wall thickness and slow down cooling rate. then we need increase gate size and locate it at the thick part of the moulding.]]> 2022-11-09 09:12:06 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2376470085 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2381408015 The type of machine that we want to introduce today is: CNC Milling Machine. It has several features such as: Flexible and versatile, High machining precision, High production efficiency, can handle complex shapes. As you know, cleaning and maintaining the machine after use is very important and necessary. Below are some maintenance procedures for CNC milling machines. First, we need to Sanitize the passages daily to avoid interruptions and control fluid flow. Second, we should Check the oil level in the lubricating oil of the CNC milling machine daily to ensure the motor's operation. Thirdly, oil need to be renew weekly to help the machine operate smoothly. more over, coolant need renewing semi-annually to prevent damage, keep engine at the correct operating temperature. Finaly, we need to check the oil filter and clean all the dirt at the bottom of the oil filter annually]]> 2022-11-13 08:36:16 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2381408015 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2386419805 https://youtu.be/WRt261rWRcU]]> 2022-11-16 11:18:35 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2386419805 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2386421372 https://youtu.be/VXunGHwrUbk]]> 2022-11-16 11:20:01 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2386421372 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2386427495 This machine tool’s name is lathe. The function of lathe is rotate the workpiece on a spindle against the tool at a certain speed to cut away excess material and produce a desired shape. In order for the lathe to work most efficiently and have high durability, regular maintenance is required. We should check water line pressure gauges, check air pressure, warm up spindle-low speed for five minutes and clean chip filter every day. Beside, we need to inspects all filters, check coolant levels, inspect oil or grease, top up oil levels weekly. Final, we hat better inspect spindle bearing, inspect drive belt, change or inspect oil twice a year. We need to maintain the lathe to help the lathe operate smoothly and to ensure engine efficiency]]> 2022-11-16 11:25:45 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2386427495 lecongtuyen2412002 https://padlet.com/lecongtuyen2412002/pro/wish/2386849173 https://youtu.be/iIWUhu-onnA]]> 2022-11-16 15:58:41 UTC https://padlet.com/lecongtuyen2412002/pro/wish/2386849173