To deliver an effective presentation, it’s essential to follow a clear structure: an introduction, the main content, a conclusion, and a Q&A session. Before presenting, you should prepare thoroughly by researching your topic, organizing your ideas logically, and rehearsing your speech. While presenting, speak clearly, maintain eye contact, and use appropriate gestures to keep the audience engaged. Avoid reading every word from your slides or speaking in a flat tone. After the presentation, remember to thank the audience, invite questions, and respond politely. Avoid ignoring feedback or ending the session too abruptly. To leave a strong impression, make good use of visual aids, share relevant stories or appropriate humor, and show confidence. A strong opening and closing, combined with enthusiasm, can leave a lasting impact and help your message resonate with the audience.

Speaking:

https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

Last week, I bought three different kinds of bearings: ball bearings, roller bearings and tapered roller bearings. I bought them from a store near my University. I purchase for my project, I desgin a robot arm. I use to ball bearing for couplings help they can roate around shaft. I use to roller bearing for shaft arm help it run smooth. I use to tapered roller bearing at grip positon because it can impact resistant.I chose these bearings because they ensure smooth motion, reduce wear and tear, and improve the efficiency of the moving parts. The quality and variety available at the store made it easy to select the right components for my project’s needs.

W2

In my design, I used flexible couplings to connect the motor to the screw. But there were some problems. The couplings could not hold the parts tightly and did not work well when the motor moved fast. Sometimes, the parts slipped, and the machine did not run smoothly. I think the couplings were too soft and not strong enough for my project. A better choice would be jaw couplings or rigid couplings because they are stronger and more stable. To fix the problem, I changed to jaw couplings and made sure the motor and screw were straight and well-aligned. After that, the machine worked better, with less shaking and better power transfer. This showed me that choosing the right coupling is very important for a working design.

Sp1+2:

https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

There are 2 types of mechanical drive: belt drive and chain drive. Belt drive is used to transmit power from one shaft to another shaft by means of friction between belt and pulley. Unlike it, chain drive transmits power between paralled shafts. Chain drive is mostly made of metal, while belt drive is often made of plastic or rubber. Using belt drive can reduce noise and vibration, but chain drive makes noise and vibrations while operating because it is made of several links. So that chain drive requires lubrication, but it doesn’t need to lubricate belt drive. The advantages of chain drive are not affected by atmospheric condition. By contrast, due to the material, belt drive is affected by weather conditions and requires more tension. Unlike chain drive has high efficiency, belt drive has low efficiency.

Writing 2:

Gear is a rotating circular component with teeth which mesh with another toothed parts. We use gear to transmit torque. It also can be used to change speed and torque or direction of power source. There are 5 types of gear including: spur gear, helical gear, bevel gear, worm and worm gear, rack and pinion. Firstly, spur gear is the simplest type of gear with teeth projecting towards or away from the center. It’s used in low-speed applications. They can't control noise at high speed. Secondly, helical gears have their teeth cut in a spiral shape. They are used for high-speed applications, large power transmission or where noise control is important. The angled teeth engage, helping them run more smoothly and quietly. Thirdly, the worm has just one continuous tooth and the worm pairs with a worm gear, which helps reduce speed. Next, rack and pinion gears consist of gear engaging a linear gear. The function of rack and pinion gears is converting rotational motion into linear motion. Finally, bevel gears have a conical form and can be used to transmit rotational power through shafts at an angle, typically 90 degrees to each other.

Hội thoại: https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

SIEMENS NX is a new CAD program; it was released for the first time in 1973 by PLM Software. NX has become popular as it’s a simple, useful, and powerful software. Designers can use it aerospace or automative companies. With NX, the user can create both 2-D and 3-D technical drawings. It also can edit data, link data from various sources. Morever, this software is programmed to collect multiple design elements into a single feature. NX has many advantages. The first advantage is that it’s very fast and flexible. Another benefit is that it can reduce the company’s mistakes and maximize productivity. And a huge pro is that designers can create a very high level of control. However, NX has some disadvantages. It requires a profestional training time before the designers can use it. Next, it’s not able to handle super complex parts or assemblies. Finally, NX is focused more on the layout of icons.

Speaking 1,2: https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

The manufacturing process shown is called die-casting, used to produce aluminum products, in this case, an aluminum wheel. The process consists of five steps. First, molten aluminum is poured into a mold to form the basic shape. Next, the mold is closed and pressurized to ensure the aluminum fills all the cavities properly. In the third step, the aluminum is allowed to cool and solidify into the desired form. After that, any excess material is trimmed off to perfect the wheel's shape. Finally, a thorough quality inspection is conducted to ensure the final product meets the required specifications. Each step contributes to the precision and durability of the final product.

Speakong: https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

There are 7 types of plastic with different uses and features. The first group is polyethylene terephthalate (PET/PETE). It’s mostly used for food and dink packaging due to its oxygen prevention. It’s also the most recycled plastic in the world. The second one is High Density Polyethylene (HDPE), its products are very safe and are not known to transmit any chemicals into foods or drinks. For example, we have grocery bags, milk jugs or playground equipments, lids and shampoo bottles from HDPE. The third group is Polyvinyl Chloride (PVC). It’s widely used in building and manufaturing such as doors, pipes, wires or replace traditional material. Next group is Low Density Polyethylene (LDPE), it’s a flexible, odorless, transparent, recyclable thermoplastic polymer. We use it for the infamous bags that are used for few times then discarded such as plastic bags, six-pack rings, containers and plastic wraps. The fifth group is polypropylene (PP), which being hard, sturdy and can withstand high temperatures. People use PP in car parts, thermal vests, yogurt containers and licing hinges. Another group is Polystyrene (PS) – a very cheap and easy to create plastic. It can be found everywhere from beverage cups, egg cartons or dinnerware. Although it’s inflammable, PP is still dangerous as it leaks harmful chemicals when heating. The last group include the plastics that can’t be identified in the six types, most well-known is polycartbonate (PC). Because of toughness and strongness, PC is commonly used in eye protection, sunglasses, sport and safety goggles.

S:

https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

The process shown in the diagram is called blow moulding. It is used to produce hollow plastic products. There are three main steps. First, plastic pellets are fed into a heated extruder. The screw inside the extruder turns and pushes the plastic forward, melting it into a soft molten state. Second, the molten plastic is forced through a nozzle to form a hollow tube called a parison. The parison is placed between two halves of a mould. Finally, air is blown into the parison through an air hose, making the soft plastic expand and take the shape of the mould cavity. Cooling lines in the mould help the plastic harden. Once cooled, the mould halves open, and the finished hollow plastic product is removed, ready for further processing or use.

W2:

From my point of view, there are 3 typical problems of plastic injection moulding. They are short shot, sink mark and void. As I know, short shots are of 2 reasons. Firstly, there is not enough plastic in the shot. Secondly, the plastic pressure loss in the mould is too high. We have 2 ways to avoid these causes. The first one is increasing fill speed, plastic and moud temperature. Next, we could increase gate size and runner. The void is created by shrinkage. It is the volume change of plastic when plastic is heated or cooled. To attack this problem, we have 3 ways. The firt way is reducing wall thickness. Then, you should slow down the cooling rate. Besides, we can increase gae size and locate it at the thick oart of the moulding. The final problem is sink mark. There are some reasons for this phenomenon as the internal stress is too high and the part has low surface rigidity. The ways to solve is simple. We need to have enough shot size and increase holding pressure, holding time. Besides that, we should reduce mould temperature and wall thichness for faster. Those are some typical problems of plastic injection moulding and the ways to attack them.

S:https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT

There are seven items in the CNC machine maintenance list. They are: checking the hydraulic pressure, cleaning the window of the door and the light, checking the cooling system level, cleaning the radiator and making the fins straight, draining and cleaning the lubrication unit, draining and refilling the cooling unit, and checking the spindle for radial and end play. The customer needs to do some tasks daily, such as checking the hydraulic pressure and cleaning the window and light. Weekly, they should check the cooling system level. Monthly, they need to clean the radiator. Semi-annually, they should drain and clean the lubrication unit, and refill the cooling unit. Annually, they must check the spindle. To do these tasks, the customer needs to inspect, clean, adjust, refill, and replace when necessary. Doing these regularly will keep the CNC machine in good condition and extend its life.

W2:

The machine tool I am talking about is a CNC machine. It is used for cutting, drilling, and shaping materials with high precision. It can work on metal, plastic, and many other materials. Some kinds of maintenance work for a CNC machine include checking the hydraulic pressure, cleaning the windows and lights, checking the cooling system level, cleaning the radiator, draining and cleaning the lubrication unit, refilling the cooling unit, and checking the spindle. We need to maintain the CNC machine regularly to make sure it works smoothly in the short term and to avoid sudden breakdowns. In the long term, maintenance helps extend the machine’s life, improve accuracy, and reduce repair costs. Regular care also keeps the machine safe for the operator and ensures the quality of the finished products.

S:

https://drive.google.com/drive/folders/1QuY6d-bPO3zxtDnZgN8Qs4UjjVwxGLjT