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When building a DIY CNC machine, selecting the right stepper motor is one of the most critical decisions you'll face. Among the most commonly used motors are NEMA 17 and NEMA 23, each offering unique advantages depending on the type and scale of your CNC project.     So how do you choose between NEMA 17 and NEMA 23? In this post, we'll compare these two stepper motors in terms of size, torque, cost, power consumption, and ideal use cases—especially for woodworking CNCs like routers, lathes, and engravers. 1. What Do "NEMA 17" and "NEMA 23" Mean? "NEMA" stands for the National Electrical Manufacturers Association. The number (17, 23, etc.) refers to the size of the motor's faceplate measured in 1/10 inches. So: NEMA 17 : 1.7 inches (43.2mm) square faceplate NEMA 23 : 2.3 inches (58.4mm) square faceplate The size also affects the motor’s torque and frame strength. Larger size generally means more torque and load...

During boiler or water heater installations, some people still try to use PVC pipes. However, this can lead to leaks, bursts, or even injuries . This article explains why PVC is unsuitable for hot water applications and what better alternatives exist.     1. Heat Weakness of PVC – How Much Can It Handle? PVC is a type of plastic that loses its structural integrity above 50~60℃ . As the temperature rises, the pipe softens, loses pressure tolerance, and may eventually rupture. Above 60℃ (140°F): Softens and weakens Above 70℃ (158°F): Structural instability, adhesive failure Above 80℃ (176°F): Pipe deformation, leaks, and bursts Using PVC for hot water is like installing a ticking time bomb .     2. Real-World Failure Cases In one apartment complex, a cost-cutting contractor used PVC for hot water lines, which ruptured during winter heating and caused severe burns . In another case, a hot water pump line melted and ad...

When diagnosing battery packs, especially BMS boards that are not outputting voltage, checking the gate voltage of MOSFETs is a fundamental diagnostic step. This test can distinguish between a FET issue and a control IC issue.     1. Why Gate Voltage Matters MOSFETs act as electronic switches. Unless a sufficient gate-source voltage (Vgs) is applied, the MOSFET remains off and no current flows between drain and source. Gate: Controlled by the BMS's protection IC Source: Usually tied to B− (battery negative) Drain: Connected to P− (load or charge return path)     2. Step-by-Step Gate Voltage Test Set your multimeter to DC voltage mode. Connect the black probe to B− (usually battery negative terminal). Touch the red probe to the gate leg of the MOSFET (usually the leftmost or rightmost pin). Check the voltage. Typically, a Vgs above 2–4V indicates the MOSFET is in conduction (on) state. If gate voltage ...

Cutting boards are essential kitchen tools used daily, but many people overlook proper hygiene and maintenance—especially with wooden boards. Poor maintenance can lead to bacterial growth, foul odors, warping, and cracks. That’s why regular sanitizing and oiling are crucial. In this post, we’ll explore effective natural cleaning methods, proper oiling techniques, and common mistakes to avoid when caring for your wooden cutting board.     How Often Should You Sanitize Your Cutting Board? Because cutting boards absorb moisture and food particles during use—especially when cutting protein-rich items like meat or fish—sanitizing them regularly is vital. Here's a general maintenance schedule: Daily: Wash with mild soap and warm water, then dry immediately. Weekly: Disinfect with natural agents like vinegar or lemon with salt. Monthly: Deodorize using baking soda. 3 Natural Sanitizing Methods 1. Vinegar Spray Mix white vinegar and water in a 1:...

The word "feudalism" appears frequently in history classes, but its meaning differs drastically between East and West. In the West, it refers to a contractual relationship between lords and vassals , while in China, it meant a decentralized system where the king granted land to relatives and loyal officials to rule various regions. In this post, we’ll explore the differences between European feudalism and Chinese feudalism (封建制) , focusing on their structure, philosophy, and historical contexts.     Feudalism in China: Zhou Dynasty’s Decentralized Governance In ancient China, feudalism (封建制) began under King Wu of the Zhou Dynasty, who stabilized the realm by granting territories to royal family members and meritorious subjects . These feudal lords (諸侯) enjoyed autonomy in their regions but were formally obligated to offer tribute and military aid to the Zhou king. Prominent feudal states: Lu, Song, Qi, Jin, Wei A layered hierarchy: Lords → Minist...

How do you usually thaw your frozen pork? Using the microwave may be convenient, but it can compromise both texture and hygiene. Today, we're sharing the top 3 safest and most effective ways to defrost pork , along with their pros and cons.     1. Refrigerator Thawing – The Safest Method Method: Keep the pork sealed in plastic wrap or a zipper bag and leave it in the refrigerator for 8–12 hours. Pros: Minimal risk of bacterial growth and preserves moisture and texture. Cons: Requires advance planning due to the long time needed. 2. Cold Water Thawing – Quick and Relatively Safe Method: Submerge the sealed pork in cold water for 1–2 hours, replacing the water once midway. Pros: Faster than refrigerator thawing and still relatively safe. Cons: Poor packaging may allow water seepage; needs more attention than fridge thawing.     3. Microwave Thawing – Fast but Risky Method: Use the microwave’s defrost setting for 3–5 mi...

Have you ever noticed that some devices seem weaker or malfunction when plugged into an extension cord? Or that appliances further from the outlet don’t operate as efficiently? That’s not your imagination — it’s likely due to a real electrical phenomenon called voltage drop . This article explains why voltage drop occurs as wire length increases, how to measure it, and practical tips to reduce its effects in everyday settings.     What is Voltage Drop? Voltage drop refers to the reduction in voltage as electric current flows through a wire with resistance . As current travels, some energy is lost as heat due to resistance in the wire, meaning the voltage received by your appliance is lower than what was sent from the source. This issue is especially noticeable in lighting systems, refrigerators, and electric motors — often resulting in malfunction, dim lights, or overheating. Factors That Cause Voltage Drop Wire Length : Longer wires introduce more...

Thermistors—short for "thermal resistors"—are temperature-sensitive semiconductor components that play vital roles in both electronics and everyday devices. In particular, NTC (Negative Temperature Coefficient) and PTC (Positive Temperature Coefficient) thermistors are widely used across industries. This post explores their working principles, structural differences, comparisons, and real-life applications in a clear and practical format.     1. What Is a Thermistor? A thermistor is a type of resistor whose resistance varies significantly with temperature. Thanks to their small size, low cost, and high sensitivity, thermistors are extensively used in control systems, consumer electronics, and automotive applications. 2. The Difference Between NTC and PTC Thermistors NTC Thermistor (Negative Temperature Coefficient): Resistance decreases as temperature increases. PTC Thermistor (Positive Temperature Coefficient): Resistance increases as tem...

Balloons are simple childhood toys, but behind their fun lies a world of physics involving gas behavior, pressure, and material limits. When a balloon suddenly bursts, it's not just an accident—it’s a demonstration of gas compressibility and elasticity in action. In this article, we’ll explore the science behind balloon bursting, focusing on gas compressibility and expansion , and how these principles are applied in real-life safety and industrial technologies.     Why Gases Compress and Expand Easily Gases have large spaces between molecules, so when external pressure is applied, their volume decreases easily. Conversely, when the pressure is released, they expand quickly. This property is called compressibility , and all gases exhibit it to some degree. Unlike liquids or solids, where molecules are tightly packed and resist compression, gases are flexible and adaptable—making them perfect for use in systems that require pressure storage or release. ...

Memory is the heart of a computer’s performance. With DDR5 memory entering the mainstream market, there is growing interest in how it compares with its predecessor, DDR4 . In this post, we break down the differences in architecture, operation, clock speeds, voltage, data transmission methods, and efficiency between DDR4 and DDR5, helping you understand the evolution of system memory.     1. What is DDR? DDR (Double Data Rate) memory transmits data on both the rising and falling edges of the clock signal, effectively doubling data throughput compared to SDR. DDR4 and DDR5 refer to the fourth and fifth generations of SDRAM standards, respectively. 2. Clock Speed and Bandwidth DDR4: 2133MHz ~ 3200MHz / Bandwidth up to ~25.6GB/s (at 3200MHz) DDR5: 4800MHz ~ 8400MHz / Bandwidth from ~38.4GB/s to 67.2GB/s DDR5 starts at significantly higher base clock speeds than DDR4, delivering substantially more data per second .     3....

Field Effect Transistors (FETs) are essential active components in modern electronics. However, not all FETs are the same—each type comes with its own characteristics and use cases. In this post, we compare major FET types—JFET, MOSFET, LDMOS, GaN FET, MESFET, and HEMT—and offer a practical guide to choosing the optimal FET based on your circuit’s purpose and frequency range.     1. Key FET Types and Their Characteristics JFET (Junction FET): High input impedance, low noise, ideal for analog amplification MOSFET: Most widely used general-purpose FET; excellent for digital and power circuits LDMOS: Preferred in high-power RF transmission; excellent linearity and voltage handling GaN FET: Suited for high-frequency, high-power applications; offers fast switching and efficiency MESFET: Used in high-speed microwave applications HEMT: Offers high electron mobility; suitable for satellites, 5G, and radar systems     2....