apps

+

+# RC-submersible-dat.md

+

+A submersible is an underwater vehicle which needs to be transported and supported by a larger watercraft or platform. This distinguishes submersibles from submarines, which are self-supporting and capable of prolonged independent operation at sea.

+

+

+

+## ref

+

+- [[RC-apps-dat]]

+

+# ROV-dat

+

+**ROV** stands for **Remotely Operated Vehicle** — an underwater robot controlled from the surface using a tethered cable.

+

+## What ROVs Are Used For

+- Underwater filming & photography

+- Marine research

+- Inspecting ship hulls, pipelines, underwater structures

+- Search and rescue

+- Deep-sea exploration

+

+## Key Features

+- **Tether cable** – delivers power and sends video/data

+- **Cameras & lights** – real-time viewing

+- **Thrusters** – movement in all directions

+- **Protective frame** – shields electronics

+- **Optional modules** – robotic arm, sonar, depth sensors, etc.

+

+

+

+## opensources

+

+https://github.com/OpenROV

+

+https://github.com/UoM-Robotics-Society/ROV-project

+

+[topic ROV == https://github.com/topics/rov?l=javascript&o=desc&s=stars](https://github.com/topics/rov?l=javascript&o=desc&s=stars)

+

+

+## ref

+

+- [[RC-apps-dat]] - [[rc-apps]]

+

+- [[ROV]]

+

+# rc-Marine-vehicle-dat

+

+- [[rc-submersible-tank-dat]]

+

+- [[RC-boat-dat]]

+

+- [[RC-submersible-dat]]

+

+- [[ROV-dat]]

+

+

+

+

+

+

+## ref

+

+- [[RC-apps-dat]]

+

+# rc-boat-dat

+

+## propeller setup

+

+- [[propeller-dat]]

+

+

+

+

+

+

+

+

+

+

+## air-propelled

+

+Catamaran: Greatly improves stability.

+

+Wind power: Fans blow air, generating a recoil force that propels the hull forward.

+

+

+

+

+

+

+

+

+

+

+## ref

+

+- [[rc-apps]] - [[rc-boat]]

+

+# rc-submersible-tank-dat

+

+

+

+- [credit link ](https://www.youtube.com/watch?v=0QS0A1Je6ME)

+

+

+

+

+

+## ref

+

+- [[rc-Marine-vehicle-dat]]

+

+

+# microscope-dat

+

+## components

+

+

+### Objective Lens

+- The objective lens is the front lens, closest to the object being observed.

+- It collects light and creates the first magnified real image.

+- It determines most of the resolution, brightness, and image quality.

+- In microscopes, common objective magnifications are 4×, 10×, 40×, 100×.

+

+**Simple idea:** The objective lens is the *main lens* that actually “sees” the object.

+

+### Eyepiece

+- The eyepiece is the lens near your eye.

+- It further magnifies the image produced by the objective lens.

+- Changing eyepieces changes the overall magnification.

+

+**Simple idea:** The eyepiece makes the image big enough for your eye to see.

+

+### Total Magnification (Microscope)

+Total Magnification = Objective Magnification × Eyepiece Magnification

+Example: 40× objective × 10× eyepiece = 400×

+

+

+## ref

+

+- [[optical-design-dat]]

+

+

+## tech

+

+- [[Lithophane-dat]]

+

+

+# 3d-print-service-dat

+

+Supported 3D formats: stl/stp/step/obj/3mf.

+

+You can upload up to 20 files at a time, with each file size less than 100MB.

+

+For full-color printing, compressed files in rar/zip format can be uploaded.

+

+Note: To ensure more accurate printing and avoid unnecessary disputes, it is strongly recommended to upload STL format files!

+

+Special reminder: Wall thickness should be greater than 1.2mm, with the thinnest part not less than 0.8mm.

+

+

+

+

+## extra

+

+### embedded nuts

+

+

+- [[fab-3d-print-materials-dat]]

+

+## ref

+

+- [[3d-print-service]] - [[3d-print]]

+

+

+

+

+

+## material

+

+### 9600

+

+适用范围: 适用于管道，卡扣，电子产品外壳，汽车壳体，仪表盘组件等。

+

+优点: 颜色更白，样件纹路佳，表面光滑，韧性、耐用性强，机械性能好。

+

+缺点: 不适宜放置高温及强太阳光环境。

+

+成型工艺: SLA立体光固化

+

+材料精度: ±0.2mm或0.3%以内

+

+颜色: 哑光白

+

+热变形温度: 59°C

+

+

+

+

+

+- [[3d-print-dat]] - [[3d-prototype-dat]]

+

+# leather-dat

+

+

+## animal leathers

+

+

+Here are the **most widely used animal leathers** in fashion, furniture, and other industries:

+

+| Animal | Common Uses | Characteristics |

+|--------|------------|----------------|

+| **Cow / Cattle (Cowhide)** | Shoes, bags, belts, jackets, furniture | Durable, thick, versatile, can be full-grain, top-grain, or split. |

+| **Sheep (Sheepskin / Shearling)** | Jackets, gloves, boots, linings | Soft, lightweight, warm, flexible; often used for winter clothing. |

+| **Goat (Goatskin)** | Gloves, bags, shoes, book covers | Soft, strong, fine grain, pliable; commonly used for luxury items. |

+| **Pig (Pigskin)** | Shoes, bags, gloves | Durable, with visible pores; often used for casual or rugged products. |

+| **Deer / Elk (Deerskin)** | Gloves, jackets, moccasins | Very soft, supple, strong; often used for high-end gloves and outdoor gear. |

+| **Buffalo / Bison** | Bags, belts, shoes, furniture | Thick, rugged, durable; has a coarser texture than cowhide. |

+| **Horse (Cordovan)** | Shoes, wallets, belts | Very dense, smooth, glossy; highly durable, often used for premium leather goods. |

+| **Exotic Leathers (Crocodile, Alligator, Snake, Ostrich, Lizard)** | Luxury handbags, shoes, wallets | Unique textures and patterns, high-end; expensive and sought-after. |

+

+### ⚡ Notes

+

+- **Cattle leather** is the most common and affordable for general use.

+- **Sheepskin and goatskin** are softer and better for clothing and gloves.

+- **Exotic leathers** are mainly used for luxury goods due to rarity and price.

+- Leather from **wild or endangered animals** is regulated under CITES, so sourcing must be legal.

+

+

+

+## Animal-Friendly / Cruelty-Free Leather Options

+

+natural leather (from animals) is often considered high-quality in terms of **durability, comfort, and appearance**, but there are also **animal-friendly or cruelty-free alternatives** for people who want leather-like materials without harming animals.

+

+### ✅ Animal-Friendly / Cruelty-Free Leather Options

+

+| Type / Name | Description / Features |

+|------------|----------------------|

+| **Vegan PU Leather** | Made from polyurethane, fully synthetic, mimics leather look and feel. |

+| **Piñatex** | Made from pineapple leaf fibers. Sustainable, lightweight, and leather-like texture. |

+| **Mushroom Leather (Mycelium Leather)** | Made from mushroom mycelium. Soft, durable, biodegradable, and eco-friendly. |

+| **Cork Leather** | Made from cork bark. Flexible, water-resistant, and natural-looking. |

+| **Apple Leather** | Made from apple peel waste. Sustainable, soft, and flexible. |

+| **Lab-Grown / Biofabricated Leather** | Made from cultured animal cells, mimics real leather without animal slaughter. |

+

+#### ⚡ Advantages of Animal-Friendly Leather

+

+- **Cruelty-free**: No animals are harmed.

+- **Sustainable**: Often made from plant waste or biofabricated materials.

+- **Durable and functional**: Many modern alternatives are strong, flexible, and water-resistant.

+- **Fashionable**: Many designers now use these materials for shoes, bags, furniture, and clothing.

+

+#### ⚠️ Considerations

+

+- **Feel and aging**: Some vegan leathers may not develop the same patina as natural leather.

+- **Price**: Certain high-quality alternatives (like mycelium or lab-grown leather) can be expensive.

+- **Processing**: PU-based vegan leather may involve plastics; biodegradable or plant-based options are more eco-friendly.

+

+

+

+

+## ✅ Affordable / Low-Cost Leather Types

+

+| Type / Name | Description / Features |

+|------------|----------------------|

+| **Bonded Leather** | Made from leather scraps + glue/resin. One of the cheapest leather options. |

+| **Split Leather** (split-grain / lower-layer leather) | Made from the lower layer of animal hide after removing the top grain. Used for budget shoes, bags, furniture. |

+| **Bi-cast Leather / Bicast Leather** | Split leather base coated with a layer of plastic (PU/vinyl) and embossed to look like leather. Low cost, looks like leather. |

+| **PU Leather** (faux leather / synthetic leather) | Fully synthetic (polyurethane or similar). Very cheap, mimics leather appearance, widely used for bags, furniture, clothing. |

+

+### ⚠️ Why These Leathers Are Cheaper

+

+- **Lower durability**: Bonded, split, bi-cast, and PU leather are less durable and can crack, peel, or wear easily.

+- **Less comfort**: Poor breathability and less natural softness compared to top-grain or full-grain leather.

+- **Shorter lifespan**: Especially bonded and PU leather, prone to peeling and cracking after a few years.

+- **Appearance difference**: Often embossed or coated; cannot fully replicate natural leather texture or the aging “patina” effect.

+

+### 🎯 Suitable For

+

+- Budget-conscious users (students, beginners).

+- Low-frequency or decorative use (temporary bags, furniture, decor).

+- DIY leather crafting or practice without risking expensive leather.

+- People who want leather-like appearance but can compromise on quality.

+

+

+

+

+

+

+## advantages of Leather Material

+

+

+### 1. Durability

+- **Tear and wear resistance**: Natural leather has a tight structure, long lifespan, and is not easy to wear or tear.

+- **Water resistance (some types)**: Treated leather (e.g., tanned leather) can have some water-repellent properties.

+- **Repairable**: Leather can be maintained, oiled, or dyed to repair damage and extend its life.

+

+### 2. Comfort

+- **Breathability**: Natural leather can absorb and release moisture, keeping skin dry.

+- **Softness**: Leather becomes softer and more conforming over time.

+

+### 3. Aesthetics

+- **High-end texture**: Leather has natural grain and luster, giving a premium appearance.

+- **Uniqueness**: Each piece of leather has distinct patterns, making products unique.

+- **Aging beauty**: Over time, leather develops a natural patina, enhancing its appeal.

+

+### 4. Functionality

+- **Insulation**: Thick leather can block wind and retain warmth, suitable for winter clothing and shoes.

+- **Moldability**: Leather is easy to shape into various forms for shoes, bags, furniture, etc.

+- **Protection**: Thick leather can provide physical protection (e.g., motorcycle gloves, jackets).

+

+### 5. Environmental Aspect (relatively)

+- **Biodegradable**: Natural leather can decompose more easily than synthetic materials (if untreated with chemicals).

+

+

+## ref

+

+- [[materials-dat]]

+

+# Rivet-dat

+

+

+

+## Semi-Tubular Rivet (Tubular Rivet)

+

+

+- Hollow at the tail, slightly deformed during installation.

+- Leaves a shaft that can act like a **pin**, allowing attached pieces to **rotate**.

+- Can also act as a **built-in spacer** if you control the gap when pressing it.

+

+管状铆钉：强调它是“中空的圆管状”，尾部可轻微展开。

+

+半空心铆钉：常用在手工 / 皮革 / 轻金属 DIY 场景，尾部只有部分空心，方便旋转或作为活动关节。

+

+

+

+

+## Spacer / Washer + Pin or Rivet

+- Place a **metal or plastic washer** between parts.

+- Insert a solid or semi-tubular rivet/pin through the washer.

+- Rivet clamps only the washer, leaving a **free gap for rotation**.

+- Works with many rivet types and is very precise.

+

+

+## cap rivet

+

+- Also called a **decorative rivet**, commonly used in leather, fabric, or light metal decoration.

+- Once installed, the head and shaft clamp the materials tightly.

+- **Does NOT allow rotation** and is not suitable as a spacer by itself.

+- Mainly used for **decoration or permanent fastening**, not mechanical rotation.

+

+

+

+

+## hand rivet tools

+

+https://www.instagram.com/reel/CjiwHKfgFZo/?igshid=YmMyMTA2M2Y%3D

+

+打锤 + 铆钉座／冲头（Hammer + Rivet Setter / Anvil / Bucking Bar / Setters） — 对于某些铆钉（尤其在皮革、布料、铜铆钉、花帽铆钉等）可以在锤子 + 座子/冲头上手工敲压固定。适合简易金属片、皮革、布料等，或者当你没有铆枪时。很多皮革／手工爱好者会用这类工具。

+

+

+

+

+

+## pop rivet

+

+### After a Pop Rivet (Blind Rivet) Is Installed, Can It Rotate?

+

+After a pop rivet (blind rivet) is pulled (installed), it becomes a **tight, permanent, non-rotating joint**.

+

+When the mandrel pulls the rivet:

+- The rivet body expands.

+- It clamps the material tightly.

+- There is **no clearance** for rotation.

+- The joint becomes fixed and cannot rotate.

+

+This is the *intended behavior* of a pop rivet.

+

+

+## info

+

+A **rivet** is a type of permanent mechanical fastener used to join two or more pieces of material together, such as metal, plastic, or leather.

+

+### How a Rivet Works

+1. A hole is drilled through the materials.

+2. The rivet is inserted into the hole.

+3. The tail end of the rivet is deformed (flattened or expanded).

+4. This creates two “heads” that clamp the materials tightly together.

+

+Once installed, a rivet **cannot be removed without destroying it**, making it a strong and reliable connection.

+

+---

+

+### Basic Structure

+- **Head**: The factory-made top of the rivet.

+- **Shank**: The cylindrical body that goes through the hole.

+- **Tail**: The end that gets deformed during installation.

+

+---

+

+### Common Types of Rivets

+- **Solid Rivet**: Strongest type, used in aircraft and heavy machinery.

+- **Blind Rivet (Pop Rivet)**: Installed with a rivet gun, used when only one side is accessible.

+- **Hollow Rivet**: Used for leather, fabric, or light materials.

+- **Semi-Tubular Rivet**: Used for rotating joints; the tail is partially hollow.

+

+---

+

+### Why Rivets Are Used

+- Strong and vibration-resistant

+- Simple and low-cost

+- Good for thin sheets and layered materials

+- Do not loosen like screws can

+

+---

+

+### Simple Explanation

+A rivet is **a metal pin that you put through a hole and squash the end to lock two parts together**.

+

+

+

+

+## Can a Rivet Joint Keep a Gap and Allow Rotation?

+

+Yes, a rivet joint **can** keep a controlled gap and allow rotation — but only if you use the correct method. A normal rivet creates a tight, permanent joint that cannot rotate. Here are the practical solutions:

+

+---

+

+### ✅ Method 1: Loose Riveting (Hinge-Style Rivet Joint)

+Do not fully squeeze the rivet tail. Leave a small clearance so the two plates are not clamped tightly.

+

+**Effect:**

+- The plates stay aligned by the rivet shaft.

+- A small gap remains.

+- The plates can rotate around the rivet.

+

+**Cons:**

+- Gap is hard to control precisely.

+- Lower strength.

+- Rotation may not be very smooth.

+

+---

+

+### ✅ Method 2: Add a Washer or Spacer

+Place **washers** or a **spacer** between the two plates, then rivet through them.

+

+**Effect:**

+- The gap is controlled by the washer/spacer thickness.

+- The rivet clamps the spacer, not the plates.

+- The joint rotates smoothly and reliably.

+

+👉 This is the **recommended** method for precise rotation.

+

+

+- [[microscope-dat]]