Duuh

CNC Machine.md

@@ -0,0 +1,236 @@
+# CNC Machining Overview
+
+The CNC (Computer Numerical Control) machine used in this lab is a large-format router capable of cutting full-sized wooden sheets using a 6mm cutting tool. It operates through instructions received from a computer, translating CAD designs into toolpaths that direct the cutting head’s movement, speed, and depth. These toolpaths ensure precision and repeatability by controlling the spindle’s rotation (RPM), feed rate (inches per minute), and cut depth.
+
+**Functionality Summary:**
+- Receives commands from a computer.
+- Follows toolpaths derived from CAD designs.
+- Cuts materials with controlled speed and depth.
+- Used for manufacturing wooden structures, furniture, and fit-based assemblies.
+
+![Insert image of CNC machine here](insert_image_path_here)
+
+---
+
+#### Safety Requirements
+
+Strict safety protocols must be followed when operating the CNC machine:
+
+- **Eye Protection:** Safety glasses must be worn to shield eyes from debris.
+- **Face Mask:** Use a face mask to prevent inhalation of fine dust particles.
+- **Clothing:** Avoid loose garments, jewelry, or accessories that may get caught.
+- **Work Area Inspection:** Check the machine and all tools before starting.
+- **Clean Environment:** Keep the machine and surroundings clear of clutter before and after use.
+- **Hearing Protection:** Strongly recommended, though not always provided.
+- **Emergency Stop:** Be aware of the emergency stop button location.
+- **Operational Distance:** Stay a safe distance from the machine while in use.
+- **Handling Materials:** Never attempt to remove or adjust material while the machine is active.
+- **Supervision:** Machine operation must always be monitored during cutting.
+
+![Insert image of safety gear or workspace here](insert_image_path_here)
+
+---
+
+#### Debris Management
+
+The CNC machine includes a built-in vacuum system that removes debris generated during cutting. This ensures:
+- Cleaner work environment.
+- Improved visibility and safety.
+- Better cut accuracy and finish.
+
+---
+
+#### Importance of Dogbones
+
+Due to the round shape of the cutting tool, internal corners in wooden joints are not naturally square. Adding **dogbone fillets** to these corners allows parts to fit tightly and accurately in press-fit constructions.
+
+---
+
+#### Material Alignment and Sacrificial Sheet
+
+Proper material positioning is crucial to cut accuracy. A **sacrificial sheet** is placed under the cutting material to:
+- Prevent damage to the CNC bed.
+- Allow cuts to go slightly deeper than the material thickness.
+- Help hold the material in place with screws.
+
+**Tips for Alignment:**
+- Max sheet size: 2440 x 1220 x 12 mm (L x W x T).
+- If the sheet is curved, place the concave side down.
+- Secure with bolts, ~30 mm away from corners and across the center.
+
+---
+
+#### Materials Used
+
+Two materials are commonly available:
+
+- **MDF (Medium-Density Fiberboard):**
+  - Smooth surface.
+  - Easy to machine.
+  - Less durable.
+
+- **Plywood:**
+  - Layered structure.
+  - Stronger and more resilient.
+  - Harder to cut cleanly.
+
+Cutting tests were conducted using MDF, optimizing speed and feed rate for best results.
+
+---
+
+#### Machine Alignment
+
+Machine calibration is required before each cutting job. For this CNC machine:
+
+- **Z-axis calibration** is automated.
+- A metal plate and wire clip are used. Once the drill touches the plate, an electrical signal finalizes the zero position.
+- Regular checks are needed for worn parts and tool integrity.
+
+---
+
+#### Drill Bit Selection Guidance
+
+Choosing the right drill bit (end mill) is essential for clean, efficient cuts and depends on your material and the operation:
+
+- **Upcut Bit:**
+  - Best for fast chip removal.
+  - Leaves a rough top surface but clean bottom.
+  - Good for deeper cuts.
+
+- **Downcut Bit:**
+  - Pushes fibers down.
+  - Leaves a smooth top surface.
+  - Good for thinner materials or laminated surfaces.
+
+- **Compression Bit:**
+  - Combines upcut and downcut features.
+  - Smooth on both sides.
+  - Ideal for plywood or double-sided finish materials.
+
+- **Bit Diameter:**
+  - 6mm (default) is versatile for general cutting.
+  - Use smaller bits (e.g., 3mm) for detailed work.
+  - Larger bits (e.g., 12mm) for faster rough cuts on thicker materials.
+
+---
+
+#### Speed & Feed
+
+Proper speed and feed rate settings are critical for effective cuts:
+
+- **Speed (RPM):** Determines how fast the tool rotates.
+- **Feed Rate (in/min):** Determines how fast the tool moves across the material.
+
+For MDF using a 6mm tool:
+- Optimal Speed: 17,000 RPM
+- Feed Rate: 60 in/min (can vary based on tool condition and material)
+
+Monitor chip formation and surface quality during tests to fine-tune settings.
+
+---
+
+#### Tips to Reduce Material Waste
+
+- **Group Parts Efficiently:** Nest your parts close together in CAD to use the least amount of space.
+- **Shared Cutting Lines:** When possible, let neighboring shapes share cut lines.
+- **Use Off-Cuts:** Save and reuse unused areas of the sheet for future small projects or test cuts.
+- **Add Labels:** Include engraved labels to organize parts and reduce re-cuts.
+- **Test on Scrap:** Run test cuts on scrap wood or corners before running the full job.
+- **Design for Sheet Size:** Design parts to maximize standard sheet dimensions (2440 x 1220 mm).
+- **Minimize Tabs:** Use just enough tabs to hold parts in place without excess material.
+
+---
+
+#### CNC Cutting Process
+
+This section outlines the full workflow for using the CNC machine, from preparation to final cutting.
+
+---
+
+#### 1. Preparation
+
+- Remove debris and previous sheets using a vacuum.
+- Unscrew and clear the CNC bed.
+- Place the new sheet (MDF or Plywood).
+- Adjust the sheet if bent; curve should face up with the middle touching the base.
+- Fasten using screws ~30 mm from the edges and along the center.
+
+![Insert preparation image here](insert_image_path_here)
+
+---
+
+#### 2. VCarve PRO Setup
+
+- Export the design as a **DXF** file.
+- Send the file to: `fablabbh.share@gmail.com`
+- Open the file in **VCarve PRO**.
+- Add a **30 mm offset** around the perimeter to avoid bolts.
+- Use **Dogbone Fillet** tool (match radius to tool size, e.g., 3 mm for 6 mm bit).
+  
+![Insert VCarve screenshot here](insert_image_path_here)
+
+---
+
+#### 3. Toolpaths: Cut
+
+- Choose **2D Profile Toolpath**.
+- Set:
+  - **Start Depth:** 0 mm
+  - **Cut Depth:** 13 mm (12 mm material + 1 mm into sacrificial sheet)
+- Select **Outside/Right** for vector machining to preserve size.
+- Tool Settings (6 mm bit):
+  - Spindle Speed: 8000 RPM
+  - Feed Rate: 80 in/min
+  - Plunge Rate: 15 in/min
+- Click **Calculate**, then **OK** to confirm warnings.
+
+---
+
+#### 4. Toolpaths: Pocket and Tabs
+
+- **Pocket Toolpath:**
+  - Used to hollow out an internal region.
+  - Useful for engravings or fitting one piece into another.
+  - Cut Depth: As required (example: 5 mm).
+  - Start Depth: 0 mm.
+
+- **Tabs:**
+  - Small, uncut sections to keep parts attached to the sheet.
+  - Prevents shifting or flying parts.
+  - Size: Usually 3 mm wide and 2 mm high.
+  - Automatically added in the Toolpath menu.
+
+---
+
+#### 5. ShopBot 3 Setup
+
+- Open **ShopBot 3** software.
+- Load the toolpath file (.sbp).
+- Move the drill head to desired origin (corner of the sheet).
+- Set:
+  - **X = 0**
+  - **Y = 0**
+- Run Z-axis calibration.
+
+---
+
+#### 6. Z-Axis Calibration
+
+- Clip the wire to the drill bit.
+- Place the **metal calibration plate** on the surface of the sheet.
+- Run the **Z-zeroing command** (machine lowers bit to touch the plate).
+- System detects contact and sets Z = 0.
+- Remove the clip and plate after calibration.
+
+---
+
+#### 7. Start Machining
+
+- Click **Start** to begin the operation.
+- Monitor the machine continuously.
+- Do not touch or adjust material until the machine is fully stopped.
+- After cutting completes, remove remaining debris.
+
+![Insert cutting process image here](insert_image_path_here)
+
+---

Cycloidal Gearbox.md

@@ -0,0 +1,266 @@
+# Two-Disc Cycloidal Gearbox Design
+
+#### 1. Project Description
+The two-disc cycloidal gearbox is designed to convert high-speed, low-torque input from a stepper motor into low-speed, high-torque output. It utilizes two synchronized cycloidal discs that rotate in opposite phases, interacting with drive pins to transmit motion to an output shaft.
+
+This configuration minimizes backlash and distributes load across multiple contact points, offering smooth and powerful transmission. The system is fully enclosed and features multiple mounting options for external attachments.
+
+#### 2. Application & Use Cases
+
+##### Applications
+- Robotics joints and arms
+- CNC rotary tables
+- Precision camera mounts
+- Automated actuators
+- Small-scale industrial machines
+
+##### How to Use
+- Mount the gearbox base to your motor using the provided holes.
+
+- Connect the NEMA-17 motor shaft to the input via the motor shaft connector.
+
+- Attach your load or mechanism to the output shaft area.
+
+- Power the motor through a driver board and microcontroller (e.g., Arduino).
+
+- Control the motion using programmed step sequences.
+
+    - Ensure lubrication (grease) between the discs and drive pins for smoother performance and longer lifespan.
+
+#### 3.  Engineering Drawings
+
+##### Description
+The design is a compact, scalable two-disc cycloidal gearbox intended for high-torque, low-speed applications. Its parametric structure makes it easy to adapt in size and material. The current prototype has a 90 mm diameter and 54 mm height.
+
+To clearly illustrate the internal mechanics, structural design, and assembly steps, the following visuals are provided:
+
+- Included Media
+    - Assembly Video – starts with an exploded view and step-by-step buildup
+
+        <p align="center">
+      <img src="images/insert.jpg" style="border: 2px solid black;" />
+          </p>
+
+    - Disassembly Video – shows teardown process in reverse order
+
+        <p align="center">
+      <img src="images/insert.jpg" style="border: 2px solid black;" />
+          </p>
+
+    - Transparent Body Image – reveals internal components without hiding the casing
+
+        <p align="center">
+      <img src="images/Transparent.png" style="border: 2px solid black;" />
+          </p>
+
+- Visual Assets & Drawings
+    - Engineering Drawing Sheet
+
+        <p align="center">
+      <img src="images/2.png" style="border: 2px solid black;" />
+          </p>
+
+    - Cross-Sectional Analysis (x2)
+
+        <p align="center">
+      <img src="images/SubSectionAnalysis.png" style="border: 2px solid black;" />
+          </p>
+
+        <p align="center">
+      <img src="images/sectionanalysis2.png" style="border: 2px solid black;" />
+          </p>
+
+    - Isometric View
+
+        <p align="center">
+      <img src="images/1.png" style="border: 2px solid black;" />
+          </p>
+
+#### 4. List of Materials & Components
+
+- ##### Standard Components
+
+| Part          | Quantity | Approx. Size                                       |
+| ------------- | -------- | -------------------------------------------------- | 
+| Bearing       | 2        | Ø65 mm (outer) × Ø50 mm (inner) × 7 mm (thickness) |
+| Bearing       | 4        | Ø32 mm (outer) × Ø20 mm (inner) × 7 mm (thickness) |
+| Stepper Motor | 1        | NEMA-17                                            |
+
+- ##### Bolts & Nuts (*with available size approximations*)
+
+Note: If a bolt is slightly longer than needed, it can be trimmed using a saw. Nut sizes should fit snugly but not too tight.
+
+1. (A) Connecting Base to Base Cover
+    - 7 × Flat Head Machine Screws (Type B)
+        - Size: M4 × 45 mm
+        - Head Diameter: ~7.5 mm 
+    - 7 × M4 Hex Nuts
+        - Edge-to-Edge: ~6.9 mm
+        - Thickness: ~3.2 mm
+
+2. (B) Drive Pins Area (Replaces 5 mm Pins)
+    - 4 × M3 × 50 mm Bolts (hex or socket head)
+        - Head Diameter: ~5.5 mm
+    - 4 × M3 Hex Nuts
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+3. (C) Mounting Points on Top of the Gearbox
+    - 7 × M4 Hex Nuts
+        - Edge-to-Edge: ~6.9 mm
+        - Thickness: ~3.2 mm
+
+4. (D) Shaft Connector
+    - 2 × M3 × 40 mm Bolts
+        - Head Diameter: ~5.5 mm
+    - 2 × M3 Hex Nuts
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+5. (E) NEMA-17 Shaft Connector
+    - 1 × M3 × 6 mm Bolt (may require sanding)
+        - Head Diameter: ~5.5 mm
+    - 1 × M3 Hex Nut
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+6. (F) NEMA-17 Connector
+    - 4 × M3 × 15 mm Bolts
+        - Head Diameter: ~5 mm
+
+- ##### 3D-Printed Components
+    - Material: PLA (tested), PETG (recommended for durability)
+    - Parts: Housing, base cover, discs, shaft connectors, output caps, circlips
+    - Infill: Suggested 40% or more for torque applications
+
+#### 5. Cycloidal Drive Strength Analysis
+
+---
+
+##### **1. Motor Output Torque**
+
+* **Motor Stall Torque**: 0.45 Nm
+* **Gear Ratio**: 21:1
+* **Estimated Efficiency**: 85%
+
+$$
+\text{Output Torque} = 0.45 \times 21 \times 0.85 = \boxed{8.03 \, \text{Nm}}
+$$
+
+---
+
+##### **2. Load Handling Capability (Based on PLA Disc)**
+
+###### PLA Parameters:
+
+* **Yield Strength of PLA**: 50 MPa
+* **Safety Factor**: 3 → Allowable stress = 16.7 MPa
+* **Contact Area (per lobe)**: 5 mm²
+* **Lobes in contact**: 4
+* **Radius from center to lobe force point**: 33.5 mm = 0.0335 m
+* **Infill Density**: 25%
+
+###### Calculations:
+
+* **Force per lobe**:
+
+$$
+F_{\text{lobe}} = 16.7 \times 10^6 \times 5 \times 10^{-6} = 83.5 \, \text{N}
+$$
+
+* **Total force from 4 lobes**:
+
+$$
+F_{\text{total}} = 4 \times 83.5 = 334 \, \text{N}
+$$
+
+* **Torque handling at 33.5 mm radius**:
+
+$$
+\tau = 334 \times 0.0335 = 11.2 \, \text{Nm}
+$$
+
+* **Account for 25% infill**:
+
+$$
+\tau_{\text{safe}} = 11.2 \times 0.25 = \boxed{2.8 \, \text{Nm}}
+$$
+
+---
+
+##### **3. Drive Pin Strength (Bolts with PLA Sleeves)**
+
+###### Assumption:
+
+* Bolts used instead of precision 5 mm mild steel pins
+* Outer diameter maintained at **5 mm** using **PLA sleeves**
+* Inner bolt shaft assumed 4 mm (typical M4 bolt shank)
+* Steel Yield Strength: 260 MPa
+
+- **Cross-sectional Area (4 mm bolt)**:
+
+$$
+A = \frac{\pi D^2}{4} = \frac{\pi \cdot 4^2}{4} = 12.57 \, \text{mm}^2
+$$
+
+- **Force per bolt**:
+
+$$
+F_{\text{bolt}} = 260 \times 12.57 = 3,268.2 \, \text{N}
+$$
+
+- **Total force (4 bolts)**:
+
+$$
+F_{\text{total}} = 4 \times 3,268.2 = 13,072.8 \, \text{N}
+$$
+
+- **Torque capacity**:
+
+$$
+\tau = 13,072.8 \times 0.0335 = \boxed{437.9 \, \text{Nm}} \quad \text{(Safe✅)}
+$$
+
+> Note: **PLA sleeves** do not contribute significantly to strength — they act as spacers or guides. Only **steel bolts** are load-bearing.
+
+---
+
+##### **4. Max Load at 50 mm Arm**
+
+$$
+F = \frac{\tau_{\text{safe}}}{r} = \frac{2.8}{0.05} = 56 \, \text{N}
+$$
+
+$$
+\text{Mass} = \frac{56}{9.81} = \boxed{5.7 \, \text{kg}}
+$$
+
+---
+
+##### Final Summary Table
+
+| Category                    | Value    | Safe?                    |
+| --------------------------- | -------- | ------------------------ |
+| Motor Stall Torque          | 0.45 Nm  | ✅                        |
+| Output Torque               | 8.03 Nm  | ❌ Exceeds PLA safe limit |
+| PLA Torque Limit            | 2.8 Nm   | ✅                        |
+| Bolt + PLA Pin Torque Limit | 437.9 Nm | ✅ (way overbuilt)        |
+| Max Load (at 50 mm arm)     | 5.7 kg   | ✅                        |
+
+---
+
+##### Final Conclusion
+
+The **cycloidal drive system is likely to fail at the PLA disc lobes under full output torque**, especially if printed with only **25% infill**. Although the **bolts (with PLA sleeves)** acting as drive pins are structurally sufficient, the **PLA disc is the mechanical weak point**.
+
+##### If tested:
+
+* The drive **will function under light loads (below \~5.7 kg at 50 mm arm)**.
+* Under full load or high-torque demand, **plastic deformation or cracking is expected at the lobes**.
+* The bolts will hold without issue, but **localized PLA wear or failure around the lobes and sleeves is likely.**
+
+##### Recommendations:
+
+* Increase **infill to at least 75%** or use a stronger material like **PETG**.
+* Consider **fillet reinforcement** around lobes to distribute stress.
+* Reduce gear ratio or torque output if high load isn't needed.

Laser Cutting.md

@@ -0,0 +1,266 @@
+# Two-Disc Cycloidal Gearbox Design
+
+#### 1. Project Description
+The two-disc cycloidal gearbox is designed to convert high-speed, low-torque input from a stepper motor into low-speed, high-torque output. It utilizes two synchronized cycloidal discs that rotate in opposite phases, interacting with drive pins to transmit motion to an output shaft.
+
+This configuration minimizes backlash and distributes load across multiple contact points, offering smooth and powerful transmission. The system is fully enclosed and features multiple mounting options for external attachments.
+
+#### 2. Application & Use Cases
+
+##### Applications
+- Robotics joints and arms
+- CNC rotary tables
+- Precision camera mounts
+- Automated actuators
+- Small-scale industrial machines
+
+##### How to Use
+- Mount the gearbox base to your motor using the provided holes.
+
+- Connect the NEMA-17 motor shaft to the input via the motor shaft connector.
+
+- Attach your load or mechanism to the output shaft area.
+
+- Power the motor through a driver board and microcontroller (e.g., Arduino).
+
+- Control the motion using programmed step sequences.
+
+    - Ensure lubrication (grease) between the discs and drive pins for smoother performance and longer lifespan.
+
+#### 3.  Engineering Drawings
+
+##### Description
+The design is a compact, scalable two-disc cycloidal gearbox intended for high-torque, low-speed applications. Its parametric structure makes it easy to adapt in size and material. The current prototype has a 90 mm diameter and 54 mm height.
+
+To clearly illustrate the internal mechanics, structural design, and assembly steps, the following visuals are provided:
+
+- Included Media
+    - Assembly Video – starts with an exploded view and step-by-step buildup
+
+        <p align="center">
+      <img src="images/insert.jpg" style="border: 2px solid black;" />
+          </p>
+
+    - Disassembly Video – shows teardown process in reverse order
+
+        <p align="center">
+      <img src="images/insert.jpg" style="border: 2px solid black;" />
+          </p>
+
+    - Transparent Body Image – reveals internal components without hiding the casing
+
+        <p align="center">
+      <img src="images/Transparent.png" style="border: 2px solid black;" />
+          </p>
+
+- Visual Assets & Drawings
+    - Engineering Drawing Sheet
+
+        <p align="center">
+      <img src="images/2.png" style="border: 2px solid black;" />
+          </p>
+
+    - Cross-Sectional Analysis (x2)
+
+        <p align="center">
+      <img src="images/SubSectionAnalysis.png" style="border: 2px solid black;" />
+          </p>
+
+        <p align="center">
+      <img src="images/sectionanalysis2.png" style="border: 2px solid black;" />
+          </p>
+
+    - Isometric View
+
+        <p align="center">
+      <img src="images/1.png" style="border: 2px solid black;" />
+          </p>
+
+#### 4. List of Materials & Components
+
+- ##### Standard Components
+
+| Part          | Quantity | Approx. Size                                       |
+| ------------- | -------- | -------------------------------------------------- | 
+| Bearing       | 2        | Ø65 mm (outer) × Ø50 mm (inner) × 7 mm (thickness) |
+| Bearing       | 4        | Ø32 mm (outer) × Ø20 mm (inner) × 7 mm (thickness) |
+| Stepper Motor | 1        | NEMA-17                                            |
+
+- ##### Bolts & Nuts (*with available size approximations*)
+
+Note: If a bolt is slightly longer than needed, it can be trimmed using a saw. Nut sizes should fit snugly but not too tight.
+
+1. (A) Connecting Base to Base Cover
+    - 7 × Flat Head Machine Screws (Type B)
+        - Size: M4 × 45 mm
+        - Head Diameter: ~7.5 mm 
+    - 7 × M4 Hex Nuts
+        - Edge-to-Edge: ~6.9 mm
+        - Thickness: ~3.2 mm
+
+2. (B) Drive Pins Area (Replaces 5 mm Pins)
+    - 4 × M3 × 50 mm Bolts (hex or socket head)
+        - Head Diameter: ~5.5 mm
+    - 4 × M3 Hex Nuts
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+3. (C) Mounting Points on Top of the Gearbox
+    - 7 × M4 Hex Nuts
+        - Edge-to-Edge: ~6.9 mm
+        - Thickness: ~3.2 mm
+
+4. (D) Shaft Connector
+    - 2 × M3 × 40 mm Bolts
+        - Head Diameter: ~5.5 mm
+    - 2 × M3 Hex Nuts
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+5. (E) NEMA-17 Shaft Connector
+    - 1 × M3 × 6 mm Bolt (may require sanding)
+        - Head Diameter: ~5.5 mm
+    - 1 × M3 Hex Nut
+        - Edge-to-Edge: ~5.5 mm
+        - Thickness: ~2.4 mm
+
+6. (F) NEMA-17 Connector
+    - 4 × M3 × 15 mm Bolts
+        - Head Diameter: ~5 mm
+
+- ##### 3D-Printed Components
+    - Material: PLA (tested), PETG (recommended for durability)
+    - Parts: Housing, base cover, discs, shaft connectors, output caps, circlips
+    - Infill: Suggested 40% or more for torque applications
+
+#### 5. Cycloidal Drive Strength Analysis
+
+---
+
+##### **1. Motor Output Torque**
+
+* **Motor Stall Torque**: 0.45 Nm
+* **Gear Ratio**: 21:1
+* **Estimated Efficiency**: 85%
+
+$$
+\text{Output Torque} = 0.45 \times 21 \times 0.85 = \boxed{8.03 \, \text{Nm}}
+$$
+
+---
+
+##### **2. Load Handling Capability (Based on PLA Disc)**
+
+###### PLA Parameters:
+
+* **Yield Strength of PLA**: 50 MPa
+* **Safety Factor**: 3 → Allowable stress = 16.7 MPa
+* **Contact Area (per lobe)**: 5 mm²
+* **Lobes in contact**: 4
+* **Radius from center to lobe force point**: 33.5 mm = 0.0335 m
+* **Infill Density**: 25%
+
+###### Calculations:
+
+* **Force per lobe**:
+
+$$
+F_{\text{lobe}} = 16.7 \times 10^6 \times 5 \times 10^{-6} = 83.5 \, \text{N}
+$$
+
+* **Total force from 4 lobes**:
+
+$$
+F_{\text{total}} = 4 \times 83.5 = 334 \, \text{N}
+$$
+
+* **Torque handling at 33.5 mm radius**:
+
+$$
+\tau = 334 \times 0.0335 = 11.2 \, \text{Nm}
+$$
+
+* **Account for 25% infill**:
+
+$$
+\tau_{\text{safe}} = 11.2 \times 0.25 = \boxed{2.8 \, \text{Nm}}
+$$
+
+---
+
+##### **3. Drive Pin Strength (Bolts with PLA Sleeves)**
+
+###### Assumption:
+
+* Bolts used instead of precision 5 mm mild steel pins
+* Outer diameter maintained at **5 mm** using **PLA sleeves**
+* Inner bolt shaft assumed 4 mm (typical M4 bolt shank)
+* Steel Yield Strength: 260 MPa
+
+- **Cross-sectional Area (4 mm bolt)**:
+
+$$
+A = \frac{\pi D^2}{4} = \frac{\pi \cdot 4^2}{4} = 12.57 \, \text{mm}^2
+$$
+
+- **Force per bolt**:
+
+$$
+F_{\text{bolt}} = 260 \times 12.57 = 3,268.2 \, \text{N}
+$$
+
+- **Total force (4 bolts)**:
+
+$$
+F_{\text{total}} = 4 \times 3,268.2 = 13,072.8 \, \text{N}
+$$
+
+- **Torque capacity**:
+
+$$
+\tau = 13,072.8 \times 0.0335 = \boxed{437.9 \, \text{Nm}} \quad \text{(Safe✅)}
+$$
+
+> Note: **PLA sleeves** do not contribute significantly to strength — they act as spacers or guides. Only **steel bolts** are load-bearing.
+
+---
+
+##### **4. Max Load at 50 mm Arm**
+
+$$
+F = \frac{\tau_{\text{safe}}}{r} = \frac{2.8}{0.05} = 56 \, \text{N}
+$$
+
+$$
+\text{Mass} = \frac{56}{9.81} = \boxed{5.7 \, \text{kg}}
+$$
+
+---
+
+##### Final Summary Table
+
+| Category                    | Value    | Safe?                    |
+| --------------------------- | -------- | ------------------------ |
+| Motor Stall Torque          | 0.45 Nm  | ✅                        |
+| Output Torque               | 8.03 Nm  | ❌ Exceeds PLA safe limit |
+| PLA Torque Limit            | 2.8 Nm   | ✅                        |
+| Bolt + PLA Pin Torque Limit | 437.9 Nm | ✅ (way overbuilt)        |
+| Max Load (at 50 mm arm)     | 5.7 kg   | ✅                        |
+
+---
+
+##### Final Conclusion
+
+The **cycloidal drive system is likely to fail at the PLA disc lobes under full output torque**, especially if printed with only **25% infill**. Although the **bolts (with PLA sleeves)** acting as drive pins are structurally sufficient, the **PLA disc is the mechanical weak point**.
+
+##### If tested:
+
+* The drive **will function under light loads (below \~5.7 kg at 50 mm arm)**.
+* Under full load or high-torque demand, **plastic deformation or cracking is expected at the lobes**.
+* The bolts will hold without issue, but **localized PLA wear or failure around the lobes and sleeves is likely.**
+
+##### Recommendations:
+
+* Increase **infill to at least 75%** or use a stronger material like **PETG**.
+* Consider **fillet reinforcement** around lobes to distribute stress.
+* Reduce gear ratio or torque output if high load isn't needed.