Manufacturing Processes Lab: CNC, Welding, Casting, and Lathe Operations
CNC Laser Cutting Machine Operations
Study of CNC Laser Cutting Machine
Objective
To understand the working principle, components, and operation of a CNC laser cutting machine.
Apparatus Required
- CNC laser cutting machine
- Design software (e.g., CorelDRAW or AutoCAD)
- Material sheet (wood, acrylic, etc.)
- Safety goggles
Theory
CNC (Computer Numerical Control) laser cutting is a non-contact thermal process that uses a focused laser beam to cut materials with high precision. The laser melts or vaporizes the material, and an assist gas removes the debris. It is widely used in industries for engraving, prototyping, and mass production.
Procedure
- Design the desired pattern in compatible software.
- Import the file to the machine software.
- Set cutting parameters: power, speed, and frequency.
- Place the material on the machine bed.
- Focus the laser and start the cutting process.
- Observe safety precautions during operation.
Conclusion
The CNC laser cutting machine provides precise, fast, and flexible material cutting, suitable for various applications in manufacturing and design.
Laser Cutting MDF Workpiece
Objective
To study the operation of a CNC laser cutting machine for cutting and engraving MDF (Medium Density Fiberboard).
Apparatus Required
- CNC laser cutting machine
- MDF sheet (3–6 mm)
- Design software (e.g., AutoCAD/CorelDRAW)
- Safety goggles
- Exhaust system
Theory
CNC laser cutting is a precision machining process where a high-powered laser beam is used to cut or engrave materials. MDF, being a dense engineered wood product, is ideal for laser cutting due to its smooth surface and uniform density.
Procedure
- Create or import a design in the machine-compatible software.
- Set the material type to MDF in the laser software.
- Adjust laser settings: power (70–90%), speed (15–25 mm/s), depending on thickness.
- Secure the MDF on the machine bed.
- Focus the laser and initiate the cut.
- Monitor the process and ensure proper ventilation.
Safety
Wear safety goggles and ensure fume extraction is active.
Conclusion
Laser cutting on MDF allows intricate designs with clean edges, suitable for model making, signage, and furniture prototyping.
Laser Cutting Choksi Board Workpiece
Objective
To study the operation of a CNC laser cutting machine for cutting and engraving Choksi board.
Apparatus Required
- CNC laser cutting machine
- Choksi board sheet
- Design software (e.g., CorelDRAW/AutoCAD)
- Safety goggles
- Exhaust system
Theory
Choksi board is a type of compressed paperboard commonly used in prototyping and model making. CNC laser cutting uses a focused laser beam to vaporize or burn the material, enabling precise cuts and engravings. Due to its composition, Choksi board cuts cleanly and efficiently with low power settings.
Procedure
- Design or import the desired shape using compatible software.
- Set material parameters in the machine software for Choksi board.
- Adjust laser settings: low power (40–60%), moderate speed (20–30 mm/s).
- Place and secure the Choksi board on the bed.
- Focus the laser and start the cutting operation.
- Ensure proper ventilation and observe safety measures.
Safety
Use protective eyewear and activate the exhaust system to remove fumes.
Conclusion
CNC laser cutting on Choksi board is ideal for quick, precise, and clean model fabrication and design tasks.
Welding Techniques and Joint Types
Electric Arc Welding and Joint Types
Objective
To study the electric arc welding process and understand different types of welding joints.
Apparatus Required
- Welding machine
- Electrodes
- Metal workpieces
- Welding cables
- Chipping hammer
- Wire brush
- Safety equipment (helmet, gloves, apron)
Theory
Electric arc welding is a fusion welding process where an electric arc is formed between an electrode and the metal workpiece, generating heat to melt and join metals. It is widely used in fabrication and repair works. Common weld joints include:
- Butt Joint: Joining two plates edge-to-edge.
- Lap Joint: One plate overlaps another.
- T-Joint: Plates are joined at a right angle.
- Corner Joint: Plates meet at a corner.
- Edge Joint: Plates are placed side-by-side with edges touching.
Procedure
- Clean and prepare metal surfaces.
- Set up the welding machine and connect electrodes.
- Weld different joint types.
- Allow joints to cool, then clean and inspect.
Safety
Always wear Personal Protective Equipment (PPE) and work in a ventilated area.
Conclusion
Electric arc welding enables strong, permanent joints across various configurations, essential in construction and manufacturing.
TIG and MIG Welding Joint Analysis
Objective
To study various types of welding joints using TIG (Tungsten Inert Gas) and MIG (Metal Inert Gas) welding processes.
Apparatus Required
- TIG and MIG welding machines
- Filler rods/wire
- Shielding gas (argon/CO₂)
- Metal workpieces
- Personal protective equipment (helmet, gloves, apron)
Theory
TIG welding uses a non-consumable tungsten electrode and provides high-quality, precise welds. MIG welding uses a consumable wire electrode fed through a gun and is faster for larger applications. Common joint types include:
- Butt Joint: Two pieces aligned in the same plane.
- Lap Joint: One piece overlaps another.
- T-Joint: One piece joins at the center of another.
- Corner Joint: Two pieces meet at a corner.
- Edge Joint: Two pieces placed side by side.
Procedure
- Prepare and clean the metal surfaces.
- Set welding parameters for TIG/MIG.
- Weld each joint type using both processes.
- Inspect the welds for quality and finish.
Safety
Wear proper PPE and ensure adequate ventilation.
Conclusion
TIG and MIG welding provide versatile and effective methods for creating various strong and precise joint types in metalworking.
CNC Engraving and Router Machine Study
Working and Applications
Objective
To study the working and applications of a CNC engraving and router machine for precision cutting and engraving tasks.
Apparatus Required
- CNC engraving/router machine
- Workpiece (wood, acrylic, MDF)
- Design software (CorelDRAW, AutoCAD)
- Clamps
- Safety gear
Theory
CNC (Computer Numerical Control) engraving and router machines use programmed toolpaths to engrave or cut materials with high accuracy. Engraving involves shallow cuts for designs or text, while routing involves deeper material removal for shaping and cutting. These machines are widely used in signage, furniture, and model making.
Procedure
- Design or import a pattern using compatible software.
- Set up the material securely on the machine bed.
- Configure tool settings (bit type, depth, speed).
- Upload the design to the machine’s control software.
- Run a test path and start the engraving or routing process.
- Monitor the process and inspect the output.
Safety
Wear safety goggles and ensure dust extraction is active.
Conclusion
CNC engraving and routing offer precise, automated solutions for material processing, increasing productivity and design accuracy.
Fundamental Manufacturing Processes
Sand Mold Preparation (Single Piece Pattern)
Objective
To study the process of sand mold preparation using a single piece pattern for metal casting.
Apparatus Required
- Single piece pattern
- Molding sand
- Molding box (cope and drag)
- Rammer
- Sprue pin
- Strike-off bar
- Trowel
- Vent rod
Theory
Sand molding is a process used in casting where a mold cavity is formed in sand using a pattern. A single piece pattern is a solid model of the object to be cast, placed in the drag box to form the mold cavity.
Procedure
- Place the drag box on a flat surface and position the pattern inside.
- Sprinkle parting sand over the pattern.
- Fill the box with molding sand and ram uniformly.
- Level the surface using a strike-off bar.
- Invert the box and remove the pattern carefully.
- Cut the sprue and vent holes as required.
Safety
Use hand tools carefully and wear protective gear to avoid injury.
Conclusion
Sand mold preparation using a single piece pattern is a fundamental step in metal casting, ensuring accurate mold cavity formation.
Lathe Machine Construction and Parameters
Objective
To study the construction and working of a lathe machine, identify its parts and attachments, and understand cutting parameters like speed, feed, and depth of cut.
Apparatus Required
- Lathe machine
- Workpiece
- Cutting tools
- Tool post
- Chuck
- Measuring instruments
- Safety equipment
Theory
A lathe machine is used for shaping cylindrical objects by rotating the workpiece against a stationary cutting tool. Major parts include the bed, headstock, tailstock, carriage, and lead screw. Common attachments include chucks, faceplates, taper turning attachments, and steadies. Lathe tools vary based on operation—turning, facing, threading, etc.
Cutting Parameters
- Cutting Speed (V): Calculated as V = πDN/1000 (m/min), where D = diameter (mm) and N = RPM.
- Feed (f): Distance the tool advances per revolution (mm/rev).
- Depth of Cut (d): Thickness of material removed in one pass (mm).
Procedure
- Identify lathe parts and attachments.
- Mount the workpiece and tool.
- Set speed, feed, and depth according to the material.
- Perform basic operations like turning or facing.
Conclusion
Understanding lathe construction and parameters is essential for precision machining and safe operation.