The metal spinning process transforms flat sheets of metal into hollow, rotationally symmetrical shapes. It’s a cost-effective and versatile technique used for a wide range of products, from simple kitchenware to complex rocket nose cones. Here’s a breakdown of the key steps involved:
Preparation:
- Material Selection: Choosing the right sheet metal is crucial. Common options include aluminum, steel, copper, and brass. Each metal has its forming properties like hardness and workability, which influence how it shapes. Thickness is also selected based on the final product’s needs.
- Mandrel Selection: A mandrel that replicates the desired final shape is chosen. These are typically made from steel or wood and ensure the formed metal sheet matches their precise contours. The mandrel surface should be smooth to avoid imperfections on the final product.
- Sheet Metal Cutting: A flat sheet of metal is cut slightly larger than the final product. This accounts for material maneuvering and trimming after shaping. Shearing or waterjet cutting are common methods used.
Machine Setup and Shaping:
- Mounting: The metal sheet is securely clamped onto the mandrel on the metal spinning lathe. A tailstock die (follower rest or live center) applies pressure to the back of the sheet, helping it conform to the mandrel during spinning.
- Tool Selection and Positioning: The spinning tool is chosen based on the desired shape. A basic roller with a smooth profile works for simple shapes, while forming rollers with specific contours are used for complex shapes. The tool is then mounted on the tool rest of the lathe.
- Spinning and Shaping: The lathe spins the mandrel and metal sheet together at high speed. The operator skillfully guides the spinning tool along the mandrel, applying controlled pressure to progressively shape the sheet metal. This pressure causes plastic deformation, stretching the outer areas and compressing the inner regions to match the mandrel’s form.
- Multi-Pass Approach: Skilled metalworkers rarely achieve the final shape in one go. They typically use multiple passes with the spinning tool, focusing on specific sections or progressively refining the shape. This multi-pass approach allows for better control, minimizes imperfections, and ensures even material thickness.
Finishing:
- Trimming: Once shaping is complete, the excess metal around the edge of the formed piece is trimmed away using shears or a trimming tool.
- Finishing Touches: The finished part may undergo additional processes like polishing, sanding, or painting depending on the desired outcome. This step improves the aesthetics and functionality of the final product.
Additional Considerations:
- Speed and Lubrication: The spinning process often occurs at high speeds to minimize friction and heat generation. Lubrication is also important, as it reduces friction between the tool and the metal sheet, aiding in shaping and extending tool life.
- Manual vs. CNC Spinning: Metal spinning machines come in both manual and CNC (computer numerical control) varieties. Manual machines rely on the operator’s skill to manipulate the tool and achieve the desired shape. CNC machines use a pre-programmed digital blueprint for precise tool movements, making them suitable for complex shapes and high-volume production.
Metal spinning offers several advantages:
- Cost-Effective: Compared to other techniques, spinning can be a relatively inexpensive way to produce high-quality parts, especially for short to medium production runs.
- Complex Shapes: It excels at creating intricate shapes that can be challenging with other methods.
- Material Versatility: The process can work with a variety of sheet metals, offering flexibility in material selection.
- Fast Production: Metal spinning can be a relatively quick way to form parts, especially for simpler shapes.
Overall, the metal spinning process is a valuable technique for a wide range of metalworking applications, offering a balance between cost-effectiveness, versatility, and the ability to produce complex shapes.
The metal spinning process can be broken down into several key steps:
Preparation (Before the Machine):
- Material Selection: The first step involves choosing the right sheet metal for the job. Common options include aluminum, steel, copper, and brass. Each metal has its own working properties like hardness and formability, which influence how it will respond to shaping. Thickness is also chosen based on the desired final product and its strength requirements.
- Mandrel Selection: A mandrel with the desired final shape is selected. Mandrels are typically made from steel or wood and precisely replicate the form the metal sheet will take. The mandrel surface should be smooth and free of imperfections to avoid transferring them to the final product.
- Sheet Metal Cutting: A flat sheet of metal is cut to a size slightly larger than the final product. This accounts for material maneuvering and trimming after shaping. Shearing or waterjet cutting are common methods used to cut the sheet metal.
Machine Setup and Shaping (On the Metal Spinning Lathe):
- Mounting: The metal sheet is securely clamped onto the mandrel on the metal spinning lathe. A tailstock die (also sometimes called a follower rest or live center) applies pressure to the back of the metal blank to help it conform to the shape of the mandrel during spinning.
- Tool Selection and Positioning: The appropriate spinning tool is chosen based on the desired shape. A roller with a smooth profile is suitable for basic shapes, while forming rollers with specific contours are used for complex shapes. The tool is mounted on the tool rest of the lathe.
- Spinning and Shaping: The lathe spins the mandrel and metal sheet together at high speed. The operator skillfully guides the spinning tool along the length of the mandrel, applying controlled pressure to progressively shape the sheet metal. This pressure causes plastic deformation in the metal, stretching the outer areas and compressing the inner regions to conform to the mandrel’s shape.
- Multi-Pass Approach: Skilled metal spinners rarely achieve the final shape in one go. They typically work in stages, using multiple passes with the spinning tool. Each pass might focus on a specific section or progressively refine the shape. This multi-pass approach allows for better control, minimizes the risk of imperfections, and ensures even material thickness throughout the part.
Finishing (After Shaping):
- Trimming: Once the shaping is complete, the excess metal around the edge of the formed piece is trimmed away using shears or a trimming tool.
- Finishing Touches: The finished part may undergo additional processes like polishing, sanding, or painting depending on the desired outcome. This step improves the aesthetics and functionality of the final product.
Additional Considerations:
- Speed and Lubrication: The spinning process is often performed at high speeds to minimize friction and heat generation. Lubrication is also important, as it reduces friction between the tool and the metal sheet, aiding in shaping and extending tool life.
- Manual vs. CNC Spinning: Metal spinning machines come in both manual and CNC (computer numerical control) varieties. Manual machines rely on the operator’s skill and experience to manipulate the spinning tool and achieve the desired shape. CNC machines use a pre-programmed digital blueprint to precisely control the movements of the spinning tool, making them suitable for complex shapes and high-volume production.
By following these steps, metal spinning allows for the creation of a wide range of unique and functional shapes from sheet metal. It’s a versatile and cost-effective method for producing high-quality parts, particularly for short to medium production runs.
EMS Metalworking Machines
We design, manufacture and assembly metalworking machinery such as:
- Hydraulic transfer press
- Glass mosaic press
- Hydraulic deep drawing press
- Casting press
- Hydraulic cold forming press
- Hydroforming press
- Composite press
- Silicone rubber moulding press
- Brake pad press
- Melamine press
- SMC & BMC Press
- Labrotaroy press
- Edge cutting trimming machine
- Edge curling machine
- Trimming beading machine
- Trimming joggling machine
- Cookware production line
- Pipe bending machine
- Profile bending machine
- Bandsaw for metal
- Cylindrical welding machine
- Horizontal pres and cookware
- Kitchenware, hotelware
- Bakeware and cuttlery production machinery
as a complete line as well as an individual machine such as:
- Edge cutting trimming beading machines
- Polishing and grinding machines for pot and pans
- Hydraulic drawing presses
- Circle blanking machines
- Riveting machine
- Hole punching machines
- Press feeding machine
You can check our machinery at work at: EMS Metalworking Machinery – YouTube
Applications:
- Beading and ribbing
- Flanging
- Trimming
- Curling
- Lock-seaming
- Ribbing
- Flange-punching