Introduction to Plasma Cutting

Summary

This video offers a practical guide to plasma cutting, covering techniques for cutting both straight lines and complex shapes like circles. The narrator explains how travel speeds and cutting directions depend on material thickness and type, with tips on achieving clean cuts and avoiding equipment damage. Key techniques include cutting at a 45-degree angle when piercing to prevent nozzle clogging, and ensuring the clean edge remains on the plate when cutting out or cutting holes. The video is aimed at beginners and experienced fabricators looking to refine their freehand and guided cutting skills.

Takeaways

• 😀 Plasma cutting speeds depend on the material type and thickness, including differences between metals like stainless steel and aluminum.
• 😀 The direction of the cut matters when shaping materials. Cutting in the opposite direction of the plasma column provides the cleanest edge on the piece to be kept.
• 😀 To cut a hole in a plate, start the cut at a 45-degree angle, then rotate to 90 degrees to avoid damaging the nozzle and ensure clean piercing.
• 😀 The plasma column rotates counterclockwise, and the cleanest edge will be to the right side of the cut.
• 😀 When cutting a circle to keep the shape, the cut should be made opposite of the plasma column’s rotation direction to maintain a clean edge.
• 😀 If cutting out a hole (piece to be discarded), the cut quality is better on the plate, not the piece that falls out, which may have a noticeable taper.
• 😀 When starting a piercing cut on thicker material, avoid punching straight down. Instead, begin at an angle to prevent material jumping back up, which could damage the nozzle.
• 😀 A 3/16th inch offset is used for template cuts, meaning the resulting hole diameter will be 3/8 inch less than the template's size.
• 😀 The speaker emphasizes the importance of practice with freehand and template-guided cutting, acknowledging the benefits of familiarity with CNC cutters.
• 😀 Plasma cutting requires understanding the nuances of material and cut direction to produce the best results and avoid waste or damage to equipment.

Q & A

Why is the travel speed important when using a plasma cutter?

Travel speed affects the quality of the cut. It should be adjusted based on the material type, thickness, and the specific cutting conditions. A proper travel speed ensures clean cuts and prevents damage to the material or the plasma cutter.

What should you consider when cutting different shapes with a plasma cutter?

When cutting different shapes, you need to consider whether you want to keep the shape or just cut a hole. The cutting direction and technique, including starting angles and adjustments for material thickness, will affect the quality of the cut and the final shape.

What is the significance of cutting in the opposite direction of the plasma column?

Cutting in the opposite direction of the plasma column ensures that the cleanest edge remains on the piece you want to keep. Since the plasma column rotates counter-clockwise, cutting opposite of this rotation gives you the best edge quality on the material.

How does the piercing technique influence the plasma cutting process?

The piercing technique is important for starting the cut. Instead of punching straight down, which could damage the nozzle or cause the material to jump, you start at a 45-degree angle and rotate to 90 degrees to maintain clean cuts and protect the equipment.

What happens if you try to pierce through thick material by punching straight down?

Punching straight down on thick material causes the material to jump back up, which can clog the nozzle or damage it. This results in a poor cut quality and potentially destroys the plasma cutter’s consumables.

What is the purpose of using a template when cutting shapes like circles?

Using a template helps maintain the desired shape and size when cutting. It serves as a guide for the plasma cutter to follow, ensuring accuracy and precision, especially when cutting circular shapes or other intricate designs.

What does the term 'offset' refer to in the context of plasma cutting?

Offset refers to the distance between the plasma cutter’s nozzle and the path that is being cut. In the case of the presenter’s setup, a 3/16-inch offset means the actual cut will be slightly smaller than the template, so you need to account for this offset when cutting out shapes.

How does the cutting direction affect the beveled edges?

The cutting direction determines where the bevel will appear. When cutting outside a template, the piece that falls out has a cleaner edge, while the plate being cut will have more noticeable beveled edges due to the counter-clockwise rotation of the plasma cutter.

Why is it important to rotate the plasma cutter from a 45-degree angle to 90 degrees when piercing?

Rotating from a 45-degree angle to 90 degrees helps prevent clogging or damaging the nozzle and ensures a smoother piercing process. This technique also minimizes the risk of creating jagged edges or incomplete cuts.

What are some advantages of practicing freehand cutting without using a CNC cutter?

Practicing freehand cutting improves manual control, accuracy, and skill in handling the plasma cutter. It helps fabricators maintain basic cutting techniques and enhances their ability to work without relying on automation like CNC machines.