Have you ever wondered how to achieve those sleek, angled surfaces that elevate your metalwork? A bevel cut adds a professional touch, in addition to bringing structural integrity to various components. With CNC plasma cutting, mastering this technique can be both straightforward and rewarding. 

Achieving bevel cuts with CNC plasma cutting requires you to be skilled enough to operate the machine at the right angles. It may require some practice to ensure the precision, but you can get consistent and high-quality cuts. 

Get the details of CNC plasma bevel cuts, their applications, and some tips for maintaining precision in manufacturing in this guide. 

Achieving Bevel Cuts with CNC Plasma Cutting 

You can achieve perfect bevel cuts with two things: using the right tools and knowing the correct techniques of adjusting the torch angle. 

Let’s discuss these things in these next sections: 

Tools and Accessories for Plasma Bevel Cutting 

Using these tools and accessories will ensure the accuracy and smoothness of all of your bevel cuts: 

a. Plasma Cutting Torch

The torch is a tool for cutting metal parts at angled cuts. The specialized torch designed for bevel cutting allows the plasma arc to be tilted at a specific angle relative to the workpiece. The tilt is what creates clean bevels. 

b. Consumables 

Consumables are the parts that wear out during the cutting process, which is critical for maintaining the machine’s efficiency. These parts include electrodes, nozzles, and shield caps. 

The electrodes are responsible for providing the electrical arc that creates the plasma, while the nozzles help focus the arc and control the angle of the cut. Shield caps protect both the nozzle and electrode from the harmful effects of spatter and double arcing, ensuring a smooth operation throughout.

c. Bevel Guide

To maintain a consistent cutting angle, a bevel cutting guide is a must. This tool is what keeps your bevels uniform and sharp. There are different types of guides, including manual bevel cutting guides that can be adjusted for various angles, magnetic guides that attach to your workpiece for extra stability, and circle cutting guides for beveling around curves or circular pieces. Each type helps make your beveling process more predictable and accurate.

d. CNC Plasma Cutting Table

If you want precision in your bevel cuts, you should invest in a CNC plasma cutting table. These tables allow the torch to move along multiple axes with incredible accuracy, so you can achieve that perfect bevel with minimal effort. The table’s ability to control the cutting head’s movements means you can automate the process, which reduces error percentage. 

e. Other Useful Accessories

Along with the primary tools, there are a few other accessories that can make a big difference: 

• An air filter ensures that the air supply stays clean, keeping your plasma arc focused and precise. 
• Personal protective equipment (PPE). Safety glasses, gloves, and protective clothing are crucial when working with plasma cutters to protect yourself from heat, sparks, and other hazards.
• Your plasma cutter also needs a power source (either 110V or 220V) and an air compressor to function properly. Some systems come with built-in compressors, but if yours doesn’t, you’ll need to set it up with the proper air pressure for precision cuts. 

Adjusting Torch Angle for Accurate Bevels 

Achieving bevel cuts with CNC plasma cutting to the desired measurements mostly depends on how well you adjust the torch angle. However, the process is a bit more nuanced than it seems. You need the skill to balance several factors, from the torch’s height to the direction of the cut. 

Why Is the Torch Angle Important? 

In plasma cutting, the nozzle’s motion and the plasma gas itself play a big role in shaping the bevel. The plasma arc, which is formed by the gas being shaped into a vortex, will naturally rotate. This motion can lead to one side of the cut having a more pronounced bevel than the other. So, the direction in which you move the torch matters in this case. If you get this wrong, you could end up with an uneven bevel, or worse, a part that doesn’t fit as it should.

Choosing the Right Direction: Conventional vs. Climbing Cuts

The direction of plasma cutting also influences the quality of a bevel cut. There are two main types of cutting directions: conventional and climbing.

1. Conventional cut: In this technique, the torch moves counter-clockwise for outside cuts and clockwise for inside cuts. While this approach is standard, it tends to produce a less-accurate favorable bevel. 
2. Climbing cut: In this method, the torch moves to the direction opposite to the conventional cut. It generally gives you the best bevel. The torch will cut to the right of the travel direction, leading to a cleaner, more consistent angle. 

Torch Height

The adjustment of the torch angle also depends on its height. Too high of a position may not allow the cut to penetrate the material fully. So, it’ll produce an excessive bevel. But if the torch is too low, it might actually contact the material, causing damage to the tip and producing a reversed bevel. 

The correct approach here is to keep the torch square to the material. It will give you equal bevels on both sides of the cut with a professional-looking edge.

Other Variables

Besides torch angle and height, there are a few other things to consider. 

• Incorrect air pressure could be a reason for inconsistent bevels. 
• Poor air quality is a potential reason for not achieving clean bevel cuts. 
• The condition of the consumables, such as electrodes and nozzles, can impact the cut’s accuracy. If these parts are worn out, the bevel may suffer. 

Applications Requiring Beveled Edges in Metal Fabrication 

Many sheet metal fabrication parts across various industries may need to have beveled edges. Some common examples are: 

Welding Preparation

Beveling metal edges before welding creates a groove that allows the filler material to penetrate more deeply. Without this angled edge, the weld may not fuse properly, weakening the joint. Such welds are imperative for industries where strong, long-lasting welds are a must—think construction, automotive, or aerospace. A good bevel makes these welds survive high-stress environments.

Pipe and Tube Joining

You’ll need bevels if you want to create a secure, leak-free connection when joining pipes or tubes. The angled edges provide a better fit between the pieces, ensuring that the weld has a larger surface area to bond to. Such secure connections are critical in plumbing, oil and gas pipelines, and other systems where fluid or gas must flow through safely.

Heavy-Duty Structural Components

In industries like shipbuilding and heavy machinery, you require bevels to create strong joints in beams, plates, and supportive components. Beveling helps to distribute stress evenly, reducing the likelihood of weak spots and increasing the component’s overall strength. 

Automotive Parts

The primary function of beveled edges in this sector is to enhance the functionality of gears. You’ll see these bevel gears in steering systems and differentials. The beveled designs help these gears to minimize friction and distribute load evenly. 

Aerospace Applications

Aerospace components utilize bevel cuts to reduce stress points on various parts and increase aerodynamic properties. You’ll find beveled edges in the connection points of fuselage and wing components, engine systems, landing gear parts, etc. 

Decorative Applications

Not all bevels are about function. Beveled edges can also be used to add a refined, sophisticated touch to various design elements. In furniture, picture frames, and architectural details, beveling creates clean, elegant lines that enhance the visual appeal of the item. 

Tips for Maintaining Precision in Bevel Cuts 

Maintaining precision in bevel cuts can be tricky, but with the right approach, you can ensure your cuts stay accurate and clean. Check out these tips for achieving bevel cuts with CNC plasma cutting accurately:

1. Adjusting for Corners

One of the most common issues when cutting bevels is that corners often have more bevel than straight edges. It happens when the machine slows down to change direction. You can minimize this by adjusting the ramping rates and start/stop values in your CNC settings. It allows the machine to transition more smoothly, reducing the extra bevel caused by slowdowns. 

If you’re working with thicker materials, cutting a larger shape that avoids sharp corners can help as well. This method puts the slowdowns into scrap areas, keeping your bevel consistent.

2. Keep Your Consumables in Top Shape

Worn-out consumables are one of the main culprits behind inaccurate bevels. If your tip gets worn down or slag builds up, the airflow may be redirected in ways that create uneven bevels. Regularly inspect and replace consumables like electrodes and nozzles to keep your cuts sharp. 

3. Maintain Perfect Speed and Height

A major factor in controlling bevel accuracy is cutting at the correct speed and height for the material and amperage being used. Too fast, and you risk having an excessively bevelled edge; too slow, and you might create unwanted dross or heat buildup. 

So, cut at a speed that’s ideal for the material thickness and amperage, and keep the torch height at the correct setting. And maintain constant air pressure with clean, dry air to minimize bevel issues. 

4. Run Practice Tests

Doing a trial run on a smaller test piece can save you a lot of headaches. For each bevel type, material thickness, and amperage setting, run a practice cut on a 5”x5” piece of metal. It’ll help you to figure out the adjustments you have to make. And never run a bevel test at speeds over 60 inches per minute. It can cause damage to the bevel head, which will slow down your entire operation.

5. Recalibrate Your Bevel Head

Recalibrate it every two weeks to maintain accuracy. Check the position between the bevel head’s rotation point and the torch head. Then, set the bevel head’s home position to ensure the torch is square to the plate. Regular re-alignment ensures your machine stays on track and reduces the risk of misaligned cuts over time.

Conclusion 

Achieving bevel cuts with CNC plasma cutting requires the right tools, torch adjustments, and careful attention to detail. With consistent practice and proper machine calibration, you can get smooth, clean bevel cuts in various applications. 

Ready to take your custom metal fabrications to the next level with precise bevel cuts? At Zintilon, we specialize in advanced sheet metal, plasma cutting, and CNC machining services. Get a free quote on your next precision sheet metal fabrication project.