Semi-Automatic or CNC Tube Bender – What’s the Better Move?

In the world of tube bending, there are a ton of options, features, controls, and concepts that can overwhelm a prospective buyer. Many of these options can be removed or narrowed down by discussing the type of bender you need: semi-automatic or CNC?

At AM Industrial, we work with all shapes, sizes, options, and brands of tube benders. Below is a brief overview of semi-automatic versus CNC tube benders that can help you determine which option makes the most sense for your specific needs.

A semi-automatic tube bender (also known as the NC series) is a basic machine that performs a sequenced set of steps to bend a part using an NC control unit with a touchscreen interface. In basic terms, the steps go like this:

1. The operator loads the part.
2. The machine clamps, bends, and releases the part.
3. The machine stops and waits for the operator to remove the part or reposition it for a second bend.
4. The machine returns to the starting position and is ready for the next bend on either the same part or a new part.

The machine can have a limit switch to set the degree of bend or an encoder attached to a programmable control to set the degree of bend. However, a semi-automatic tube bender will NOT reposition the tube between bends. In order to automatically produce a tube with numerous bends with limited operator involvement between each bend, you may need a CNC tube bender.

A CNC tube bender (Computer Numerical Control unit) performs the same functions as a semi-automatic tube bender but with less operator involvement thanks to the use of computer-controlled servos. A CNC tube bender automatically positions the tube between bends, including the rotation of the tube (B-Axis) and the distance between bends (Y-Axis). Both of these measurements are critical and can be difficult to control with a NC tube bender.

Once the machine positions the tube in place, it goes through the same clamping, bending, and releasing steps as the semi-automatic machine. But instead of the operator repositioning the tube manually, the machine uses the carriage to hold and move the tube to the next location before making the next bend.

Now that you know the differences between a semi-automatic and a CNC machine, you still need to determine which one to buy from AM Industrial. To make this decision, it’s important to consider four main factors:

1. Number of bends per part – If you are doing single-bend parts, such as 90-degree elbows for electrical applications, a semi-automatic machine is often sufficient because it will usually make a single bend just as quickly and as accurately as a CNC machine. If you have multiple bends in a part, such as an exhaust system or a fuel line, a CNC machine delivers improved repeatability with less operator involvement and a high performance rate.

2. Quantity of each part – If you are doing custom work for headers on a racecar one day, a custom set of handlebars for your motorcycle on the weekend, and then a roll-cage for a dune buggy after that, a CNC machine may be more hassle than it’s worth. A semi-automatic machine offers greater flexibility and more control of custom, one-off parts. If there’s a likelihood that you will be making multiples of an item that has several bends in it, a CNC machine would be the better option because the part program can be stored and recalled at a later date.

3. Your business’ future – In this ever-changing world, new opportunities are always being presented. While a CNC machine with less operator involvement may seem like the best option, keep in mind that an NC machine will generally do the same work as a CNC machine can do if you have a little extra time. If you foresee an increase in the demand for a product you’re producing or developing, then a CNC machine may give you a competitive edge because you’ll be able to run at a faster rate and have a lower cost per part over time when compared to a competitor who’s using a semi-automatic machine to make the same part.

Semi-automatic and CNC machines are both very useful pieces of equipment and have their place in the tube bending world. Using the wrong machine on a given application can lead to increased start-up costs, complicated set-ups, inaccurate bends, and many sleepless nights worrying about the parts you have to make tomorrow. Contact AM Industrial Group today to discuss your specific project needs and make an educated decision that will yield the best results.

Machine data is best collected from machine manufacturers to ensure safer operation inside of designed parameters. Information above in no way supersedes that data.