3 Key Elements to Consider Before Proceeding with Tool Radius Compensation in CNC Milling

Posted On: November 9, 2021

Tool radius compensation, also referred to as cutter comp, cutter diameter compensation, is one of the widely used functions in CNC milling that determines the machining accuracy and quality. Most CNC machines have a built-in feature as cutter diameter compensation that helps detect the position of the cutter’s center while performing a specified job. It makes programming the actual tool path easier, whilst allowing the programmer to use the part geometry precisely. However, before enabling radius compensation in CNC milling, it is critical to keep an eye on some of the elements. This post discusses a few points that lead to the proper usage of the feature during CNC milling operations.

Best Practices to Follow while Performing Radius Compensation in CNC Milling

There are several reasons that substantiate the utilization of radius compensation in CNC milling. It not only allows for fine tuning the tool path and contributes to a finished machining, but also helps in adjusting part dimensions, without the need of changing or modifying program. It is one of the difficult programming features available with command names G41 G42 cutter compensation, line left, and line right, among others.

The following are three guidelines to consider when setting up tool radius compensation on typical three-axis milling machines.

• Making a prior setting of X and Y axes is required in almost all versions of cutter radius compensation. This is done to get the tool to a right position from which tool length compensation can be started. It is recommended to have the prior positioning of X and Y at least the cutter’s radius away from the initial surface to achieve accurate machining. As simply explained, if you are using a 1-inch cutter, for example, keep it at least 0.5 inch away from the first surface you are planning to machine.

• It is important to cancel cutter radius compensation that has been already applied and establish a new setting every time when a new shape is machined. Many times, users commit the mistake of setting cutter radius compensation only once and then machine many contours. Users must be cautious to turn off cutter radius compensation and then re-enable it for each contour to be machined. In case you miss cancelling cutter radius compensation, it is obvious that the next tool’s movements will also be under the influence of cutter radius compensation, which was already applied for the last machining.

• When using G02 or G03 to define an inner (fillet) radius, the tool should fit within the radius. In other words, the milling cutter’s radius must be lower than or equal to the radius you’re trying to machine.

During CNC milling operation, getting the tool in the correct position is not enough to guarantee a clean part as there would be more gap between the cutting edge and the workpiece surface. You have to set up your CNC mill with tool radius compensation in order to eliminate such gaps to assure an optimum finishing. As tools are fragile and expensive, it is important to check the tool radius compensation on your machine, which in turn ensures that the tool is compensated for cutting effectively and efficiently. Needless to say, the feature allows for more precise control over your tools’ positions when machining parts. To get the cnc milling process accurate with the application of the right tool radius compensation, it is advisable to partner with state-of-the-art CNC machine shop like BDE Manufacturing Technologies (BDE). Talk to an expert in the company and check their competency when it comes to tool radius compensation in CNC milling.

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