Converting a Mill to a CNC

For many mill owners, do-it-yourself projects provide a relaxing way to escape day-to –day pressures. For some, the idea of turning a manual mill into a faster, more efficient, CNC operated tool seems like the next perfect project. But before jumping headlong into making the conversion to a CNC machine, it’s best to know what to expect of an automated machine in terms of movement, cutting ability, flexibility, and overall efficiency.

Although manual mills can be good for fashioning a single component, when it comes to manufacturing a workpiece that warrants repeated product runs a CNC mill may be a better choice. Because CNC machines offer increased precision and repetition of the automated process, they are often employed in factories that specialize in larger product runs of one specific component. However, a manual mill can be turned into a CNC machine for efficient at-home use.

A CNC mill saves time during production because the cutting movements are fast and precise. In order to achieve the necessary movements, a CNC mill moves along a series of axes, ranging from two to five, to execute the desired cuts. However, a mill used for do-it-yourself purposes is likely to have fewer axes. A greater number of axes increases the degree of flexibility, enabling the machine to achieve otherwise difficult angles, as are common among specialty products manufactured in shops. Programmable software allows the CNC machine to repeat the desired process, which saves time and increases overall efficiency.

Despite the use of software, a programmer still plays an integral role in the success of a CNC mill. In order to begin the process, specify the cutting movements, and run the machine, a programmer must use a coordinate system to enter commands. To ensure the process runs smoothly, the programmer must align the cutter with the “0” point (the designated starting point) before the machine is run.

Many programs offer CNC storage that allow a programmer to save key coordinates, thus eliminating the need to re-enter commonly used coordinates and commands. Such storage spaces are often referred to as offsets. Offsets are a helpful way to specify and save the length and radius of the cutting tool, the depth of the desired cut as well as to designate and save the “0” point.

To learn what’s involved in converting a mill, visiting several websites with step-by-step instructions may prove helpful. Below are several different ways to go about the process.

Converting a Manual Mill into a CNC Machine

When preparing to convert a mill into a CNC machine there are several preliminary steps that should be taken. When dealing with a basic mill, the preparation typically involves removing components so that a CNC system can be configured. On a manual Taig mill, for example, the gibs and the leadscrew must be loosened so that the leadscrew mounting bolts and leadscrews can be removed. The mill tables can be removed and brushings replaced with adjustable brushings. The Z-axis is prepared in a similar manner, by removing and installing a new leadscrew in preparation for the automated components.

The components that distinguish a manual mill from a CNC are not numerous but they are important. The addition of a stepper motor and power supply, a controller, interpreter software, and a CAD/CAM package are the basics elements a mill requires to operate as a CNC machine. However, depending on the kind of mill machine, the exact specifications for these components will vary from project to project.

3 thoughts on “Converting a Mill to a CNC

  1. I often deal with the spindle side of projects like you are mentioning. I am going to recomend them reading this artical before jumping into a conversion project they may not have the full concept of.


  2. Why does the leadscrews have to be replaced when doing a retrofit? What is wrong with using the leadscrews the machine is delivered with?

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