How to Turn Your CNC Mill into a Jig Grinder

How to Turn Your CNC Mill into a Jig Grinder

Many machine shops occasionally require the extreme precision and surface finish that a jig grinder provides. Jig grinders are known for their ability to produce very accurate holes, complex geometries, and extremely fine finishes that are difficult to achieve with standard machining processes.

However, dedicated jig grinding machines are not always practical for every shop. They are expensive, take up valuable floor space, and are often used only for specialized jobs.

For many manufacturers, a more flexible solution is to adapt equipment they already have, such as a CNC milling machine.

What Is a Jig Grinder?

A jig grinder is a high-precision machine used to grind holes and contours with extremely tight tolerances. These machines are commonly used in:

• Tool and die manufacturing
• Mold making
• Aerospace components
• Precision gauges and fixtures

Unlike standard machining, jig grinding uses a small grinding wheel rotating at extremely high speeds to remove material in very small increments. This process allows machinists to achieve exceptional accuracy and surface finish.

The Challenge of Owning a Jig Grinder

While jig grinders offer excellent precision, they also come with several limitations.

High cost
Dedicated jig grinding machines can require a large capital investment.

Specialized equipment
They require dedicated space and are typically used only for specific operations.

Limited flexibility
Many shops only need jig grinding occasionally, which makes owning a dedicated machine difficult to justify.

Because of this, many machine shops look for ways to perform jig grinding operations using equipment they already have.

Turning a CNC Mill into a Jig Grinding Solution

One practical solution is to use a high-speed spindle attachment on a CNC milling machine. These attachments allow the machine to run small grinding wheels at extremely high speeds, enabling precision grinding operations similar to those performed on a jig grinder.

This approach allows machine shops to:

• Use existing CNC equipment
• Reduce capital investment
• Perform precision grinding when needed
• Increase overall machine versatility

With the right spindle attachment, many CNC machines can handle a wide range of precision grinding tasks.

The Role of High-Speed Grinding Spindles

High-speed grinding spindles are designed to rotate at extremely high RPM while maintaining stability and precision. This allows small grinding wheels to remove material efficiently and produce very fine finishes.

At Vulcan Tool Company, we manufacture the Vulcanaire Spindle Attachment, a high-speed grinding spindle designed to expand the capabilities of CNC machines. By mounting the Vulcanaire attachment to a CNC mill, shops can perform precision grinding operations without purchasing a dedicated jig grinder.

Applications for CNC-Based Jig Grinding

Using a high-speed spindle attachment such as the Vulcanaire can be ideal for several applications:

• Precision hole finishing
• Mold and die work
• Tooling and fixture manufacturing
• Finishing hardened materials
• Tight tolerance features

This allows manufacturers to achieve jig grinding-level precision while using the CNC equipment already available on the shop floor.

A Cost-Effective Alternative

For many machine shops, converting a CNC milling machine into a jig grinding solution provides the best balance between performance and cost efficiency. Instead of investing in a dedicated jig grinder, manufacturers can expand the capabilities of their existing machines.

The Vulcanaire Spindle Attachment offers a flexible and practical way to perform high-speed grinding operations directly on a CNC mill.

If your shop is looking for a way to add jig grinding capability without purchasing another machine, we would be happy to discuss your application.