Architecture of a CNC on Ivo's CNC Corner

Motor Types

Mon, 01 Jan 0001 00:00:00 +0000

Motor Types#

CNC machines use stepper motors for precise movement of each axis. The stepper motors are able to turn a fraction of a degree at the instruction of the CPU.

Here you can see side by side an open-loop motor and a closed-loop motor.

Stepper motors contain 2 electromagnetic coils. The coils are energized in sequence, which in turn rotates the shaft one step at a time.

Grbl Variants

Mon, 01 Jan 0001 00:00:00 +0000

Grbl Variants#

There are 3 major families of the Grbl firmware.

Grbl#

Project website: https://github.com/gnea/grbl

The original Grbl firmware targets the 8-bit microcontroller Atmega 328p, the same one found in Arduino Uno boards. It has a few major limitations:

Only 3 axes are supported - X, Y and Z
Because of the limited ROM size, not all features can be used at the same time. Each firmware has to choose which subset of the available features to include
Because of the limited RAM size, the command buffer is quite short, meaning it can slow down for complex toolpaths

Still, despite its limitations, it has enough capabilities to power most hobbyist CNCs and remains one of the most popular choices to this day.

Spindle Types

Mon, 01 Jan 0001 00:00:00 +0000

Spindle Types#

We’ll do a quick overview of the different spindle options and how they can be controlled.

Here you can see side by side a 400W DC spindle, a 1.25HP trim router, and an 800W water-cooled VFD spindle.

DC motor#

Most hobby-level machines come out of the box with a simple DC spindle. Such DC motor spindles are often underpowered and have low-quality bearings.

Sender Software

Mon, 01 Jan 0001 00:00:00 +0000

Sender Software#

There are 3 main options for interfacing with your CNC machine. A dedicated sender software, a design package, or an offline controller.

Dedicated sender software#

A dedicated sender software has only one purpose - to operate the CNC machine. It will provide the best experience if you only need to execute your existing G-code files.

Such software will show the current machine state, tool position, and other information.