As an engineer, I had been interested in CNC machinery for a number of years before I ever considered building a CNC machine of my own. The parts required to make even a simple CNC tool used to be quite expensive but with the proliferation of Arduino microcontrollers and similar open electronics and software, building a CNC machine is becoming viable for the average electronics/hardware hobbyist.
Where I live, there used to be a large number of electronics/hardware surplus stores around that I would visit in search for parts to use in my various projects. Rummaging through these surplus stores, I would always some surplus stepper motors around for prices that were about 1/10 of what you could buy them new. At the time (15 years ago) the driver and controller electronics required to make these stepper motors useful in a project were out of the reach of the average do it yourself maker. If you could afford the electronics you would probably just end up building something driven with a DC servo motor.
The CNC mill that I built about 7 years ago used a stepper driver chip that cost between $20 – $30 US dollars. The stepper driver chip had to be driven by a programmed micro-controller that I would buy as part of a kit for an additional $20 – $30 dollars. The driver chip and control board combination was enough to drive a single stepper motor. For a 3 axis CNC machine that’s $150 just for the driver electronics. As an example of how much the price has dropped you can now buy a drive board used with most common 3D printers for about $5 on ebay. The 3D printer driver I am using as an example is only good for 2.5 Amps compared to 3 Amps for what I used in my CNC mill but you get an idea on how much this stuff has changed in less than 10 years.
Here is a picture of my first CNC machine – a mill. I originally built the mill to make custom parts for my car. My car hobby has slowed down considerably but my interest in CNC is still pretty active.
Here’s a close up video of the mill cutting a piece of rectangular brass stock into a piece of hex stock for use as a nozzle in my 3D printer:
My second crack at building a CNC machine was a lathe. I built the CNC lathe on a hobby lathe platform built by the same company that made the base platform I used for the mill.
This is a close up of the mini mill turning a brass nozzle for my 3D printer project.
My latest CNC build was intended to be a multi-purpose machine capable of CNC routing, 3D printing and SMT pick and place operations. At the time of this writing, I’ve only completed the 3D printer part of the machine. Here’s a video of the printer in action: