CNC controller is the electromechanical bits that connect the computer to the machine.
Types of CNC Controllers
Industrial OEM CNC Controllers
Industrial OEM CNC Controllers are the ones used on Industrial CNC Machines like Haas. They’re the very hind end of the market.
These are not very common for DIY projects due to their expense. Not only is the controller itself expensive and fairly hard to come by (though one does see them from time to time on eBay), but Industrial OEM Controllers expect premium sub-components too. Industrial Quality Servo Drives, Home / Limit Switches, and all the rest really run up a hefty price tag in a hurry.
While these controls are expensive, lately I’ve seen controls such as the low-end of the Siemens line coming down in price in places like eBay. It looks like they’re testing the low-end market. If they keep coming down, these controls may make more sense on a DIY CNC Project than it seems.
I’m not going to talk further about these controls as they’re a pretty advanced topic. You might find the article I did that analyzes what features Hobby CNC Controllers are missing compared to industrial controls intersesting.
CNC Retrofit Controllers
Just a small step down from Industrial OEM Controllers are CNC Retrofit Controllers like Centroid.
These controllers are marketed for converting manual machines to CNC, for example, a Bridgeport manual milling machine. They’re also sold as a way to update obsolete controls on industrial CNC Machines to bring the more up-to-date features and performance.
They’re still not cheap, but they’re starting to fall into the range of what a DIY CNC’er might afford.
PC Based CNC Controllers
There are three main players in this market:
Mach 3 & Mach 4
LinuxCNC
FlashCut
All three have good reputations with varying trade-offs of features, functionality, price, and ease of use.