The GRBL Project

Arduino Uno vs Pico Smackdown? In a word, nothing is wrong with the Uno. But, there is nothing wrong with the original IBM PC. Though, I...

OR Having 2 different boards has lead to a number of people asking which one they should use. Hopefully I can help you work through this...

I've been designing a new CNC controller breakout board based on the Raspberry Pi Pico. We are calling it the PicoCNC. This is a very...

I regularly get questions about using relays. So, this blog entry's goal is to make it easier to understand. Relays are often used in CNC...

The screw terminals on the breakout board are used to drive relay coils. As such, they are set up as an open collector output and used...

Terje at io-Engineering has created a fantastic builder for grblHAL. This allows you to build custom firmware files with no software...

When I started out, one of the more confusing aspects of CNC machines was the concept of Feeds and Speeds. It seemed like a lot of math...

Ethernet is a great feature of the T41U5XBB and RP23CNC. It is very easy to set up and use. Because the Ethernet interface uses transformers, the PCB is galvanically isolated from the Ethernet cable and is not a conduit for EMI. USB, on the other hand, is not isolated and EMI can be an issue. Also, Ethernet IP is a self correcting protocol. Any error packets will be rejected and resent. This procedure will allow you to connect to a router that dynamically assigns an IP addre

In pictures - an assembly guide for the T41U5XBB. This guide assumes you have bought the optional assembly kits. Though it should be very similar if you sourced your own parts. [Update Jan 2026: The blue potentiometer has been removed from the kit. V2.20 and later have a potentiometer built in.] Gather the parts and take inventory. Assembly kit and PCB There should be 2 1x24 sockets, 2 1x40 pin header strips, 1 2x3 pin header, 1 2x6 pin header, 10K trimmer potentiometer and

Good connectors are a must when you build a machine. A poor connector that shakes loose can be maddening. But, good connectors can be...