This is an older project (started in 2018) but is probably the most useful thing I build, and is therefore one of my favorite projects.
The lasercutter has a useable work area of 80x110cm. It uses a 50W laser tube that can cut upto roughly 10mm wood. I use it mainly to cut plywood parts, but it can also cut acrylic sheet, fabric, etc. It can also engrave things with text, paterns, or even images.
It is controlled using a Teensy which runs grblHAL, commanding NEMA23 stepper motors.