I’ve completely rebuild my RPI Controller box.My old controller box had an Arduino with a Protoneer CNC Shield on top. The Arduino was controlled by my laptop, which blocks me from doing other stuff while a job is running. The steppers (NEMA17) were driven by xxx drivers. It did a pretty decent job as long as I didn’t push it to its boundaries. It had a hard time to keep steady while doing some tougher materials than MDF 🙂 When I started with my first machine, all was completely new to me and I did not want to spend much money on my first motors so NEMA17 sounded like a good choice back then. I soon realized these are too weak for their job assigned to them. I will be using these motors in another project soon.
So, out with the old, in with the new! I bought a complete set of drivers, powersupply and motors online. It has 2 powersupplies, 4 drivers and 4 NEMA23 motors (3Nm). The moters a somewhat bigger in size as well so I have to adapt my machine a little bit. But back to the controller box.
First, I wanted to skip the use of my laptop. I did some research online and found bCNC. A pretty decent program and it also runs on Linux. I wanted to make a standalone box, so I decided to control everything with a Raspberry PI. It now has a Raspberry PI model 3b+. On top of the RPI I’ve connected the Protoneers PI CNC Hat. My machine has 2 Y-rails so there are 2 motors connected to the Y-axis. I decided to connect the data lines coming from the RPi to two drivers and not to configure the A port on the HAT as an Y-output. Maybe in the future I make a 4-th axis with that output.
Some details on the motors:
powersupply: 2 x 250W 36V 7A 115/230V Switching Power Supply
I also connected all the limits (X+, X-, Y+, Y- and Z+), a probe input and an emergency knob. There are 3 usb ports on the box (1 on the front and 2 on the rear) and a HDMI ouput. Also I made to switchable 220v outputs to control the power to the spindle and the vacuumcleaner (which has a tornado system, separating dust from the airflow, also diy).
This box also has nicer inlets and outlets, more durable than on my first box. All in all, I think it turned out pretty good. It runs bCNC, has WIFI to get my gcode from my dropbox and it frees up my laptop.