This DIY Device Controls Mains Power to Your 3D Printers via OctoPrint

If you care about 3D printing efficiency, then you probably already use OctoPrint. It is really handy software for controlling 3D printers through an interface that, when configured to be, is accessible from anywhere. If you’re at home and want to start a job on a 3D printer at your office, you can do that! Except, with most setups, you’d have to leave the 3D printer on all the time to allow for that possibility. This DIY power controller device changes that, giving you the ability to toggle mains power to your 3D printers via OctoPrint.

The utility here is obvious: you can turn on the power to your 3D printers remotely, so you can start jobs from anywhere without leaving the printers on 24/7. If you use OctoPrint and spend time away from your printers, this could be very useful to you.

First, a quick disclaimer… As creator CHWTT points out, this is a device that connects to and controls mains AC power. That means it has the potential to be dangerous — both during the build phase and the in the long term, if it isn’t done properly. But it isn’t that risky if you understand the principles. If you don’t, then either avoid this project or talk to a professional electrician.

Inside of the 3D-printed device enclosure is a Raspberry Pi single-board computer, which runs OctoPrint. If you’ve been using OctoPrint, you likely already have that. The Raspberry Pi sits above a custom PCB that does all that magic. That “magic” is the work of good old-fashioned relays—essentially switches for high voltages that are controllable with low voltages. In this case, the low voltage control signals come from the Raspberry Pi’s GPIO pins through transistors.

The device has two power inputs and two power outputs, all of which are standard IEC sockets. You can select the socket models that are appropriate for your region and equipment. There are fuses for protection and you can select those models suitable for your voltages, too.

Configuring OctoPrint is very easy with the GPIO Control plugin. Simply select the GPIO pins you have connected and tie them to a function (power to each printer). That’s it! After that, you can toggle power to each printer through the web interface whenever you need to do so.