The newer machine I have I decided to upgrade for a variety of reasons. New control board, stepper motor drivers, touch screen, and a single board computer to enable me to monitor it remotely through the interwebz.
Biggest thing, is it is nearly silent. Before (and the other printer) you could hear it a couple rooms over. Not super loud, but a faint R2D2 being violated kinda noise. If in the room it was fairly noisy.
The machine is a Creality Ender3 - which is a fairly cheap and very popular printer. The stock control board and screen are housed in a small compartment at the front of the printer. The upgrades required the electronics to be moved to the rear (which I now treat as the front) and I printed compartments to hold all the new stuff.
Here are some pics, if anyone is interested in seeing them :
Here are the printed compartments with the new control board, stepper drivers (orange boards on the control board,) raspberry pi single board computer, and voltage regulator for the pi.

Everything slid into the back of the printer. I am going to cut plexiglass or print covers for the compartments.

Everything more or less together. I am printing a holder for the little camera, and have some wiring to organize but the machine is back up and printing. I printed a case for the top touch screen that provides printing through wifi and SD card. Bottom scree is stock I just modded the bracket to allow it to be mounted vertically and on the back of the printer. It displays realtime datat on movement, temps, and time remaining.
