My question is, can a simple small UPS provide a solution for power dips? Both from before and after the UPS?
I don't need the UPS to run the machine for hours, just for catching the power dips. Having juice for a save shutdown in a power outage is just a bonus. Would a UPS be fast enough to handle power dips? I could imagine it takes time for the machine to detect a dip and switch to battery. I would imagine a capacitor would be faster.
I've got a 3d printer in a 70 year old building. Wiring is, let's say, not optimal. And my printer disconnects quite regular from the print server (Octoprint). I've done all I know to keep the serial connection going. I have shielded USB with ferrite beads. I have isolated the 5V on the USB to prevent back powering. I am using a big enough power supply for the Raspberry Pi, powered USB hubs for the camera's. And so forth.
I notice the LED, connected to 230V, flickers when the stepper motors move. The machine disconnects on many factors, turning a light on or even off, the coffee machine, etc. I also notice the power dips in other electronics like crackling in the radio speakers.