Go for the used Prusa MK3S+. People used to pay a premium for assembled and tested printers. As long as you can get the printer to you without being banged up in shipping it’s good. Really shipping would be my biggest concern.

I have a MK3S+ and it just prints. I print for my Etsy shop and don’t really feel the need for a backup printer. I have 1600+ hours of printing on it. In that time I’ve had one nozzle clog and one blob. I do a little dust filter on the filament so i don’t often get clogs https://www.printables.com/@Fohn23_807562/collections/641537

I’m totally happy with just the smooth sheet. The textured sheet is supposed to work better printing PETG but I’ve been able to get perfect PETG prints on the smooth sheet using windex as a release agent.

Depends on how you define purple. If violet is close enough to purple for you then that “purple” would be a single spectral color, a single or continuous set of wavelengths. If it’s just a little more like magenta it would be a non-spectral color. A combo of red and blue light.

Plenty of non-spectral colors. Most things we see are non-spectral colors. Single pigments give off multiple wavelengths. Most things have combos of pigments on top of that. Emission spectra are multiple wavelengths.

My daughter has it. It makes the cars touchscreen a customized extension of the apps interface. So maps or whatever is running on the car’s screen. Some of the controls on the side of the screen also interact with the phone. It’s more integrated than a bluetooth connection.

I got an 1 gig Orange pi zero 2 with a 2 port USB expansion board. I got it from ali express with a 32gigabyte micro SD card, USB to USBC charging cable for like $40.

I 3d printed a case for it. Provisioned it with a heatsink, fan, 18W USB power supply, and a UPS.

I use it as an octoprint server, the extra USB ports go to a webcam and a fan if i feel like it. It’s been reliable but I’ve only had it a month. Transferring jobs is nearly instant plugged into gigabit ethernet. Transfer is via API key not web interface. Seems to do alright in the CPU department. It has to parse some of the larger jobs for a minute.

Prints perfectly. Only had one resent packet USB packet so far. After it prints rendering out 1080P time-lapses was slow. It would hit like 70% cpu usage and take hours. Rendering out 1080P octolapses with fewer frames and less movement would hit 98% cpu use but be done very fast - like 10 min.

They just announced an orange pi zero 3 with a similar form factor (but not exactly the same) and larger faster memory.