I've recently done some major surgery on my Robo3D R1+, pulling out the 8-bit Arduino+RAMPS control board and replacing it with a 32-bit BigTreeTech SKR Pro v1.2 on which I'm running RepRapFirmware. This gives me direct Web control of the printer (without OctoPrint), easier configuration, and quieter operation (thanks to Trinamic 2208 stepper drivers), among other benefits. I've chronicled the whole experience here: https://www.rodsbooks.com/robo3d-upgrade/ The brief version: The BTT SKR Pro v1.2 plus Trinamic 2208 stepper drivers plus BTT TFT35-E3 LCD control panel plus third-party WiFi module plus a few odds and ends cost about $150. Physically installing the hardware required creating a custom mount and cutting away part of a "wall" on the under-compartment of the printer: With that physically installed and wired up (the photo is mostly pre-wiring), I installed the LPC/STM32 fork of RepRapFirmware and configured the printer. It took some fiddling, but I eventually got it all working, and better than before. Among other things, I'm delighted at a new feature: I can now level the X-axis gantry with a simple G32 command. Prior to this upgrade, the two Z-axis lead screws would tend to go out of sync with one another, resulting in a misaligned X-axis gantry that produced spurious Z-probe activations and an inability to perform a G29 bed level or even home the Z axis. That's no longer a problem. (Marlin 2.0 seems to support a similar feature, but I've grown to really dislike Marlin, so I never seriously considered a Marlin upgrade to get that feature.) RepRapFirmware also provides a visualization of G29 height-map data, which really highlights how bad the Robo3D R1+'s bed can be: That's just one probe. It tends to vary a lot from one probe to another, I suspect because the bed's alignment can get thrown off when removing/replacing it and/or because of the little blobs of plastic that tend to get left behind because of probing. Either way, it's a good motivator to do something about the Z probe, and the visualization provides an easy-to-use tool to help evaluate possible solutions. Anyhow, I'm very happy with this upgrade. I never really liked the printer's original control board or Marlin, especially not after experiencing a Duet 2 WiFi in a Kossel XL that I built a couple years ago. I've also now got one spare stepper driver output, which I intend to use in a future upgrade to a dual-extruder setup.