Core One+

Features

Shipped in the community firmware.

• Accurate bed temperature MK3.5 MK4 CoreOne CoreOneL

  The stock firmware adds up to 10 °C to the bed thermistor reading before the PID controller, display, and API see it. The offset was a workaround for the MK3's bed thermistor error; it was retained for gcode compatibility on the MK4 and copied to the Core One, where neither the thermistor nor the bed physics justify it. The community firmware removes the compensation.

  Download from GitHub
• Streamlined filament change with preserved preheat CoreOne

  The stock Change Filament command (M1600) always parks, homes, and heats the nozzle before unloading, even when the filament is auto-retracted and could be cold-unloaded. The standalone Unload command (M702) already skips these steps for retracted filament; Change Filament does not. The community firmware aligns the two code paths.

  Download from GitHub
• Reliable Wi-Fi and configurable NTP CoreOne MK4 MK4S XL MINI

  The ESP NIC firmware drops idle Wi-Fi connections every ~75 seconds on quiet networks, WPA2/WPA3 transition-mode authentication fails on both ESP32 and ESP8266, and the NTP client is hard-coded to prusa3d.pool.ntp.org. The community firmware fixes all three.

  Download from GitHub
• Bed leveling shim estimation from probe data CoreOne

  The Core One's bed is mounted on three Z lead-screw mounts. To level it, shims must be placed under the mounts to correct tilt. The stock firmware provides no probe-based measurement for this. The community firmware adds M1962, which probes the three mount points with the load cell, computes relative height differences, and recommends shim thicknesses.

  Download from GitHub

Under investigation

Known problems that aren't fixed yet — documented so they can be.

• "Absorbing Heat" waits longer than necessary CoreOne

  The firmware estimates frame temperature with a step formula that has no documented physical basis. Preliminary measurements show the dominant heat path is conduction through the metal spacers between bed and frame, not the air gap. Wait times at ABS temperatures stretch to ~16 minutes. This analysis is work in progress.

• Second-order input shaping for axis crosstalk CoreOne

  The stock firmware applies one input shaper per axis. On CoreXY kinematics, each motor excites both logical axes, and a single shaper cannot place a deep notch at both resonance clusters. A cascaded second-order shaper places independent notches at each cluster.

Mods & tools

Hardware improvements and calibration essentials.