Build your Rep5x Marlin firmware

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Board Size Display Motors IK Build

Select your control board

Rep5x requires a board with at least 6 stepper drivers (X, Y, Z, E, C, B).

BTT Octopus V1.1

8 stepper drivers, STM32F446, abundant I/O

Recommended

BTT Octopus Pro

Enhanced version with more features

Coming soon

BTT SKR 3

Compact board, requires expansion

Coming soon

Other board

Manual board configuration

Coming soon

Need a different board? Ask on Discord and I'll add support within a couple of days!

Printer dimensions

Configure your build volume and motion limits.

Build volume
Auto-adjust for Rep5x toolhead

→ 200mm used (−20mm for Rep5x)

→ 200mm used (−20mm for Rep5x)

→ 170mm used (−100mm for Rep5x)

Homing directions

Depends on endstop location

Depends on endstop location

Select your display

Choose the LCD screen you'll be using with your printer.

BTT Mini 12864

Compact display with RGB backlight, encoder knob

Recommended

RepRap Full Graphic

Standard 128x64 LCD with SD card slot

BTT TFT35

Touchscreen display with dual mode support

No display

USB/Serial control only (headless)

Backlight colour

Motor configuration

Configure stepper drivers, steps per unit, and motor directions.

Stepper drivers

Motor socket assignment

Default assignment: X=MOTOR0, Y=MOTOR1, Z=MOTOR2_1, E=MOTOR3, C=MOTOR4, B=MOTOR5. This matches the standard Rep5x wiring for BTT Octopus.

Steps per unit
Motor directions

C-axis (yaw): Inverted by default for CNC convention where positive C = clockwise when viewed from above.

Inverse kinematics parameters

Configure the 5-axis inverse kinematics for your Rep5x toolhead.

Axis homing positions

Coordinate value assigned when C-axis hits home switch

B-axis travel limit (±value, e.g., 135 → -135° to +135°)

Toolhead geometry

Y-offset from yaw axis to nozzle

Z-offset from tilt axis to nozzle tip

LB B-axis

LB is the distance from the B-axis pivot to the nozzle tip

Don't worry about exact values. LC and LB can be fine-tuned later using the IK Calibration tool after your printer is assembled. Start with the defaults and calibrate once everything is working.

Higher = smoother motion but more CPU load

Review and build

Review your configuration and download the firmware files.

Configuration preview


                        


                        
                        

                            
Download options


                            

                                

                                
                            


                            

                                
Manual build instructions

                                
    
                                    
  1. Download the config files above
    2. 
                                    
  2. Clone DerAndere-Marlin repository
    3. 
                                    
  3. Replace files in Marlin/ with downloaded configs
    4. 
                                    
  4. Build with PlatformIO: pio run -e BTT_OCTOPUS_V1_1
    5. 
                                    
  5. Find firmware.bin in .pio/build/
    6.