Need correct M669 matrix for Core-R-Theta on Fly-E3-Pro-V3 (STM32F4 RRF 3.5.4)

[kevgeiger2]

Hi Joshua,
I’m building your Core-R-Theta printer 1:1, using the same mechanical setup and also the Fly-E3-Pro-V3 board.
The basic XYZ+C motion works perfectly, homing works, endstops work — but I cannot get your 4-axis kinematics line to load on my firmware.

Your original line:

M669 K0 C0:0:0:0:1 X-1:0:0:1:0 Z0:0:1:0:0 B0.22222222:0:0:0.222222222:0

My board returns:

Error: M669: array too long for parameter 'X'

Firmware info:

FIRMWARE_NAME: RepRapFirmware for STM32F4 based Boards
FIRMWARE_VERSION: 3.5.4
FIRMWARE_DATE: 2024-11-27 23:16:40
Board: Fly-E3-Pro-V3 (e3pro3_f4)

So it seems the STM32F4 RRF build supports matrix kinematics,
but it expects different array lengths for X, C, Z, or B.

Could you please provide the correct M669 matrix format for this board / firmware?
Or confirm which exact firmware build you used for your original project?

I already have the slicer working and just need the correct M669 configuration to enable the 4-axis non-planar motion.

Thank you very much in advance!