Long STL filename breaks communication with printer

Just spotted this. I'm trying to print STL file with name '


This somehow bugs the firmware and after slicing (slic3r) and clicking print the host continues to show 'warning seems like we missed a ok - continue sending' 

The display area on the printer LCD where the filename is shown on the first row is empty


  • After renaming the STL file and re-slicing the warning error message is gone
  • Do not expect firmware to support such long filenames. Some may others not. Not that any firmware can print stl files - you need to slice it first and give it a shorter name. This is a memory problem firmwares have. Most have only 8kb for everything so every byte more can cause problems. Repetier supports 26 chars = 2 directory entries by default.
  • yes I can understand that and is all fine. But is it not better if Repetier-Host trim/cut the filename to this exact size before sending to printer firmware. ?
  • It is the firmware trimming filenames in this case. Host just takes what it gets. Limits are define din repetier.h

    #define MAX_VFAT_ENTRIES (2)

    /** Total size of the buffer used to store the long filenames */


    #define SD_MAX_FOLDER_DEPTH 2

    Increase MAX_VFAT_ENTRIES to 3 and you get 39 chars used by firmware along with higher ram usage, which is only an issue for deltas.
Sign In or Register to comment.