I am also going mad abóut A rumba card i had marlin in it but every distance become 5 times too long in repetier host x manuel 10 mm got more than 50 mm 10 mm become 100 mm where to change i have TK 300 LOOKSLIKE LUZLBOT TAZ 4 BIG BELTWHEEL 36 I THINK THE FIRMWARE WAS MADE FOR A BELTWHEEL WITH 12 RIBS.