Hi Disneytoy
I used M666 successfully. All my values are negative I.e M666 X-1.65 etc. set the M666 value for your first tower, X?. Then home the carriages then run the script to take the head to the base of the tower. I use a piece of square aluminium tube which is exactly 12mm and set my script to take the carriage to Z12. This enables me to jog up and down in RH to find the value to adjust M666 by. I started with M666 X-5 Y-5 Z-5. You should be able to see the carriages home and then drop by the relevant M666 value. Try going from -5 to -10 on one carriage to see the effect. Once the first tower is set go to the next. Don't forget to home after each change to M666 and don't forget to send an M500 command to lock the values into EEPROM. Also make sure EEPROM is enabled in config.h.
Andy
I used M666 successfully. All my values are negative I.e M666 X-1.65 etc. set the M666 value for your first tower, X?. Then home the carriages then run the script to take the head to the base of the tower. I use a piece of square aluminium tube which is exactly 12mm and set my script to take the carriage to Z12. This enables me to jog up and down in RH to find the value to adjust M666 by. I started with M666 X-5 Y-5 Z-5. You should be able to see the carriages home and then drop by the relevant M666 value. Try going from -5 to -10 on one carriage to see the effect. Once the first tower is set go to the next. Don't forget to home after each change to M666 and don't forget to send an M500 command to lock the values into EEPROM. Also make sure EEPROM is enabled in config.h.
Andy