No I am not suggesting that you change the offset in the slicer, I am suggesting that you set up the correct tool offsets in the G10 commands in config.g. You can also send G10 to adjust them any time you need to. EDIT: I think we may be talking at cross purposes. Do you have a dual nozzle single head machine and you want to set the nozzle offsets from centre for each tool? If so, use G10. Or, if you are simply saying that the machine doesn't home to X=0 but homes to X=-38.3, then find the M208 S1 command in config.g and change the X parameter to -38.3.