I found the same problem in my printer.My printer is the same as kossel,and I try to add dual extruders on the printer,but failed.when I send G-code 'T1',and the send 'G1 Xxx Yxx',the printer moves up in all 3 delta axes.How did you fix the problem?Should I fix the codes in codeseen'T' that you found?Do you mean that the Marlin Firmware could not support for dual extruders of delta?ou Thanks foby richard8386 - Delta Machines