B and C axis callibration

[jolliesconcept]

I am facaing broblem with the B and C axis.B and C Zero position is correct but when you try to make B axis to 90 it only move to around 80 but shows 100 in the machine display.Same way C axis when in zero ok.If you give a rotation of 360 degrees it rotates more than 360 degree to around 540 degree but display shows 360 degree.our machine is a 5-axis vertical milling machine with siemens 840 Di control.pls see the attachment for the Rotary table type