i have a problem with dividing head (A AXIS) machine is vmc FANUC 18M
when i switch on the machine all axis goes fine to home position XYZ&A
No (APC) provided with the machine. the problem is after switch off the machine and next day i zero return the axis as usual the A axis gives me error about 10 degrees comparing with the previous homing position,
so if some one could tell me where is the problem and how to fix it
for example, do i need to set zero reference for A Axis ? if yes what is the procedure??
any help will be appreciated
what A-axis use for?for tools magazine?if that right,i think your a-axis used PMM (power mate manager). U can acces PMM with press SYSTEM, then press RIGHT softkey untill PMM menu appear.if u want zeroing the axis,set the parameter 11 in PMM bit 0 and 1.
What kind or Brand of Rotary table do you have assembled?
thnx for ur reply
it's a dividing head with small chuck diameter about 200 mm capacity,can be fixed on the table in horizontal or vertical positions only
the manufacturer is LCM the motor drive is fanuc
what i need is how to correct the 10 degrees error?
i saw the parameter 1815 it;s value all zero
about the parameter i don't have a back up and i don't think i need the back up because it's only a matter of how to reset zero again for the A axis .
thnx again for any help
Do you see the A axis in the screen? if you do zero return without powering off the CNC, Does the position change everytime you do the zero return?
So, the axis varies 10 degrees, or did it suddenly shift 10 degrees and stay there on zero return?
Grid shift is parameter 1850, that controls distance from marker pulse to actual zero. If it varies back and forth every day or whatever, I've seen where the zero return switch is too close to the marker pulse on the encoder, sometimes getting the pulse right at the switch, sometimes getting the next marker pulse. A small adjustment of the switch usually cures that.
thnx for ur reply
the situation is when ever i switch on the machine and zero return the A axis, i get 10 degrees different comparing with the marker on the scale and even if i rotate the axis in manual (handle) mood and call back zero return again it goes to same position(machine still switched on)
plus in relative value when i set zero to relative and turn the axis manually and then call back zero return it goes back to same position and the relative value doesn't give me my zero reading where i set it to zero
i believe that i need to set zero reference point for the axis again (only for A axis)
about ur qustion alexfanuc , yes i see the A axis on the screen and the reading is changing as the axis rotating in general the machine works fine exept the problem of the A axis .
for example i send a program from pc to machine (4 axis program) i have to finish the machining complete with out interference in the program like optional stop or switch off the machine and finish the program next day .
if i do so i lose the angle position where i stop last time
thnx again for any help or suggestions