Fanuc 15ma - Kafo milling machine problem!

[F.Sharifi]

Hi All ! Kafo milling machine with Fanuc 15 Ma , without any error message with random action many time that i have turn off the machine and turn on in next day i found the between 4-6 mm in X axis displacement and the same for Y axis i meen i cant go back to zero - zero point of part in case of i must turn off machine and leave the shop for next day !

would be glad for any kindly hints !

[Al_The_Man]

Before you turn the machine off, have you tried sending the axis back to zero, using both G28 and the home routine?
Are you talking Machine zero or part zero?
Al.

[F.Sharifi]

Hi Al .. i mean part Zero i check the machine zero home position is always good , and No iam not trying to do G28 before turing off the machine ... this is helpful for save the origin ?

[bborb]

<F.Sharifi wrote:>
<i check the machine zero home position is always good >

Your work offset is the distance from machine zero (home) to part zero. Your vise or part that is clamped to the table is not moving overnight. I have to think your Machine zero (home) is changing. I'd set a travel dial up to read zero when the machine is at home, or even a scribed line on some fixed sheet metal since you say it varies over 1/8 inch, and see how consistent it homes in the morning.

[F.Sharifi]

i have check with digital dail gauge (0.001 micron accuracy ) all axis home position and repeat more than 20 times , and see all home position is the sam , even in the morning or middle of working or end of working before machine off ! .... i mean thats only in the morning after machine goning to home position , not go to G54 as i set before ! i see just one rule always going to plus ..for example if i set the G54 for X10.000 and Y 20.000 in this problem i see the X always going to X14.000 or 16.000 and Y going to 24.000 or 26.000 ! .... please let me know your idea .

[bborb]

So you set the indicator to read zero at the end of the day Tuesday and when you come in on Wednesday and turn machine on, then zero (home) machine, the indicator reads zero still? Following your explanation, the values in G54 have progressed this way:
Monday's G54 values= X 381.000 Y 203.200
Tuesday's G54 values= X 387.000 Y 209.200
Wednesday's G54 values= X 393.000 Y 215.200
Thursday's G54 values= X 399.000 Y 221.200
Friday's G54 values= X 405.000 Y 227.200
This means you've lost/gained almost an inch by Friday.
How large are the parts you run? Have you noticed any deviations in the accuracy of the machine? I'm trying to decipher if your problem could be mechanical but an inch is huge. Has there been any mechanical repairs to the machine prior to this problem (new belt, pulley, etc.)

[F.Sharifi]

Hi Again ... many thanks for your attention , i never seen before something like that ... i must say your tabale is correct but i have to check and re allocated G54 every morning ! the machine is full mechanivally servied and overhalled by 3 mounth before ...everythings is new ! ... i thinks the problems is in control system , do you know there is somthing in DGN regarding Position Record POR signal to save the last register position ... i thinks must be ...please help me