Fanuc 18M Z return

[pinguS]

Hi
Just bought a VMC 700 mill, 2nd hand, but having problem with getting the Z to return to home position, I have been told that its something to do with the Z interlock or something.

Any one have any information please...

Just to note, I have tried to jog machine down, and then homing.
Also to keep hold of Z- in home, but this doesnt even make it move.

It does move around using the Jog mode, and I know its Abosolute referencing, etc which it automatically knows its home position, once turned on but I'm currently getting alarm 300 - APC Alarm - Z RN (need to home).

any help please...

Oh also, the spindle does not orientate, just keeps spinning and then throws alarm about spindle orientation not reached....

[Al_The_Man]

Did you get the manuals with the machine? If all else fails, If you have the PMC ladder listing and can display it and can find the Z homing routine, you can usually trace the reason for the hold up in the zero routine, the highlighted objects show the parts of the path that are completed.
It could be something to do with the spindle orientation, although of course you need it to tool change, it is seldom programmed in to enable zero.
Al.

[pinguS]

OK so...
1. Display the PMC ladder
2. Look for something along the lines of Zero Routine or Z something.
3. Anything highlighted is completed, but any thing else in that routine is likely the problem.

Would there be some sort of link regarding the Z return and spindle orientation, and if I find anything, does the ladder normally provide enough information to correct it.???

cheers.. in advance

note using M19 to try and orientate the spindle does the same, i.e. makes it spin like its drilling air!!

[Al_The_Man]

Obviously you have an issue with the orientation, usually the sensor is bad or mis-adjusted.
For the ladder if you can find a rung that uses the Z home PB, (there is not going to be many), may be only one if lucky.
This will indicate the rung to trouble shoot, unfortunately you have to do alot of decifering to track the problem. There is a Defined bit that has to be set in the PMC to let the CNC side know it wants to zero the Z, I only have the BMI book for the 15 but it is probabally close to the 16/18. I can look it up if you cannot find the rung.
If you have a hard copy ladder listing with comments/labels, it helps.
Al.

[brianaldrich]

did you try holding keys P and CAN and then turn the control on hold them till it boots all the way up if that works there a bit you have to reset

[pinguS]

I have tried the P and Cancel, nothing happens. Which is the bit you have to reset??

Oh and check this, the edit screen just doesn't respond anymore, everything works like jog, etc. But on edit I cannot change between programs or even go down the current program, last thing I did was to output all the programs from the machine, even though the APC alarm is still active.

[alloyspec]

pinguS,
You told us that it was a VMC 700 but you did not mention who's machine. I bought a Hardinge VMC 700 that had a similar problem. It had a broken 10-24 screw in the coupler to the spindle orient encoder. The shaft would spin in the coupler. When I bought the machine it also had 3 broken toolholder cups that I could no longer get through Hardinge and I finally repaired them myself.
Good Luck,Alloyspec

[Ozemale6t9]

Originally Posted by pinguS Hi Just bought a VMC 700 mill, 2nd hand, but having problem with getting the Z to return to home position, I have been told that its something to do with the Z interlock or something. Any one have any information please... Just to note, I have tried to jog machine down, and then homing. Also to keep hold of Z- in home, but this doesnt even make it move. It does move around using the Jog mode, and I know its Abosolute referencing, etc which it automatically knows its home position, once turned on but I'm currently getting alarm 300 - APC Alarm - Z RN (need to home). any help please... Oh also, the spindle does not orientate, just keeps spinning and then throws alarm about spindle orientation not reached....

Check the APZ bits (4) of parameter 1815. There is one for each axis and they should be set to 1. This is how the machine knows that zero is set for each axis. Also, if you have absolute encoders, bit 5 (APC) for each axis should be 1.

Your alarm 300 is caused by either one of the encoders being disconnected at some time, or the battery/ies in the servo amps going flat. I am not familiar with your machine, but when I have had alarm on machines I service, I need to set the machine to its approximate home position, then turn the APC & APZ bits to 0 (message to power off after changing - ignore until you have done both) for which ever axis needs to be homed (best to do one axis at a time), then power off the machine. Allow a minute or so then repower machine. Upon repowering set the same two bits to 1 and restart the machine. Again allow a minute or so. You will then need to check your positions against a known datum, and repeat the above procedure, moving the axis the required amount as necessary to achieve the true position. Typical datums are the gridshift amounts from centre and top of the machine table. Unless you have replaced the batteries when you bought the machine, it may be advisable to take this opportunity to do so. If they are the reason for this alarm, you will go through this all again next time you turn of the machine.

The spindle orientation problem may be related, ie if it has an encoder, disconnecting it may have caused the same problem. But it could be any of a number of things, including but not limited to, adjustment of the pulse sensor, dirty pulse ring, faulty proximity sensor, dead battery in spindle amp, orientation position not set in parameters, orientation speed to low/high, etc, etc.

Hope this has helped.

regards, Oz

[timlkallam]

home is position is lost you need to rest home

Change PWE to 1( WRITE ENABLE)
Confirm Parameter 1002.1 = 1
Confirm Parameter 1815.5 = 1
Change Parameter 1815.bit 4 to 0
Check parameter 1320 and 1321 and record the settings
Change parameter 1320 to +99999999 and 1321 (Z) only to -99999999
Turn off the power to the machine
Turn on the power
Using the MPG line up the marks on the Z axis column with the mark on the head
Change parameter 1815.bit 4 back to 1 (Z axis only)
Turn off the power to the machine
Turn on the power
Place the Rapid Transverse knob to F0
Zero return Z axis using Z+ button
Change parameters 1320 and 1321 back to the original settings recorded earlier.
Change PWE back to 0.

The 300, 306 and 307 alarms are normal when the motor is removed or battery power is interruped and will be reset once this procedure is completed.
bit 4 is the 5th number starting from the RIGHT (7 6 5 4 3 2 1 0 )

[pankajdeore]

Originally Posted by pinguS Hi Just bought a VMC 700 mill, 2nd hand, but having problem with getting the Z to return to home position, I have been told that its something to do with the Z interlock or something. Any one have any information please... Just to note, I have tried to jog machine down, and then homing. Also to keep hold of Z- in home, but this doesnt even make it move. It does move around using the Jog mode, and I know its Abosolute referencing, etc which it automatically knows its home position, once turned on but I'm currently getting alarm 300 - APC Alarm - Z RN (need to home). any help please... Oh also, the spindle does not orientate, just keeps spinning and then throws alarm about spindle orientation not reached....

Restart your machine and Hold the Q+Cancel Button and try. I think it will work.

[alphonso]

On my 18mc controls: press and hold (letter) O, P and Cancel buttons when turning on power. If that doesn't sort out Z home, then something is broken or out of adjustment.

[pinguS]

Sorted, it was the cable from the Encoder to the unit in the back.

God that took a long time