[Electrify]

Hello, I have a Dusan milling machine with fanuc 18m control. When the connection between the spindle motor and the spindle is disconnected, the tool collides with the work piece without rotating the spindle and causes the tool to break. How to activate the spindle non-rotation alarm?????

[zavateandu]

Look for a parameter called SAR taht will look for the spindle arrival rotation request
do you have belt between motor and spindle?
Do you have ecnoder attached to spindle shaft or a proximity sensor?

[Electrify]

I did not find the mentioned parenter. The connection between the motor and the spindle is through a gear and a position coder is used to display the speed of the spindle. Can you help me more?

[Electrify]

I checked the 3708 parameter, the sar parameter only checks the rotation of the spindle motor, I need to check the actual speed of the spindle with the setpoint speed

[guhl]

SAR - is an output signal of spindle VFD and it must be procceded in ladder. Usually there is the M-command, which activates this function.
You should put it after SxxxM4(3) block

[Electrify]

thank you. I checked that sar only checks the rotation of the motor and does not check the difference between the setpoint speed and the actual spindle speed. In other words, if the spindle speed is lower than the setpoint value, the program It executes G01 and causes tool failure.
I want the device to alarm and stop if the mechanical connection between the spindle and the motor is broken or the speed difference between the spindle and the motor is too large.

[guhl]

thank you. I checked that sar only checks the rotation of the motor and does not check the difference between the setpoint speed and the actual spindle speed. In other words, if the spindle speed is lower than the setpoint value, the program It executes G01 and causes tool failure.
I want the device to alarm and stop if the mechanical connection between the spindle and the motor is broken or the speed difference between the spindle and the motor is too large.

Then you should use spindle encoder and command feed per routine.
I would advise you take additional gauge with comparator, but where will you get reference? - because your cnc uses serial spindle most likely.
Are your belts getting broken often?

[Electrify]

Our spindle has a position coder, can't we use it?

[guhl]

Our spindle has a position coder, can't we use it?

May be your spindle encoder intended for rigid tapping?
If so, i'm not sure if it is coupled all the time.
Or you can observe real spindle speed during machining?

[Electrify]

The encoder counts all the actual revolutions of the spindle.

[guhl]

The encoder counts all the actual revolutions of the spindle.

So why don't you use feed per revolution Mode (G95)?

[Electrify]

Can you explain more?

[guhl]

Can you explain more?

If your spindle stops axis wil stop as well

https://www.kennametal.com/in/en/resources/engineering-calculators/miscellaneous/speed-and-feed.html

[oetkbyentc]

You could look at G26 speed fluctuation detection. There are a few parameters to configure for the function but it works well.
There are a few engine manufacturers that require this function to be setup on any machines that produce certain parts. Another option would be a ladder modification to use interlock and SAR via an alarm.
SAR check via parameter has its pitfalls as it is easily bypassed using Dry Run and if memory serves it is only examined at the start of a block vs continuously.
And as mentioned in earlier posts feed per rev. is another option.

I know the manuals state it is T control only. But I have seen it used on M controls. I'm not sure if it is software version dependent or what control series support it.