Centroid Community CNC Support Forum

Problem identified: Encoder quadrature error when motor RPM exceeds around 4000 RPM. Suggestions are most welcome.
I don't need to do tapping at this time. Complete diagnostic is needed when I have the time.
1) Your value from Parameter 78? 0.0000
2) Your value from Parameter 34? 2000.0000 Encoder's pulses/rpm per the device's label
3) Your value from Parameter 36? 0.0000
4) The number you have entered for "Max spindle (high range)" on the Control Configuration table? 6,000

Also, given your current configuration of the spindle drive, how fast will it turn the motor if given a 10V reference command?
With the encoder disabled the motor will run at 6,000 RPM, it's rated maximum.

Thanks to all for your help

Yes, the encoder is connected to the motor.

A quadrature encoder with 2000 lines will make 8000 pulse
Most of the cheap ones are limited to 3000rpm from the electronics, with 1000 line they are ok for 6000rpm
to read out the spindle speed with 1:1.16 and the encoder on the motor it will put out pulse / 1.16 for one revolution on the spindle

Uwe

Since you have P78 = 0, the RPM display on the screen does not depend on the spindle encoder in any way.

The RPM display on the screen will be the intended / commanded / expected RPM. In Auto mode, that would be the CNC "S" code, multiplied by the spindle speed override percentage you have selected on the jog panel or VCP.

If the motor turns 6000 RPM at maximum reference (10V), and the spindle turns 1.16 times for every turn of the motor (per your post on 8/25/25), then you should enter 6960 RPM as the "Max spindle (high range)" value on the Control Configuration screen.

Since you are not using the encoder for spindle speed display or for rigid tapping, you could change Parameter 35 to zero.

Then there would be no problem with quadrature errors, because the control would simply ignore the encoder signal.