Spindle accelerates too fast

My spindle errors out when I try to directly set the speed too high.

My spindle motor is capable of spindle speeds up to 6000 rpm. I can reach the 6000 rpm level if I slowly step up the spindle speed; such as manually increasing the spindle speed by 100 rpm increments up to 6000 rpm; but if I issue a M5 S5000 or greater, the spindle controller issues an overload condition and the mill shuts down. I can issue a M5 S4000 with no problem.

I am assuming that the overload condition occurs because I am trying to force the spindle to the higher speed at too high of a rate. (i.e. the acceleration level is too high.)

The spindle section of my ini file is as follows:

#********************
# Spindle
#********************
[SPINDLE_9]
P = 0.0
I = 0.0
D = 0.0
FF0 = 1.0
FF1 = 0.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 6000.0
OUTPUT_SCALE = 6150
OUTPUT_MIN_LIMIT = 0
OUTPUT_MAX_LIMIT = 6000

note: The slight change in the OUTPUT_SCALE value to 6150 is there to adjust the spindle speed to its true measured spin rate.

Is there a way to slow the rate that Linuxcnc changes the spindle speed? I really have no need for instantaneous changing of the spindle speed.

Thanks.

If this is a VFD controlled spindle you should be able to do this by proper VFD setup

You can also do this in LinuxCNC by using the limit2 component to limit the acceleration:

linuxcnc.org/docs/html/examples/spindle....#_spindle_soft_start

Yes properly configuring your VFD for your motor can make a huge difference, in how they perform. I bought a new machine that did not have the VFDs properly configured for the spindles, and getting them set right made a huge difference. Noticable increases in torque at high speeds and much more. Do carifully read your manual for the VFD and set all its parameters to what they need to be for your setup.