Please help me understand how to configure the PWM settings correctly for my VFD/Spindle using UCCNC. I've read the docs, but a little extra theory/understanding would help.
Do I set the “PWM Frequency” setting based my motor’s “basefrequency” or “max frequency” or lowest frequency my spindle is suggested to run. And how does this related to the min/max duty % settings?
I understand that 1 rpm = 60 HZ... so sending a 200 Hz signal from UCCNC to my BOB to my VFD should have 12,000 rpms.
I have a .75KW Delta VFD S1 and a .75KW Teknomotor, or at least will have soon from Damen CNC!
For example is my understanding below correct?
Based on my spindle specs (Base frequency 200Hz = 12000 RPMand Max 400 Hz = 24000 RPM, the lowest operating is at 100 Hz = 6000RPM). Motor plate pic below.
UCCNC Settings
PWM Frequency = 400Hz
PWM min duty(%) = 50%
PWM maxduty(%) => 100%
Then does min duty at 50% translate to 400 Hz?
g-code S24000 would trigger UCCNC PWM signal spindle to runat 400 Hz? (this is 100% duty?)
g-code S12000 would trigger UCCNC PWM signal spindle to runat 200 Hz? (this is 50% duty?)
With this configuration, anything below 200 Hz or less than12000 RPM UCCNC will not let to go lower than that limit and anything over 400Hz 24000 rpm, uccnc will limit it to a max of 24000 rpm.
I guess I could lower my PWM min duty to 25% since I can runspindle at 6000 rpm.. but 12000 is where it gets peak torque and horse power on the power curve charts.