[mactec54]

The output I am using on my BoB is 0-10VDC. It is not a PWM signal. My breakout board offers only 0-5V PWM and 0-10VDC.

I can see on the frequency display on the VFD that it never commands the above 400 HZ. I also have a photo tach that reads speed is not exceeding 24,000 RPM.

The VFD drive components are not seeing anything out of the norm b/c the voltage from my BoB to the VFD is only 0-8VDC - which is the problem I had that started this whole thread.

No one has disputed that you spindle is running at 400Hz= 24,000RPM I have setup hundreds of these and repaired them also this is normal

Lastly - this comment here regarding the need for a converter is flatly wrong. I connected the 0-5V PWM from my BoB directly to ACM/VI terminals on the VFD, set PD070=0 (configures input for 0-5V) and everything works perfectly fine.

You got lucky the PWM must be very good for it to be working without a converter as your VFD Drive can normally only work with an Analog input 0-10v or 0-5V ( Check the Manual )

For posterity should anyone stumble upon this later, this was my final solution -

PD070=1 (0-5V)
PD072=400 (Higher frequency. i.e. 5V = 400Hz)
PD073=100 (Lower frequency. i.e. 0V = 100 Hz)

And this is what everybody does already if they have a problem with the 0-10v this is nothing new users here have been doing it this way for many years we also mentioned this in other posts here in this thread

Default freq. of the PWM signal by default from AVID/Warp9 is 2kHz.

So you are using the Smooth Stepper you have never said that before that changes a lot of things

I would suggest you go through the Warp9 setup manual, they have a section on how to setup your spindle as your settings by default will not be correct

https://warp9td.com/index.php/gettin...epper-and-mach

[Wood768dGuy]

No one has disputed that you spindle is running at 400Hz= 24,000RPM I have setup hundreds of these and repaired them also this is normal

See this statement here:

Yes this means you are pushing higher Frequency into the spindle for the low voltage compensation not ideal as the spindle is only rated for 400Hz but if it lasts ok and works go for it

Sounds a lot like you think I'm pushing a frequency higher than the rated 400Hz.

You got lucky the PWM must be very good for it to be working without a converter as your VFD Drive can normally only work with an Analog input 0-10v or 0-5V.

Respectfully disagree, found several other threads where others have fed a 0-5V PWM into the 0-5V input - lots of Shapeoko users, etc. This is ultimately what lead me to try it despite the fact you said it wouldn't work. The place people run into issues is if the frequency of the PWM is too low - I tested and the speed is rather unstable < 1000 Hz.

I have an AVID CNC, which I stated in my initial post - it ships with an Ethernet Smoothstepper and pre-configured from AVID to be set up correctly to control a spindle. I did review thoroughly the settings and they are set up correctly.

There is a serious mismatch in the certitude of your suggestions and accuracy contained therein.