VFD wiring to CNC Shield ??

[Bruce]

I'm doing more research on VFDs and I'm trying to put together a control wiring diagram between the CNC Shield and the VFD.

I see a Spindle Enable, Spindle Direction, Coolant enable. I don't see a discrete signal for Stop Spindle.
Typically you need a Start signal, Stop signal, and the speed reference signal. I'm assuming the spindle direction signal I don't need. 
If I enable the PWM spindle speed control signal it looks like I lose the spindle enable signal.  I keep looking at this... but it looks like I'm short some control signals.

How are those of you using a spindle VFD have the control wired to the CNC shield? 
 

[Derek the Admin]

I think that you are correct about losing the digital high and low signal when you have PWM enabled. The way GRBL handles this is that in software it will not generate a PWM signal unless M3 is active. I am willing to bet that you can work with the spindle direction signal to generate your spindle on command though. You might also be able to utilize coolant signals (M8) as a spindle on.

The last Yaskawa VFD I worked with didn’t need separate on and off signals by the way.

Hope that is at least partially helpful.

[brandon]

Ok this one is a doozie...

So the exact wiring will differ from one VFD to another. But with mine I think I had to go into GRBL arduino settings (not just the $$ settings, like into the firmware) and make a change to swap Z+ limit switch and SpnEnable pins around. For whatever reason, even on the newest GRBL version using it the default way didn't work for me IIRC. So then I have my Z limit switch wired into SpnEnable. The Z+ limit switch is wired to a 0-5v -> 0-20mA circuit. So when you give an RPM value with gcode it sends a voltage increment to Z+ limit switch pins. So if you tell it to go 5000rpm with max RPM 10k and minimum set to 0 it would send 2.5v to the converter and send 10mA to the VFD, which, if set correctly, would send half the max frequency to the VFD then ultimately give you the RPM you desire.

But again wiring from one VFD to another would differ and also the settings. If you look into it, I'd try to find a VFD that has good online documentation with spindle/CNC use so it's easier to hook up. The first spindle I bought was a joke because it didn't come with the VFD pictured on the listing so I sent it back and was able to get one with one of those Huanyang VFDs. Definitely not the highest quality one but at least it had backing info online for this specific use.

[Bruce]

I'm looking at an authentic HuanYang drive. I even asked the question on the Amazon page if the drive was a real HuanYang VFD.
OK, so I can start and stop the drive with the Spindle direction command tied to the RUN input. Closed : Drive On , Open : Drive Off.

I'm up on the Arduino pin 11 and 12 switch for the PWM enabled use.  I may wait before using the PWM anyway.  If I can get the spindle to shut off after running a job, I'll be happy for a start.