So I’ve even tried using Avids Mach 4, just tried it and left the spindle at default 6000 and it worked! BUT…it’s set for 18000 and no go. Tried S318000 it sets but won’t run set it back to 6000 and it runs, I can increase the percentage up to 16500 (275%) and it stays running, try to kick it to 18000 and it shuts off. How does this make any sense 🤦🏽‍♂️

Check the "pulley" setting, I forget what it's called in Mach4, it's different than Mach3 but has the same effect. It's mentioned in Andy's setup documentation on their site.

Get hold of Andy over on Warp9 and he can even Teamviewer in and check your setup IF he can find time!! He's a pretty busy guy.

Have you set up your spindle pulley info in Mach4? Mach4 figures out the %PWM by looking at the S word as a % of the maximum spindle speed.

Are you using the relay on the PMDX-126 to command Run or Forward to the VFD or are you using the Run or Forward directly from the PMDX-107? The PMDX-107 derives the run status by looking at the PWM. If the PWM ever becomes absolutely 100% (never pulses) the PMDX-107 will turn off. We often recommend that users set up the maximum pulley speed to just over the maximum S word that you plan to use. For example if you have a 24000 RPM spindle, set the maximum pulley speed to 24005 so that the PWM never saturates to 100%.

Hey Steve! Actually sent an email to you and support a couple of weeks ago but never heard back. Appreciate the assistance, I configured it based on the ESS recommendations, set my maxRPM and Max Spindle RPM to 18000, minRPM to 0. How would I know if I’m using the Fwd from the 126 vs the 107? It’s wired to my 107 from the VFD, then just configured using pins 1-14/1-16 for Fwd and PWM. I’ll try setting maxRPM to 18005.

If the VFD is only wired to the PMDX-107, then the 100% PWM problem could exist if the SmoothStepper allows a full 100%. Even 99.99% avoids the problem.

Well got it working then shut it all down and stepped away. Kept PC on, came back later to run some tramming/squaring using Mach 3, no issues. Figured i'd start the swap to 4 now that the spindle issue was resolved. NOPE, same thing, except now it wont even kick using the settings from before, i feel like i'm going crazy. Set the spindle speed (pulley) to min 0/18005 max, set to 300Hz(tried 1000/even 25 for giggles) no dice. Messed with it for another 1.5 hrs to see if I could replicate getting it to work like earlier but no go. Just shutdown the computer and i'll try again tomorrow. Once configured, are the settings saved? Shouldnt my spindle rpm setting show under the spindle once i click the enable button?