I am using the PWN 1.5 air cooled 80 w spindle and seems to work on g sender with the Sienci labs VFD that came with the Altmill. My firmware is set to H-100 on default. Is that where it needs to be or does it change to Mod. I am running into other problems like unable to Zero my Z and XY axis now Not even sure its related. Just on inquiry on Firmware setting with the original VFD from Altmill.