I recently picked up a tormach 1100 series 1 with no upgrades. My question is when you do the vfd upgrade they change the main control board. But what is different about it? And by looking up the vfd part number it says its obsolete. So i was wondering if I can get the vfd for the 1100M and eventually get the 1100M spindle cartridge and then it would almost be the same as the 1100M with 7500 rpm. Does anyone know why this wouldn't work? Thanks for all your help.