I am taking the plunge and converting my Prazi lathe to cnc, including a VFD spindle drive. The drive specs can drive the motor from "0 to 6900 rpm " with apparantly a flat torque curve. My question is should I drive the spindle 1:1 off the motor or should I use a step down ratio ? I don't see using the extreme speed range as this is way more than the spindle is currently , likely max 3000 rpm.
Thanks for the advise
Wayne