Originally Posted by lgalla  Are servos less costly than steppers?May be checkout Granite Devices dual drives.http://www.granitedevices.fi/index.p...c-servo.1drive Will power 2 servos on the X and one more drive will power Y&Z.The cost would be around $150 per axis about the same as steppers.
Keling has DC servos for about $100.I do not know if they are usable with the Granite Devices dual drives.Basically it appears servos can be more cost effective than steppers.
http://www.kelinginc.net/ServoMotors.html
Larry |
The DualDC drive was developed using Keling servos (Nema 23 and 34) as test motors, so the perfect matching is guaranteed.
DC servos are generally a good choice for machine tools as their high inertia iron rotor provides stability against cutting forces & inertial loads. AC/BLDC servos start shining if extreme speeds & accelerations are required (>3000 rpm & low inertia). In heavy industrial use they also benefit from longer life time.
In my opinion rack & pinion is not very good choice for machines where cutting forces are present. It is one of the least rigid solutions.