Novice Tutorials, schematics

[johnnydoughey]

I am a novice at CNC, but pretty good at fabricating...
what I am looking for is a tutorial which show the relationship between step motors and servos (are they just AC or DC motors, or are they somehow specialized), what are the drives (until today, I thought the drives were the step motors or servos), how does one match the drives with the motors, what size (I'm used to working in HP, not OZ/IN sizes...
I've been reading many of the forum posts, but you guys are in a whole different level than me, and, although I usually catch on pretty quickly, I need some info a little more basic....
Thanks much for your suggestions...

[ViperTX]

Welcome.

Steppers are special motors...where if you turned the shaft you would feel the detents or poles.....torque is generally higher at low RPM and rapidly decreases as the RPM increases.

Servos can be AC or DC motors...brush or brushless....torque is generally constant across their RPM range.

Drives or drivers are the electronics that cause the motors to spin....most of the hobbyist drivers are step/direction type....the professional drivers for servos are 0 to 10 volt.

Drives/drivers are matched by type (stepper or servo (AC, brushed, unbrushed)). The stepper drivers are further matched by how the windings for the stepper are driven (polar, bipolar, etc.) and each is matched based on operating voltage and current.

[Al_The_Man]

Originally Posted by johnnydoughey what I am looking for is a tutorial which show the relationship between step motors and servos (are they just AC or DC motors, or are they somehow specialized), what are the drives (until today, I thought the drives were the step motors or servos), how does one match the drives with the motors, what size (I'm used to working in HP, not OZ/IN sizes..

You obviously require a drive that will supply the demands of the motor,
You will see Motors rated at Continuous Stall current/Torque, Maximum Stall Torque, (max current before demagnetization).
Modern drives are invariably PWM (Pulse Width Modulated), This allows the use of drive power supply voltages that exceed the voltage rating of the motor by virtue of the PWM controlling the mean/max current limit.
Most current drives also operate in the Torque or current mode, as opposed to older velocity style that required Tachometer feedback.
These drives will control motor current (and hence torque) by virtue of a either a Digital signal or a ±10vdc analogue signal that is directly proportional to the current delivered.
Al.