Re: Acorn isn't closed loop?
Most modern servo systems close the loop within the servo drive.
Most servo drives accept step and direction input.
'the loop' being positional (rotational) feedback from the motor and the power output to the motor.
Steppers are (usually) open loop. Power is sent to the motors with no feedback. The drive / controller assumes that the desired movement has occured.
Closed loop systems detect when the desired movement has / has not occurred and correct.
7xCNC.com - CNC info for the minilathe (7x10, 7x12, 7x14, 7x16)