Rev B Dec 2019
Page 3
Chapter 3 Operation
Chapter 3 Operation
3.1 Using the HDR50
3.1.1 Background
The hybrid stepper motor used in the actuator, with its rotor that consists of 50 individual magnetic teeth, is ideally suited for
micro-stepping applications. Aside from the obvious increase in resolution provided by increasing the steps per revolution from
200 to 409,600, micro-stepping also ensures smoother low speed motion by allowing the discrete 1.8º step size, which
produces vibrational noise, to be reduced to much smaller steps with inherently lower resultant vibrational noise.
The rotation stage utilizes a worm gear assembly which provides one complete rotation of the platform for every 66 turns of
the stepper motor. When used with the BSC20x series or MST602 controllers, the stepper motor provides 409,600 steps per
revolution resulting in 66 x 409,600 steps per revolution of the stage. This results in a 360/(66 x 409,600)° or 13.3 x 10
-6
degrees of platform rotation per microstep.
The HDR50 stage is connected to the Stepper Motor Controller via a flying lead terminated in a D-type type connector. A 3m
extension cable (PAA613) is also supplied.
Manual control of the stage can be achieved by switching off the drive to the motors and turning the knob on the motor housing.
Please refer to the relevant controller manual.
3.2 Selecting the Stage Type
To ensure that a particular stage is driven properly by the system, a number of parameters must first be set. These parameters relate
to the physical characteristics of the stage being driven (e.g. min and max positions, leadscrew pitch, homing direction etc.).
To assist in setting these parameters correctly, it is possible to associate a specific stage type and axis with the motor controller
channel. Once this association has been made, the server applies automatically, suitable default parameter values on boot up of the
software.
Caution
Before the HDR50 is plugged in or unplugged, the relevant stepper motor controller must be switched off or the associated
drive channel disabled. Failure to do this may result in damage to the controller, the stage, or both.
Caution
The electrical limit switch does not operate when the motor is being turned by hand. Care must be taken to avoid fouling if the
drive is turned past the limit switch.
