Baader Steeldrive II motor focuser for Diamond Steeltrack Focusers and other Focusers
The aim of the development of the Baader Steeldrive II was not simply yet another motor focuser, but a complete platform which can adapt to the individual needs of amateur astronomers. That's why the "brain" of the Steeldrive II is not located in the tiny housing of the motor itself, but in a separate controller which also provides a keypad for manual control.
With a Steeldrive II motor focuser, you can automatically control your focuser with a computer as well as use the keys of the hand control for precise, vibration-free focusing.
The Steeldrive II consists of a motor unit, which is connected with a timing belt to the focuser's slow-motion-control to work without backlash, and of a control unit with the electronics, which also doubles as hand control. You can connect up to two temperature sensors at the same time, one on the motor unit and one on the control unit. One sensor is included with the Steeldrive II to compensate the drift automatically, if there are large temperature differences.
A control unit can control one motor unit at a time, but you can use a computer to control several controllers parallel.
The motor is designed to move to a saved position with highest precision if it is used together with the homing sensor – even if it has to move several kilograms over the complete travel of the focuser!
High precision focusing of heavy loads
The high-torque stepper motor is directly engaged with the focuser via a timing belt. This eliminates the backlash (and potential cause of defects) induced by gearboxes which would have to be used with lower power motors. The Steeldrive II can quickly move loads up to 8 kg with high precision. The focusing resolution is 2.5μm.
The intuitive hand control makes it possible to find and save the focus point very fast. Several modes are available to move the focuser:
Normal mode: The focuser moves as long as a key is pressed.
Jogging mode: Each keystroke moves the focuser for a distance which is configurable in the SteelGo-software (e.g. 0.1 mm).
Single step mod: Each keystroke moves the focuser for the smallest possible way (ca. 2.5 micrometer).
The configuration of limits, saving and resetting of positions and (de)activating of the temperature control can also be done with the hand control. Brightness of backlight illumination and status LEDs are also configurable.
Contactless Homing Sensor
The Steeldrive II motor unit features a contactless (wearfree) homing sensor (hall-effect sensor). It is activated by a magnet attached to the moving part of the focuser. It enables precise homing and repeatable approach of saved absolute positions as well as reference of the mechanical endstop. A simple mount for this magnet to be attached to the focuser is included in the scope of delivery. For Baader Diamond Steeltrack® focusers, an adapterring made of metal is available separately.
However the Steeldrive II can also be used without the homing sensor as the absolute position is kept in a persistant circular eeprom buffer. Even if a power failure occures, the absolute position is loaded upon restart of the Steeldrive II, as long as the focuser wasn't moved by hand.
Two digital temperature sensors may be used simultaneously. One of each may be connected to the motor- and the controller unit. For the automatic temperature compensation, the specific sensor to be used can be selected, or the average temperature of both sensors may be used (eg. measuring the temperature above and below the telescope tube, or inside and outside), depending on your needs. The temperature compensation factor is for example calculated with the SteelGO software and can then be saved locally on the Steeldrive II controller unit. The compensation period and ∆T threshold can also be adjusted. The temperature compensation may then also be used in standalone mode of operation (without a connected computer).
12V/1A PWM power output (PID-controllable)
The Steeldrive II features a 12V/1A power output. It can be used with an optionally available adapter cable from Steeldrive II Controller AUX Port to Cinch with common dew-cap heaters #2957262 with up to 10W. The power can either be set in the SteelGo software, or you set a desired temperature for one of the temperature sensors. This prevents undesired heating of the telescope, because you keep the dew cap just above the dew point. It can also be used to control the exact temperature (+/-0.1 °C) of e.g. optical filters.
Made in Germany
All mechanical parts are CNC-milled from Aluminium in our workshop. The electronical boards are also designed and made in Germany. We only use high-end electronical components. The electronic circuit boards are additionally protective coated.
Low Power Consumption
The motor current is automatically reduced while in holding state. The Steeldrive II then consumes approximately 0.7 W.