When automated depowdering equipment manufacturer, Solukon, needed space-saving and robust drive components for its range of depowdering systems, it turned to motion control equipment specialist Stober.
When printed parts are produced using the selective laser mounting process they are full of powder, the removal of which was previously carried out manually by shaking, tapping or suctioning. Solukon wanted to automate the process of depowdering metal parts manufactured using 3D printing technology, as in complex components that have a labyrinth of channels, removing the power can more easily be done using an automated system.
The Solukon SFM-AT350, a two-axis swivel system designed to produce medium sized parts integrates Stober’s Lean bevel geared motors, and its extremely compact Lean planetary geared motor, which solved Solukon’s space and reliability issues. Also, as the encoderless Lean motor series is an inexpensive and rugged alternative to synchronous servo motors, this was an added benefit for the manufacturer.
Solukon’s depowdering systems are based on its ‘Smart Powder Recuperation’ (SPR) technology, where the powder is made flowable by automated swivelling around two axes and systematic vibration excitation. Launched in 2021, the SFM-AT350 is one of Solukon’s latest depowdering system developments. As the system’s turntable can rotate endlessly and the horizontal axis can simultaneously move up to 250 degrees, even complex rotation patterns can be easily programmed. Users benefit from time savings of up to 90 percent compared to manual cleaning processes.
Compact drives for a compact machine
Solukon’s co-founder, Andreas Hartmann explains: “The SFM-AT350 features a particularly low chamber volume and a compact design. This was a major concern for us in order to keep the inerting time and required amount of inert gas as low as possible. To achieve a compact design, we needed particularly space-saving drive solutions during development, both for the endless rotation of the turntable on which the component is mounted and for the horizontally moving swivel arm.”
Udo Cyrol, head of Stober’s south-east sales centre, continues: “Previously, Solokon used servo drives in the depowdering systems, but in order to build even more compactly without losing performance, we recommended our sensorless Lean gear motor.”
The advantages are that a high-precision planetary gear unit and a first-class helical bevel gear unit, combined with an energy-efficient, encoderless and rugged Lean motor are particularly efficient for precisely fitting, compact machine concepts. In addition, the motors have up to 96 percent efficiency qualify for energy efficiency class IE5, which means that Solukon is already at a level of technology that will not to be expanded for several years.
Removing the need for an encoder
With the Stober Lean geared motor, speed and torque can be controlled infinitely from a zero position to maximum speed with full torque control, and it operates completely without sensor elements.
This also means that only a single-shielded standard power cable is required as it reduces installation effort considerably. Lean geared motors are also well-suited to automation tasks that involve rotation and vibration, as is Solukon’s depowdering system.
The encoderless concept of the Lean motor contributes to its high durability. Despite the absence of an encoder in the motor, the speed deviation is less than one percent, and the positioning accuracy is ± 1°. Since there is no encoder, the Lean geared motor series is particularly suitable for dynamic automation tasks.
Efficient double-axis drive controller
The Lean geared motors at Solukon can be controlled with Stober’s SC6, a 45mm wide drive controller with integrated power supply. The machine manufacturer uses this as a double-axis controller with a nominal output current of up to 2 x 19 amps. The compact stand-alone device is ideal for drive-based applications with up to four axes.
For functional safety, Stober developed the SU6 safety module, which is optionally available for the drive controllers. This offers the manufacturer an economically attractive solution for STO and SS1 safety functions via the PROFIsafe safety protocol.
The SC6 is predestined for use in safety-instrumented systems up to SIL 3, PL e, category 4. Designers can, for example, implement an emergency stop in accordance with EN 13850 – or avoid an unexpected start-up in accordance with EN 14118. The functionality of the controller’s communication interface is also Profinet certified.
“The highly dynamic drive controller operates quietly and reliably in the background, even during demanding movements”, explained Cyrol.
An extremely satisfied Andreas Hartmann says: “Stober provided us with excellent support during the development of the 2-axis swivel system. With the components installed, we succeeded in creating an extremely compact footprint with strong performance. And with the low-backlash geared motors, we were also able to improve the tracing of the tracks and created better transitions during the tilting movements. This makes the SFM-AT350 a highly functional workhorse.”
According to Solukon, the processes downstream of 3D printing, such as depowdering, must be increasingly standardised and to do this do this, it is necessary to be able to handle ever higher numbers of pieces. “Our solutions meet the highest functionality and safety standards and are approved for the efficient, reliable removal of difficult-to-handle and reactive materials such as titanium and aluminium,” Hartmann said.