News | April 15, 2021

Perfect Finish Through Automated Surface Finishing

Grinding and polishing are used to finish surfaces, either with coarse material removal for further processing or as final processing to achieve a perfect finish of the workpiece. This requires sensitivity and precise readjustment. Experienced employees perform these tasks intuitively, but manual processing is tedious as well as expensive and does not always deliver consistently good results. Modern robot-based automation solutions can take over these tasks and shine with optimum performance. The result: Perfect surfaces with reduced time and costs. In order to offer users new process automation opportunities, SCHUNK, the competence leader for gripping systems and clamping technology, has expanded its portfolio with tools for robot-supported surface finishing. A win-win situation for employees and company alike.

In wood and metal processing as well as in the automotive and aerospace industries, perfect surfaces are essential. Manual polishing, grinding and brushing is often exhausting and requires a lot of effort. Automated processes offer an attractive alternative to this, because with the help of the robot, flawless results can be achieved – with significantly reduced time and costs and lower workplace risks. With the new AOV and MFT-R units from SCHUNK, the changeover to automated surface finishing is easy and effortless. In addition, SCHUNK provides valuable support in the introduction of automated processes with feasibility studies and extensive process know-how.

The right tool for every purpose
The new machining tools from SCHUNK are specially designed for automated applications and thus guarantee perfectly finished surfaces at all times. The AOV random orbit sander is the "specialist" for grinding and polishing workpiece surfaces. The pneumatic unit is driven by a vane motor with a maximum speed of 10,000 RPM. The axial bearing of the motor ensures flexibility so that constant pressure forces act on the workpiece surface. Even with initially very uneven surfaces, perfect polishing and grinding results can be achieved. Via two air connections, the pressure force can be controlled separately in two directions, i.e. during retraction and extension, and varied as required (range: 6.7 N to 67 N). This ensures that the AOV machines with a constant pressure force, even in overhead applications. The random orbit sander can be optionally equipped with backer pads of different diameters (125 mm or 5" or 150 mm or 6"). Optionally, the grinder can be equipped with a connection for the extraction of the removed material. Contamination of the robot cell and the resulting downtime can thus be prevented at low cost.

Users who require a particularly flexible and robust polishing spindle for polishing and brushing workpieces with axial flexibility will find the MFT-R the optimum solution. The spindle is equipped with a pneumatic vane motor, which has a maximum speed of rotation of up to 5,600 revolutions per minute. For a perfect finish of the surfaces, the speed of rotation can be reduced to a minimum. The robust motor only runs for a short time and thus reduces the processing time. Due to the gimballed system, the balancing force and the radial compliance of the tool can be individually adjusted. Depending on the pressure setting, the flexibility can be regulated from 9 N to 70 N. The user can select the optimum value for each workpiece and thus achieve high-quality and reproducible results in any installation position. Any workpiece tolerances can be compensated and the path programming of the robot becomes much easier. The MFT-R is also particularly user-friendly due to its other functions: The optional axle fixation makes it quick and easy to switch between pendulum and radial compensation. Different workpiece geometries can thus be flexibly machined with just one tool – an economic advantage that almost halves the investment costs. The MFT-R is available as a stationary unit or can be mounted flexibly (axially or radially) on the robot. SCHUNK offers prefabricated adapter plates for this purpose, which saves valuable time during construction.

The PCFC unit rounds off the SCHUNK portfolio. If a workpiece must be machined with a previously defined force, the compensation unit renders valuable services. The PCFC ensures that a consistent compliance force is acting in any position. This is made possible by using a position sensor. It compensates the weight force together with the pressure control valves provided by the customer. The PCFC can be combined with various tools and therefore is suitable for numerous application purposes.

More precision and variety with manageable programming and design effort: this is how efficient automated surface finishing is with tools from SCHUNK.

Source: SCHUNK