Apex advances drilling accuracy with SEW drives

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Industrial OEM, Apex Automation and Robotics, utilises the latest technological developments from SEW–Eurodrive to produce an innovative sawing/drilling automatic machining centre that optimises accuracy, throughput and virtually eliminates wastage.

In the development of sophisticated drilling and cutting tools, one Australian company leads the way in the design of innovative automated machining equipment. Apex Automation and Robotics, located in the north–western suburbs of Sydney, designs and builds factory automation machinery and robotic systems. As a typical Apex solution is often a ‘one off’ design, the company also manufactures specialised components in its own workshop. Furthermore, provision of all electrical circuitry, switch- and control-cabinets – and the necessary programming – is included as part of the solution.

All of Apex’s designs are engineered to maximise product quality and production throughput. This was demonstrated clearly with one of the company’s most recent developments, an ‘automatic machining centre’ (AMC) for polymer foam panels. Apex Automation teamed up with motor and drives company, SEW-Eurodrive, to design a servo motor-based system with faster throughput and greater precision. 

 

Foam to fly and float

Industrial polymer foam is a critical element of a wide variety of structures where lightweight rigidity is required. Produced in varying densities, polymer foam can be used in the construction of wind-turbine blades, aircraft fuselages and marine structures, such as boat hulls. The outer ‘skin’ of these structures is usually made of fibreglass and the PVC foam is glued to the inside of this skin using epoxy resin. 

The polymer foam is supplied in sheet form in sizes up to 1.2 m by 2.6 m and thicknesses of 5 mm to 50 mm. In order to help the resin infusion process and maximise adhesion, the sheets must have holes drilled through and grooves cut in the surface.

Traditionally, a single polymer foam sheet was placed on a dedicated cutting machine to form the grooves, and then transferred to a second purpose-built machine to be drilled. This long process often resulted in low throughput and high wastage, as the registration – the alignment of the holes in the grooves – was not accurately executed. Importantly, the design of Apex’s AMC resulted in a compact machine with high throughput, and that virtually eliminated wastage. 

 

Precision perforation

The AMC forms grooves spaced 20mm apart along the length of each sheet. Holes are drilled into each groove and spaced 20 mm apart along the length of each groove. The largest sheets can have up to 8,320 holes drilled into the 64 grooves. Half–size sheets can be processed at 100 sheets per hour, resulting in more than 300,000 holes being made each hour. 

Apex Automation and Robotics was chosen to design and build the machine against international competition. According to the company’s General Manager, Dany Seif, it was the speed and precision of the Apex design that secured the project. “The traditional processing of the foam sheets incurred lots of rejects and needed multiple machines to get the same output,” he said. “We were able to meet the throughput requirement on a single machine and provide the required accuracy of 0.2mm.”

“Since we design and develop highly specialised automation machines we have to keep our finger on the pulse of the industry,” said Seif. “We want to use the best and most suitable technology for the purpose without over specifying the requirements of the equipment.” Apex Automation’s desire to use the most appropriate technology was one of the reasons for deciding to partner with SEW-Eurodrive.

 

Registration is key

In operation, the design that Apex developed with SEW–Eurodrive provides far greater accuracy than the traditional process, in terms of the positioning of the various cutting tools. A sheet of foam is placed in the AMC and motor-driven saw modules then cut up to 64 grooves in one pass on the upper and lower surfaces. Following this, a bank of drill bits is positioned and then raised to create holes of a pre-determined depth. The drills are repeatedly moved along the length of the sheet until all the holes are made. All motion processes within the AMC are managed by a single SEW-Eurodrive MOVI-PLC. Combining both conventional sequential PLC control and motion control into a single compact platform, it links all of the AMC’s motion control elements.

The saws and drills each move in their allotted sequence to produce the precisely aligned grooves and holes.  “We opted to control the whole unit using a MOVI–PLC,” according to Apex’s Project Manager Angelo Di Lorenzo. “This is the brains of the operation where the sequence of movements required for a particular size and weight of PVC foam sheet is programmed and stored. Once the parameters are entered, the MOVI–PLC then choreographs the motion of the saws and drills.” All the components communicate with each other using SEW’s communications protocol, S–Bus.