Feature on Grinding and Surface Finishing

ROS installs Rösler shot-blasting machine

Less weight, compact design and improved sustainability – a producer of injection-moulded components has proven that these goals are achievable economically with high-performance plastic materials. The company is increasingly producing previously metal workpieces from duroplast and thermoplast materials. Therefore, the capacity for de-
flashing these components requires increasing. For this purpose, the customer ROS GmbH & Co KG chose shot-blasting solutions from Rösler. An RSAB 470wire mesh belt machine ensures fast and efficient processing in continuous flow, while an RWS 1200swing satellite table machine is utilised for high-quality, consistent de-flashing of single workpieces. The special dual chamber design of this machine practically eliminates any unproductive idle equipment times.

Jürgen Bär, responsible for planning in the industrial engineering department at ROS in Coburg explains: “Deciding factors for choosing Rösler were our good experience with the
shot-blast machines we’ve been using for a long time, the compact, space-saving and sturdy equipment design, and Rösler’s comprehensive knowledge in the field of plastic de-flashing. Moreover, we needed the continuous flow shot-blast machine quickly. Rösler generously supplied a machine from their customer experience centre within a few days.”

The flexible, high-capacity RSAB 470 shot-blast machinede-flashes components made from duroplast and thermoplast PPS-GF materials, while the RWS 1200swing satellite table machine de-flashes components made from PPS-GF with outer dimensions of up to 163 mm.
In line with the production cycle of the injection moulding machine, up to four workpieces are de-flashed simultaneously within a processing time of 40 seconds.
For further information www.rosler.com

Apex Tool invests in Studer S31 cylindrical grinder

At the Apex Tool Group GmbH (ATG) in Westhausen, a new S31 cylindrical grinding machine from Studer is proving truly universal. From individual components to medium series, the machinecost-effectively and flexiblygrinds gear and control shafts for the company’sCleco brand ofelectric and pneumatic assembly tools.

ATG produces almost all the essential screwdriver components in-house, which applies in particular to motor and gear shafts, levers, valves, cams and housings.

“We need to grind our motor and gear shafts to an accuracy of just a few microns,” revealsNiko Schindelarz, supervisor -machining. “This is essential to ensure the extremely quiet running and long service life of our screwdrivers.”

But this was still a very complex process until just a few months ago. Only one proven grinding machine, purchased in the early 1980s, was available for cylindrical grinding. In order to grind the large number of 30 to 650 mm long shafts with diameters between 3 and 65 mm, it was necessary to reset the machine manually, over and over again. The search therefore began for a new cylindrical grinder.

Schindelarz explains it was firstly necessary to prepare the requirement analysis, in order to obtain approval for the necessary budget from the commercial manager in the US group.

“However, we were able to demonstrate on the basis of operational benefits that the higher initial investment – in comparison with competitor products – would quickly prove profitable,”he says.

Production engineers atATG are now able to grind the entire range of shafts on just one machine. Furthermore, the S31 cylindrical grinding machine is easily accessible for workpiece and grinding wheel set-up, despite the complete enclosure.
For further information www.studer.com

OPG invests in brand new surface grinder

Gateshead-based Omega Plastics Group (OPG) has recently been successful in securing orders of over £2m for a wide range of multi-impression fully hardened production tools. This results in the manufacture of hundreds of core and cavity inserts, together with side cores and other ancillaries for customers.

OPG’s recent business-winning success was instrumental in its investment decision to extend the company’s surface grinding capability, thusimproving efficiencies and catering for multiple insert set-ups and larger X, Y and Z-axis grinding capacities. The machine is also equipped with dust extraction, an 800 x 400 mm magnetic table and a coolant filtration system.

Following a frustrating six-week period of window shopping and searching for a viable solution,the agility of the team from RK International Machine Tools resulted in the delivery of asurface grinder within three weeks from placement of order.

The new PERFECT PFG-D4080AH surface grinder was supplied and delivered to OPG on a short lead time and included the installation of a digital readout prior to shipping.This acquisition will allow the company to reduce its reliance on the laborious task of sub-contracting this type of work. Also through the ability of NC programming and auto down-feed will expand the multi-tasking approach of the company’s skilled workforce, and allow the machine to run unattended.

A survey based on the workflow of current production demands estimated that the time saved by investing in the new surface grinding machine will result in efficiency gains of 3%, resulting in saving over 180 hours compared with the company’s smaller manual machines.
For further information www.rk-int.com

Twin-spindle blast machine etches tubular parts

Guyson International, a UK manufacturer of industrial finishing equipment, has recently manufactured and installed into a UK manufacturing company an automated Multiblast RSB twin-spindle blast system for the external blast etching of various tubular components. The new system incorporates two rotating blast stations with matching top clamps to hold the product securely, while two vertically traversing blast guns produce a uniform blast etch finish over the length of the parts.

Twin spindles in combination with the top clamp design provide optimal manual process capacity with an operator able to load and unload two components simultaneously. Once the safety-interlocked front door is opened, the operator simply centres the components between two pairs of conical spring-loaded clamps for processing.

A roof-mounted servo drive vertically raises and lowers the twin Guyson Model 900 blast guns, with blasting taking place on the upward vertical traverse, while a compressed air-wash to remove any residual surface dust or blast media activates on the downward stroke. The servo drive facilitates the programming of different speeds for the blast and air-wash phases of the program, delivering greater productivity and shorter cycle times.

The blast system is fitted with a large front opening door allowing easy component loading, while a side door provides further access for maintenance and adjustment purposes. Interior lighting permits a clear view of the blast etching operation.

After blasting, a Guyson CY600/12 cyclone reclamatorextracts the used blast media. This operation separates the reusable blast media from the dust, blast debris and undersized media, reducing the possibility of contamination in the blast media which could reduce the consistency of the surface finish. A Guyson model C800 twin cartridge dust collector completes the system.
For further information www.guyson.co.uk

Milling and grinding large parts in one set-up

German machining centre manufacturer Roeders is introducing a new production centre, the RXU 2000, for manufacturing large components requiring a high degree of precision. The three-axis machine is not only for 3D milling but also for jig, vertical or profile grinding. Availability in the UK and Ireland is through sole sales agent Hurco Europe.

The machine is for cutting hardened materials and has a working volume of 2000 x 1800 x 800 mm, where the intentionally limited Z-axis travel ensures maximum accuracy. Both the Y and Z axes feature the machine builder’s robust Quadroguide design, while the large machine bed is effective at damping vibrations. The maximum table load is 5 tonne.

A combination of milling and grinding in a single set-up on the same platform is particularly suited to mould and tool making, and to producing high-accuracy parts for machine building. Linear drives in all axes, as well as an advanced temperature management system for the entire machine, ensure high levels of precision, even during long machining runs, reports Hurco. Dimensional accuracy to within 5 µm, and roundness of 1 to 2 µm depending on bore size, is achievableacross the machining envelope.

A 22,000 rpm, 101 Nm HSK-A63 spindle is available for high metal removal rates. Alternatively, spindles up to 80,000 rpm are available for different applications. On request, the machining centre is configurable as a double-spindle machine, for example with a high-precision air bearing spindle alongside the main spindle.
For further information www.hurco.co.uk