The ability to carry-out the highest standards of cylindrical grinding is a prerequisite when manufacturing high-precision gears and associated components. In order to achieve the necessary demanding levels of dimensional, roundness and surface-finish specifications, Chesterfield based Ondrives recently purchased an advanced Studer S31 cylindrical grinding machine.
Ondrives can trace its origins in the precision gear industry back over 80 years. The company’s long history and in-depth knowledge in the manufacture of premium quality gears and gearboxes has enabled it to gain a global reputation. Based in an impressive 3200m2 facility, Ondrives skilled staff have access to a wide range of advanced gear manufacturing equipment.
Having enjoyed excellent service from a Studer S21 cylindrical grinding machine since 2011, the decision to install a second Studer machine was prompted by the need to increase the company’s high-precision internal, external and thread-form grinding capacity and to help satisfy ever increasing customer demand for its gear related products.
When compared to Ondrive’s existing S21 model, the Studer S31 cylindrical grinding machine has increased the company’s between centres grinding capacity from 400mm to 1000mm. The advanced new machine will also boost the efficiency of its precision grinding work.
Explaining the decision to purchase the Studer S31, Ondrives Managing Director, Ben Hinchliffe said. “A growing order book and the need to increase our capacity recently created the need for a second high-precision cylindrical grinding machine. We have enjoyed excellent service from our existing Studer S21 cylindrical grinder and the machine continues to efficiently produce high-quality ground components.
“Having researched the market to ensure that we secured the best possible machine, and after evaluating the available high-precision cylindrical grinding machines, we concluded that, although the Studer S31 was slightly more expensive than the other machines we looked at, it was by-far the most technically capable option. In addition, as the service and support we have received from Studer, and from UK Studer agent Micronz, has always been first-class, this gave us further confidence to proceed.
“To satisfy our challenging requirements, with the help of Mark Maurice, the owner of Micronz, the advanced Studer S31 cylindrical grinding machine was specified with the addition of several advanced options including a synchronous driven tailstock. This enables our operators to complete grinding work in a single set up, rather than making multiple changeovers. The Studer S31 has more than doubled our between-centres grinding capacity, increasing our precision grinding capabilities and this has significantly raised our efficiency levels.”
Studer’s global customers include companies from demanding industries such as the gear manufacturing, machine tool, automotive and aerospace sectors. Areas that value the highest standards of precision and productivity. The global reputation enjoyed by the Studer brand is based on more than 100 years of in-depth experience in the development and production of precision cylindrical grinding machines.
The Studer S31, as purchased by Ondrives, is an advanced cylindrical grinding machine that was designed for the individual, small-batch, and large-scale production of short to long-sized workpieces. The S31 has a centre height of 175 mm and is available with between centre options of, 400, 650, 1000 and 1600 mm.
A solid Granitan base forms the foundation of a superior cylindrical grinding machine that guarantees maximum levels of precision, performance and reliability. Developed by Studer, Granitan has proven its value over many years. The excellent cushioning characteristics of the S31’s machine base helps to ensure the outstanding surface quality of ground workpieces and also increases the service life of grinding wheels.
Reduced set-up and resetting costs, especially in single-part or small-batch production, are made possible by the S31’s turret wheelhead with several grinding wheels. Users’ efficiencies are further boosted by the ability to perform complete machining in a single clamping.
The S31’s swivelling wheelhead is equipped with water-cooled, roller-based, maintenance-free motor spindles with stepless speed control and the latest generation of contact sensors. The shaft ends hold external wheelheads with a diameter of 500 mm and a width of 63 (80 F5) mm. For internal grinding, powerful high-frequency spindles are used. Customers are able to configure wheelhead to match their specific needs.
The machine’s versatile universal workhead enables both live-spindle grinding and grinding between centres. The low-maintenance workhead is equipped with roller bearings and has an excellent roundness accuracy of under 0.0004 mm, which can be optionally improved to under 0.0002 mm during live spindle operations. Fine adjustment allows for taper corrections in the 1 µm range during live spindle operations. As with the machine’s tailstock, its workhead is equipped with a pneumatic lifting device to facilitate movement during setup and resetting. The S31 can also be equipped with a chuck workhead specifically designed for grinding chuck parts.
Grinding of shapes and threads is made possible by the position and speed controlled C axis. The C axis features an indirect measuring system on the drive motor and is suitable for thread grinding and simple form grinding. For maximum form accuracy, a direct measuring system is mounted on the workhead spindle (high accuracy C-axis). Due to their high dynamic rigidity, the axis drives absorb the acceleration and grinding forces.
The addition of a synchronous driven tailstock to Ondrive’s Studer S31 allows the complete machining of workpieces in a single set-up. As this beneficial option helps to avoid complex changeovers to additional operations costly downtime is eliminated and impressive efficiency gains are achieved.
The 90mm travel of the S31’s tailstock barrel simplifies the changeover to a new workpiece, whilst component families can be quickly set-up with minimal effort, leading to further productivity increases.
The S31’s synchronous driven tailstock increases dimensional accuracy related to form and positional tolerances on the ground workpiece, enabling the most challenging of quality requirements to be met.
Studer’s synchronous driven tailstock is hydraulically operated and is equipped with an electronic measuring system which allows simple readjustment. Both closing speed and positioning speed can be adjusted individually with control valves.
The S31 is equipped with a Fanuc 0i-TF and all controls are clearly and ergonomically arranged making operation easy and efficient. Further aiding ease of use, the machine’s portable control unit (PCU) enables set-up close to the grinding process.
Complementing Studer’s famous hardware, the company’s easy to use, feature rich StuderWIN software enables the full potential of the company’s cylindrical grinding machines to be realised. Simple programming can be achieved by the novice or by skilled operators thanks to the use of StuderPictogramming. StuderFormHSM save time by enabling efficient and fast form grinding, whilst optional StuderWIN programming can be used to efficiently create grinding and dressing programs offline.
