Based in two neighbouring hi-tech manufacturing facilities in Birmingham, Columbia Precision Ltd has been supplying complete precision engineering solutions to demanding markets such as the aerospace, defence, motorsport, petrochemical, electrical and medical industries for more than 34 years. The company’s specialist skills include the development and production of complex prismatic parts that can be supplied in kit form and as complete tested subassemblies.
A policy of continuous investment in modern plant and human resources has enabled Columbia to remain at the forefront of precision engineering capabilities. The use of the latest CNC technology, diagnostic monitoring and none destructive testing equipment, complemented by stringent quality control systems, ensure that all company products meet and surpass the most stringent of criteria.
The award of a major, long term contract by a multi-national aerospace customer for the production of parts requiring high-precision grinding, in addition to the unrelenting insistence of ‘cost-down’ reductions from other aerospace customers, recently prompted a major investment in a Studer S33 twin wheel grinder.
Ted Yarnall, Columbia Precision operations director, explains: “We hold and conform to all leading industry accreditations including AS9100 Rev C, ISO9001, SC21 and Nadcap. A major part of our company philosophy is to make continuous investment in advanced machining technologies to allow our skilled team to deliver premium quality, accurate and on-time solution to our customers.
“To enable the continued delivery of premium quality components related to an important, long term contract, and to help ensure the contract’s profitability, we identified the need to invest in a suitable grinding machine. To ensure that we purchased a machine that best suited both our current and foreseeable needs, we looked at several alternative grinders.
Although each machine had its own merits, the Studer S33 twin wheel grinder represented by far the best overall package. In addition, Studer’s long list of machine options enabled us to precisely specify a machine that matched our exact requirements. Although the S33 cost slightly more than the alternatives, as we were aware Studer’s outstanding reputation for quality and reliability, and also the many advantages that the machine would deliver, we were happy to place an order.
“Columbia’s willingness to pay a premium price to enable the procurement of the best possible machine tools is reflected in the impressive production efficiencies we are able to achieve and in the high-quality of our output. Our high-yield, high-quality machining techniques enable us to tender competitive prices for the most challenging of production contracts and also helps us to grow our reputation for the quality of our manufactured components.
“Based on the figures supplied by Mark Maurice, the owner of Micronz, the Studer UK agent, we were able to calculate an economical return on investment period for our new Studer machine. Although, given the S33’s outstanding performance since its installation, we now anticipate an even quicker ROI. For instance, when performed on our existing conventional grinder, the grinding tasks related to the production of parts for our major contract, took nearly an hour to perform per unit. Now, the twin wheel Studer S33 is able to complete the grinding of each component in just over six minutes. In addition, we are now able to obtain more uniform and consistent grinding results.
“We have achieved further time efficiencies due to the Studer S33’s shortened set-up and processing times. In fact, as well as enabling the economic completion of existing contracts, our new Studer grinder will allow us to submit extremely competitive prices for a lot more high-precision grinding work.”
The Studer S33 CNC Universal Cylindrical Grinding Machine is manufactured with distances between centres of 650 mm (25.6in) and 1,000 mm (39.4in) and was designed for grinding medium-sized workpieces in individual and series production.
A solid Granitan S103 machine base forms the basis for the robust S33 machine. This foundation provides the advantageous dampening properties that help ensure the surface quality of ground workpieces. The helpful thermal characteristics of Granitan also ensure that temporary temperature fluctuations are efficiently compensated for, resulting in first class dimensional accuracy.
The machine's longitudinal and cross slide, V and flat guideways are moulded directly onto the machine base and are treated with a non-abrasive Granitan S200 slideway coating, whilst the patented knobbed structure of the guideways largely eliminates the slip-stick effect or floating of the slides that can occur on conventional setups. The guideways also provide high accuracy throughout the machine's entire speed range with high load capacity and excellent dampening levels.
Rapid changing from the use of centres to live spindle grinding is achieved by withdrawing the S33’s tailstock to its park position, this frees up the space required for internal grinding. Reference points from grinding wheels to dressing tool and workpiece can be registered quickly with the help of Quick-Set, Studer's software- controlled setup device.
Studer's turret wheelhead, with two motor spindles and an internal grinding attachment, enables the grinding of more complex workpiece geometries in a single clamping. Alternatively, the wheel-head can also be equipped with 2 Internal spindles and 1 external spindle. The high-quality water–cooled external motor spindles that contribute to grinding accuracy are manufactured entirely in-house by Studer. Thanks to the machine's geometry the entire distance between centres can be traversed with both external grinding wheels.
The S33 universal workhead enables both live spindle grinding and grinding between centres. All low-maintenance workheads are equipped with roller bearings and feature excellent roundness accuracy figures of less than 0.0004 mm (0.000,016 in), which can be optionally improved to less than 0.0002 mm (0.000,008 in) during live spindle operations. The machine can also be fitted with a specially designed heavy-duty chuck workhead for chuck applications. Fine adjustment allows for taper corrections within the 1 um range throughout live spindle operations. If required, the S33 tailstock can be equipped with a hydraulically actuated barrel retraction forworkpiece changeover, and a pneumatic lifting process facilitates movement during set-up and resetting. As with the S33 tailstock, the machine's workhead is also equipped with a pneumatic lifting device to facilitate movement during set-up and resetting.
The Studer S33 uses a Fanuc 0i-TD CNC control with integrated PC and 15in touch screen. All controls are clearly and ergonomically arranged, while an important role is played by the manual control unit, which facilitates set-up close to the grinding process. The user interface, Studerwin, plus the software modules of Studergrind, create a stable programming environment and contribute to the overall efficiency of the machine. Windows control enables standardised programming of all of the S33's different systems.