Higher production, greater accuracy, less scrap, lower operating costs
More and more companies are experiencing big increases in production without having to invest in new machine tools simply by upgrading to Chick Workholding, which enables more components to be presented to the spindle at each set-up. The US-made clamping systems are supplied in the UK through 1st Machine Tool Accessories.
A good example is at Tranquil PC in Trafford Park, Manchester, which designs and produces low-energy information technology systems. The family-run company secures its computer housings for machining in Chick equipment, benefitting considerably compared with when parts were clamped in conventional wind-up vices.
James Thompson, who operated the company’s three XYZ machining centres, explained, “Winning a large contract in 2012 from Royal Mail for the supply of 2,500 digital signage computers focussed our attention on improving workholding effeciency.
“To fulfil the order we bought our third XYZ fitted with a 4th axis indexer and tailstock for supporting a four-sided Chick System 5 Multi-Lok. Twin jaw sets on each side enable two components to be held simultaneously.
“It means we can fixture eight computer housings at a time, reducing the number of tool changes and releasing me or our other CNC setter / operator for extended periods to attend to other jobs.”
This walkaway time, which is typically two and a half hours, is a big factor in reducing production cost per part. It has allowed Tranquil to maintain an 8:30 am to 5:30 pm shift, whereas during busy periods the firm often used to work up to 17 hours a day, seven days a week, to cope with the production volumes.
Another significant contributor to lowering manufacturing costs is the ability to access two faces of a component in one clamping at each of the eight stations of the Multi-Lok. Previously, the top, bottom, front and back of the aluminium housing had to be machined in four seperate set-ups whereas now they are completed in two. Four fully machined housings therefore come out of the machine each time the doors open.
James Thompson quantified the benefits. He estimated that metalcutting cycles are reduced by 5 per cent due to fewer tool changes. Improved accuracy and repeatability of workholding compared with conventional vices leads to fewer out-of-toleance parts, and a 50 per cent reduction in handling lowers the risk of damage. Scrap rates are therefore 5 per cent less overall, rising to 15 per cent for some Tranquil products.
Set-ups have been halved, again promoting accuracy by reducing accumulative errors each time a part is reclamped. Setting up is in reality even faster, as the soft machined jaws on the Chick clamps are accurate enough to be relied upon for workpiece positioning. In contrast, positioning stops have to be fitted to the firm’s other vices to achieve similar precision, which entails extra time for workpiece placement.
Aluminium jaws for the Chick Multi-Lok are machined by Tranquil with the assistance of 1st MTA. An applications engineer from the Salisbury supplier took Tranquil’s CAD file of the digital signage computer for Royal Mail and produced the required jaw designs, which were sent to Trafford Park for production on one of the XYZ machining centres. Similar has been done for other long-running OEM jobs, such as projects for OneLan and HD Connect, as well as for Tranquil’s own NUC computer housings. Each jaw is usually made to accept components for both Op 1 and Op 2 to ensure flexibility.
Another XYZ machine in the factory is fitted with Chick workholding, but in this case two One-Lok quick-acting clamps. They employ a ratchet system to avoid having to turn a normal vice handle perhaps several dozen times to secure the component. Just a few turns are sufficient once the jaws are close to the part.
The One-Loks can be used seperately on the machine table or in tandem to hold a large aluminium billet, such as for producing computer cases for Ubuntu.
These Chick products are also fitted with machined soft jaws that snap on and off quickly. Repeatability is just as high as with System 5, unlike with Tranquil’s traditional vices which provided less control and often required offsets to be entered into the machine control.
Mr Thompson said that overall there is far less operator interaction with the machine, mirroring the situation with the other XYZ with Chick clamping.
A further point he made was that the workholding units are sealed design that discourages ingress of swarf, which can result in components not sitting properly in the jaws. With tolerances down to 0.1 mm specified for the computer housing, accurate and repeatable clamping is highly beneficial.
Each of Tranquil’s XYZ machining centres produces up to 15 kg of aluminium chips per hour, requiring the use of programmable, high pressure coolant nozzles for effective swarf removal. It is therefore not difficult to see how problematic swarf entrapment in the clamps would otherwise be at the factory.
The Chick One-Lok and the range of Chick System 5 products are available from 1st MTA. If you have any questions or queries about the products mentioned in this article, please don’t hesitate to contact us on 0800 783 0510 or enquiries@1mta.com.
