Pragmatism and attention to detail when devising methods for workpiece clamping has boosted production efficiency at International Safety Components (ISC) to the point where manufacturing costs at the Bangor factory are comparable with those in the Far East.
Applications engineer, Regan Irwin, is responsible for driving forward innovative workholding arrangements on the company’s lathes and machining centres. He commented, “The 1st Machine Tool Accessories website is one of the first I visit when buying new vices and other clamping equipment, as the range on offer is so vast.
“In the last couple of years, we have invested in 10 of their Chick Workholding System 5 Qwik-Lok workholding systems. They are used on our machining centres alongside 15 Qwik-Loks of an earlier design to secure complex parts, often in multiples, in soft jaws machined for specific applications. It avoids having to use costly bespoke fixtures.
“Earlier this year (2013), we sourced a Chick One-Lok from 1st MTA for our toolroom. This lighter workholding device is easier to move on and off a machining centre table and much quicker to adjust than our conventional vices. “We make good use of other 1st MTA products as well, such as Mitee Bite knife edge clamps for gripping plate to allow skimming during the machining process.
“We utilise the same manufacturer’s Pitbull fixture clamps, which grip firmly on just 3 mm of material, reducing billet size and saving money for any given job. Yet they still allow, for example, a 16 mm diameter end mill to take up to 7 mm wide, 9 mm deep cuts from the edge of a 7075 aluminium block.”
Expansion collets and ID expansion clamps for workholding in vices and fixture plates, plus Kitagawa 6” and 8” three-jaw chucks for turning centres, are among other 1st MTA products in regular use in the Bangor factory. The Kitagawa chucks are part of a vast selection of standard and special, manual and power chucks, including open centre and closed centre versions. There is also a comprehensive programme of collet chucks. All are available in a wide range of sizes.
ISC is the leading UK manufacturer and exporter of industrial working-at-height safety products used in climbing, rigging and rescue in over 25 countries. The company manufactures in excess of 250,000 karabiners per year, pulleys, harness buckles, rope back-up devices and many other products that are characterised by their wide range of sizes, complexity and extensive variety of materials used. The latter include 7075-T6 and 6082-T6 aluminium, EN1A-L, EN8-DN, EN19T and Hitenspeed steels, 303, 304, 316, 17-4PH and Duplex stainless, and 10% aluminium-bronze. It is the combination of complexity and in some cases very tough materials that has resulted in the wide adoption of US-made Chick clamping systems across the shop floor at ISC.
According to Mr Irwin, the latest Qwik-Lok System 5 incorporates design changes that improve rigidity, speed and repeatability of clamping. Stainless steel rather than aluminium anvils secure quick-release jaws, which no longer need a dowel to be tapped through to complete the process. Jaw change is many times faster than was previously possible, speeding setup, minimising machine idle time and maximising output.
Security of workholding is promoted by a pull-down action as the jaws are wound shut. The dual-station clamping units squeeze the two moveable jaws from either end against a central fixed jaw to cancel the opposing forces, resulting in even pressure and repeatable workholding. Either one clamping station or both can be used to secure components.
Aluminium jaws are machined to match the often complex shapes of components, several of which can be held simultaneously in each vice. Multiple workpiece clamping shortens floor-to-floor time per component and minimises tool changes during a batch run.
The rigidity with which parts are secured allows heavier cuts to be taken than would normally be possible using conventional workholding practices. Cycle times are therefore shorter and productivity is raised. Furthermore, high accuracy is assured – more than adequate to hold the 20 microns on hole diameter and 0.1 mm positional tolerance specified on most of ISC’s drawings.
For some production applications requiring longer runs, Mr Irwin has made special sizes of zero-point steel fixture plates that clamp over both anvils on a Chick Qwik-Lok, in place of the jaws. A high degree of repeatability is achieved and by having two plates, one on the machine and one being set up, large batches are completed with little spindle downtime. 1st MTA supplies standard sizes of foundation plates to provide similar pallet-style quick-change flexibility.
The toolroom at Bangor is where jigs and fixtures are produced for fly presses and metalcutting machines on site as well as for product assembly. Metals from aluminium to tool steel are routinely machined. In this department, which doubles as a prototyping facility for new product development, the Chick One-Lok from 1st MTA provides effective workholding on a Haas vertical machining centre.
Unlike traditional machine vices that require dozens of turns of the operating handle between fully opened and closed, One-Lok features a fast-acting adjustment mechanism. It allows the moveable jaw to be unlocked and slid quickly to approximately the position it is required along its full travel, after which a few turns of the handle secure the part.
Ken Williams, one of ISC’s toolmakers, advised, “The problem with our older vices is that the moveable jaw tends to lift when clamping a part.
“In contrast, the One-Lok’s pulldown action holds the component firmly, allowing me to take heavier cuts without risk of the part moving in the jaws.
“Another benefit is the hinged handle, which allows me to open and close the jaws faster during the non-clamping part of the traverse when the One-Lok is mounted across the machine table, rather than from front to back.
“A handle fixed at 90-degrees would interfere with the table and need to be adjusted on each turn.”
1st MTA has specialist engineers available to carry out site visits, advise on the most appropriate workholding methods for individual applications and demonstrate their performance under production conditions. Telephone – 01725 512517 or email – enquiries@1mta.com
The Chick One-Lok and System 5 Range are available from 1st MTA. If you have any questions or queries about any of the products mentioned in this article, please don’t hesitate to contact us on 0800 783 0510 or enquiries@1mta.com.
