Dudley-based Precision Chains Ltd
manufactures heavy duty conveyor chains for use in machinery for a range of industrial sectors including quarries, agriculture, food industry, escalators in the London Underground, water treatment, palm oil manufacture. The smallest chain link is 2in and the largest can weigh as much as 25kg.
Started in 1957, the company, now part of Leeds-based John King Chains Group
, makes both imperial and metric-sized roller chains and works with customers to specify the type of chain, its load capabilities and its attachments for buckets or similar, supplying customers throughout Europe, the USA, Malaysia, Indonesia and Africa. The design of the chain revolves around its pitch, the roller and bush and pin diameters and the width and thickness of the side bar to arrive at its rating in kN. Options include spiral grooves for lubrication and solid or hollow pins. As part of its service, the company also manufactures sprockets to suit the chains it supplies.Pictured left: Garry Gray Programmer Setter Operator holding a part with spiral grooving
Precision Chains general manager Ian Thomas said: “Our challenge was to find a better way of manufacturing the rollers, pins and bushes. Previously we had to turn the parts and then mill them, cross drill, drill down the centre and finally counterbore and deburr them. All these operations were labour-intensive and time-consuming with set ups on up to three machines, not to mention all the handling involved. Furthermore, moving between these machines has an impact on accuracy. These components are crucial to chain manufacture and when you see the volumes required in each chain and the advantages of multi-axis and live tooling, it was clear that we could make some significant savings.”
Precision Chains selected an XYZ TC320 LTY mult-axis turning centre with parts catcher, swarf management and Hydrafeed bar feeder. It also features a Siemens 828D control with ShopTurn for easy programming of the Y axis and live tools. The machine can chuck up to 300mm diameter and has a bar capacity with the bar feeder of up to 78mm diameter. It is equipped with tooling supplied by SHeffield-based Ceratizit UK and Ireland Ltd
with two sets of live tools for cross drilling, milling flats and machining lubrication spirals. The company also doubles up with some tools carrying out both turning and facing operations.
Mr Thomas added: “We ordered the machine from Devon-based XYZ Machine Tools
in February 2023 and took delivery at the end of March enabling us to benefit from tax breaks for capital equipment. The speed of delivery was an important factor in our decision. Now, we run the XYZ TC320 LTY from 7.30am to 9.30pm making a complete component in one operation with one operator occasionally checking the machine while completing other tasks. We have also been able to dispose of two machines which we no longer required.”
A further advantage has been an increase in the accuracy and repeatability of the parts. Previously setting and machining was done using special jigs and fixtures and the company had problems with accuracy in across flats features plus, for the spiral grooves, it had to use a milling machine with dividing head to achieve what can be done automatically in one cycle on the XYZ TC320 LTY.
Mr Thomas continued: “With our conventional methods we would turn parts during the day and mill them in the twilight shift. Now it is all done in one go. We have halved the milling time and eliminated all the handling and special jigs we used to use, and got rid of all the transport and handling.”
Four people have been trained on the XYZ TC320 LTY at XYZ Machine Tools’ Nuneaton office and, working from drawings they took with them, they were quickly confident in using the machine and Siemens control. Mr Thomas concluded: “Now they have no problems setting and operating the machine. They got to grips with it really quickly. The XYZ TC320 LTY has done everything we expected and more.”
Upgrading the machinery in the factory to new technology is important for Precision Chains as, like many companies, it has an ageing long-serving workforce and it is finding it difficult to recruit new talent. In the last 12 months it has recruited four apprentices and believes that investing in the latest equipment combined with instruction from experienced employees is the way forward.