Most of us are familiar with a bicycle chain but, Precision Chains in Dudley makes giant versions! These are used in the quarrying industry, agriculture, the food industry, in escalators in the London Underground, water treatment, palm oil manufacture and many more heavy-duty applications. The smallest chain link is 2 inches and the biggest can weigh as much as 25kg for one link.
Started in 1957, the company is now part of the John King Chains Group based in Leeds. It 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.
Ian Thomas, General Manager of Precision Chains says, “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 very labour intensive and time consuming with setups on up to three machines, not to mention all the handling involved. Furthermore, moving between these machines has an impact on accuracy. These parts 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 chose an XYZ TC320 LTY with parts catcher, swarf management and Hydrafeed bar feeder. The XYZ TC320 LTY has 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. The machine is equipped with Ceratizit tooling with two sets of live tools for cross drilling, milling flats and machining lubrication spirals. The company also doubles up with some tools doing both turning and facing operations. Ian Thomas adds, “We ordered the machine from 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 part in one operation with one operator checking the machine from time to time while completing other tasks. We have also been able to dispose of two machines which we no longer need.”
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 cycle on the XYZ TC320 LTY. Ian Thomas says, “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. Ian Thomas adds, “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 believe that investing in the latest equipment combined with instruction from employees that know the business back to front, will make a career in engineering at the company very attractive.