As well as machining, Dobson and Beaumont also specialises in thread rolling. The company cold forms bolts and special fittings to work harden the thread, thus improving overall thread strength by more than 25% when compared to typical thread-cutting operations.
To machine parts before rolling, the Blackburn-based company has purchased two Nakamura-Tome turning centres – an AS200LMSY and an SC100X2 – from the Engineering Technology Group (ETG).
The company that works across the fastener, diesel pump and engines, motorsport, oil and gas and petrochemical, marine and defence, subsea, wind energy and aerospace markets and has seen turnover grow by 60% in the last 2 years with an additional 35% growth projected for 2023.
During Covid, the manufacturer reflected upon its position, as Managing Director Mr Richard Guest said: “We reviewed our processes and ageing plant list and instigated a plan for investing in new technology. We machine a lot of parts in batches that can vary from 4 or 5-off through to 50, 100 and beyond, and our turning centres were all single spindle machines. This meant that most of our turned parts required secondary operations. We needed a twin-spindle turning centre, and the Nakamura-Tome AS200LMSY twin-spindle turning centre from ETG was a perfect choice – but we have now taken this a step further with the addition of the SC100X2.”
The company machines Titanium, Inconel, Stainless Steel, Super Duplex, Duraheat to tolerances in the region of +/-0.0125mm with thread-rolled parts often being critical components in their respective assemblies. The Nakamura-Tome AS200LMSY immediately replaced two ageing machines to free up shop floor space, add machine capacity, and reduce power consumption, set-ups and labour.
The Nakamura SC100X2 was the solution for the increased workload. Installed and running at the end of 2022, it is already reducing cycle times by upward of 30%. This is credited to several factors. Firstly, the new SC100X2 offers superimposed machining, said Mr Guest.
“The superimposed machining is a game-changer for our business, we can now hit parts with two tools simultaneously by overlapping operations between main and sub-spindles. This has reduced cycle times noticeably already. On high-value motorsport studs that we produce frequently, we have cut the cycle time from 3 minutes to 1minute 30 seconds.”
The sub-spindle can move not only toward the main spindle for component pick-up, but can also move synchronised with the lower turret for machining operations that can be conducted whilst the upper turret is machining on the main spindle. One of the key benefits of the machine is the 70bar coolant pressure. This evacuates swarf during heavy machining cycles and eliminates the need for pecking cycles when drilling. It also enables the company to machine more challenging materials whilst supporting the reduction of cycle times and extending tool life.
Mr Guest added: “We are machining a lot of hard materials such as MP35N and AERMET 100, which has a tensile strength of 1900Pa. Before the arrival of the SC100X2, we had to sub many of these parts out, which created an additional 2-3 weeks to our lead time. Now, we can machine these very difficult parts in-house and keep lead times to just days whilst eliminating additional subcontract costs. We also machine a lot of difficult studs and bolts in regular quantities from 50 to 500-off, with the HPC on the SC100X2, we can machine the parts in-house with remarkable efficiency. Another factor we are noticing is the increase in our tool life with the high-pressure coolant.
“The next step for Dobson & Beaumont is to put increasingly more new and legacy work through the Nakamura SC100X2 to reduce the burden on our other turning centres as well as in the milling department. With the barfeed and part-catcher, we also have the opportunity to automate the production of complex work. In fact, in the coming weeks, our workload will see both the SC100X2 and AS200 running 24 hours a day. The investment in the two new Nakamura’s, has created enthusiasm on the shop floor and who knows – we may be looking at more Nakamura machines from ETG in the future."