OPEN MIND TAKE FIVE-AXIS MACHINING TO NEW LEVELS FOR MOTORSPORT SUBCONTRACTOR

Just a short distance from Silverstone, the JRM Group specialises in the design and bespoke manufacturing of solutions for the automotive, motorsport, aerospace, marine and medical industries. The Daventry-based company is also home to a prestigious racing division that has progressed through rallying, FIA GT1 and the GT3 endurance competition. When the ISO9001-accredited manufacturer invested in its first five-axis machine tool, it realised a high-end CAM system was a necessity.

The current plant list at the JRM Group includes a range of CNC and manual turning and milling centres.Recent investments include a DMG Mori LaserTec 30 SLM additive machine and a CLX450 turning centre, but it was the arrival of its first of three DMU 75 monoBLOCKfive-axis machining centres in 2017 that demanded an equally prestigious CAM solution. This is where Open Mind Technologies entered the fray with its HyperMILL CAM suite.

Discussing the introduction of five-axis machine tools and HyperMILL, CNC machinist and programmer at JRM Group, Mike Sutton, says: “We needed to progress our capabilities into five-axis machining and simultaneously realised that our existing CAM package was limited to three-axis machining. Undertaking due diligence with a complete review of the marketplace, we opted for HyperMILL, a decision influenced by the realisation that a lot of our motorsport customers and Formula One teams use this CAM software. It was a fantastic move as our experience of HyperMILL has been fantastic.”

The 40-employee company manufactures everything from prototypes and small batches for the motorsport, aerospace and defence industries, to jigs, fixtures and 3D-printed components, processing a complete array of materials. The closest that the JRM Group gets to production machining is a five-part wishbone assembly for a high-performance sports car customer in Germany that requires several hundred assemblies a year.

Looking at wishbone components produced on a five-axis DMG Mori machine, Sutton continues: “We’re currently using a cycle in HyperMILLcalled arbitrary stock removal, machining 25Cr 04 steel with a 40mm high-feed face mill. The tool is running at 8m/min feed rate with 0.5mm cuts. The cutting tool manufacturer recommended the 0.5mm cut, as the way to machine with high-feed cutters is to take small depths of cut at high speed. This is different to trochoidal milling, where you take larger depths of cut with a smaller radial value.”

When programmed with an alternative CAM system, the wishbone components had a cycle time of 4 hours. By adopting strategies such as arbitrary stock removal in HyperMILL, JRM has improved the machining strategy and cut the cycle time to 3 hours and 5 minutes. The 25% saving per part is impressive, especially when considering the company produces hundreds of wishbone parts a year.

This is just one example of how machining cycles within HyperMILLare making a positive impact on productivity at the JRM Group,as Sutton continues: “We have two seats of HyperMILLand the flexibility to program parts from home, the office or on the machine. Before joining the JRM Group, I hadn’t used CAM for almost 20 years. Today I’m using HyperCAD-S for designing all the jigs and fixtures we produce, and then all the strategies in HyperMILLto reduce my programming and cycle times. I can create models, jigs and fixtures by generating the geometry, surfaces and lines in HyperCAD-S. It may be a challenging thought process to design and clamp some of the parts that we have to machine, but with HyperCAD-S at least we know the drawing and creation of the jigs and fixtures is a straightforward process.”

At the JRM Group, producing jigs and fixtures is a significant role. For example, the company has recently won an order to 3D-print a family of up to 30 motorsport components, which will need finish-machining. To undertake this task, JRM will 3D-print the parts, but the company also requires the use ofHyperCAD-S to design the fixtures for clamping the non-uniform parts for finish-machining – a process undertaken with HyperMILL.

“HyperMILLwas new to me when I joined the company, but now I’m using strategies such as Z-level finishing, optimised roughing, drilling cycles, contour milling, ISO machining and 3D free-path milling with complete confidence. The more I use HyperMILL, the more my programming skills are developing.”

With impressive levels of support from Open Mind and an ever-improving level of experience, JRM is maximising the machining strategies within HyperMILLto reduce cycle times, programming times and machine set-up timessignificantly, while also reducing secondary finishing operations, and improving tool life and spindle longevity.

One example is the 3D advanced milling/complete finishing cycle, as Sutton explains: “We frequently machine large aluminium clutch covers that require a high-quality surface finish. The clutch covers incorporate a lot of flat and round surfaces in different directions and, to get the optimal surface finish, the tool path needs to move in the right direction with an optimised step-over. By applying HyperMILL’s complete finishing cycle, we don’t have to pick individual surfaces or create tool paths that need optimising, we can just select the optimal step-over rate –HyperMILL does the rest. On the clutch covers, we select a small step-over rate of 0.1mm and the machining strategy will automatically determine the tool-path directions for the best surface finishes. This may take longer to machine, but we allocate such cycles to lights-out machining, returning to finished components that require no secondary hand finishing, the following day.”

3D optimised roughing is another strategy within HyperMILLthat further enhances machining performance.

“When we use the 3D optimised roughing cycle in high-performance mode, we can plunge the tool to a large depth and then remove the material radially,” says Sutton.“This strategy reduces the stress and forces placed upon the tool and spindle. By plunging to the full depth, we can use the full tool flute length. Furthermore, by setting a metric step-over value, HyperMILLwill automatically calculate the step-overpercentage based on the tool diameter and the volume of material that requires removal. This enables us to achieve maximum material removal rates while prolonging tool life.”

Concluding on the company’s experience of HyperMILL, Sutton says: “It’s difficult to quantify the savings that we are achieving with HyperMILL, as our production is predominantly low-volume work. However, it’s evident that our business is enjoying success and continuous growth and, throughout this period, our tool life is improving, as is our spindle utilisation and throughput. Additionally, our programming times are continually falling as our experience with HyperMILLgrows and the ongoing development of the CAM system yields greater efficiencies. Essentially, we’re continually increasing our productivity,while our programming and machining times [and our tooling costs] are not escalating in line with output.This is credit to an extremely efficient CAM system.”
For further information www.openmind-tech.com

Alstom opens national training academy

Alstomhas opened its national apprentice Training Academy in Derby. Following investment of £250,000 over the past two years, the new Training Academy was officially opened by Derby MP, Dame Margaret Beckett, accompanied by Nick Crossfield, managing director of Alstom UK & Ireland.Alstom is committed to helping its apprentices develop the skills and knowledge required for a rewarding career in the rail industry and help develop a talented workforce that is equipped with skills for the future. Some 120 new apprentices and graduates will join Alstom this year.

The new Training Academy, featuring 17 permanent teaching staff, is in a central location on Alstom’s Derby site and offers 1600 sq m of practical learning space. The facility also features a training hall containing a carriage and cab from the AVENTRA programme – the UK’s largest train manufacturing programme in a generation currently on the lines at Derby – where apprentices can gain practical experience working on carriages before joining a live manufacturing team.
For further information www.alstom.com/careers

Grob sets dates for open house event

Machine tool manufacturer Grob is staging an open house at its Mindelheim, Germany headquarters on 21-24 March. The company will have over 30 machines on show – including four-axis and five-axis machining centres –running live cutting demonstrations. Grob’s liquid-metal additive manufacturing systems will also be in the spotlight, providing economical production of near-net-shape aluminium components. Technical partners at the event will includeSeco, Guhring, Schunk, Open Mind, Haimer, Blum, Heidenhain, Siemens, Lang and Hexagon among others.
For further information https://event.grobgroup.com/en/

Another civil nuclear MOU

Sheffield Forgemasters has signed an MOU to collaborate with Holtec Britain on the development of components for its SMR-160 reactor.Following similar agreements signed with three other nuclear power companies, the MOU with Holtec will see Sheffield Forgemasters develop the design of Holtec’s SMR-160 components to identify the best routes to manufacture.The company says that the latest MOU positions it at the apex of the UK’s manufacturing supply chain for the small modular reactor (SMR) market and builds on its long history of supplying components into civil nuclear projects across the globe.
For further information www.sheffieldforgemasters.com

REPEATABILITY OF NAKAMURA MACHINES PUTS AEROSPACE SUBCONTRACTOR ON RUNWAY TO SUCCESS

With more than 38 machine tools on the shop floor, Shannon Precision Engineering (SPE) is a major subcontract machining outfit in the Republic of Ireland. With a world-class manufacturing strategy that utilises systems like Kaizen, the SPE staff includes Six Sigma black belts and lean manufacturing green belts. To ensure production meets the stringent quality levels the company sets, it has recently invested in two Nakamura-Tome turn-mill centres, the WT150II and the SC100X2, supplied by UK sole agent, the Engineering Technology Group (ETG).

SPE is a second-generation family-run business that was founded in 1978 by Dominic Murphy senior. Starting with three manual machines in a 500 sq ft unit with one customer and two employees, the company has grown into a major player on a global scale for heavily regulated industries. Today, SPEboasts a modern 40,000 sq ft purpose-built unit with future plans for expansion and the most cutting-edge machinery powered by the latest CAM technology. Notably, the company has individual and collective training programmes to promote continuous development in its ambitious team.

The 80 employee manufacturer is AS9100 and ISO9001-certified, and the company frequently works on high-profile projects for blue-chip clients that include Airbus, Lear, Bombardier, Collins Aerospace, Liebherr, Safran, Spirit and many other leading names in the aerospace, automotive, offshore, rail and power generation sectors.

Machining everything from Inconel, titanium, Hastelloy, duplex stainless steel and Nitronic 40 and 60, as well as hardened steels, the stability and performance of the machine tools at SPE are of paramount importance. With the company winning a significant automotive order, along with major opportunities in the aerospace sector, SPE needed a new strategy in its turn-mill department.

Recalling the situation, Dominic Murphy, managing director at SPE, says: “On some projects, we’ve been struggling with repeatability when machining particularly difficult materials. For instance, we won a contract to machine electro-mechanical connections for the aerospace industry made from Nitronic 40 and titanium, and we needed to be very responsive with our changeovers and lead times. With regular batches from 200 to 500, and up to 20 different part families in the series, the project has some very ambitious cycle time targets. With tolerances of ±5 and ±10µm on many features, we didn’t want to be chasing repeatability – we needed a more robust process than we had.”

The County Clare company investigated the turn-mill market extensively and it was the Nakamura WT150II that won the day with cycle times more than 20% faster than its rivals.

“We gave ETG and other vendors a series of components as a prove-out,” says Murphy.“ETG built a machine set up around the family of components and they delivered a turnkey solution to our facility that was best suited to our requirements. We already have a lot of turn-mill centres on-site, so the Nakamura-Tome WT150II wasn’t just about cycle times. We needed a turnkey solution that could meet our ambitious cycle times and tight tolerances with relentless repeatability for long batch production – the Nakamura-Tome WT150II certainly delivered on that. Unlike many machine tool brands, Nakamura is a specialist in turn-mill centres; their pedigree stands out. We really liked the compact work envelope as well as the ability to bar feed up to 71mm diameter, which gives us options on some of our larger components.”

The twin-spindle, twin-turret turning centre provides 15/11kW and 11/7.5kW of power to the main and sub-spindle respectively. Complementing the spindle power are 5.5/3.7kW motors on the left and right tooling turrets to provide high-performance milling capabilities. With simultaneous cutting on both the upper and lower tool turrets on opposing spindles, the WT150II provides balanced turning to reduce cycle times significantly, reports ETG.

While ETG Ireland managing director Jamie Fletchmore was visiting SPE, Murphy mentioned an extremely complex automotive part that required machining on three machine tools, a four-axis horizontal machining centre and two single-spindle turning centres. With an annual output of 40,000 units, the forged automotive tensioning assembly component was permanently absorbing the capacity of all three machines. The solution was the Nakamura-Tome SC100X2.

The SC100X2is a twin-turret multi-tasking machine that utilises two tools on either side of the upper turret for superimposed machining, making it a logical solution for Swiss-style parts greater than 25 mm in diameter.Operators can also use the upper and lower turret simultaneously, turning the machine into a true twin-spindle, twin-turret machine, providing more ways to solve complex machining problems.

As a point of note, the machine’s design contributes to faster cycle times compared with other machining processes, reports the company. The SC100X2automatically unloads the workpiece once complete, minimising manual intervention and downtime. When the machine completes a cycle, the parts catcher grips the part and places it on a conveyor, removing it from the machining environment.

Alluding to the automotive components, Murphysays: “We’ve run this family of parts for more than two years and we’ve investigated the market for a solution on numerous occasions – without success. There just hasn’t been a machine on the market that can do the parts in ‘one hit’, until now.”

He continues: “The challenges have included the turning of two spindles on either side of the part that is 40-50mm off-centre. Added to this, we have to mill features that require long-reach tools to overcome interfering features. ETG has overcome this issue with the SC100X2. The machine has cut our cycle time by almost 50% from 14 minutes to 7.26, but more importantly, it has freed the capacity of two single-spindle turning centres and a four-axis horizontal machining centre whose capacity we desperately needed. We’ve reclaimed three machines and two employees, and massively improved our throughput. We are delighted with both of our new Nakamura-Tome machines.”
For further information www.engtechgroup.com