3D printing facility relies on Mitsubishi EDM from ETG
As an industry-leading design, development, test and production facility for additively manufactured (AM) products, Alloyed Ltd recently encountered challenges with its supporting EDM machining processes. As a company at the cutting-edge of technology, the Stone based business turned to the Engineering Technology Group (ETG) and it's Mitsubishi EDM solution.
Borne out of a merger between OxMet Technologies and Betatype in 2020, Alloyed delivers a mixture of capabilities for digital metal applications from the development and production of customised alloys for traditional and additive manufacturing (AM), process optimisation and control, through to the production of metal parts. Alloyed separates its business model into three different segments, the Industrial Division delivers solutions for aerospace, motorsport, space, automotive customers and more, the Electronics Division develops next-generation technologies with world-leading brands through AM and the Medical Division works with surgeons to design and manufacture customised orthopaedic implants.
With a complete suite of Renishaw metal additive machines, one area that was causing a bottleneck was an unreliable wire EDM machine used for removing parts from base plates following 3D printing. With the existing EDM machine, issues included constant wire breakages and the resultant manual re-threading, unreliable wire performance, water tank leakages, and a G-Code programming CNC interface that was difficult to operate and integrate with other technologies on-site. One of the most disappointing issues for Alloyed was the frequent wire breakages that would stop the machine mid-cutting cycle. Without an operator constantly present, the Staffordshire company would never know if the machine was in-cycle or awaiting operator intervention — losing countless production hours.
The search for a new EDM solution was already underway when Dr Stephen McCain, the Machine and Systems Manager at Alloyed got engaged in the process. “Our team were already considering a replacement EDM machine. At the same time, we became involved in a project to evolve a concept through to production. With an opportunity to manufacture Titanium 64 AM parts on a production scale, we started asking subcontract manufacturers with wire EDM capacity to see if they could cut details on the thin-walled parts as well as cut them from the base blocks — this was a trial in the capabilities of their EDM machines more than individual skillsets. Speaking to subcontractors with a wide array of EDM technology who were floundering with the intricacies of the part, we quickly realised what machines were incapable of meeting our needs. We found the Engineering Technology Group (ETG) and their Mitsubishi EDM solutions; their experts provided us with a solution to meet all of our needs.”
Ease of use
Alloyed spoke to ETG’s resident EDM expert Scott Elsmere, and the Mitsubishi MV2400S Type II wire EDM was identified as the perfect choice for the business. Working with an existing EDM machine that required G-Code programming, a skillset that was thin on the ground in this fast-paced high-tech business — Alloyed wanted a machine with incredible ease of use. The new MV2400S EDM that was ordered in April and delivered in May incorporates Mitsubishi’s intuitive AD Series CAD/CAM system — a feature that has instantly slashed programming times.
As Stephen says: “We can export STL files and any other CAD files into the Mitsubishi and it eliminates most of our programming problems. We load the CAD file to the machine and it automatically programmes the job. It detects what part of the component requires processing and it selects the machining parameters with some very simple data input. For us, we just ‘press play and walk away’.”
For any jobs that may require programming on the machine, the 19-inch display interface demonstrates unrivalled ease of use. As Stephen continues: “The functions are extremely easy to understand with intuitive diagrams that guide us through the process. We recently needed to cut some precision shims and a subcontractor wanted to charge us 50 pounds per shim — we clamped a batch of shim material together and programmed and machined them on the EDM in minutes.” Stephen jokes, “I now have a lifetime supply of shim and it has barely cost us anything.”
“What has also been useful here is the support of ETG. Not only did ETG supply complete training on the machine and the CAD/CAM system, but they also wrote a lot of our programs and tested them for us. This service has been remarkable.”
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Rarely is a machine bought just for its control system, but the control system on the Mitsubishi MV2400S has delivered more than ease of use. Alloyed claims that programming each job is more than 75 percent faster than the previous wire EDM machine. It gives the shop floor staff greater confidence when programming and they can easily draw shapes as per their requirements. However, the control system delivers so much more.
“We only need to enter a few parameters and the AI system calculates the rest. We can enter the material type and our desired surface finish and the AI technology in the machine control will remove the ‘trial and error’ approach. If we require a surface finish of Ra0.3, we input that into the control — the cutting data and number of passes will be determined by the smart control system. It even governs the speed of the wire automatically by constantly determining the material thickness changes throughout the process. This increases our productivity times another 40 to 50 percent compared to the previous machine.”
Alloyed additively manufactures a multitude of materials from aluminium and nickel-based alloys to steel, bone alloys, metal matrix composite, copper and even platinum. With such a diversity of materials that are continually being tested, the company 3D prints plates of test cubes in different dimensions for stress, tensile, hardness testing and even CT scanning. A typical test plate may consist of 10 rows of printed cubes — with the new Mitsubishi MV2400S applying its AI technology, the cutting time has fallen from one hour to less than 25 minutes. This typifies the productivity saving achieved with the new EDM machine. However, the productivity and programming benefit don’t tell the whole story.
One of the biggest savings for Alloyed is eliminating manual intervention that was continuously required to re-thread the wire each time it broke — each re-thread would take between 5 to 15 minutes. A short intervention may not be considered too much of an inconvenience, but when the wire continually breaks — it turns into a significant issue. For example, the frequently produced plates of test cubes that are efficiently machined 50 percent faster on the new Mitsubishi would require eight to ten wire re-threads with the previous machine. Manually re-threading the wire eight to ten times at a minimum of five minutes per re-thread was adding a minimum of 40 minutes to a job that only required one hour of cutting. Extending the previous 50 percent cycle time improvement to more like 100 percent+.
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Alluding to this, Stephen says: “The Mitsubishi MV2400S has an outstanding automatic wire re-threading system that gives us the confidence to walk away from the machine and leave it to run. Our team members will run a number of machines simultaneously — being present on one machine consistently isn’t how we work. The automatic wire re-threading can even be conducted when cutting a large job with a considerable distance between centres. Again, this is another feature that enables us to ‘hit play and walk away’ from the machine with complete confidence.”
With a new annealing system that reduces the wire curl ratio to less than ten percent and a wire break point insertion for thick workpieces, precise automatic wire re-threading is assured. This is complemented by other precision features such as linear shaft motors and optical drive systems to create a circular accuracy of one micron.
In conclusion, Stephen says: “Above all, we trust the new Mitsubishi machine. It is precise, reliable, accurate, easy to use and it’s a machine that we know we can set up and leave to run. Wire breakages will no longer disrupt production as the Mitsubishi will just auto re-thread the wire and continue. We are now working with ETG on new workholding solutions and possible automation integration for production purposes if the need arises. We are even looking at more Mitsubishi wire machines for some of our other facilities too.”