Product category:
EDM wire cutting
News Release from: Charmilles Technologies Corporation | Subject: Robofil 4030SI Wire EDM machine
Edited by the Manufacturingtalk Editorial
Team on 26 November 2002
Subcontract wire EDM service continually
updated
Having always tried to provide as wide a wire erosion service as possible a Birmingham subcontractor maintains the policy of steadily replacing its earlier wire eroders.
Located in Balsall Heath, Birmingham, Eldermeek have always tried to provide as wide a wire erosion service as possible To do this, wire eroding components to within 2 micron working tolerances, the company has been steadily replacing its earlier wire eroders with the latest Charmilles Wire EDM machines
This article was originally published on Manufacturingtalk on 22 Mar 2001 at 8.00am (UK)
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In launching its revolutionary 'twin wire' Robofil 2030SI-TW, Charmilles has designed a system that allows machining with two different wires in automatic mode and cuts production times by 30%.
"Delivery times required by customers are getting shorter," said Chris Mathias, "therefore we need machines that can run reliably and accurately, unattended during the night.
Wire EDM is often the last process for many jobs, so there is very little time left before the jobs are presented for wire erosion, particularly in precision engineered components and some press tool work." Chris Mathias explained that by using the very latest machines, including the acquisition of a Charmilles Robofil 4030SI Wire EDM machine in January, it is now possible to cut parts for an electrical connector blanking press tool on a Tuesday, for deliver on Thursday.
The customer assembles the tools on Friday and produce the connectors on the following Monday.
Further reading
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Achieving a cutting speed of 400mm2/min, believed to be for the first time in the world, the generators fitted to the latest wire EDMs use a new current pulse shape.
Award for toolmaker thanks to CNC investment
Toolmaker Avenue Mould now has two Charmilles Roboform 20 CNC spark eroders, fitted with Erowa tooling, and an automated Roboform 35 fitted with Erowa's PX robot
Subcontract engineer expands wire erosion facility
Subcontract engineering company Bedestone is continually expanding its operations and has increased its wire erosion capacity, investing in the latest technology from Charmilles Technologies
In capacity terms, Eldermeek Ltd can cut workpieces up to 1200mm x 700mm x 400mm and weighing up to 1000kg.
The company operates four Charmilles machines; a Robofil 510 and Robofil 290, a Charmilles HD8 fast hole-drilling machine and the Robofil 4030SI.
Chris Mathias said that the purchase of the Robofil 4030SI was part of an ongoing machine replacement programme to concentrate on Charmilles machines.
Why Chris Mathias favours the Charmilles product is that he has found them to be more accurate over a long working period.
"Some makes rely on rotary encoder's fitted to the ballscrew's, we regard that as Ospeculative positioning'! Whereas, the Charmilles machines use linear glass scales which measure the true axis positions.
To us, accuracy is the most important criterion." "Until we acquired the Robofil 4030SI, we had no chance of working to closer tolerances than one thou (0.013mm), but we are now confident in quoting for high accuracy work.
Some customers think that a two-stage operation - rough and skim - is all that is necessary.
But to get to within 2 microns, on an EN24 workpiece, it takes typically one rough cut and five skims.
Also, the material has to be in the proper condition, that is, there should be no built-in stresses.
Materials should be fully stress relieved if such close tolerances are required to be met."Picking up a profiled copper plate, Chris Mathias said that it is now possible to profile it within 2 microns because the Robofil 4030SI is temperature controlled, "So the machine is working at a stable temperature, regardless of conditions in the workshop.
It is one of the reasons why we bought this particular machine." "Having the Robofil 4030SI has also changed our approach to wire EDM, " explained Chris Mathias.
"We now think more in terms of multiple set-ups and run the machines unmanned.
Typically we fixture three or four parts in a row on the Robofil 4030SI, Robofil 510 and Robofil 290, and run the three machines unmanned through the night." "We try to provide as wide a wire erosion service as possible," explained Betty Mathias.
She showed a large, short, 500kg double throw camshaft, which required a cam profile modification.
It was achieved by wire eroding a wide dovetailed section in the cam perimeter, and wire eroding a new profiled insert, which is then dovetailed and secured in place.
An ongoing job was wire eroding sections from octagonal aluminium bus shelter columns.
"These used to be bandsawed, and separate aperture covers had to be made," said Betty Mathias.
"Now, using 0.3mm wire, we cut out the aperture, and use the off-cut as the aperture cover for the column." On the Charmilles Robofil 510, a forked piece, about 287mm by 184mm, with section widths of about 50-75mm wide, was being profiled from 10mm mild steel plate.
The job used to be flame-cut, profile-milled and hand-dressed.
The Robofil 290 was profiling carbide electrical stamping dies.
This machine was acquired using Charmilles innovative finance package which sees an initial rental period with an option to buy within six to 12 months.
Jobs have included producing stripping plates and dies for pastry cutters for the food industry and profiling brass plate for heat exchangers.
"We can be cutting mild steel one minute and then brass or titanium the next, as well as silver, gold or platinum," said Chris Mathias.
"Some jobs require digitising, particularly the jewellery jobs.
We can also provide a fast blanking tool service, in that we can digitise a slug and produce the top and bottom tool inserts.
The slug gives us the blanking clearance.
If necessary, the slug can be used as a punch for short-run work." Work carried out for Birmingham's 'Jewellery Quarter', required brass plates to be profiled for a series of skeleton clocks.
Other jobs include producing football league logos in silver or other precious/semi-precious metals for affixing to trophies, or developing prototype rings, ear-rings and parts for broaches and necklaces, as well as cutting the die pieces.
Eldermeek also carries out modifications to mould tooling and press tools.
For example, one of the jobs on the Robofil 290 was modifying a lost wax mould tool.
Another example was in the 4030 SI, where corners were being cut in an injection moulding tool.
Depending upon job complexity, most of the programming is centralised.
The simpler jobs, such as cutting a simple hole profile, would be programmed at the machine.
Eldermeek can accept electronic file formats such as DXF, IGES and AutoCAD DWG.
Chris Mathias can modify and detail designs, as required, on screen before compiling wire erosion programs.
"We are continuing to upgrade our machines and still have one or two to be replaced," said Chris Mathias.
"The Charmilles machines are very user friendly, reliable and accurate, and hold their specifications over long periods.
They give us the flexibility and dependability to give our customers exactly what they want.".
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