Diamonds are forever
This logic has spurred Walter into developing the ‘two-in-one’ machining concept around its multi-axis Helitronic Diamond machines, currently the Vision Diamond 400 L (for tools of 3mm to 420mm long), the Power Diamond 400 (3mm to 380mm diameter and 520mm long) and the Diamond Evolution (1mm to 165mm diameter and up to 255mm long).
While the time and financial rewards of the elimination of separate set-ups for grinding and erosion are undoubtedly attractive to existing tool manufacturers and regrinding companies processing carbide/PCD tooling, Walter Ewag UK – a member of the United Grinding Group – adds another major benefit of the two-in-one Diamond concept for firms which may be considering entering the PCD market.
“The fact that the machine user can perform both eroding and grinding or combinations of the two means that investing in a Helitronic Diamond is effectively a risk-free introduction to the PCD market,” says sales director, Neil Whittingham.
“If it happens that the PCD business does not develop as expected for that company, then the same machine can simply revert to being a cost-effective way to grind carbide and HSS tools,” he adds.
The affordable (and compact, (occupying a floorspace of just 4.2m²) Helitronic Diamond Evolution is the ideal entry-level machine for the production and regrinding of PCD tools with diameters up to 165mm and lengths of up to 185mm (end face operation) and/or 255mm (shank length).
This size range accounts for up to 90% of PCD tooling consumption worldwide according to Mr Whittingham, and that includes increasingly complex geometry PCD tooling in various forms such as solid tips, sintered spirals and PCD on diameters, as used for milling and reaming, and straight PCD plates and chamfered PCD tips for drilling.
The machine can grind and erode a wide range of carbide and PCD styles including shank, profile, circular and roll mills, multi-step tools and countersinks, as well as cutting and profile cutting plates. And its PCD tool programming routines include the erosion of PCD on tool diameters and the production of K-Land, variable spiral and ball nose gash.
In addition to a robot loader that can boost automation (unmanned) operation by automatically handling up to 72 HSK tools or 7,500 cylindrical tools (diameter-dependent), the machine also features an HSK spindle which, being shorter than an NCT spindle, offers excellent stability and electrode surface quality during dressing, as well as longer life for the dressing insert.
The machine is also equipped as standard with Diamond Plus software that in addition to simplifying and speeding up the programming of complex PCD forms also enables production times to be reduced by up to 40%, and cutting edge quality to be improved – edge chipping down to just 5µm at 10µm grain size.
Diamond Plus is just one of the technology innovations that Walter has developed to continually make the tool erosion process more efficient and cost-effective on its Helitronic Diamond range. For example:
The Helitronic Tool Studio software now includes erosion functionality for the fast and easy programming of ‘what you see you can grind and erode’ – in addition to fast 3D live simulation routines. The functionality also allows, for instance, the design and programming of complex tool geometries, including individual tooth geometries and tool parameter scaling.
Software routines now enable automatic electrode/grinding wheel changing and robot loading for high levels of automation/unmanned operation: as standard a four-station grinding wheel/electrode changer (eight-station optional) and optional robot loading solutions: the top loader for up to 500 tools; a robot loader for up to 7,500 tools; or a robot loader 25 which has a capacity for tools weighing 25kg including grippers.
Fine Pulse Technology routines – said to set new standards in terms of PCD tool surface and cutting edge quality, as well as process reliability, courtesy of improvements to the machines’ generator as well as the erosion software.
Marked differences to PCD tools of 10µm grain type that have been eroded by other machines can be seen with the naked eye. On Diamond machines, the surface finish is like that of a polished (ground) tool – and even coarse-grained PCD types can be fine-finished with perfect surface qualities.
With such super-fine finishes achievable with Fine Pulse Technology, PCD tool providers can achieve excellent levels of tool surface quality and cutting edge within similar processing times as before. Also, subsequent steps in production can even be eliminated because no re-sharpening or polishing is required.
“The result,” says Mr Whittingham, “is a range of machines and easy-to-use technologies that enable companies of every size can use to produce world-class PCD tooling.”
Walter Ewag UK www.walter-machines.com