CNC MACHINES

Halifax Numerical Controls (HNC) has partnered Huddersfield-based Rollertech to develop a rubber roller grinding machine

Halifax Numerical Controls (HNC) has partnered Huddersfield-based Rollertech to create a rubber roller grinding machine.

Carl Slingsby, founder & proprietor of Rollertech, recently had an idea for a new type of grinding machine & needed someone that could translate these ideas in to a workable design & build a machine.

Contact was then made with HNC, culminating in a signed agreement.

HNC would carryover out the design & build a prototype with the assistance of Rollertech, then jointly create the new machine in line with Carl Slingsby’s vision.

Rubber roll grinders are usually in the form of a universal grinder with the table traversing in the X axis.

two of the problems when grinding shafts such as those 3000mm long is that the machine has to be over once that length to accommodate the table traverse.

This in turn causes further problems with the inertia of moving a three tonne component back & forth.

To help overcome this problem the machine needs to be so heavy; it almost becomes unwieldy with prices often quoted in hundreds of thousands of pounds.

He carried out some research, which told him the market demanded a 3m machine, although maximum diameters seemingly fell in to two distinct categories – 600mm & 1250mm.

Slingsby, who regularly visits his customers around the world, is always keen to discuss & comprehend their manufacturing problems & had noted a number of his customers struggle with the longer & larger diameter rollers.

The heavy-duty,  enclosed machine is fully electronic in operation & capable of grinding rubber rollers up to 3m in length with a maximum component weight of three tonnes, while maintaining an end-to-end accuracy of 20 micron.

Working within a timeframe, a fully developed 600mm variant emerged, which was duly designated the Rollertech RT 3000.

To provide the rigidity & accuracy required, linear ways are utilised throughout.

The machine is compact with the component rotating during the grinding method but remaining stationary in the longitudinal axis as the wheelhead now traverses in the X axis in addition to the Z as per conventional machines.

Programming is by the latest Fanuc GE Oi-D touch-screen CNC controller.

The axes are driven by Fanuc GE high-torque DC motors by heavy-duty ballscrews.

it’s further been developed to enable customers to prepare programmes for specialist shapes & patterns as required.

A multitude of programmes has been developed & incorporated in to the control including parallel, convex & concave grinding along with grooving cycles giving herringbone, chevron & diamond patterns, to name but a few.

Grinding replaces milling to cut production time

Constant’s milling-based method of producing blades and anvils used in the printing industry for automatically creasing and folding paper and card seemed doomed to failure, due to difficulties in maintaining the tolerances demanded by the high-speed machine and because of the projected increase in production output to meet the order demands of the print finishing specialist.

C Dugard has recommended a switch from milling-based methods to grinding methods after the introduction of a higher performance folding machine by a long-serving customer at Constant Precision.

Following trials on a Chevalier smart B-1224-II surface grinding machine, the new method more than halved the original processing time for the one ranges of parts required and ensured a high level of quality.

However, Constant undertook a close study of possible methods of manufacture with several machine gizmo suppliers, and it was C Dugard’s application team at Hove that suggested a switch from milling to grinding.

‘These have come from the customer’s research and development activities as well as prototyping projects that have led to production batches of up to 1,000 components for the printing, medical and laser, food packaging, construction equipment and security sectors, in addition to the local university,’ they added.

‘A lot of work over the years has involved specialist and often very difficult components,’ said Charlie Constant, managing director of Constant Precision.

some of these parts were machined on the Dugard Eagle 660 vertical machining centre; C Dugard being a machine supplier with which Constant has developed a close working relationship based on the level of service and support they has received.

Certain projects outline the skill level of the nine-employee company, such as the complete machining of an engine block and head for a vintage racing Maserati that was worth in excess of GBP1.25m.

So, when facing the problem of the new design of tooling, Constant called C Dugard in to see how the milling method on the OI gizmo steel components could be improved to enable his customer to reproduce on-the-fly creasing and folding of up to 5,000 folds on 400g/m2 A4-sized material in an hour to a positional tolerance of +0.1mm.

Constant also considered outsourcing the finish production of the blade and anvil; however, when possible suppliers looked at the number of variables in the component dimensions that could cause them headaches, they either priced the job right out of court or immediately declined to quote.

The six types of matching blade and anvil vary from between 350mm and 500mm long and each is 12mm wide and 40mm deep.

Batch quantity can often run to 200 pairs a month.

Each side of the triangular category has to blend in to either a large radius over the 12mm width or a flat face, according to the material to be folded.

walking down the centre of each blade is a raised triangular category  1mm wide with a critical 0.1mm radius at the top.

Both radii are critical with tolerances having to be held within 0.03mm, and the overall straightness of the grooves and triangular category have to be within 0.05mm to prevent scratching, marking and out-of-position folding of the material factors, which would lead to immediate rejection by the customers of both printer and finisher.

The anvil has a 1mm-wide slot with a 0.1mm radius walking down its length that has to marry up to and provide a datum for the blade and material to be creased and folded.

Key to the three-axis CNC grinding machine method was the multi-function programmable control that has variable graphic simulation for grinding and wheel dressing cycles.

After several discussions with C Dugard, an initial single fixture was devised for the Chevalier machine to produce three part at a time that, once proven, led to a double fixture that would enable one blades or anvils to be ground at the same time using a paired grinding wheel.

This allows the speed of the review sequences to be varied in both forward or reverse by the operator using the machine’s electronic handwheels.

Preset dressing cycles can also be initiated at any time during the grinding cycle without resetting.

This level of flexibility was important to Constant as, depending on his customer’s requirements to cater for unusual or different papers, inks and finishes, the profiles may have to vary slightly – and these can be accommodated with rapid and simple manipulation of the program.

With the machine ordered, Constant then faced a problem with its installation – his 2,400ft2 factory in Kempston had no room for the machine so they had to set about finding new premises.

While there, C Dugard’s application engineer produced five basic programs including the dressing sequences for the single and twin-wheel setting for the single grinding pass.

In the interim, C Dugard offered the facility of its showroom in Hove for his setter/operator to create the method and run production.

While lease negotiations and fitting out of the new premises were underway, Constant’s customer then suggested the machine be temporarily installed in its own research and development department.

This was not straightforward as the grit and grade of the wheel and dressing speeds had to be balanced in order to prevent wheel breakdown on the tight radii set on both component types and also to avoid burning of the component surface.

It also involved C Dugard in re-siting the machine at the customer, then at Constant’s new facility along with re-commissioning the machine after its move.

This would permit the one companies to discuss and try out modified forms on experimental blades and anvils.

Today, with the method developed and in production, by changing from milling to grinding using the Chevalier machine, the cycle time for each blade and anvil has been reduced by  60 per cent.

Still working with C Dugard, Constant is developing wheels and improving dressing cycles and their frequency, making full use of the flexibility of the machine’s CNC to further improve the method.

Jones and Shipman (JandS) has launched the next-generation Ultragrind CNC cylindrical grinding machine

The Ultragrind CNC is designed for the precision production environment such as aerospace & higher volume manufacture including automotive, as well as high-precision sub-contract machining for biomedical, high-end system tool/die sets, F1 & motor sport engineering.

Jones & Shipman (JandS) has launched the next-generation Ultragrind CNC cylindrical grinding machine that is designed to offer more power & accuracy, and increased component weight handling.

‘We will be demonstrating a working prototype at the CIMT event, so visitors to the show will be able to see all the machine’s advantages,’ said Mike Duignan, sales & marketing director of Jones & Shipman.

Built on a one-piece bed design, the machine combines rigidity, stability & stock removal rates while maintaining precision.

A modular wheelhead design ensures customers have a wide choice of external & internal grinding spindle combinations, effectively allowing the customer to specify a custom machine, but without the cost & build time associated with it.

The modular wheelhead design gives wheel sizes up to 500 x 100mm (diameter) & wheel spindle power up to 15kW, with ultra rigid spindles providing substantially increased metal removal rates & increased productivity.

Angular wheelhead positional accuracy & repeatability are assured by a high-precision 1deg Hirth coupling.

An optional true B-axis programmable to 0.001deg utilising feedback from a high-accuracy encoder mounted directly to the rotational spindle axis means infinitely variable positional resolution can be achieved.

The machine currently offers 650mm or 1000mm between centres (with larger machine length capacities planned) & centre heights of 180mm, 200mm & 250mm.

The increased diameter capacity (of up to 500mm) means there’s options to cater for larger mass components up to 450kg, & odd-shaped components, which can result in high rotational inertia.

The Ultragrind machine uses Jones & Shipman’s Windows-based graphical programming application suite, which further builds on the Easy application that removes the requirement for operators to input code, although ISO programming is fully supported & codes can be viewed & used if required.

The application is built around a Fanuc 320i with touch-screen control process.

This reduces the time needed for operator training, machining set up & changeover times.

A full suite of dressing & grinding programs are obtainable for the operator.

A wide range of additional options including gauging & auto loading are also available.

Jones & Shipman set up pages permit the operator to digitise diamond & wheel positions by means of a simple touch-screen interface.

High-energy liquid jets are finely controlled to cut and shape features

NanoMatrix, the developer of a new approach for performing small-scale fabrication, offers its customers micro and nano machining services and equipment.

High-energy liquid jets are finely controlled to cut and shape features with sizes below 50 nanometers in a wide variety of materials.

The company’s proprietary technology includes the control of high-energy liquid jets to cut and shape features with sizes below 50 nanometers in a wide variety of materials.

“At the scale they are working, the jet’s stream of individual molecules seems to produce a machining effect similar to sand blasting” says John Thomas, Director of Business Development for NanoMatrix.

Effects are created mechanically and no harsh chemicals are required to support the method.

The processes developed by NanoMatrix are environmentally friendly.

The method is also tolerant of contaminants so it can be used in environments with less stringent cleanliness controls.

Currently, NanoMatrix is focusing its efforts on joint development projects with customers and business partners.

“We have found that there’s a number of companies that are interested in exploring alternatives to building next generation products since their current tool kits are limited.” NanoMatrix is working with a variety of MEMS/NEMS, photonic devices, and optics companies to develop solutions to problems associated with fabricating products with feature sizes that are often smaller than the wavelengths of visible light.

In optics applications, for example, our method can be used to selectively change the surface profile of a lens while leaving the overall optical performance unchanged.

NanoMatrix, Inc.

is also developing a general-purpose workstation for customers who wish to work independently on development and prototyping projects.

Grinding machine builders, Blohm and Jung, combine

The German builders of CNC surface grinding machines, Blohm and Jung, have merged to form Blohm Jung in order to improve market opportunities.

Koerber Schleifring reported that two German builders of CNC surface grinding machines, Blohm Maschinenbau and K Jung, have merged Blohm builds production machines and systems

Jung builds surface customised grinding systems.

The two specialists in the field of surface and profile grinding believe that together, they have better market opportunities and very good prospects for the future.

The brands and their technological characteristics, as well as the companies’ respective factories in Hamburg (Blohm) and Goeppingen (Jung), are being maintained and no job losses are planned.

The merger of Blohm and Jung represents a strategic development of the Sschleifring (Grinding circle or club – Ed) companies in the field of surface and profile grinding.

The two companies’ practical expertise will be combined by means of technology transfer and targeted staff training.

In future, the sales team will be in a position to represent the whole spectrum of surface and profile grinding technology.

Schleifring told manufacturingtalk that the merger will result in greater competence, more detailed advice and customer support, and greater area coverage.

A full product portfolio will now be offered worldwide as a ‘one-stop shop’ in both standard products and systems.

In addition, the cooperation that was already practised in the research and development area in the past will be intensified so that the new company will be able to react more quickly to market requirements and present innovative product solutions in a more targeted way.

An extension of the product programme to new, common machine platforms will help the company to open up new market sectors and offer customers better, more efficient and commercially more interesting solutions as a result of the synergies that are generated.

The management of Blohm Jung will be headed by Krister Bruhn and Uwe Henning, long-standing CEOs of the companies Blohm and Jung respectively.

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