Cnc Machines

Kyal Machine Tools has introduced the Alzmetall GS 1000 five-axis high-precision vertical machining centre (VMC).

In addition to conventional, high-speed and hard-metal milling and drilling, the VMC can also perform turning operations up to 600 rev/min.

The GS 1000 has a gantry design with frame parts made of EN-GJS 500 (GGG 50) and EN-GJL 300 (GGL 30) steels.

Features include rapid axis feeds of up to 60m/min at spatial acceleration of 17m/s2.

The machine is equipped with a high-frequency motor spindle up to 24000 rev/min.

The A-axis opening-width diameter is 1070mm and distance of spindle to table is up to 801mm.

Alzmetall has introduced torque drive technology at the A-axis and C-axis (Model GS 1000/5-T).

Applications include medium- and high-volume production machining, modelling and prototyping, small batch production, mould, die and tool manufacture.

Special applications include: five-axis simultaneous machining of spatially geometric and non-geometric surfaces; machining jobs with high-frequency oscillating axis movements, such as turbine-blade machining; high-end finishing jobs in the tool and die industry; and turning operations at up to 600 rev/min.

Advantages include maximum use of the machining space with a non-disturbance range around the C-axis of 1070mm and a non-disturbance range of 980mm around the A-axis.

It also features a maximum distance between main spindle and the C-axis rotary table of 801mm.

The C-axis rotary table is placed 100mm below the A-axis.

A workpiece with a total height of 500mm can still be swivelled into a 90-deg upright table position.

Torque drive technology responds to highest controlled dynamics and guarantee high accelerations and speeds.

There are no mechanical driving elements and therefore no frictional wear and no inaccuracies while reversing.

Sealed four-fold coupling into the C-axis at centre of the C-axis rotary table for hydraulics and pneumatics access to interface hydraulic workpiece clamping systems at pressures up to 250 bar.

The design characteristics of frame include a basic frame body (monobloc) carrying machine table, axis-structures and tool magazine.

Both side walls as well as both cross sections are machined as a pair to guarantee highest geometrical precisions for mounting the guideways.

The coordinate unit is structured as box-in-box.

The monobloc core body moves in X-axis and carries the Z-axis unit.

The Z-axis column unit has four guideways with the main motor spindle inserted.

User benefits include: streamlined force-circuit between workpiece and tool; negative impact of force and temperature influence; lower tool costs; contour consistency at high path velocity; lifetime of machine tool spindle guarantees extremely high parallel path precision through double drives each at X- and Y-axis.

Design characteristics include: * Two A-axis torque drives are integrated in both sidewalls of the gantry machine frame * The C-axis torque drive is integrated into the swivelling A-axis module * Three-phased AC-synchronous motor with permanent magnet * Thermal division of both A-axis torque drives to gantry machine frame * Autonomous cooling system for the torque drives * Chip removal * Swarf tunnel located immediately below machining table Access to application: * Working space access from top, accessible by crane * Automatic access door feature open/close (Option) * Operator’s working position is directly at machining table Options include the following: * High-frequency motor spindle 18000/24000rev/min * Tool magazine up to 150 positions * HSK – A63 tool clamping system * Chip conveyor * High pressure coolant supply through spindle * 3D measurement system * Automatic workpiece handling * Automatic tool (wear) control * Dust extraction * Pallet changing system * Graphite machining.

The installation of two machining centres from Hurco Europe has allowed Lancashire subcontractor AandG Precision to attract more work and produce components more efficiently in fewer setups.

The company is a producer of complex components used in key military and civil aircraft programmes.

It is also active in a number of other sectors, including defence, marine, petrochemical, motorsport, rail and pharmaceutical engineering.

In addition to the batch production of high-precision components, AandG provides a range of additional services, including prototyping, subassembly manufacture and reverse engineering.

One long-running job, an aluminium part, used to be produced in three setups on a three-axis machining centre at the subcontractor’s Poulton-le-Fylde works.

The complexity of the component necessitated a lot of step-down profile generation using a ball-nose milling cutter, so overall machining time was around one hour.

The same part has been reprogrammed and is now completed in a single, eight-minute cycle on the company’s first five-axis machining centre, a Hurco VMX42SR, which was installed in mid-2008.

There is a large saving in machining time and the two setups are eliminated, considerably reducing the cost of manufacture.

Another component to benefit from one-hit, five-axis, prismatic machining, in this case after a turning operation, is a steel eye bolt that previously required three separate operations on a three-axis machining centre.

The bolt is of relatively simple design, so there is little difference in overall machining time, but two setups are saved.

Michael Pinder, a director of AandG, said: ‘Generally, we do not reprogram existing components to run on the five-axis Hurco unless they are ongoing jobs and savings are significant.

‘However, the availability of the machine has changed the way we approach the machining of new components.

‘In the first year after we started operating the VMX42SR, we produced 73 different parts on it in titanium, aluminium and various steels including stainless.

‘A proportion of those contracts we previously would not have won, as the prices for producing them conventionally would not have been competitive,’ he added.

He added that the machine was not purchased in anticipation of receiving new contracts, but was bought on spec after a number of customers repeatedly offered AandG five-axis work that it could not fulfil.

Several machines were shortlisted and reviewed at Mach 2008.

One reason for choosing the Hurco was said to be the powerful 36kW/12,000rev/min spindle.

Another was the Ultimax twin-screen control, which includes a special version of the proprietary Winmax software, specifically designed to simplify the programming of complex multi-sided parts.

A further significant factor in the purchasing decision was the swivelling-head design with horizontal rotary table, which, according to Pinder, offers a larger working envelope than the more usual configurations based on a vertical spindle and a two-axis trunnion-mounted table.

In some instances, components are set up in the space at the side of the rotary table on the VMX42SR for second-operation work to be carried out.

At the end of 2008, AandG installed a second Hurco machining centre, this time a three-axis VMX60t with 2m capacity in X.

This was said to be in response to an approach from an existing customer that wanted some ribs machined, knowing that the subcontractor had the necessary ISO 9001:2000 and AS9100 approvals.

The rib contract was limited, but Pinder found that once the machine was installed, its existence on the shop floor created work as soon as customers heard that the facility was available.

Several different jobs approaching the machine’s capacity have already been won as a result.

Additionally, some smaller jobs can be fixtured in separate vices on the table to meet demand when the smaller machines are working flat out, so very little time is wasted.

Programming of the Hurco machines is carried out either at a PC in the office running Winmax software or on the shop floor at the Ultimax control.

In the case of the five-axis machine, most programming is done offline as components tend to be complex.

Customers mainly supply Catia models that are converted to STEP files.

Open Mind’s Hypermill CAM software converts these into efficient cutter paths that are post-processed and downloaded to the Ultimax control.

The reverse is true of program preparation for the VMX60t.

So far, most has been done at the machine, owing to the simpler nature of the work, with the exception of the ribs.

Pinder said: ‘The conversational control [of the Ultimax] is the easiest to use of all our CNC systems and is practically foolproof.

‘The operator simply follows instructions on the touch screen, working his way down, filling in the boxes.

‘At any point, pressing the “draw” button produces a component graphic on the second screen that shows exactly where he has reached in the program,’ he added.

AandG’s purchase of the two Hurco machines is part of an expansion programme over the past 18 months that has seen more than GBP1m spent on plant acquisition and buying, extending and refurbishing its previously rented Poulton-le-Fylde premises – a Grade 2-listed corn mill.

Hardinge Machine Tools, a milling, turning and grinding machine tool manufacturer and workholding equipment supplier, has boosted its five-axis machine tool product portfolio with the GX 250 5-AX.

GX 250 5-AX machines – which have a small, compact footprint – provide customers with: the ability to machine completed precision parts in single (one-hit) or reduced setups; improved part accuracies, thanks to fewer work-handling operations; reduced operator interventions; and increased work throughput.

The multi-purpose machines are suitable for the manufacture of complex small-sized high-precision parts for the medical, aerospace, computer and electronics sectors.

As a result of their price and functionality, the GX 250-5AX machines are said to be ideal for manufacturers looking to step up to five-axis technology and/or for manufacturers looking for an additional five-axis machine tool capability at an affordable price.

There are three models in the GX 250 5-AX range: the S, the P and the HP.

All models have a rigid C-frame fixed-column design for extra rigidity and axis travels of 300mm x 400mm x 430mm in X, Y and Z and corresponding traverse rates of 30m/min.

Positional accuracy and repeatability are 0.007mm and 0.004mm respectively.

The machine’s five-axis capability is delivered through the use of its A axis (tilting +30/-120 degree at 33.3rev/min) and C axis (rotating 360 degrees continuous at 33.3rev/min).

Positional accuracy and repeatability of the A and C axes are 20 arc seconds/four arc seconds and 10 arc seconds/three arc seconds respectively.

The rotary tilting action of these two axes allows cutting tool access to all available faces of a component, while the control provided by the Heidenhain iTNC 530 enables complex five-axis simultaneous machining at high feed rates.

The GX 250 5-AX machines are equipped with different spindle options depending on model type.

These options are: a 17kW 12,000rev/min (BT 40) coupled spindle (greased) on Model ‘S’; a 17kW 15,000rev/min (BT 40) coupled spindle (oil/air) on Model ‘P’; and for high-speed, high-precision machining a 23kW 20,000rev/min (HSK A63) motorised spindle on Model ‘HP’.

Through-spindle coolant is an option on the 20,000rev/min-rated machine.

The GX 250 5-AX has a 210mm-diameter table and is able to handle workpieces (250m x 240mm) with a maximum weight of up to 75kg.

The machines have a 20-station (30-option), swing-arm, bi-directional ATC for extra productivity and flexibility, inbuilt dynamic collision protection for greater security (on the HP machines) and, among their many options, can be equipped with linear scales on the X, Y and Z axes and a Filtermist oil/mist extraction unit.