Established, different, affordable - XYZ's Challenger 5-axis machining centre

4 min read

No stranger to 5-axis machining, having offered 3-axis vertical machining centres fitted with 2-axis tables for some time, XYZ Machine Tools has introduced an as-built simultaneous 5-axis machining centre. But the company’s applications manager, Mike Corbett, is at pains to underline the new addition’s differentiating strengths

Called in full the ‘XYZ UMC-5X The Challenger’, the gantry-type unit boasts design features that will set it apart, while also being offered, in typical XYZ Machine Tools (01823 674200) fashion, at a competitive price, the company states.

Some key top-line details are that the Taiwan-built machine boasts more than two hundred unit sales across Europe; others trying to compete at the lower cost end of this technology have chosen China as their supply base, observes XYZ Machine Tools’ managing director, Nigel Atherton. Boasting a 600 mm diameter table, 500 mm Z-axis travel and straddling both low (3+2-axis) and medium technology levels (5-axis simultaneous), this puts it in the area of largest demand for 5-axis machine tools, Corbett says. And at £153,000 for a Siemens 840 DSL-fitted machine and £164,500 for one outfitted with Heidenhain iTNC 640, this puts the model well below units of similar quality that would fall between £250,000-£300,000, he suggests.

The timing of the introduction is right Corbett adds, with 25% by volume of the European vertical machining centre market (2015 figures) taken by 5-axis machines and with the UK and Ireland together taking 170 units per year, placing them fourth in Europe.

A reflection of increasing part complexity and the desire for one-hit, efficient and profitable manufacturing, he states, and adds that multiple operations demanding multiple machines attract multiple costs: £30,000/year for every additional person to run a machine, power to run each piece of equipment and coolant, with disposal being the major cost.

The machine is suited to both new and established users, says XYZ

With the UMC-5X, the company is aiming at both typical XYZ customers, likely to be first-time 5-axis users, and those already active in 5-axis machining, but offering them more cost-effective levels of accuracy and precision. That being so, the machine is suitable for both those that require 3+2-axis machining and companies looking for 5-axis simultaneous machining, the applications manager underlines – there are no options on this, the machine is a full 5-axis unit as delivered.

Corbett goes on to highlight some core design features that attracted XYZ to this model. “With a wide X-axis and good support [for the spindle] in the Y-axis over the table [both axes are set above the machining area], the gantry design allows us to give our customers the ability to produce precision parts, with lots of capability for heavy cutting.” And this rigidity message is underlined as he points to the sturdy base casting (total machine weight is nine tonnes-plus) and large, INA roller guideways (full specification, taking in important CNC unit key features, below).

An important detail that may initially confuse is the Y-axis travel of 600 mm that is split from centreline as -100 mm (away from the operator) and +500 mm (towards the operator). Corbettexplains: “It makes sense when the table is pivoted through 90° [towards the operator]. Because we have 500 mm travel from the centre of rotation of the table. If you have a job 500 mm high, we can still get to the front of it. Others may have, say, 750 mm of X or Y travel, and that looks a lot, but it is distributed equally about the centre of the table. As soon as they pivot the table, the travel is halved and they can’t get to the front of a part. This offset Y-axis pays dividends, once you start moving your part around on the tilting table. We think that is going to be quite important to our customers.”

Concludes XYZ managing director Nigel Atherton: “We have looked long and hard to find what we feel is the right solution to 5-axis machining and, in the UMC-5X, I believe XYZ Machine Tools has a machine to meet the needs of a wide variety of customers, from those just starting out in the 5-axis arena, to those already well-versed in this technology.

“The machine is a perfect fit with our existing range, in that it combines excellent value for money with extremely high specifications, which, we know, will make it attractive to XYZ customers.”

XYZ Machine Tools will have some machines of varying specifications available from stock, with non-stock machines available on a lead time of some four months.

Detail design & specification pointers

■ High torque spindle – water-cooled inline Siemens 1PH8133 offering 12,000 rpm (15,000 optional) and 30 kW at 1,100 rpm and 239 Nm (S6; 40% duty); BT40; through-spindle coolant 20 bar (70 bar option)

■ High speed spindle – Kessler 18,000 rpm unit (24,000 rpm option) offering 25 kW at 6,000 rpm and 40 Nm (S6; 40% duty); HSK-A63 connection; through-spindle coolant 20 bar (70 bar option)

■ Linear axes – 600, 600 and 500 mm travel (X, Y, Z); roller, not ball, INA linear guideways, 45 mm wide; 45 mm diameter high accuracy C3 grade ballscrews; 12 mm pitch for high rapid feed (36 m/min); direct motor driven, avoids backlash errors; Heidenhain 1 micron resolution linear scales that compensate for thermal variations (inherent in all machine tools); 6-7 micron circularity accuracy

■ Rotary axes – Italy-made, LCM trunnion tilting/rotary table fully integrated into the machine with same bearing size at each end (other designs do not have both-side support, or have a smaller bearing on the non-drive side); Heidenhain encoders mounted directly to shaft for both A and C, improving accuracy; easy loading access, due to bearings at side, not front and back; 600 kg capacity

■ Rotary C-axis – torque motor driven (90 rpm, 707 Nm [S6 rating]); maintenance free; hydraulic brake; ±5 arc-secs accuracy

■ Tilting A-axis – ±120° range; worm-gear drive (16.6 rpm – torque motor option [most rotation takes place in C]); worm-screw is cemented and hardened steel with a unique precision-ground profile for a wide contact area with the crown; crown is self-lubricating Bronal that allows preloading, which offers increased dynamic accuracy and no backlash; hydraulic brake; ±30 arc-secs accuracy

■ Toolchanger – 24-position carousel or 32-, 48- or 60-station chain-type

■ Key control functions (both CNCs) – Blum tool measurement; Renishaw part set-up and measurement; conversational programming format, including for 3+2-axis programs; dynamic collision monitoring; high speed machining supported, with programmable surface quality/accuracy/velocity trade-offs available; tool centre point programming for both CNCs, avoids gouging; Tool Tip Position Z-axis control (patented), prevents inaccuracy caused by temperature and centrifugal force at different spindle speeds); Axial Accuracy Control (patented), takes temperature input from 24 sensors to compensate for thermal distortion; Spindle Vibration Supervision, detects vibration and acts across three levels – operator warning, reduced spindle speed and axis feed, machine stop; kinematics option (centre of rotation of tables detection/compensation, maintains best accuracy)

First published in Machinery, June 2017