A Heller HF 3500 Gen2 horizontal machining centre in pallet-change configuration
Heller has introduced a second generation of its HF-series of five-axis, horizontal-spindle machining centres (HMCs), which it is marketing under the slogan 'Be A Performer'.
The HF 3500 and HF 5500 incorporate a multitude of improvements that are featured on the company’s website here
. The recently introduced fourth generation of Heller H-Series four-axis HMCs also shares this page. All machines are available in the UK and Ireland through the German manufacturer’s subsidiary Heller Machine Tools Ltd
in Redditch, where both of the HF machines are assembled as well as many of the H-series models.
Since their launch in 2016, the robust, dynamic, five-axis models have been available with a fixed table or an automatic pallet changer. The working volume of the HF 3500 remains 710 x 750 x 710mm, but the larger model has gained 30mm in the Z-axis, so travels are now 900 x 950 x 930mm.
Both machines are available with either an HSK-A63 or HSK-A100 tool interface and in three versions, POWER, SPEED and the new option of PRO. The latter is intended for long periods of simultaneous five-axis machining. Pallet change in action on the HF 3500, showing the rotary table in the background supported by the swivelling trunnion
Designed to raise cutting performance, innovations in the second generation include an approximate halving of the minimum distance between the spindle nose and the centreline of the 225deg swivelling trunnion; the availability of twin motors and ballscrew drives for moving the trunnion/rotary table assembly in the Z-axis, with position feedback via linear scales; and the offer of six new spindles produced in an automated facility at Heller’s headquarters in Nürtingen.
As before, a column travelling over the bed executes the X-axis motion, while Y-axis movement is performed by the spindle head moving up and down the column.
Other notable improvements in Gen2 machines include increased stiffness of key components, shorter chips-to-chip times and faster tool change from a chain-type magazine with up to 240 pockets or a rack-type magazine with up to 405 positions.
The high-end PRO package additionally offers 10m/s2
acceleration in X, Y and Z. The guideways employ linear roller bearings, enabling high dynamics and rapids up to 90m/min, while the rotary axes have direct drives and stable YRT bearings. There is also increased feed force in the Z-axis, dynamic motors driving the rotary axes and the option of adding a turning function using a high-speed rotary torque table.
Maximum table load has been increased on the HF 3500. It is 650kg on the PRO and up from 400kg to 550 kg on the SPEED to match the standard POWER model. Information on the mass of each pallet and fixtured component can be entered into the pallet management software. This is especially beneficial when configuring a flexible manufacturing system linked by multi-pallet storage from Fastems or Erowa.
It enables automatic monitoring of load weight so that rapid traverse in the Z-axis can automatically be reduced for heavier loads. The dynamics of the rotary axes may be similarly adjusted when the pallet weight is high. An integrated, five-point media interface with 80 bar or 200 bar hydraulic pressure is provided to actuate fixtures in the work area and feed data back to the control.
The use of stainless steel in the machine construction, notably in the working area and the tool and workpiece setting stations, enhances durability. Steep side walls promote efficient evacuation of swarf. LED lighting has been improved in all operator areas and a camera can be integrated above the tool change door. Easy access to the working area, a short distance from the front of the machine to the spindle and a low component loading height ensure ergonomic machine operation.
As regards the spindles, new is the availability of a pair of DC (dynamic cutting) universal direct-drive motor spindles, HSK-A63 (16,000rev/min, 56kW, 180Nm) and the HSK-A100 (12,000rev/min, 45kW, 400Nm).
There is also a PC (power cutting) spindle rated at HSK-A100 (10,000rev/min, 45kW, 360Nm) and an HSK-A100 (13,000rev/min, 45kW, 228Nm SC (speed cutting) spindle). Two further spindles with an HSK-A63 interface are rated at 12,000rev/min, 45kW, 228Nm (PC) and 18,000rev/min, 45kW, 103Nm (SC). A view of the HF 3500 automatic tool change arrangement pictured right
To minimise non-productive times, Heller has succeeded in achieving a big reduction in run-up times for the new spindles, maximum revs now reached in 1.4sec for the HSK-A63 variants and 1.8sec for the HSK-A100.
All feature Heller’s Zero-Spindle system for rapid interchangeability, leading to maximum machine availability coupled with low service costs. It is noteworthy that all of the manufacturer’s compact spindles feature ease of servicing and integrated leakage checking to prevent damage.
A facing slide system for internal boring and external turning is available, with control of the requisite U-axis already integrated into the machine’s Siemens Sinumerik 840D SL control.
Heller4Industry functions are very much in evidence for enhancing production efficiency and for machine monitoring. The optional software suite is universally applicable from a single machine with or without a network connection, through multi-machine sites, to multi-site operations with cloud-base communication.
The standard umati (universal machine technology) interface enables machine and production data acquisition. Monitoring of potential collisions, energy consumption, axis wear, spindle condition and tool overload and breakage are all application options.