ONA RX7

$250,000 - $400,000 Updated 2026-03-16

Key Specifications

X Travel

700 mm (27.6 in)

Y Travel

500 mm (19.7 in)

Z Travel

400 mm (15.7 in)

max workpiece size

1,100 x 850 x 400 mm (43.3 x 33.5 x 15.7 in)

max workpiece weight

1,500 kg (3,307 lb)

positioning repeatability

1 um

Overview

The ONA RX7 is ONA Electroerosion's high-speed sinker EDM, featuring linear motor drives on all axes for dramatically faster electrode movement and superior surface quality compared to conventional ballscrew-driven sinker EDMs. Developed at ONA's engineering center in Durango, Spain, the RX7 represents the upper tier of the company's sinker EDM range, targeting demanding aerospace, automotive stamping, and precision mold applications where cycle time and repeatability are mission-critical.

Linear motors eliminate the mechanical compliance and backlash associated with ballscrew drives, enabling the RX7's axes to respond to generator discharge commands with microsecond precision. This tight coupling between the generator and the drive system produces a more stable arc gap during burning, which translates to higher material removal rates at equivalent surface finish targets compared to conventional architectures. ONA rates the RX7 at 30-40% higher material removal rates versus ballscrew-equipped machines in the same generator power class. Positioning repeatability is specified at 1 um, supported by linear glass scale encoders on all axes.

The RX7's working envelope covers 700 x 500 x 400 mm (X/Y/Z), accepting workpieces up to 1,100 x 850 x 400 mm and weighing up to 1,500 kg. This range covers large progressive die shoes, multi-cavity injection mold bases, and aerospace structural tooling components. The machine uses ONA's iDos Pro generator platform, which includes expanded pulse shape libraries and real-time arc stability monitoring with automatic discharge energy adjustment. A 500-position electrode magazine is available, enabling fully automated 24/7 operation in cell environments.

The control is ONA's latest CNC generation with a 21-inch HD touchscreen, integrated CAM import (IGES, STEP, DXF), and remote monitoring via ONA's machine connectivity platform. Thermal compensation uses a network of temperature sensors throughout the machine structure with real-time geometric correction. The dielectric system features automatic conductivity control and fine filtration to 5 microns, maintaining consistent dielectric quality across long unattended runs.

Full Specifications

Parameter	Value
X-Axis Travel	700 mm (27.6 in)
Y-Axis Travel	500 mm (19.7 in)
Z-Axis Travel	400 mm (15.7 in)
Max Workpiece Size	1,100 x 850 x 400 mm (43.3 x 33.5 x 15.7 in)
Max Workpiece Weight	1,500 kg (3,307 lb)
Positioning Repeatability	1 um
Surface Finish	Ra 0.08 um (3 uin) achievable
Drive System	Linear motors, all axes
Encoder System	Linear glass scale encoders, all axes
Generator	ONA iDos Pro digital generator with real-time arc stability control
Electrode Changer	Up to 500 positions (optional)
Dielectric	Oil with automatic conductivity control, 5-micron filtration
CNC Control	ONA latest-generation CNC, 21-inch HD touchscreen
Connectivity	ONA machine connectivity platform (remote monitoring)
Machine Weight	8,500 kg (18,739 lb)
Machine Dimensions	3,200 x 2,800 x 2,500 mm (126 x 110 x 98 in)

Strengths & Limitations

Strengths

Linear motor drives on all axes eliminate ballscrew backlash, delivering 30-40% higher material removal rates at equivalent surface finish versus conventional sinker EDMs
1 um positioning repeatability with linear glass scale encoders meets the tolerance requirements of aerospace and precision die work
Surface finish capability to Ra 0.08 um covers mirror-finish requirements in plastic injection mold cavities
Up to 500-position electrode magazine enables fully automated multi-electrode cell operation with no operator intervention
1,500 kg workpiece capacity handles large progressive die shoes and multi-cavity mold bases
Real-time arc stability monitoring with automatic discharge energy adjustment maintains process consistency during long unattended burns

Limitations

Linear motor system adds significant cost over ballscrew-equipped sinker EDMs — price premium versus the ONA AX3 is substantial
ONA brand recognition in North America remains lower than Sodick (which pioneered linear motor sinker EDMs) or Makino
Complexity of the linear motor drive and iDos Pro generator requires skilled technicians for maintenance and troubleshooting
Service coverage outside Spain and major European markets may involve longer response times for field service
Large machine footprint and weight require substantial foundation preparation and overhead clearance

Best For

Aerospace tooling and precision die shops where cycle time reduction and 1 um repeatability are worth the premium investment High-production automotive stamping die manufacturers burning large multi-cavity die sections with multiple electrode changes Mold shops producing optical-quality or mirror-finish cavities requiring Ra 0.08 um or better surface finishes Facilities running 24/7 lights-out EDM cells with 500-electrode magazines and remote monitoring Large mold and die manufacturers in Europe and South America with established ONA service relationships

Frequently Asked Questions

01 Why choose linear motors for sinker EDM?

Linear motors eliminate the mechanical compliance, backlash, and wear of ballscrew drives. In sinker EDM, the electrode must retract and advance thousands of times per minute in response to discharge conditions. Linear motors respond to these commands in microseconds rather than milliseconds, producing a more stable arc gap and higher material removal rates at the same surface finish target. Sodick pioneered this approach, and ONA's RX7 applies the same principle.

02 What is the ONA RX7 price?

The ONA RX7 typically prices between $250,000 and $400,000 new, depending on the electrode changer configuration and optional accessories. The significant price premium over conventional sinker EDMs is justified by higher throughput and tighter tolerances in demanding applications.

03 How does the RX7 compare to a Sodick sinker EDM with linear motors?

Both ONA's RX7 and Sodick's linear motor sinker EDMs use the same fundamental drive technology. The differences lie in generator design, control software, and tooling ecosystems. Sodick has a larger North American installed base and denser service network. ONA's RX7 is competitive on specifications and offers a European design alternative at similar or slightly lower price points.

04 Can the RX7 operate fully unattended?

Yes. With the 500-position electrode magazine, the RX7 can execute complex multi-electrode burn sequences entirely without operator intervention. ONA's connectivity platform allows remote monitoring of process status, alarms, and completion notifications from any internet-connected device.

05 What workpiece materials does the ONA RX7 handle?

The RX7 handles all electrically conductive materials including tool steels (H13, D2, P20, S7, M2), hardened stainless steels, tungsten carbide, titanium alloys, nickel superalloys (Inconel, Waspaloy), copper alloys, and PCD. The iDos Pro generator includes pre-tested parameter sets for each material class.