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SINUMERIK 840C

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Seond Hand Siemens SINUMERIK 840C for Sale cheap | Asset-Trade
Term Description

Buy & Sell Used Machine Tools with Siemens SINUMERIK 840C CNC Control

The Siemens SINUMERIK 840C was a pioneering technological milestone of the 1990s, forming the core computing platform for heavy-duty gantry mills, multi-slide turning centers, and production transfer lines prior to the introduction of the 840D. Featuring a distributed multiprocessor architecture, an integrated SIMATIC S5-155U PLC, and a PC-based Man-Machine Communication (MMC) system running MS-DOS/Windows, the 840C set new standards for multi-channel axis synchronization and system openness.

Typical Machine Applications & Heavy Builders

In the secondary market, the SINUMERIK 840C is predominantly found on robust, heavy-duty machinery with proven cast-iron longevity:

  • Gantry & Bed Milling Centers: Waldrich Siegen, Waldrich Coburg, Schiess, Droop & Rein, Dörries Scharmann.
  • Multi-Turret & Multi-Spindle Lathes: Index (G200, G300), Traub, Gildemeister TWIN and MF-Twin production lathes.
  • Heavy Machining Centers & Flexible Lines: Heller, Hüller Hille, Burkhardt + Weber in automotive and energy sectors.

Key Technical Specifications & Architecture

  • Axis Coordination: Capable of managing up to 30 axes and spindles distributed across up to 6 independent execution channels.
  • Drive System: Paired with modular SIMODRIVE 611A (analog) and early SIMODRIVE 611D (digital) servo drives.
  • Industrial Interfaces: Integrated hard drive and floppy drive storage, standard RS232 / V.24 DNC serial communication.

Inspection Checklist & Maintenance Best Practices

When evaluating a pre-owned machine tool running an 840C controller:

  1. Storage Media & Parameter Backups: Verify that recent disk image backups of the MMC unit and floppy disk archives of NCK/PLC parameters are complete. Retrofitting mechanical hard drives with solid-state CF or SSD modules is strongly recommended.
  2. Backup Batteries: Replace the lithium buffer batteries in NCK and PLC modules strictly while the machine is powered ON to prevent permanent parameter loss.
  3. TFT Display Retrofits: Aging 14-inch or 10-inch CRT cathode ray tube displays can be cost-effectively upgraded with bright, reliable drop-in LED/TFT conversion panels.

Heavy Machinery Inventory: Explore our Waldrich Coburg gantry mills and Index turn-mill centers equipped with 840C controls.

Lifecycle & Retrofit Advisory: Classic Industrial Control

Controllers from this era offer cast-iron electrical reliability. Operators and buyers should observe three essential operational practices:

  • Backup Battery Maintenance: The 3.6V lithium buffer battery retains all critical NCK/PLC parameters and zero offsets. Crucial: Always replace the battery while the control is powered ON to prevent catastrophic parameter loss!
  • Monitor & Memory Retrofits: Aging CRT cathode ray monitors can be upgraded with drop-in, energy-efficient LED/TFT conversion panels. Mechanical hard drives or floppy units can be updated with rugged solid-state CF/SSD adapters or USB DNC emulators.
  • Spare Parts Availability: Reconditioned modular drives, power supplies, and CPU boards remain widely accessible via certified industrial electronics specialists.

📄 Technical Documentation & PDF Manuals for SINUMERIK 840C

Download verified technical specifications, brochures, and programming guidelines:

Note for Service Technicians & CNC Programmers: Inquiring about wiring schematics, parameter manuals, or PLC backup archives? Contact our engineering team.

Selling a Machine Tool with Siemens 840C or Liquidating Industrial Assets?

Asset-Trade directly purchases heavy milling machines, horizontal borers, and CNC turning centers with SINUMERIK 840C controls. We provide professional equipment appraisals, rapid payment, and turnkey heavy-rigging dismantling. Contact Asset-Trade today for your free valuation and direct purchase offer.

Machine Filter

Product Type

Make

Year

Control

Location

Machine Information
Manufacturer: INDEX
Model: GU 800
Control: CNC > SIEMENS > SINUMERIK 840C
Year of build: 2001
Location:
Used INDEX GU 800 lathe with C-axis for sale The used INDEX CNC lathe GU 800 is ideal for companies looking for a high-precision CNC lathe for precision machining. This machine was completely overhauled in 2010, including the geometry… Learn more
Machine Information
Manufacturer: DMG GILDEMEISTER
Model: CTV 250
Control: CNC > SIEMENS > SINUMERIK 840C
Year of build: 2001
Location:
Used DMG Gildemeister CTV 250 - Vertical CNC Lathe CNC Controlc SIEMENS 840C Technical Data Max diameter: 250 mm Strocke X x Z : 800 x 300 mm spindle power : 22 kW spindle speed : 20 - 5000 tr/min Turret : 12 posts all driven… Learn more
Machine Information
Manufacturer: MONFORTS
Model: DNC 5
Control: CNC > SIEMENS > SINUMERIK 840C
Year of build: 2001
Location:
Used MONFORTS DNC 5 CNC lathe with Promot Cellmaster loader 2x Machines Available Extensive Spare parts kit available New price approx. 50,000 Euros Technical specifications Control: Siemens Type: 840 C Rotating diameter: 520 mm… Learn more
Machine Information
Manufacturer: GLEASON PFAUTER
Model: G 320
Control: CNC > SIEMENS > SINUMERIK 840C
Year of build: 1996
Location:
Used GLEASON- PFAUTER G 320 - Gear grinding machine with numerical control Specifications: Siemens control 840 Modulus of 0.5 to 7 Workpiece diameter 10-330 mm Number of teeth 10-600 Speed ​​: 2300 U / min X horizontal grinding wheel… Learn more

Frequently Asked Questions about used SINUMERIK 840C

What is the spare parts availability for the Siemens SINUMERIK 840C today?

Although the 840C has reached end-of-lifecycle from Siemens, a thriving market of certified electronics repairers stocks refurbished NCU boards, SIMODRIVE 611 modules, power supplies, and monitors, allowing cost-effective maintenance.

Can a SINUMERIK 840C CRT monitor be upgraded to modern LCD/TFT?

Yes. Direct drop-in plug-and-play LED/TFT conversion monitors are readily available, matching the exact mechanical dimensions and electrical RGB/EGA video timings of the original CRT monitors.

How are NC programs transferred to the SINUMERIK 840C?

Programs are traditionally transferred via the RS232 / V.24 serial interface connected to a DNC system, or via the onboard 3.5-inch floppy drive. Modern USB floppy emulators and Ethernet bridge modules can also be retrofitted.

Does Asset-Trade purchase machines with 840C controllers directly?

Yes. Asset-Trade acquires second-hand heavy machine tools, boring mills, and multi-axis lathes running SINUMERIK 840C controls directly, providing turnkey decommissioning, heavy crane rigging, and logistics.