Technical Evaluation of the Stama MC 734 MT-G

CNC 6-Axis Turning-Milling Center (Year 2013)

1. Technical Evaluation Overview

The Stama MC 734 MT-G is a 6-axis turning-milling center manufactured in 2013, designed for complete machining on multiple sides within a single setup. The machine is described as fully functional and configured with both a main spindle and a counter spindle, each integrated with a swiveling rotary table, enabling complex, synchronized machining operations.
The system includes an HSK63 milling spindle rated at 10,000 rpm and a 120-position tool magazine, supporting high tool availability for multi-operation cycles. A short bar loader (IRCO ILS MUK) and a hinged belt chip conveyor are installed, indicating suitability for automated or semi-automated production environments.
Reported operating hours are 33,520 hours runtime with 22,595 hours of axis motion, which provides a useful indicator of mechanical utilization, though duty cycle and load intensity are not specified.

2. What to Check Before Buying

Given the machine’s complexity and operating hours, inspection should prioritize spindle condition and kinematic accuracy. Both the main spindle and counter spindle should be evaluated for bearing noise, runout, and thermal behavior. The swiveling rotary tables require verification of indexing accuracy, clamping rigidity, and backlash under load, as these directly affect multi-axis precision.
The HSK63 milling spindle should be tested across its speed range to confirm vibration levels and tool interface condition. Tool change reliability within the 120-station magazine should be verified, including tool recognition and transfer mechanisms.
The bar loader should be tested for feeding consistency and synchronization with the main spindle. Clamping devices—Hainbuch SK80 Axzug and Axfix systems—should be inspected for wear, concentricity, and compatibility with intended workpieces. Auxiliary systems such as the high-pressure coolant system with cooler and chip conveyor should be run under operating conditions.

3. Typical Industrial Applications

Based strictly on the stated configuration, this machine is suited for complete machining of complex rotational and prismatic components requiring turning, milling, drilling, and multi-side access in one cycle. Typical applications include automotive, powertrain, hydraulic, and general mechanical components where reduced setups and high positional accuracy are required. Use beyond the verified spindle speeds, tool interface, or clamping capacity should not be assumed.

4. Common Risks in Used Machines

Common risks for used multi-function turning-milling centers include wear in rotary/swivel axes, spindle bearing fatigue, and reduced accuracy due to cumulative kinematic tolerances. High tool counts introduce potential issues with magazine wear and tool change reliability. Automation components such as bar loaders may exhibit mechanical or control wear if maintenance has been inconsistent.

5. Maintenance and Service Considerations

Maintenance needs depend on actual service history, which is not detailed. Regular attention should be given to spindle lubrication and cooling, rotary axis clamping systems, tool changer mechanisms, and high-pressure coolant filtration. Given the machine’s axis hours, verification of preventive maintenance records and geometry checks is advisable. Long-term service planning should also consider availability of Stama-specific spare parts and technical support for spindle, rotary table, and automation components.

Final Note:
While configuration, operating hours, and major equipment are clearly stated, critical information—such as CNC control type, axis travel limits, spindle power, accuracy specifications, and detailed maintenance history—is important. These elements should be verified through documentation review and on-machine testing before forming final technical conclusions.