Suitable Workpieces for Fixed-beam CNC Lathes

Fixed beam CNC lathe (fixed beam structure) is especially suitable for processing the following types of workpieces due to its strong structural rigidity and good stability:

1. Large-size and heavy workpieces

Typical workpieces: large shafts, discs, flanges, hubs, turbine rotors, etc.

Advantage: fixed beam structure without moving beam, strong load bearing capacity, can stably support large weight workpiece, avoid vibration or deformation caused by inertia of moving parts.

2. Workpieces with high precision requirements

Typical workpieces: precision gear blanks, aerospace parts (e.g. engine casing), hydraulic valve bodies, high-precision moulds, etc.

Advantage: high bed rigidity, low thermal deformation, suitable for processing with tight tolerance requirements (IT6-IT7 grade) and low surface roughness (below Ra1.6).

3. Complex contour or shaped parts

Typical workpieces: cams, crankshafts, turbine blades, non-circular cross-section parts, etc.

Advantage: with multi-axis linkage (e.g. C-axis, Y-axis) and power turret, it can complete mill-turn compound machining and realise complex geometry in one clamping.

4. Rotary body with moderate L/D ratio

Typical workpieces: short and thick shafts, sleeves, short pipe fittings (L/D ratio <5).

Note: Extremely long and thin shafts (e.g. L/D ratio >10) may need to be equipped with tailstock or tool holder, and the Z-axis travel of the fixed beam lathe should be matched with the length of the workpiece.

5. Difficult-to-machine materials

Typical workpieces: high-temperature alloys (e.g. Inconel), titanium alloys, hardened steel (HRC50+), etc.

Advantage: High rigidity structure can withstand large cutting force, suitable for low-speed heavy cutting or intermittent cutting.

Types of workpieces that are not suitable

Extra-long workpieces: limited by the lateral space of the machine (the fixed beam cannot be moved).

Miniature parts requiring frequent tool changes: may not be as efficient as a magazine type lathe if tool positions are limited.

Large quantities of simple parts: may not be as economical as slant-bed or palletised CNC lathes.

Selection Advice

Fixed Beam vs Moving Beam: Moving beam CNC lathes (moving beam) are more suitable for scenarios where the height of the workpiece varies a lot (e.g. large vertical lathes), while fixed beams are more suitable for stable heavy cutting.

Extended function: If the workpiece needs milling, drilling, etc., choose the model with power turret or B-axis model compound model.

The core advantage of fixed-beam CNC lathe is its rigidity, so it is outstanding in the field of heavy-duty, high-precision or difficult-to-machine materials, but it is necessary to match the machine travelling and function configuration according to the specific size of the workpiece and process requirements.

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