Fixed Beam Gantry VS Vertically Moving Beam Gantry

Core Structure

The beam is fixed to the two columns and   cannot move vertically. Z-axis motion is achieved by the spindle ram.

The beam and the two columns form an   integrated structure, allowing the entire beam to move significantly along   the column guides in the Z-direction.

Motion Method

- X-axis: Spindle head moves along the   beam
  - Y-axis: Worktable moves
  - Z-axis: Spindle ram moves

- X-axis: Spindle head moves along the   beam
  - Y-axis: Worktable moves
  - Z-axis: The entire beam moves, carrying the spindle head along

Rigidity/Stability

Excellent. Since the beam is fixed, the   structural rigidity of the entire gantry framework is very high, minimizing   vibration and deformation.

Good. However, the beam lifting mechanism   introduces additional connection points, theoretically making the overall   rigidity slightly lower than that of a fixed beam structure of the same   specifications.

Machining Precision

Typically higher. High rigidity ensures   excellent dynamic stability, maintaining higher precision, especially during   heavy cutting.

Precision is also very good, but the   lifting motion of the large beam component requires high control standards   and may be slightly affected by factors such as thermal deformation.

Load Capacity

Strong. The worktable directly carries   the workpiece, typically offering high load capacity (ranging from several   tons to hundreds of tons).

Very strong. The load capacity is equally   impressive, and the movable beam makes it easier to hoist oversized and   ultra-heavy workpieces.

Pros and Cons

Pros:
  1. Best rigidity, suitable for heavy cutting and high-precision machining.
  2. Simple structure, high reliability, and relatively easy maintenance.
  3. Generally lower cost.
 
  Cons:
  1. Machining height (Z-axis travel) is limited by the length of the spindle   ram and is fixed.
  2. During tool changes, the spindle head may be positioned very high, making   tool replacement inconvenient.

Pros:
  1. Extremely large Z-axis travel, capable of machining very tall workpieces.
  2. The spindle head always remains at the optimal working height,   facilitating convenient tool changes (fixed tool change point).
  3. Excellent accessibility, making it easy to clamp oversized workpieces.
 
  Cons:
  1. Slightly lower overall rigidity.
  2. More complex structure, resulting in higher manufacturing and maintenance   costs.
  3. The large inertia of the moving beam demands higher requirements for the   drive system, potentially resulting in slightly slower acceleration.