Working principle of crowning axis of press brake

What's Crowning Axis?

During the processing of the bending machine, especially when bending long lengths, thick plates or high-strength materials, the middle part is prone to inconsistent bending angles due to "upper or lower die deflection (bending deformation)" —— that is, the angles on both sides are normal, and the middle angle is too large (angle open).
In order to solve this problem, the "Crowning Axis" was designed to automatically or manually adjust the deformation of the middle part of the workbench to ensure consistent bending angles.

Common types of crowning axis

1. Manual Mechanical Crowning

✅ Features:

Manually adjust the compensation amount (usually with a wrench or handwheel);

The structure is a wedge-type, generally just a whole row of inclined irons, thick in the middle and thin at both ends;

No motor or CNC system is involved.

✅ Structural composition:

Fixed base, movable inclined block, adjustment screw or handwheel

✅ Working principle:

Manually rotate the handwheel, move the inclined block, raise the middle of the lower die workbench, and manually set the compensation amount for different plate thickness/lengths.

✅ Advantages:

Low cost;

Low failure rate and simple maintenance;

Suitable for small factories or scenarios where only one type of plate is processed.

❌ Disadvantages:

The operation depends on experience and is not friendly to novices;

The accuracy is not high, and the angle consistency is easily affected by human factors;

It cannot automatically adapt to different processes, and it must be readjusted every time the plate thickness is changed.

2. Automatic Mechanical Crowning

✅ Features:

Controlled by the CNC system, the compensation value is automatically set;

Most of them use a servo motor + screw drive structure to drive the wedge group;

The accuracy and consistency are much higher than the manual type.

✅ Structural composition:

Fixed wedge group, mobile wedge group, motor + screw or rack structure, position feedback system (encoder)

✅ Working principle:

The CNC system (such as EASYCAT、DELEM、ESA、CYBELEC, etc.) automatically calculates the deflection according to the input plate thickness, mold, length, etc.;

Automatically issues instructions to control the motor to move the wedge;

Achieve compensation deformation in the middle area and accurately offset the deflection.

✅ Advantages:

Automatic compensation to improve efficiency;

Cooperate with program switching, the angle is always consistent;

Not dependent on operator experience, suitable for multi-variety and multi-batch production.

❌ Disadvantages:

The cost is slightly higher;

The maintenance requirements for motors and screws are higher.

Summary comparison table