Estun E21

Estun E21 press brake controller: Precision & Reliability for Press Brake

The CNC press brake retrofit E21 focuses on the core essentials: speed, accuracy, and ease of use. It provides a cost-effective solution for shops requiring consistent repeatability without the steep learning curve of high-end software.

all the key buttons are micro switches. It has passed through the EMC, high temperature, and vibration testing, which make sure stable and long usage life for overseas markets.

 

Estun E21 Feathers: Download the E21 Operation Manual Guide

• CNC Press brake Back gauge retrofit control
• Control the common motor or inverter
• Intelligent positioning
• Holding pressure unloading time setting
• Workpiece counting
• 40 programs stored, 25 steps per program
• Unilateral positioning
• Concession function
• One-key backup/restore
• mm / inch
• Chinese / English

 

 

Core Technical Capabilities of the E21

The strength of the E21 lies in its dedicated positioning control. By managing the X and Y axes, it ensures that your flange length and bending angle remain precise across thousands of cycles.

• Intelligent Positioning: Controls the backgauge (X-axis) and the stroke (Y-axis) with a high-resolution encoder system.
• Program Memory: Stores up to 40 programs, with each program supporting up to 25 steps—ideal for multi-bend components.
• Retraction Function: Automatically retracts the backgauge fingers during the bending cycle to avoid material interference, preserving the life of your tooling.
• One-Key Backup: Simplifies parameter recovery, ensuring your machine stays online even after a system reset.

 

 

How to Set the Retract Function (DX & DLY）

On the programming page (either Single-step or Multi-step), use the arrow keys to locate these two specific fields:

1. DX (Retract Distance)

What it is: The physical distance (in mm) the backgauge moves away from the sheet after the punch makes contact.

1）How to set it: * Navigate to the DX field.

2）Input a value—typically 10mm to 50mm depending on the length of your flange.

Pro Tip: If you are bending a very long flange that “swings” upward significantly, a larger DX value ensures the backgauge is completely out of the “collision zone.”

 

2. DLY (Retract Delay Time)

What it is: The time (in seconds) the controller waits before initiating the retract movement.

1）How to set it: * Navigate to the DLY field.

2）Input a value—usually 0.1s to 0.5s.

Why it matters: If the backgauge retracts too early (before the punch pinches the metal), the sheet might slide, ruining your precision. If it retracts too late, the sheet will hit the fingers as it bends.

 

 

3.The Step-by-Step Programming 

1）Pinpoint the Pinch Point: The Y-axis (the ram) moves down.

2）Trigger the DLY: As the Y-axis reaches the point where the metal is held tight, the DLY timer begins.

3）Execute the DX: Once the delay time ends, the X-axis (backgauge) moves backward by the DX amount.

4）Complete the Bend: The ram continues to the bottom of the stroke while the backgauge is safely tucked away.

 

While the E21 requires manual input for retract parameters like DX and DLY, higher-end models simplify this process significantly. Let’s look at how the E21 compares to the CNC-level E200 and E300 series.

 

Technical Comparison: Estun E21 vs. E200 vs. E300

1. Estun E21: The Simple NC Specialist
The E21 is designed for shops that need to move away from manual handwheels but don’t require complex multi-step automation.

• Control Type: Simple positioning. It sends signals to move to a coordinate and stops.
• Axis Control: Primarily X (Backgauge) and Y (Stroke/Depth).
• Key Limitation: It does not support servo-drive bus communication (like CANbus). It usually pairs with frequency inverters.
• Best For: Simple 90-degree bends, high-volume single-step parts, and budget-friendly retrofits.

 

2. Estun E200 Series: Entry-Level CNC

The E200 (and E210) is a significant step up because it introduces Servo Control and a much larger program library.

• Servo Integration: Specifically designed to work with servo motors for much higher positioning speeds and precision (+- 0.01mm).
• Axis Control: Typically handles X and Y, but with much smoother motion profiles.
• Features: Includes a built-in angle calculation function (you input the angle, and the controller calculates the depth) and a larger LCD screen for better data visualization.
• Best For: Precision sheet metal shops that need faster cycle times and more frequent program changes.

 

3. Estun E300 Series: Full CNC Multi-Axis Control
The E300 is a complete CNC solution. It moves beyond simple “up and down” movements into complex multi-axis synchronization.

• Axis Capacity: Can control up to 4+1 axes (X, Y, R, Z1, Z2 + Crowning).
• Graphical Interface: Often features a much more modern interface that can display the bending sequence.
• Crowning Control: Automatically manages the hydraulic or mechanical crowning system to ensure the bend is consistent across the entire length of the sheet.
• Programming: Supports more complex “workpiece” logic where the controller manages the entire sequence of a multi-bend box or cabinet automatically.
• Best For: Complex fabrication, high-precision stainless steel work, and heavy-duty machines where “R-axis” (height) and “Crowning” are essential for quality.

Feature	Estun E21 (NC)	Estun E200 (CNC)	Estun E300 (Advanced CNC)
Control Concept	Simple Positioning (PTP)	Intelligent Servo Logic	Multi-Axis Bus Control
Primary Motion	X, Y Axes	X, Y Axes (High Speed)	X, Y, R, Z1, Z2 Axes
Drive Interface	Frequency Inverter (AC)	Servo Drive (Pulse)	CANbus / Servo System
Angle Calculation	Manual: Input depth value	Auto: Input angle & thickness	Advanced: Full sequence logic
Crowning Control	Not Supported	Manual / Basic	Automatic (Hydraulic/Mech)
Program Storage	40 Programs / 25 Steps	100 Programs / 40 Steps	200+ Programs / 40+ Steps
Positioning Accuracy	+- 0.1 mm	+- 0.02 mm	+-0.01  mm
Display Type	Monochrome LCD	Large HD LCD	Industrial Graphic Screen
Typical Machine	Torsion Bar Press Brake	Precision Bending Machine	High-End Syncro Press Brake