NC feeders, also known as servo feeders, are automated devices designed to achieve precise material feeding using advanced CNC systems. These systems typically include a PLC, a servo motor, and a servo driver, which drive the feed rollers through a synchronous pulley. NC feeders are primarily categorized into two types based on their relaxation mechanism: pneumatic NC feeders and mechanical NC feeders. While both types operate on similar feeding principles, they differ significantly in their relaxation actions.

Types of NC Feeders

Pneumatic NC Feeder

A pneumatic NC feeder connects to the press machine’s relaxation cam group. The press machine’s relaxation cam provides a signal to the feeder’s solenoid valve. This valve controls the relaxation cylinder to move the upper roller, achieving the relaxation action. Although this process is relatively slow, it doesn’t require additional auxiliary components, making it widely applicable across various settings.

Mechanical NC Feeder

In contrast, a mechanical NC feeder uses a relaxation lever device installed on the press machine’s slide block. As the slide block moves down, the lever presses the feeder’s relaxation bearing, causing the upper roller to relax. This type of feeder requires extra equipment on the press machine’s slide block, limiting its compatibility. However, it offers a fast relaxation action, ideal for high-speed, short-stroke processing environments.

Why Choose Pneumatic NC Feeders?

In the stamping industry, pneumatic NC feeders are often recommended as standard machines. They are easier to install and adjust, making them suitable for a broad range of applications. Many customers may not be familiar with mechanical NC feeders, although these might be better suited for high-speed, short-stroke stamping tasks.

Operational Guide for Mechanical NC Feeders

Starting the Front-End Machine

Typically, this involves starting a leveling machine or a material rack if leveling is not necessary. Allow the machine to slowly release the material.

Material Feeding and Thickness Adjustment

Lift the relaxation handle of the feeder and insert the material head between the upper and lower rollers. Allow the material to pass through the rollers, then lower the relaxation handle. Adjust the material thickness handle to ensure the relaxation bracket can swing with a 5mm gap. Secure the adjustment by tightening the fastening screw.

Adjusting Feeding Start Time

Set the feeding start time according to the stamping process requirements. This involves adjusting the feeding angle, corresponding to the crankshaft angle of the press machine at which feeding begins. Input the desired feeding time angle on the press machine’s touchscreen.

Adjusting the Feeder Relaxation Device

Adjust the feeder’s relaxation device based on the stamping process needs. When the mold’s guide pin inserts into the guide hole, adjust the relaxation screw until it touches the bearing on the feeder body. This should allow the upper roller to relax the material with a gap within 0.5mm. Secure the adjustment by locking the fixing nut.

Setting Basic Parameters

On the control panel of the electrical control box, set the feeding length and number of feeds. Adjust the feeding speed to match the actual production requirements.

Trial Stamping Using the Feeder Handle

Manually operate a single stroke in manual mode to confirm the actual feeding length, as there might be slight discrepancies due to rounding. Ensure the feeding length meets the requirements before proceeding to continuous stamping.

Starting Automatic Feeding

Once the trial confirms the correct feeding length, activate the feeder’s automatic function for continuous feeding and stamping production.


NC feeders, whether pneumatic or mechanical, play a crucial role in the efficiency and precision of stamping processes. Understanding the differences between these types and their specific operational requirements can help optimize production and ensure the best results for various applications. By following the detailed operational guide for mechanical NC feeders, users can maximize their equipment’s performance and enhance their stamping operations.

NC Feeder
NC Feeder