Waddington Electronics Inc.

office 800-688-2645 - 417-864-3636
fax 417-864-3667


Tech Brief:

PRF Servo Feeds

Waddington Electronics has delivered industrial control systems and, specifically, computer-driven servo systems to the machine tool and metal stamping industries for over 54 years.


We have experience with all types of electric, hydraulic, air and electronic servo systems and have implemented them across a variety of applications.


Some milestones along the way include: A 16-spindle deep-hole drilling machine that makes transmission shafts for Chevrolet, 5-axis CNC deep-hole drilling machines for making transmission parts for the NATO tank, 3-axis CNC gear-cutting machinery for cutting gears as large as 72 inches in diameter, and a 5-axis CNC gear hobber that, at the time, had never been produced in the United States. And now the best servo driven roll feeds ever built.


The design of the PRF series of servo-driven roll feeds is based on the cumulative knowledge and experience gained in our 54-year history.

Feed body design is based on a heavy-duty feed frame that is dowel-pinned after alignment, adding strength to the frame and preventing the frame from ever going out of alignment. All bearings are ball type and require no lubrication.

Very low inertia feed rolls and a variety of zero backlash power train designs allow proper selection of feed power and speed characteristics to match the most demanding applications. The brushless servo system allows for extremely high indexing rates; and, zero backlash between the motor and the feed rolls allows very high servo system gain, resulting in exceptional stock positioning accuracy.

Zero Backlash Drive Train

The ZERO BACKLASH direct-coupled drive train approach of the direct drive machines has proven itself in hundreds of applications and is free of the shortcoming's which plague servo systems that include gears in the drive train. Gear sets must have some backlash when factory new and only get worse as they wear.

The Belt Driven drive train of the SF, LD, LC, and HD Series feeds offers increased pulling power and a compact overall design.

Zero Maintenance

The zero maintenance philosophy applied to all Waddington feeds dictates the use of high reliability brushless motors, tachometers, and position feed- back devices. Additionally, the high mechanical shock encountered in the punch press environment mandates the use of only the most rugged feedback devices.

High-performance Brushless Servo motors eliminate the problems associated with brush arcing and commutator wear during the high rates of acceleration required for press feeding. Brushless design is what makes PRF motors truly maintenance-free.

Optimum efficiency of the servo system is not obtained by sacrificing positioning performance with the inherent inaccuracy of gear reduction, but by the proper selection of motor characteristics and feed body style.

Position Feedback Devices

Position feedback devices are perhaps the single most important device in the servo system.

Roll Gears

All Waddington feeding machines have gears between the top and bottom rolls. This approach greatly increases stock gripping force and prevents stock slippage during acceleration and deceleration of the feed rolls. Also, the PRF gear set allows consistent accuracy across the full thickness rating of the feed with no adjustment.

Variety of Pilot Release Options

One of the most important aspects in feeding progressive dies is the need to release the feed rolls during the piloting portion of the press stroke. We offer a variety of pilot release options including our striker bar, high-speed air, belt-driven cam and super-speed servo-driven release mechanisms. Our high-speed air pilot release can operate up to 300 spm on some models and generally up to 250 strokes per minute on all models. The servo-driven pilot release operates up to 1800 spm.

Flexibility for Changing Needs

PRF Feeds come with feed advisor to precisly calculate optiomal acceleration rates that cover a variety of applications. To remain flexible in the face of changing customer needs, acceleration rates can be changed in the field to meet those needs, ensuring the feed you buy today will meet the needs of tomorrow.


Waddington Electronics stands confident in our ability to deliver the highest quality roll feeds on the market and we back all our roll feed products with a

2 year warranty!