When a press is running, every part of the system has to work in sync. One piece that often gets overlooked is the feeder. The feeder is the part that moves the strip or sheet into the die so it can be stamped.
A reliable feeder can mean smoother jobs, better quality parts, and fewer stops. An unreliable one can lead to wasted material and lost time. That’s why many shops look closely at their choice between an air feeder and a servo roll feeder.
Before we compare them head-to-head, it helps to understand how each works and why the decision can have a big impact.
What Is an Air Feeder?
An air feeder uses compressed air to move metal strips or sheets into a press. It works with cylinders that grip and push the material forward. This design has been around for a long time because it’s simple, sturdy, and easy to add to many presses.
Here are the basics:
- Operation: A cylinder powered by air clamps onto the strip, moves it forward, and then releases it. Another clamp holds the strip steady between movements.
- Control: The length of each feed is set by adjusting stops or by setting the stroke length.
- Setup: It’s quick to mount on a press, and many shops like that it can be used with a range of tools.
Key Benefits
- Low cost: Air feeders are usually less expensive than servo systems.
- Simple upkeep: With fewer moving parts, there’s less that can break. Regular checks on seals and valves, plus clean, dry air, are usually enough.
- Flexibility: They can be used for short or medium-length feeds and handle many kinds of jobs.
Limits to Know
- Accuracy: Air pressure can vary, which affects repeatability. For very tight jobs, this can be a problem.
- Speed: They can’t match the high strokes per minute possible with a servo.
- Air use: Since they rely on compressed air, leaks or weak pressure can drive up costs and cause downtime.
You may also hear about different feeder names. A pneumatic feeder is the same general idea—it uses air to drive the motion. A rapid air feeder is a popular brand model in this category.
Even a rotary airlock feeder, though often used in bulk material handling, still works on the same air-powered principle. These examples show how the term “air feeder” covers a broad group of designs.
What Is a Servo Roll Feeder?
A servo roll feeder uses electric motors and rolls to pull the strip into the press. Instead of air cylinders, it relies on a servo motor that gives very precise control over how far and how fast the material moves. Many newer stamping lines use this style because it works well with modern dies and faster presses.
Here’s how it works:
- Operation: A pair of rolls clamp the strip. The servo motor turns the rolls forward for the set distance. The rolls then release when the die closes and reset for the next stroke.
- Control: Feed lengths, speeds, and timing are set through a control panel. Programs can be saved and reused.
- Setup: Once installed, operators can change between jobs quickly by loading the right settings.
Key Benefits
- Accuracy: A servo system can hold tolerances as tight as ±0.02 mm. That’s far more repeatable than air-driven motion.
- Speed: They can handle very high strokes per minute while staying on time with the press.
- Flexibility: Different lengths and speeds can be programmed without mechanical changes. This helps shops that run many part types.
Limits to Know
- Up-front cost: A servo roll feed usually costs more to buy than an air unit.
- Maintenance: While less air is needed, servo systems have motors, belts, encoders, and software that require care.
- Complexity: Operators may need more training to use all features.
Some shops may refer to these units as a servo feeder for press. That term highlights that the servo system is designed to work in sync with the stamping press. No matter the name, the advantage is the same: higher precision, better speed, and more control over the process.
Why the Right Feeder Choice Matters
The feeder you choose can shape how well your press runs day after day. It affects quality, output, and even how much money you spend to keep jobs going.
Here’s why it matters:
- Accuracy and Scrap: If parts need tight tolerances, a servo feeder can save material by reducing errors. If parts are more forgiving, an air feeder may be enough.
- Speed and Output: Shops aiming for high production runs may need the faster feed windows of a servo system. For smaller jobs or slower lines, an air feeder can keep up.
- Upkeep and Downtime: Air feeders are simple but depend on a strong air supply. Servo units need more technical care but offer fewer surprises if maintained well.
- Cost Over Time: Buying price is only part of the story. Compressed air can be expensive to run, while servo systems can pay for themselves through higher accuracy and reduced scrap.
Making the choice comes down to your shop’s needs. If you run many jobs with different lengths, a servo will likely pay off. If you want a lower starting cost and run simpler dies, an air feeder may be the smarter call.
Air Feeder vs Servo Roll Feeder: Which One Fits Your Needs?
Choosing between an air feeder and a servo roll feeder is not always simple. Each type has strengths that make it better for certain jobs. To make a smart choice, it helps to look at four areas: accuracy, speed, upkeep, and total cost. These points will show you how the two feeders compare in real shop conditions.
Comparison Table: Air Feeder vs Servo Roll Feeder
| Factor | Air Feeder | Servo Roll Feeder |
| Accuracy | Uses air cylinders to grip and push the strip. Accuracy depends on air pressure and seal condition. Works fine for general jobs but can drift on close-tolerance parts. | Uses servo motors with feedback controls for very precise movement. Can hold tolerances to ±0.02 mm. Ideal for jobs that demand consistent accuracy. |
| Speed | Handles low-to-medium press speeds. Stop-and-go motion of cylinders limits very high strokes per minute. | Handles high-speed presses with ease. Programmable acceleration and deceleration allow smooth feeding even at 1,000+ SPM in advanced models. |
| Upkeep | Needs clean, dry compressed air. Regular checks for leaks, seals, and valves. Simple design makes repairs easy. | Requires care of motors, belts, encoders, and software. Needs more technical knowledge but built for long-term reliability. |
| Energy Use | Relies on compressed air, which is costly to produce. Small leaks can waste thousands in electricity each year. | Runs on electricity only. More efficient in long-term use, especially in high-production shops. |
| Cost (Up-Front) | Lower purchase price. Popular for budget-conscious shops and simpler jobs. Brands like rapid air feeder are widely used. | Higher purchase price. Investment pays off with accuracy, flexibility, and reduced scrap over time. |
| Flexibility | Feed length adjusted with mechanical stops or stroke length. Good for repeat jobs with little change. | Programs stored and reused for quick changeovers. Different feed lengths and speeds set with the control panel. |
| Best Fit | Great for shops running simpler dies, moderate speeds, and jobs with loose tolerances. A pneumatic feeder is easy to add to many presses. | Best for shops needing tight tolerances, high speeds, or many job changes. A servo feeder for press gives the control needed for modern die work. |
Accuracy
Accuracy means how close each feed is to the exact length needed. It also means how steady that accuracy stays over many strokes.
- Air feeder accuracy: An air-driven system uses pressure to push or pull the strip. That means results can change if air pressure drops or if seals wear. For simple jobs with loose tolerances, the accuracy is often good enough. But for close-tolerance jobs, small changes in feed length can add up.
- Servo roll feeder accuracy: A servo uses an electric motor with feedback controls. That gives very precise movement. Many servo systems can hold to within ±0.02 mm. Some high-end designs go even tighter. If your parts need exact spacing, a servo roll feed will keep you in range stroke after stroke.
Summary: For general jobs, an air feeder works fine. For precision parts, a servo is the clear winner.
Speed
Speed is about how many strokes per minute (SPM) a feeder can handle while staying accurate.
- Air feeder speed: Air systems can move strips quickly, but they struggle at very high SPM. The stop-and-go action of air cylinders creates limits. They are best for low-to-medium press speeds.
- Servo roll feeder speed: Servo systems can run at high SPM and keep accuracy. They can also change acceleration and deceleration to match the press cycle. That makes them better for presses that run fast or use progressive dies.
Summary: For short runs or slower presses, air is fine. For high-output lines, a servo is built for speed.
Upkeep
Keeping feeders in good shape is key to avoiding downtime. Each feeder type has different needs.
- Air feeder upkeep: The biggest factor is air quality. Moisture, dirt, or oil in the lines can wear out seals and valves. Regular checks of regulators, hoses, and fittings help. Air leaks are common, and even small leaks can waste energy and cause weak strokes. Still, the design is simple, and many repairs are low-cost. A pneumatic feeder is known for being easy to maintain if air is clean and dry.
- Servo roll feeder upkeep: Servos do not rely on compressed air, but they have motors, encoders, belts, and software. These parts need more technical care. Rolls must stay clean and set to the right pressure. Software backups are also a smart habit. While upkeep may take skilled work, the systems are built for long-term use with fewer surprise failures.
Summary: Air feeders are simple but depend heavily on air quality. Servos are more complex but steady when maintained.
Total Cost
Cost is more than the purchase price. Energy use, downtime, scrap, and repair all add up.
- Air feeder cost: These units cost less up front. But they rely on compressed air, which is one of the most expensive energy sources in many shops. Air leaks are common, and they can waste thousands of dollars each year. Still, for shops with lower budgets or simpler jobs, the lower first cost can be attractive. Many models, such as the rapid air feeder, are popular for this reason.
- Servo roll feeder cost: Servos cost more to buy, but they save in other ways. They use electricity directly instead of compressed air. They also reduce scrap by keeping feeds accurate. Faster changeovers save labor time. Over years of use, the savings can balance or even beat the higher purchase cost.
Summary: Air feeders win on starting price. Servo feeders often win on lifetime value.
Which Fits Your Shop?
Every shop has different needs. To decide, think about these questions:
- How tight are the tolerances on your parts?
- How fast do your presses run?
- Do you have strong air systems with a clean, dry supply?
- Is up-front cost or long-term savings more important?
Here’s a simple way to match needs:
- Choose an air feeder if you want a lower purchase price, your jobs allow some tolerance, and your press speed is moderate.
- Choose a servo feeder for press jobs if you run high speeds, need very tight accuracy, and want flexible programs for many parts.
Even though both are feeders, they serve very different roles. Some shops even use both—air units for smaller jobs and servo units for high-precision lines.
Other Feeder Types You May Hear About
In your search, you might see a few other terms. It helps to know what they mean.
- Rotary airlock feeder: This is used in bulk material handling, like powders or grains. It also runs on air-driven motion, but it’s not usually for stamping presses.
- Rapid air feeder: This is a brand of air feeders known in the press world. They are widely used for their simple setup and reliability.
- Pneumatic feeder: This is another way of saying air feeder. Pneumatic means powered by compressed air.
- Servo feeder for press: This phrase highlights that the servo system is made to match the press cycle. It shows the link between the feeder and the press operation.
Knowing these terms helps you sort through options and match the right feeder to your jobs.
Conclusion
Both feeders have their place in stamping. An air feeder offers a budget-friendly, simple setup for steady jobs. A servo roll feeder delivers higher accuracy, faster speeds, and flexible programs for demanding work. Choosing between them means balancing up-front costs with long-term savings.
If you need precision and plan to grow output, a servo is likely worth the investment. If you want a quick, low-cost setup, air may be the right path. The key is to balance your needs, your budget, and your production goals.
For expert guidance and proven equipment, reach out to Durant Tool Company today to find the best fit for your press line.
FAQs
How long do air feeders usually last?
With clean air and regular seal checks, an air feeder can last many years in a busy shop.
Can servo feeders work with thick materials?
Yes. Many servo feeders are built to handle wide and thick stock, but capacity depends on the model.
Do air feeders need electricity?
They need compressed air to run, but may also use a small electric connection for timing signals.
Are servo feeders harder to install?
They take longer to set up than air feeders, but can stay in place and switch jobs quickly once installed.
What happens if shop’s air pressure drops?
An air feeder may lose accuracy or stop feeding if the pressure falls too low. Regular air checks help prevent this.