Servo Drives - Motion Control Tips

Drives and controls for robotics: See them at the 2019 Robotics Summit

May 16, 2019 By Lisa Eitel Leave a Comment

In a couple weeks, the 2019 Robotics Summit (focused on the design, development, manufacture, and delivery of commercial robotics) will take place in Boston. It will be co-located with the DeviceTalks event at the Seaport World Trade Center. One display will be an array of precision processing and powering technologies for robotics.

Elmo Motion Control • Booth #118 — This is a top visit if you’re interested in drives and controls for on-robot (distributed) control. We recently touched on some multi-axis solutions for these setups in a visit at Automate:

In fact, you will get to see Brian Mason (who gives the booth tour in the above video) on Wednesday, June 5th at 2:00 at the Robotics Summit, when he will present on motion control in robots. You’ll also get to ask him questions about miniature network-based servo drives and novel ways to power and control robot joints for less cabling.

Infranor • Booth #139 — Look for servo drives and servomotors here, and give us a shoutout on LinkedIn if you end up having a conversation with this company about new robotics applications for semiconductor, packaging, or aerospace industries (and are at liberty to divulge a vague detail or two).

Performance Motion Devices • Booth #145 — Little-known fact about PMD … this company is well-versed in sharing motion fundamentals with the industry. So if your primary engineering focus is in fact not motion control and you attend the Summit, say hello to the team here to get answers to questions you’ve always wanted to ask but felt were elementary. Performance Motion Devices sells multi-axis motion products (and ICs, digital drives, and amplifiers, and machine boards) and provides technical support on these technologies.

PI • Booth #151 — Physik Instrumente makes regular appearances in our editorial for its precision subsystems. Piezomotors feature large in a lot of miniature designs — see what we did there? — although this company integrates a whole host of other actuator and motor types as well as various kinematics iterations. Check out this FAQ for more on the kinematic possibilities for some robotics: What’s the difference between serial kinematics and parallel kinematics in multi-axis motion design?

This is a piezo motor from Physik Instrumente (PI) that moves to 200 mm/sec. It has an integrated driver.

Kollmorgen • Booth #202 — Catch up on the features and case studies we’ve done (listed below) on how to size and apply servomotors, frameless motors, and stepper motors to robotics and other applications. Then go see the engineers from Kollmorgen at the Summit to see what new robotics applications they observe on the horizon for these technologies — especially for collaborative robots, industrial articulated robots, and medical robots … and particularly those employing frameless motors (a huge trend in the industry) as well as harmonic gearing for high torque density and smaller and faster robots.

Trends in electric motors Part II — Scott Evans sets record straight on motion design

Difference between continuous ratings and holding continuous loads (an ac servo-motor terminology primer)

Thermal time constants and managing PMAC servo motor overloads

Frameless motors and gearmotors for robot design at XPONENTIAL 2019

JF Shaw • Booth #212 — You’d be hard pressed to think of a component used in automaton and robotics that this company doesn’t supply, as they include sensors, connectivity equipment, motors, and drives; mechanical offerings relevant to the application of robots include spur gears, industrial belts, pulleys, and couplings … as well as whole assemblies and end-of-arm tooling including electrical and pneumatic grippers. We editors at motioncontroltips.com are just learning of the capabilities from this supplier ourselves, so stay tuned in coming months to get more on its engineers’ expertise in the design and integration of various industrial applications.

ADVANCED Motion Controls debuts family of compact FlexPro digital servo drives

May 14, 2019 By Miles Budimir Leave a Comment

The FE060-25-EM is the first servo drive of the new FlexPro digital drive family from ADVANCED Motion Controls (AMC). Designed with compact form and power density in mind, the micro-sized FE060-25-EM can outperform larger-sized digital servo drives and still be integrated into tight spaces.

At just 1.5 x 1 x 0.6 in. (38 x 25 x 16 mm) in size, the footprint of the drive is approximately the same as two standard postage stamps. In other words, four of these drives can fit on a standard business card. Even with its small size, the FE060-25-EM can supply brushed, brushless, stepper, and linear servo motors with up to 25 A continuous current and 50 A peak current.

AMC_Image_FE060-25-EM features include:

10 to 55 Vdc supply voltage
Highest power density servo drive from ADVANCED Motion Controls to date
EtherCAT Communication
Incremental encoder and BISS C-mode feedback
Torque, velocity, and position operating modes
Configuration and full loop tuning
IMPACT architecture

IMPACT (Integrated Motion Platform And Control Technology) is the architecture that makes AMC’s FlexPro drives possible. The stacking of circuit boards with creative selection and placement of high-power components allows for much higher power density than previously produced servo drives.

A developer version is available for proof-of-concept and testing purposes – part number FD060-25-EM. It comes with an FE060-25-EM soldered to a larger board equipped with various connectors for simplified interfacing.

The small size of the FE060-25-EM makes it perfect for cobots (collaborative robots), AGVs, portable devices, lab and warehouse automation, military equipment, and any other integrated design.

For more information, visit www.a-m-c.com.

Automate 2019 April 8 through 11: See Elmo Motion Control + future of motion control

April 5, 2019 By Lisa Eitel Leave a Comment

Elmo Motion Control a leading provider of motion control technology, will be showcasing its latest innovation during the 2019 Automate tradeshow from April 8-11, 2019 in Chicago … booth #7729. Amongst Elmo’s state-of-the-art products, visitors will find the award-winning Double Gold Twitter servo drive, the Platinum Maestro multi-axis motion controller, and for the first time the 4-in-1 fully integrated motion control system.

With an insightful look to the future, Elmo has been creating products and solutions for more than 30 years, aiming to answer the ever-growing requirements and demanding applications of Industry 4.0.

The Double Gold Twitter stands out as one of the smallest STO-certified (SIL-3) servo drives in the market, delivering over 10kW of qualitative power, and providing continuous current of up to 160A (80V) and 140A (100V). Thanks to its compact size, this miniature drive can be placed on a moving load, within a motor, or in-between robotic joints, helping engineers to save space, improve machine performance, reduce the amount of cables, and eliminate electrical cabinets, while still delivering unprecedented power capabilities.

The 4-in-1 complete motion control solution is Elmo’s latest innovation to answer the market requirement for a highly integrated all in one solution taking care of both high-power servo capability as well as advanced multi-axis control.

The ultimate servo technology with the best of safety

As safety takes the forefront of many operations, Elmo ensures products comply with the highest possible standards (IEC 61800-5-2 SIL-3, Cat4 PL-e), by integrating safety over EhterCAT – FSoE (Fail/Safe over EtherCAT), and advanced functional safety. Elmo equips manufacturers with top of the line foolproof products that increase their operation’s productivity, lowers operational expenses, and improves safety methods to create truly smart and efficient operations.

Elmo Motion Control (Elmo) designs, produces and implements comprehensive, field-proven motion control solutions that helps clients discover their machine’s potential. The company’s R&D department combines intelligent motion control technologies, real-time programming and control algorithms with advanced digital hardware to enable leaner, more flexible machines. Controlled by the Elmo application studio (EAS)—a software environment that cuts integration time and maintenance costs—Elmo’s servo drives and multi-axes motion controllers minimize a machine’s footprint and cabling, improve throughput, and give original equipment manufacturers (OEMs) a competitive edge. Founded in 1988, the company is headquartered in Israel, employs more than 300 staff worldwide, and has a dedicated presence in the United States, China, Germany, Italy, Switzerland, Korea, Poland and the United Kingdom. For more information, visit www.elmomc.com.

Servo drive controls highly dynamic processes with greater precision

March 26, 2019 By Miles Budimir Leave a Comment

With the latest upgrade to its ACOPOSmulti multi-axis servo drive, B&R now enables even shorter cycle times down to 50 μsec. Highly dynamic processes can now be controlled more precisely than ever.

For demanding motion control applications, such as those found in the printing and packaging industries, movements must be controlled quickly and precisely. The ACOPOSmulti’s short cycle time of 50 µsec for current, speed and position control opens up new possibilities for virtual sensor technology.

Using a virtual motor position encoder eliminates the need for an encoder, encoder cable and evaluation unit in the servo drive and at the same time increases availability. Other special functions for more precise control and faster reactions can be implemented using virtual sensor technology. These include model-based control with autotuning and a repetitive control function for predictive lag error compensation.

For more information, visit www.br-automation.com.

Don’t forget these two things when selecting an amplifier for a servo-motion application

January 29, 2019 By Lisa Eitel Leave a Comment

Using software to size motion designs is rewarding because engineers can efficiently predict which products are suitable for the application at hand. But key considerations (sometimes missed) when selecting a servo amplifier are those of dynamic braking and regenerative resistor braking.

By Sixto Moralez • Regional Motion Engineer
Phil Drexler • Regional Motion Engineer | Yaskawa America Inc.

Design engineers who are running sizing calculations for a servo application should consider dynamic braking as well as regenerative braking requirements when selecting a servomotor and digital amplifier for that design. The terms are sometimes used interchangeably, as both types of braking involve processing regenerative energy. But as we’ll explore, there is a subtle difference between dynamic braking and regenerative braking.

We’ll also explore how to leverage the benefits of servo amplifiers that include dynamic-braking provisions.

What is dynamic braking?

If the servo axis suddenly turns off while the servomotor is operating and the axis is running at some non-zero velocity — for example, due to loss of power or an emergency stop triggered by an alarm — the digital servo amplifier can no longer control the servomotor. That means unless there’s some mechanism to prevent coasting, that axis will indeed coast until all of the kinetic energy from the load and its own rotating inertia is expended.

Dynamic braking is the quick stopping of a spinning servomotor by connecting resistance between the Servomotor’s terminals.

Because mechanical losses in the system usually expend only a small amount of energy, the coasting distance can be quite long. This long stopping distance may spur equipment damage and/or personal injury.

Here, dynamic braking is helpful. It uses the regenerative power produced by the rotating servomotor to brake the servomotor. The servomotor’s kinetic energy converts to electrical energy and is expended as heat (through resistors) to stop the servomotor. In short, dynamic braking is the quick stopping of a spinning servomotor by connecting resistance between the servomotor’s terminals U, V, and W.

With default parameter settings, the digital servo amplifier will apply dynamic braking to stop the servomotor when a Group 1 alarm occurs. The user can modify the setting of this parameter by using Yaskawa’s free SigmaWin+ Version 7 software.

Consider some examples of when the dynamic braking circuit might be activated.

Servo alarm: With default parameter settings, the digital servo amplifier will apply dynamic braking to stop the servomotor when a Group 1 alarm occurs. In some cases, users can modify the setting of this parameter by using drive-manufacturer software.

Over-travel: Hitting the over-travel limit switches in the forward or reverse direction.

Main power off: Turning off the main power supply to the digital servo-amplifier circuit or servomotor.

Shown here are a couple examples of where regeneration is helpful — where gravity and tension come into play.

What is regenerative energy?

In a servomotor system under the control of a digital servo amplifier, when the output torque of the servomotor is opposite the direction of the shaft rotation, the motor acts as a generator … and the resulting energy flows back into the drive. The energy returned to the drive is regenerative energy. Three examples of when regeneration occurs during motor operation are decelerating a moving load; lowering a vertical load; and an overdriven nip roll.

Shown here is how Yaskawa’s networkable Sigma-7 Series Servopack digital amplifiers can handle the energy from a backdriven motor.

That leads to the next question — what is regenerative resistor braking? Here, regenerative energy is returned to the drive during deceleration because the motor must apply torque opposing the rotation’s direction to stop the load.

For example, when lowering a load without a counterweight, the force of gravity drives the load down, and the motor must apply torque opposite the direction of downward rotation to control the load.

Shown here is a sample regeneration profile upon axis deceleration.

Likewise, in the case of an overdriven nip roll, the motor must apply torque opposite the direction of rotation. In both cases, regenerative energy returns to the drive. Whenever regenerative energy returns to the digital servo amplifier, the bus capacitors absorb the energy … and the dc bus voltage rises.

Of course, if there’s a large amount of energy, the energy must dissipate to protect the drive. A braking transistor turns on to let current flow from the bus through a braking resistor. This process is known as regenerative resistor braking.

Digital servo amplifiers from some manufacturers have built-in resistors to dissipate some regenerative energy … though if the amount of regenerative energy processed by the built-in resistor is exceeded, the design will need an external regenerative resistor.

Word to the wise: Use (full-featured) servo-sizing software

Using servo-sizing software from some manufacturers to size motion applications lets engineers verify the regenerative and dynamic braking parameters specific to the application. Here the engineer can enter details about the system mechanics, motion profile, and other details such as input voltage and the servomotor brake parameters. Such software ultimately identifies one or multiple servomotor and digital servo amplifier combinations that will work in the application at hand. Some such software can even return speed-torque curves and regeneration values for each machine-build option.

Click to enlarge. This example of sizing software (on the Yaskawa SigmaSelect software’s regeneration tab) shows how such tools can identify whether the design will need additional components such as external resistors.

Though no one size fits all, servo systems verified upfront for dynamic braking and regenerative resistor braking will deliver longer life. Yaskawa’s networkable digital amplifiers (Sigma-7 Series Servopacks) include dynamic braking provisions in their amplifiers. For more information, visit yaskawa.com/products/motion/sigma-7-servo-products.

Figure 7: When the servomotor operates as a generator, power returns to the amplifier — often to charge the drive’s bus-smoothing capacitor. Beyond this capacitor’s capacity, a regenerative resistor goes into action to consume the remaining power. But where such an approach is still insufficient (or the drive doesn’t have regenerative resistors) an external regenerative resistor must connect to the drive to handle the remaining power. That’s common for axes with high load-to-motor-inertia mismatches. External regenerative resistor units such as the one shown here connect between drive terminals; then software configuration of the amplifier allows identification and handling of the external resistor unit’s power capacity.

New panel-mount servo drives from AMC for brushed, brushless dc motors

January 10, 2019 By Miles Budimir Leave a Comment

The AB25A100 PWM servo drive from Advanced Motion Controls is designed to drive brushless and brushed dc motors at a high switching frequency.

The drive is fully protected against over-voltage, under-voltage, over-current, over-heating and short-circuits across motor, ground and power leads. Furthermore, the drive can interface with digital controllers or be used stand-alone, and requires only a single unregulated dc power supply. Loop gain, current limit, input gain and offset can be adjusted using 14-turn potentiometers. The offset adjusting potentiometer can also be used as an on-board input signal for testing purposes. This drive can use quadrature encoder inputs for velocity control.

The new servo drive operates on 20 to 80 Vdc input, 15 A continuous (25 peak) output. DIP switches and potentiometers provide for loop tuning, current limit adjustments and drive configuration. Other features include velocity feedback via incremental encoder, Hall Sensors, or tachometer, current, velocity, and fault monitor analog output signals, and four-quadrant regenerative operation. Certain models also feature optical isolation between high and low power signals as standard.

For more information, visit www.a-m-c.com.

New dual-axis AKD2G servo drive from Kollmorgen

November 29, 2018 By Miles Budimir Leave a Comment

Kollmorgen’s new dual-axis AKD2G Servo Drive is one of the most power-dense industrial servo drives on the market. It substantially reduces mains wiring, fuses, and filtering to save significant panel space and cost. The AKD2G features expandable I/O (without increasing the size), removable memory, dual-channel STO, and the first drive-resident graphic display in the industry.

Other highlights include: Workbench interface, optimized hybrid connector, and fast speed with its multicore Compute Engine Servo on a Chip. The AKD2G’s current loop update rate of 1.28 µsec accommodates changing load conditions immediately. Velocity and position loop updates are at 62.5 µsec and 125 µsec respectively.

The AKD2G also offers plug-and-play compatibility to Kollmorgen motors, including the company’s recently released AKM2G. The AKM2G is a configurable, high-performance synchronous servo motor with increased power density and improved torque/speed ratio, allowing OEMs to get up to 30% more performance out of an equivalent size motor or achieve the same performance with a smaller motor. Together, the AKD2G and AKM2G create a powerful servo motor system solution.

For more information, visit www.kollmorgen.com.

When do you need a linear amplifier versus a PWM drive?

November 29, 2018 By Danielle Collins Leave a Comment

Servo drives — also referred to as servo amplifiers — can be classified by the type of output stage they use: pulse-width-modulated (PWM) or linear. Of the two types, PWM drives are more common in general motion control applications because they provide more power to the motor, have higher efficiency, and are generally smaller and lower cost. However, while they are sufficient for most industrial applications, PWM drives create both audible noise and EMI (electromagnetic interference). They also produce minute vibrations that can interfere with sub-micron level positioning.

For applications that require extremely smooth motion, no audible noise, and little or no EMI, linear servo drives — commonly referred to as linear amplifiers — are preferred over PWM drives.

EMI “noise” can interfere with other electrical equipment in the vicinity of the drive and can be especially detrimental to the operation of sensors. Although filters can be used to remove the noise, they often reduce the speed of the sensing signals.

These differences in performance are a result of the operating principles that each drive employs. A PWM drive delivers a specified amount of voltage to the motor by switching the voltage across the transistors on and off at a very high frequency — typically in the range of 20 kHz. (When the voltage is switched on, the transistors are said to be saturated.) This switching creates pulses, and the switching frequency controls the width of the pulses — hence, the term “pulse-width modulation.” The ratio of on-time to off-time during switching determines the average voltage supplied to the motor.

In a linear amplifier, the transistors are always on to some degree, allowing voltage to flow continuously through the transistors and to the motor, rather than being switched on and off. This makes matching the amplifier’s output voltage to the motor and application requirements even more critical and, in some cases, more complex, than with PWM drives. Factors such as the motor’s torque constant, back EMF, and resistance all play a role in determining the required output voltage from a linear amplifier.

Because there is always some voltage flowing through the transistors, linear amplifiers experience significant power dissipation, and in turn, relatively low efficiency — typically in the range of 50 percent, although it can be lower. (In contrast, PWM drives often have efficiencies of 90 percent or better.) Of course, the power is dissipated as heat, which means a linear amplifier needs a large heat sinks to protect the transistors, increasing size and cost and often restricting their practical applications to those with power requirements of 100 W or less.

Despite these drawbacks, the lack of power switching gives linear amplifiers the benefit of very low audible noise and virtually no EMI. They also have a higher current loop bandwidth, and no dead band at the zero current crossing.

Linear amplifiers provide much better position stability than can be achieved with PWM drives.
Image credit: Trust Automation

Drives that exhibit a dead band — as PWM drives do — cannot accurately provide the low levels of current required as the motor switches from positive to negative torque (or velocity) — i.e., at the “zero crossing” of the current waveform. This makes it difficult to control very small movements, which can cause dithering and long settling times. Unlike PWM drives, linear amplifiers don’t experience a dead-band, which allows them to provide much better velocity control and settling characteristics.

A dead band is essentially a flat spot in the current waveform at its zero crossing.
Image credit: Electronics Tutorials

High current loop bandwidth, low EMI, and smooth motion characteristics make linear amplifiers the best choice for ultra-high positioning applications. They’re often used in precision stages to drive linear motors or voice coil actuators in semiconductor, medical, and optical equipment.

The term “linear” amplifier has nothing to do with whether the motor being driven is a linear or rotary version. Linear amplifiers can be used on both linear and rotary motors, either brushed or brushless.

Feature image credit: Bardac Corporation

Application example: Motion components on a typical form-fill-seal machine

November 12, 2018 By Lisa Eitel Leave a Comment

Form-fill-seal machines are used to package edible powders, dry food, and liquids into bags and pouches. It’s a common machine design that comes in versions for both continuous and intermittent operation. No matter the design, top design objectives for form-fill-seal machines are high throughput with minimal downtime and the ability to reconfigure the machine to satisfy changing production requirements.

Mitsubishi Electric Automation Inc. offers an array of solutions in its Pak/iQ suite to improve the builds of such packaging equipment with reliable machine performance and communication of system analytics for IIoT functionality.

Consider the build shown in the illustration.

Bulk food product enter from the top as servo-driven axes pull bag material off roll stock (spools). The funnel hood shapes the plastic sheet into a cylinder. Then a thermal heat sealer melts together bag edges; bags are filled from above as the web travels downward. Vertical film index drives time this function to match the machine’s operation cycles. From there, the bags get their final cutting and sealing — and then go onward to conveyors that carry them away.

On this machine, a PLC (in the form of an iQ-F compact controller) provides necessary functions while helping OEMs keep cost down. Programming of the PLC is through simple parameter setting: iQ-Monozukuri Packaging software gives engineers sample programs, sample GOT HMI screens, and auto-generated function blocks — including those for rotary-cutter, camming, long-dwell, flying-shear, box-motion, and mark-detection tasks.

To command and drive the motion tasks, the machine build uses an FX5 Simple Motion controller, MR-JE Series servo amplifiers, and (on the conveyor) an FR-E700 Series VFD. Two of the MR-JE Series servos are for web-index control; one is for the sealer axis. The three servo-driven motor axes are networked through fiber-optic-based SSCNETIII/H. Servo-network refresh rates to 0.222 msec allow accurate control.

Capabilities of Mitsubishi-outfitted form-fill-seal machines include auto-generated function blocks for camming as well as advanced synchronization that’s easy to configure … for fully synchronous multi-axis performance. The hardware also allows for direct control of the VFD from the HMI.

Digital printing pairs with a machine capable of handling its varied output

November 11, 2018 By Lisa Eitel Leave a Comment

VITS International makes sheeting and finishing machines for packaging, printing, and converting. The OEM saw the digital-printing market needed finishing capable of commercial production speeds. So VITS designed and built the SPRINT Variable Data Finisher with a Bosch Rexroth drive and control platform to meet the demand.

This is a VITS Variable Data multi-web finisher.

Digital inkjet printers can execute output comparable to that of traditional web-offset printing — at near-commercial rates to 1,000 feet per minute. Digital printing also allows variable data printing to dynamically vary the number of pages and content on the pages — even handling significantly varied page dimensions. Such capabilities enable incredible customization but complicates the finishing of printed web. So finishing systems on digital printing lines must be able to quickly cut, collate, and assemble disparate pages into final readable pieces.
“We decided to develop such a finishing machine to support both offline and inline finishing,” said VITS International president and CEO Deirdre Ryder. The result is VITS’ SPRINT Variable Data Finishing System that turns variable print material into finished product at up to 1,500 fpm. The SPRINT machine works for inline systems (which get and finish a single web directly from the digital printer) and offline multi-web finishing (for processing multiple webs into a single finished signature or book).

“Our printing customers want to output larger products at faster rates of speed,” said VITS director of product applications Kim Markovich. “Particularly for direct mail, being able to finish multiple webs and ribbons with suitable register control means printers can assume more work.” SPRINT finishing machines include independently driven axes controlled by a Rexroth IndraMotion MLC motion control system. A Bosch Rexroth L45 controller employs Sercos III for deterministic synchronization of drives and fieldbus communication for I/O.

The inline machine version usually has 10 to 12 driven axes; multi-web offline versions can have up to 30. A Rexroth cross-communication card with Sercos-III-based communication helps synchronize VITS finishers with inline-mounted printing presses (also sporting Rexroth controls). Machine modules trigger various functions to convert printed web into books or mailers with Rexroth IndraDrive servo drives and IndraDyn servomotors for actuating the functions.

Offline multi-web machines interface with paper rolls on register splicers. These continuously feed web at a constant-tension infeed with precise gain and control to prevent issues.

The paper goes through a station that slits it in half and stacks the halves.
The paper halves travel to a ribbon-gathering station and onward to a station that folds the ribbons in half.
The paper web goes through a shear-slitting station for edge trimming.
Finally, the web goes through a variable-data rotary cutter that slices each page to size and collates finished product for the final binding or saddle stitching.

Maintaining registration for all these steps is core to ensuring all pages in all signatures are cut to the same dimension. Nothing prints perfectly, so the length of any print usually varies ±0.001 in. from page to page … which is an error that can accumulate quickly over hundreds of fast-moving pages.

“We use the built-in intelligence of Rexroth drives to dynamically maintain web registration — and keep the central controller’s processing power free,” said integrator Bruce Parks of Parks Consulting, who helped on the machine design. A virtual master holds all drives in synchronization. Tension zones between drives maintain tension during web splitting, merging, and cutting. Controls can also command groups of drives to adjust tension … and bring the web into register with the virtual master.

SPRINT Finishing machines use the Rexroth IndraMotion for Printing automation platform with independently driven axes under a central IndraMotion MLC motion controller (similar to the one here).

SPRINT engineers used the IndraMotion for Printing version of Rexroth’s MLC system to automate tasks via IEC 61131-compliant motion logic and PLCopen function blocks — and software libraries specific to printing and converting. “IndraMotion for Printing includes tools for most web-handling tasks. These and Rexroth’s PLCopen function blocks helped us build functions and camming profiles for our proprietary Clear Channel registration,” said Parks. Clear Channel registration control allows the cutting thousands of pages per hour while maintaining precise page registration impossible with legacy finishing systems. It enables faster size changes as well as cut tolerances impossible with standard finishing systems.

Another strength of the SPRINT machine is its rotary cutter … capable of handling images of 5 to 25 in. and configurable to cut different width chips — blank spaces between pages on the paper. Machine operators trigger the change with a push of a button. At the cutter station, twin knives slice the chip out; the knives are spaced by the width of the chip … and cutting must be synchronized with the speed of the web through the station. “Our camming lets users cut output of variable size with multiple knives and still maintain chip size — because the camming always synchronizes with the web speed through the cutting zone,” said VITS director of new product development John Salamone.

This is the first machine series VITS built on a Bosch Rexroth control and drive platform. “We had a great relationship with the previous supplier. Bosch Rexroth gave us similar commitment … and Rexroth technology let us quickly develop equipment with accuracy no competitors have. So now Rexroth-equipped machines of ours working flawlessly all over the world.