Machine Retrofits and Safety

Controls and hardware on many machines continue to work for 10, 20 or more years, well past the time when cost-effective replacement parts or clear migration paths are readily available. And automation vendors have bent over backwards to support the installed base. But in many cases, enough is enough, and the time is right for replacement because components are becoming obsolete, more productiv...

03/01/2005


AT A GLANCE

 

  • Automation enlivens old iron

  • 'Better than new' retrofit performance

  • Easier setup, communications

  • Safety underlies every retrofit

Sidebars:
Safety should support all retrofit activities

This article contains online extra material.

Related reading


Controls and hardware on many machines continue to work for 10, 20 or more years, well past the time when cost-effective replacement parts or clear migration paths are readily available. And automation vendors have bent over backwards to support the installed base. But in many cases, enough is enough, and the time is right for replacement because components are becoming obsolete, more productive technologies are available, and upgrades are safer and more reliable.
Is it worth it? What if you could reduce errors by half, slash cycle time 75%, rejuvenate for 10% the cost of new, or save $10,000? Five reconstructive examples and safety advice follow.

Half the rotary axis error

Stellex Monitor Aerospace Inc. has completed five of ten CNC retrofits on Cincinnati Milacron gantry-style milling machines used in the production of various titanium and aluminum aerospace components, such as struts, landing gear, and bulkheads. Siemens Machine Tool Business supplied the turnkey retrofits to the machines, built in 1978.

Originally equipped with Acramatic 'Big Blue' controls, these machines now have Siemens digital servo motors and drives, Siemens Sinumerik 840D CNCs, running on a Microsoft Windows XP platform with 3D five-axis cutter compensation and five-axis real-time kinematic transformation. Stellex Monitor VP Gary Kahrau says results include reduced set-up time, improved part surface finish, reduced secondary finishing operations, and significant improvements in overall productivity.

In addition to retrofit services, Siemens also provided mechatronics/machine engineering analysis that 1) collects critical real-time machine performance data; 2) establishes optimized parameterization of the CNC and servo drives; and 3) verifies optimized performance of the machine. Kahrau says that servo analysis, ball bar tests, acceleration/deceleration tests, bi-direction compensation work-up, and other protocols were key to results.

'Our machinery accuracy is better now than when the machines were new, plus our five-axis gantry has never performed so well, and the rotary axis error was literally cut in half,' Kahrau says.

Retrofit lathe makes more motors

Baldor Electric improved machine productivity and functionality by retrofitting lathes with its own servo/motion equipment. John Mazurkiewicz, motor product manager at Baldor, says the company liked CNC lathes, because older, dedicated (hydraulically operated) band lathes were slow, difficult to setup, and didn't easily allow wear-based tool changes. Changing from one length band to another also was time consuming.

Since a new CNC lathe for this would cost $100,000 or more, Baldor looked at retrofitting Acme Gridley lathes, which had been placed in storage and nearly offered for scrap. New electronic controls and ball screws replaced the hydraulic components to give Baldor the needed adjustability to cut the range of parts (2.6-12.0 in.). Savings exceeded $30,000 per unit compared to new.

'The machine now lends itself for easy changeover from one part to the next and can be performed in a matter of seconds. No editing of G-Code programs is necessary as the software construction and presentation is done with a series of selections of screens,' says Mazurkiewicz.

'The operator only needs to select the setup selection on the HMI and enter part length, rabbet depth and speed of the spindle, which are selected by only one button push each,' he explains. 'The prime safety provision is that errors are kept to a minimum via the program checking for a 'range' of inputs for each.' For example, Mazurkiewicz continues, 'smaller or larger values for length will not be allowed and faster spindle speeds will not be allowed and errors in depth of rabbet input are kept within a range. Cycle time for the improved retrofitted machine is now more than four-times faster, 8 to 8.5 seconds versus the previous 30 to 35 seconds.'

10% of the cost of new

Retrofits for the semiconductor industry can translate into rejuvenated equipment for as little as 10% of the cost of a new system, according to P.C. Lindsey, president of Micro Processing Technology Inc. (MPT), a National Instruments Alliance Member. 'In place of the old proprietary control system, the customer receives a new control system based on a personal computer that can be transferred to new PC platforms using off-the-shelf boards so it never becomes obsolete.' NI's LabView is the programming language used. CompactRIO, with an FPGA (field programmable gate array), 'allows us to do real-time control directly, without having to design special circuits. It also simplifies the wiring of the system and eliminates the need for a custom PC interface board.'

Machine Control, motion control, networks

This is how the Matrix Integrated Systems boards looked before the retrofit from National Instruments.

MPT did a retrofit project with Analogee Corp. The process equipment is a System One photo resist stripper, originally manufactured by Matrix Integrated Systems Inc. (MISI). Lindsey says MISI is no longer in business, but several hundred of its systems are still in use. Computer control and system monitoring require 8 analog inputs, 5 analog outputs, 73 digital I/O lines, and an RS-232 port. MPT used three NI data acquisition and control boards. Analogee Corp. designed a PC board and wiring changes to the system, and MPT wrote the software application in LabView. Analogee personnel tested existing actuators and sensors.

Lindsey says, 'There are 20 systems in the field running the new controls. Several have been in operation for over two years. The retrofit kit sells for $40,000, installed. One of biggest reasons for obsolescence is that parts for the control systems are no longer available. A viable and reasonably priced option is to retrofit the equipment with a new control system.'

On a roll: Retrofit speeds

Sometimes the need for a retrofit sneaks up an inch at a time.

Machine Control, motion control, networks

National Instruments automation retrofit onto Matrix Integrated Systems semiconductor machinery offers real-time control at 10% the cost of new equipment.

Plus Mark, the division of American Greetings that manufactures Christmas gift wrap, has 30-year-old machines that operate as well as new models, with high-speed, high-accuracy cut-and-roll production from a retrofit. On average, Plus Mark rolled 2.2 extra inches of gift wrap on each cardboard core, due to accuracy limitations. At more than 70 million rolls per year, the company was losing more than 150 million inches annually, enough paper to wrap from Los Angeles to New York City. Hourly manual checks by operators created more waste.

For shorter rolls, operators selected lengths with a proportional infinite variable (PIV) gearbox. For longer lengths, a counter, clutch, and brake were used. The system permitted selection of lengths only within one-inch increments, and accuracy varied with temperature and with clutch and brake wear. To reduce expenses and downtime, Plus Mark had to retrofit or buy new machines, according to Tom Dubois, industrial engineer with Plus Mark. Competitors had just purchased new equipment.

System integrator Jim Jones, president of Automation Insights, designed and implemented the Plus Mark retrofit at 10% of the cost of a new machine. The system measures each roll and supplies operators with a digital readout. Roll lengths can be selected within 0.1-inch increments. Automation Insight retrofit more than 50 Plus Mark machines with compact GE Fanuc Series 90-30 PLCs, to close all control loops—position, velocity, and torque—within the controller.

Machine Control, motion control, networks

Large, complex aircraft parts made at Stellex Monitor have smoother surfaces because of a Siemens control system retrofit.

The old system required twice-weekly chain tightening and annual replacement or rebuild of the PIV, says Danny Garber, Plus Mark master mechanic. 'The system eases maintenance with cleaner, simpler operation,' Garber says. Cut-to-length accuracy has improved by 70%, Dubois says. 'Overall, we've cut maintenance costs in half and increased uptime by approximately 40%. We're now running faster than we would be with a new machine,' Dubois concludes.

Rare replacements

When replacement parts are priced higher than retrofitting with new controls, it might only be the retrofit effort itself that stands in the way. Jeff Buehler, Daimler Chrysler account manager, Bosch Rexroth Controls, aims to ease integration concerns with a frame-full of components designed to replace popular and reliable legacy controls on many machine tools. The Bosch Rexroth TK1 kit isn't completely plug-and-play, but very close, Buehler says. A bit of reprogramming is required, it can be set up in under 48 hours, and the kit is about $10,000 less than replacing the existing Trans01, DCS, and MAC motor.

Machine Control, motion control, networks

The Bosch Rexroth TK1 retrofit kit aims to ease machinery integration.

Even so, as a proof of concept, Buehler installed the first one free at a Kokomo, IN, DaimlerChrysler Powertrain facility on an R&B Machine Tool (now Lamb) dial transfer line machine, controlling a horizontal drill that cuts a notch in a plate. It's worked without known incident since April 2004, after about an hour of on-site training for operations and maintenance staffs.

'There are about 10,000 Bosch Rexroth 1970s and 1980s-era Trans01 controls [from Rexroth Indramat 6502 processor], in the Detroit area alone,' Buehler says. 'We've explained to customers that the cost of replacement components is ever increasing, which means the cost of maintenance and repair is increasing. They're mature and out of the main production stream, so one-for-one replacement is going to be costly. With the TK1 kit, we took existing, proven components and put them on a frame with the same mounts, to eliminate much of the mounting and hardware fabrication for the customer that is often necessary on retrofits.'



Online Extra
More details about five retrofit applications mentioned in the main article follows below, along with advice about machine guarding, and links to related reading. All images here also are 'Online Extras,' beyond what the print edition featured.

Seven dispelled myths about machine safeguarding
Some common points to remember about machine safeguards came recently from Sam Boytor, president, Fox Controls Inc.

1. Risk assessment is not a road map for litigation; it helps create proper guarding, documentation, and training to avoid injury and resulting legal actions.
2. Documentation and methods to create risk assessments should be consistent, based on latest information, help fix the problems, and put in a format unable to be changed after an incident.
3. Because standards refer to one another, a whole desk full of information is required to do a proper risk assessment if it’s done manually. (Software tools for risk assessment/reduction can be consistent enough so 10 people could get the same outcome on the same line installed at 10 different plants.)
4. An emergency stop doesn’t have to shut down a whole line, only the area affected. It must be a positive opening mechanical device and cannot be software based unless it is a certified controller for such use according to NPFA 79. Less than 1% of E-stops are properly integrated, Boytor estimates.
5. Line reset and restart require full line of sight, or some way of knowing that the area is clear, such as with cameras.
6. Machine guards must be held in place in such a way that they cannot be removed or defeated by readily available means.
7. Machine safeguards do not have to make machines difficult to run and maintain. For instance, if hazardous motion is stopped when a guarded perimeter is breached, there’s no need for a maintenance technician to replace coupling guards, but rather, just close the door with the proper interlocks in place, Boytor explains.

Fox Controls offers machine guarding training, integration and a safety lab to meet “increasing pressures for domestic OSHA compliance (ANSI B11) and the European Export directive (CE).” Hardware products include a configurable “Plug and Play” safety control system called a “Safe-T-Station” with models including Press Control. A software product for performing risk assessments called Menusafe is also available.

Machine Control, motion control, networks

This Fox Controls Inc. before and after shot of a conveyer safety retrofit clearly shows the added fence, gating, and emergency stop.

CompactRIO: small, flexible logical retrofit
CompactRIO’s reconfigurable nature and high performance of FPGAs along with the highly automated National Instruments (NI) LabView programming environment are said to allow machine builders to save money and quickly customize and retrofit machines. NI CompactRIO is an advanced reconfigurable control and acquisition system designed for applications that require ultra-high performance and reliability. This low-cost embedded architecture combines a real-time embedded processor for stand-alone deterministic operation and communication interfaces; a reconfigurable I/O (RIO) FPGA core for flexibility in timing, triggering, and synchronization; and industrial, hot-swappable I/O modules for direct connection to industrial sensors and actuators.

P.C. Lindsey, president of Micro Processing Technology Inc. (MPT), a National Instruments Alliance Member, says, “In the event that we can no longer purchase some of the sensors and actuators used on a system, CompactRIO allows us to use simpler sensors and actuators with interface and control circuitry in the CompactRIO reconfigurable FPGA circuitry.”

New semiconductor process equipment can range in price from several hundred thousand dollars to as much as several million dollars for some of the more sophisticated equipment to process 300- mm silicon wafers, Lindsey says. “There are a large number of different kinds of equipment and many steps in the process to fabricate a semiconductor device or circuit. Maintaining a consistent and repeatable process in each piece of semiconductor process equipment is extremely important to achieve an acceptable yield of finished units. The cost of adding a new piece of process equipment is also very high because of the process engineering costs involved in proving that the new equipment produces an acceptable and consistent process, and that the process performed by the new equipment can be successfully integrated with all other process steps without decreasing the yield or changing the characteristics of the finished devices.”

Machine Control, motion control, networks

Safety was a consideration, Lindsey suggests, because, “In designing the new control system, there were several new features that we were able to add due to ease of programming complex control functions in LabView. Overall safety of the system has been improved by the addition of extensive status checking in the software before each step in the processing sequence is allowed to proceed. Service and maintenance have been simplified by the addition of a status screen for all inputs to the computer and addition of a manual control screen that allows all control functions and wiring to be tested independent of system operation.”

Retrofits are particularly important for the secondary market for used semiconductor processing equipment. “When the top manufacturers of silicon devices and circuits move their processes to larger diameter wafers, other companies purchase the equipment used for the smaller diameter wafers,” for MEMS, GaAs, InP devices, or ICs. “These companies have the same problems finding parts for the control systems so retrofitting with new PC-based controls and off-the-shelf components is a great solution,” Lindsey adds.

Baldor lathe retrofit: detailed spin
In building electric motors, the end plates are mated to the motor housing that contains the stator via mating rabbets in the end plate and in the motor housing. Precision machining determines the air gap and concentricity of the rotor to the stator; accuracy affects motor performance and efficiency, explains Baldor Electric’s John Mazurkiewicz, motor product manager. To retrofit the Acme Gridley band lathe(s), Baldor had to:

  • Strip old hydraulic components, sandblast, and repaint castings;

  • Assemble and attach new ball screw(s) and servo motor(s);

  • Attach new equipment enclosure containing power conditioning, servo drives and associated electronic components;

  • Manufacture new sheet metal housing(s) and enclosure(s); and

  • Author new software specific to this operation.

The above cost approximately $70,000 (each) to produce. Cost of new equipment was $100,000 and higher. Advantages of retrofit versus buying new are that:

  • Existing “iron” is still good. Most of the time, mechanical devices (if properly maintained) are still well within operating specifications.

  • Replacement costs become prohibitive, so keep the iron and replace the actuation system, electronics, and create interactive software.

Disadvantages of using and running unautomated equipment:

  • Difficult to maintain in operating status;

  • Setup and changeover time increases;

  • Program or operating systems no longer supported or nobody is available who can make desired changes to system to tailor it to new manufacturing needs; and

  • Some electronic components seem to be the area where obsolescence has taken its toll. Replacements are often no longer manufactured or have been discontinued.

The original equipment was hydraulically operated. Settings and adjustments were performed by moving a limit switch to a new location. This made setup and changeover time consuming and inaccurate. Scrap rate to get a first article was high. Cycle time of the hydraulics was taking too long to meet the demand of desired production run of parts. More machines would have had to be installed to meet this requirement of part demand.

The new Baldor parts incorporated into the machine were: NextMove/BX motion controller, FlexDrive servo drives, BSM80 brushless servo motors, 15 hp Vector motor and drive for spindle, Operator HMI remotely mounted on CANbus, and Baldor digital I/O module remotely mounted on CANbus. Advantages with the retrofit lathes were many. Servo motors and ball screws had advantages versus hydraulic cylinders.

  • Servos use less power;

  • Servos require less maintenance;

  • Servos require less space compared to and including cylinders, pump, reservoir, and plumbing.

Machine cycle time, about four times less, is now 8-8.5 seconds, to perform the following functions:

  • Move from a tool home position to face the part off to finished length;

  • Chamfer edge of cut;

  • Rabbet cut to depth; and

  • Angle cut off to inside of part to remove any burr.

Each of these operations happens on both ends of the motor housing at the same time, although the rabbet depths can be set independently. Operator load/unload of part is straight into and off of the chuck, versus having to lift the part into the machine and load to a perpendicularly mounted mandrel. Since size of the motor band being cut can change from part to part, there needed to be a way to let the system know when a longer band one was on the chuck, to avoid a system crash. Provisions were made in the software such that if the following error on the initial move into position by the cutters resulted in more than 0.005-in. error, the machine would self-protect by shutting the spindle down and informing the operator of the error, Mazurkiewicz says.

Wrapping up
“We didn’t have a lot of extra room on the machines, and we had to keep controls accessible and out of the operators way,” says System integrator Jim Jones, president of Automation Insights, of the Plus Mark retrofit. “Operators need to get in the machines and check the web for accuracy. With Series 90-30 PLC, we have all the power that we need in a small module.” A DSM motion module in Series 90-30 controls the GE Fanuc B Series servo and gearbox. The servo system simplifies machine operation by replacing clutch, brake, and proportional infinite variable (PIV) gearbox. The new controls afford easy plug-and-play integration. With this embedded solution, data are automatically and seamlessly exchanged between the PLC and motion controller. A web speed sensor allows the servo to follow the main drive.

'With the GE Fanuc system, I could concentrate on design and implementation without having to worry about product integration,' Jones says. 'Benefits ranged from having to use only one software package for machine control, motion control, and servo control to simply plugging in pre-finished cables. This complete package bought me the extra time I needed to plan the best retrofit possible. Now that we're past the prototype stage, additional machines can be retrofitted within 24 hours.' All drive parameters are stored in the controller in a standard motor database. By reducing the number of mechanical drive-train components, the servo system increases machine reliability and provides greater accuracy. Controlled accelerations and decelerations decrease jarring for less wear on other machine components—which results in longer life and lower maintenance.

'Rolls cut and drop 20 to 30 times per minute,' says Tom Dubois, industrial engineer with Plus Mark. 'With the old system, machines experienced a sharp jolt with every completed roll. Now, the motion is smoother and quieter, and our equipment will last several more years.' All-digital GE Fanuc system delivers accuracy within 1.0 mm and supplies the greatest resistance to environmental changes, reduces setup time, and delivers significant throughput advantages, Dubois says. Automatic Spooler Verlin White operates a retrofitted machine and has seen an increase in product quality. “The machine operates faster, and we're able to produce tighter rolls,” he explains. “Additionally, the paper pulls out smoothly from the feed end.”

Operators access the control system from a terminal on the machine or from a central station. A LAN connects the machines and permits remote monitoring and control through a graphical human machine interface. At the terminal, operators can select a cut length, obtain a digital readout of the actual length of the roll, and sample the average length for the past five rolls. Indicator lights quickly show whether a roll was long, normal, or short. The easy-to-use system requires minimal training, and a single person can operate a machine, says the manufacturer.

TK1 kit, related programming
Jeff Buehler, Daimler Chrysler account manager, Bosch Rexroth Controls, explained that the TK1 retrofit kit components include:

1. Trans200– motion controller (4 servo axes, 3 spindle axes capability) with SERCOS interface to the servo controllers; PLC interface, discrete or various fieldbus options; Ethernet for data transfer. (It’s mounted on TK1 frame.);
2. HDC Duradrive digital servo controller IP65 (on TK1 frame);
3. MHD digital servo motor; and
4. BTV06 HMI for operation, diagnostics and operation (on TK1 frame).

The system could be expanded to control the vertical-slide hydraulic cylinder with an additional servo motor and a servo controller, if needed, Buehler says. To ensure handshaking through the PLC was same as before, engineering staff supplied PLC code. Bosch Rexroth Engineering, along with plant engineering, ensured that PLC handshaking was the same as before through proper sequence testing. Bosch Rexroth also supplied required I/O requirements of the Trans200 for PLC interface. In this case it was 24 V dc discrete I/O modules. Various fieldbus options also are available depending on the PLC, which was reviewed beforehand for quick modification before safety testing. Buehler’s team also rewrote the existing Trans01 motion program into G-code for the Trans200.

The Trans200, introduced in 2004, controls milling, drilling, and tapping for transfer-line stations. The kit improves communications, diagnostics, tolerances, cycle times, and repeatability, Buehler says. Trans200 upgrade options include additional encoders for positioning, probes, adaptive depth positioning, adaptive feed positioning, tool correction programming, and Ethernet interface to a host PC for data transfer.

Large parts from Stellex Monitor
Founded in 1948, Stellex Monitor operates a 250,000 square ft modern facility, producing struts, spars, landing gear, bulkheads, crown-beam assemblies, and other medium-to-large parts from titanium, aluminum, and stainless steels for commercial and military aircraft and aerospace vehicles, including the space shuttle. Customers include the major airframe builders, including Boeing, Northrop-Grumman, and Lockheed Martin.

The oldest Cincinnati five-axis gantry mills retrofitted were built in 1978 and, according to Stellex Monitor VP Gary Kahrau, “They actually perform better now than when they were new, owing to the significant improvements in CNC technology.” He says Sinumerik 840D CNC includes specific features for five-axis aerospace cutting unavailable from other control suppliers. Siemens development engineers worked closely with Boeing’s Fabrication Division in Wichita, Kansas, and EADS’ military group in Augsburg, Germany, over the past five years to develop and refine a suite of five-axis aerospace machining specific software features, available to all Siemens 840D users, Siemens says.

“The open architecture of the control allows us to create our own screens and integrate with our ERP system,” Kahrau says. “We store all our data on a proprietary ERP system. Data files are dispatched to the (Siemens) 840D, where our custom Shop Workstation program resides. It handles the handshake of the data files with the control. This program is fully integrated with the control’s tool management system, as well.”

With the real time five-axis kinematic transformation called Traori, a more accurate and substantially faster control scenario is achievable. Traditional CNCs require a post processor to convert a part’s workpiece definition data to machine coordinate data. During post processing, valuable information about the part is stripped from the data. This reduced data set is then sent to the CNC. The 840D control can directly accept the part’s workpiece definition data using Traori. Complete workpiece definition enables the 840D to calculate smooth and accurate cutting motions, as well as accurate three-dimensional cutter compensation. Gone are the short G01 blocks for the A- and B-axis positions that create surface imperfections called “faceting.”

According to Kahrau, “With the extreme metal removal rates, deep pockets and long contours typically encountered in aerospace production, this unique feature of Sinumerik 840D has demonstrable upsides every day for Stellex.” When running the same part on different gantry mills, Traori provides different compensation for the particular machine kinematics, thus virtually eliminating specific part programs for each machine configuration. This provides flexibility in moving production from one machine type to another. If desired, Sinumerik 840D can also accept traditional machine coordinate data from a post processor. This enables a user to apply old part programs again. Even with this old programming method, the 840D provides a benefit using a unique feature called CompCAD. When CompCAD is activated, the 840D calculates, in real time, a fifth-order polynomial spline path through the G01 machine position data blocks. Thespline is both curvature and velocity steady for transitions. This avoids contour violations, increases efficiency of acceleration/deceleration curves, and eliminates slowdown/speedup at block transitions. The net effect is a reduction in machining time and improved component surface finish by reduction of “faceting.” Stellex’s Kahrau adds, “A cutter diameter compensation and customizable tool management system onboard the 840D give operators quick and accurate information in real time, plus it has the capability to accept additional features, as the application demands.”

Siemens says the CNC, servo motor and drive retrofit package, designed specifically for Cincinnati Milacron five-axis gantry mills, can be installed in four weeks of machine downtime.



Safety should support all retrofit activities

Safety remains part of the the foundation for all retrofit activities, especially in the U.S. where safety regulations focus on risk assessment of installed machinery, rather than directing how machinery should be built.

Sam Boytor, president, Fox Controls Inc., has seen the need for greater attention on retrofit safety since he started selling safety devices more than 15 years ago. Now as a system integrator and safety trainer, the need is so great his company works exclusively on machine safeguarding. He serves on eleven ANSI B11 committees (sponsored by AMT—The Association For Manufacturing Technology), is committee chair for ANSI B11 TR4 Subcommittee on programmable safety controllers, and meets monthly with safety directors of John Deere, General Motors, Toyota, and Chrysler, and manufacturers of safety components, among others.

'It's not illegal to make unsafe machinery in the United States,' Boytor says. 'It should be, but it isn't. The minute the unsafe machine hits the plant floor, though, OSHA can issue a citation to the user. In Europe, safety directives specify how machines will be built, and the regulatory agency can fine the machine builder as well as the user. In the U.S, a risk assessment according to performance-based standards determines what level of guarding must be required after machines are built and before they're allowed to operate.'

And how are manufacturers doing with machine safety? 'Very little is done out there,' Boytor says. 'There's a huge need. Almost all safety is done by retrofit in the United States. We're doing some major campaigns at companies like Alcoa, Anheuser-Busch, and John Deere, taking solutions implemented on one line to facilities around the country. Bigger companies like these are bringing plants into compliance with safety standards. It's difficult to do, and there's a learning curve, but having a corporate standard makes it easier to create policies and then budget for needed improvements.'

In some instances the human resources department is responsible for safety, Boytor says, because it often hands out eye protection. Obviously machine safety is significantly different; machine-safeguarding experts with plant-floor experience have a better chance at avoiding injury for themselves and others. 'Everyone does a form of risk assessment, but it usually is not a documented, task-based risk assessment, with attention to risk reduction. OSHA's general duty clause says there needs to be a process in place that focuses on hard-guarding first, devices second, signage third, and training fourth.

After being involved in perhaps 10,000 risk assessments in 10 years, Boytor has dispelled more than a few myths on risk assessments, documentation, and the nature of machine safeguards. To read more, see this article online at

Machine safety costs/benefits

'How much safety is enough?' is the $64,000 (or perhaps $64 million) question, considering damages, litigation, lost productivity, image loss, and other fall-out from injuries or loss of life incidents. Options are many, through process design, integration with controls, enclosing hazards, locking out access, sensing intrusion, and allowing for an emergency stop of the process.

'Safety pays,' according to J.B. Titus, Siemens, safety integrated manager, discrete industries, in a presentation at Pack Expo International. Integrating safety and controls can make safety measures a greater source of reliability, lowering overall costs of operations... if it's done correctly.

Integrated safety allowed Pearson Packaging System Case Erector Packaging Machine assembly time to decrease from 368 to 96 hours, a 70% time savings. Integrated safety allowed another machine builder savings of $126,000 per machine, with reduced panel space, reduced hardware and engineering time, and lower cost to end-users, Titus explains. To realize savings, there's a need to understand related regulations, including IEC 61508, NPFA 79, RIA 15.06, FPA, ANSI B11.19, TR4 2004, and OSHA guidelines.