Breach of Contract – Conveyor System
In 2018 Mr. Terpstra served as an expert in a case between a cardboard box manufacturer and a conveyor company. The case related to the ability of the supplied conveyor systems to meet expected levels of performance and reliability.
Mr. Terpstra conducted an on-site inspection of the subject conveyor system for the defendant’s council, Finn Dixon & Herling.
After the inspection of the equipment, a report was generated related to potential failure modes, system installation, and system maintenance. The report included a large number of pertinent photos and is being used in settlement negotiations.
This case is still pending.
Case Details:
Supreme Court of the State of New York, County of Orange.
President Container Group, plaintiff, against System Corporation, dba Systec Conveyors, defendant.
Index No. EF003834-2018.
Machine Tool Update
The challenge was to extend the life of a 35+ year old machine tool. The control hardware was no longer supported and failures were becoming more common. After servicing the machine for more than four years it was finally impossible to find replacement components.
It was agreed that the long-term solution was to replace both the controller and servo drives of the large boring bar. Replacing the CNC controller with a newer version was relatively straightforward with a minimum of software changes required. After much research new servo drives were found that would work with the very old servo motors. Repair services for the servo motors were also located for the customer.
Before Updates
After Updates
Breach of Contract – Automotive Supplier
In 2018 Mr. Terpstra served as an expert in a case between an automotive company, a first-tier supplier and a second-tier suppler.
At the request of defense council, Foley, Baron, Metzger & Juip, he reviewed thousands of pages of documents from all three parties relating to a quality issue with a part manufactured by the second-tier supplier. A report was created relating to responsibility for the quality issue according to standard quality practices.
Mr. Terpstra was deposed for this case but the case was settled before testimony was required.
Case Details:
State of Michigan, The Circuit Court for the County of Oakland, Business Court.
General Motors, LLC vs. Magna Powertrain of America, Inc. vs. Feintool Tennesee, Inc.
Case No. 2017-160166-CB
Shield Support Analysis
A company that provides radiation shielding and contamination control products for commercial nuclear power, nuclear medicine and industrial radiography lacked FEA analysis capabilities.
Innalytical Solutions provides FEA analysis for this client when failure of their products could be catastrophic. These analysis range from very simple static analysis to studying the reaction of structures to the random vibrations of an earthquake. In some cases these analysis must be approved by various government agencies.
Industrial Safety Incident
In 2018 our founder provided a safely analysis of a series of industrial packaging systems for a large plastics company, after a safety incident had occurred.
Breach of Contract – Bagging System
In 2017 our founder provided an analysis and report for litigation between a packaging system integrator and a customer. The case related to the ability of the mixing & bagging system provided by the integrator to meet expected levels of performance and reliability.
Industrial Accident
In 2017 our founder provided analysis of an industrial machine that was involved in a fatal industrial accident.
Breach of Contract – Steel Cutting System
Trade Secret / Breach of Contract
In 2015 our founder provided an expert opinion report for litigation between two companies that had been formed out of a single company. The case concerned breach of contract and the use of trade secrets. In May of 2015 he was deposed for this case. In June of 2015 he testified in the Court of Chancery of the State of Delaware with regard to the same case. The technical portion of the case, which he addressed, involved the improper use of SolidWorks CAD models by the defendant.
Brush Trim Cell
The challenge was to trim the bristles of a molded brush head that came in a range of sizes and shapes.
The solution was a simple cell with adjustable motions that allowed the brush diameter to be set anywhere within a defined range. The corner radius could also be adjusted within a wide range.
Innalytical Solutions completed the mechanical design of this system and programmed the PLC / HMI unit. Images used courtesy of Better By Design.
Patent Infringement – Food Packaging Machine
In 2013 our founder provided an expert opinion report for litigation between two manufacturers of food packaging systems. The case related to a patent infringement, and in particular, how stress was carried through the frame of that machine. The case was settled before his deposition was to occur.
Shutoff Valve Analysis / Simulation
The challenge was to ensure that a shutoff valve, operating 5,000 feet below sea level, had adequate clearance to function in spite of the great water pressure applied to the device.
Innalytical Solutions completed a finite element analysis of the valve design to verify the deflection did not affect its operation. Images used courtesy of Deep Sea Innovations.
Once the FEA analysis was completed, the customer requested an animated video that would explain the operation of the valve, and also demonstrate that it would operate at the bottom of the sea. The animation shown below was created in SolidWorks and proved invaluable to the customer.
Insulated Glass Panel
The challenge was to assemble insulated glass panels utilizing a very unique spacer between the glass panels.
The solution included a spacer transport system, a rotary assembly / forming station, as well as a gas fill station.
Innalytical Solutions led the design of each of these systems including Finite Element Analysis of components when required.
Patents
Click on image to view full patent.
Parabolic Microphone
The challenge was to create a better long-range microphone for sports television.
The solution was a totally new design based on very old technology. The input of the audio engineers was used to create a product that addressed their concerns as well as safety concerns. The design led to the creation of an entirely new business which is now believed to be the largest manufacturer of parabolic microphones in the world.
Three different sizes of parabolic microphones have been developed as well as a “pro-sumer” version intended for non-broadcast customers. In addition, two U.S. patents have been issued for the design of these products.
Images courtesy of Klover Products, Inc.
Patent
Click on image to view full patent.
Axle Assembly System
The challenge was to assemble a large axle assembly with a totally flexible / reconfigurable system while using only battery powered torque wrenches for the assembly process.
The solution was a series of portable assembly cell along with hand powered transfer carts and assembly fixtures carried by Automated Guided Vehicles (AGVs) .
Innalytical Solutions provided the mechanical design for the entire system. Images used courtesy of Midwest Engineered Systems.
Storm Damage to CNC Machine
In 2011 our founder provided an expert opinion report to the owner of a machine shop related to the potential of a thunder storm causing damage to a computer numeric controlled (CNC) machine tool. This report was used in negotiations with his insurance company.
Roof Rack Analysis
Our customer was faced with a significant hurdle. Their sensor system was not allowed in certain European countries because of concerns for its safety. The sensor, used widely in the United States, was mounted to the roof of a station wagon and driven down streets and highways while data was being collected. The concern was that the weight of the sensor exceeded the rated roof rack capacity of the automobile manufacturer.
The solution was to provide a thorough Finite Element Analysis of the sensor and its support structure mounted to the automobile roof. The combined assembly was subjected to dynamic loads of up to 60 Gs to determine the stresses placed upon the individual components.
As a CAD model of the automobile was not made available, a model of the automobile roof was generated using a 3D laser scan of an actual automobile. This model was then used to complete the analysis.
Robotic Assembly & Packaging Cell
The challenge was to install various components into injection molded plastic parts coming directly from the injection molding machine.
The solution was a robotic cell with interchangeable tooling that allowed 11 different automotive parts to be assembled and packaged for shipment to the assembly plant.
Innalytical Solutions completed the mechanical design of this system. Images used courtesy of Better By Design.
Tumbler Broaching Cell
The challenge was to automatically broach the slots in a small lock tumbler.
The solution was a dial based cell that could broach and inspect the lock tumbler.
Innalytical Solutions provided the mechanical design for the system. Images used courtesy of Midwest Engineered Systems.
The adjacent image is a SolidWorks rendering of the cell.
Super Bowl Television Stage
We were proud to assist our customer, Northern Lights Productions, in the design and analysis of a television set for Fox Sports’ coverage of Super Bowl XLV. The set was designed using our customer’s ModTruss system and configured to provide a cantilevered roof that provided an unobstructed view of Cowboys Stadium. The roof structure also provided support for television lights.
Semi-Automatic Tire Assembly
The challenge was to provide a machine that would disassemble a three piece rim assembly and then assemble the complete pneumatic tire. The tires are used on off-road equipment excavating equipment and weigh up to 1,500 pounds. The tire design presented many ergonomic and safety issues as the tires ranged in size from 50” to 65” in diameter and from 12” to 24” in width.
A concept was proposed that assisted the operator with as much of the disassembly & reassembly process as possible while providing as safe an environment for the operator as possible. The proposal was accepted and the machine was purchased with a 24 week delivery.
The final machine automatically removed the “lock ring” that kept the rim parts securely connected but provided an ergonomic method of re-installing the lock ring after the tire had been installed.
In addition to leading the mechanical design, we also created the logic which controls the machine and a user-friendly operator interface which accommodates up to 16 different rim sizes.
Photos courtesy of Titan Systems.
Modular Lift Table
The challenge was to design a scissors lift table that could be readily converted from hydraulic to pneumatic power or changed between three different lifting capacities.
The solution was a modular design with bolted joints. Five basic frame sizes were utilized to build the seven standard configurations. These standard frames were then mated to one of fifteen standard table tops or optional modules such as a tilt table.
In addition to the mechanical design, we also conducted Finite Element Analysis of many components and certified the load testing of the completed units.
This image is a SolidWorks rendering of the pneumatic version of the lift table.
Photo of the actual lift table. Used by permission of MII Equipment, Inc.
Photo of the physical load testing of the prototype lift table. Used by permission of MII Equipment, Inc.
Steam Heater
The challenge was to design a mechanism to drive an internal adjustment (regulation) using an external electric motor, while also providing feedback from the adjustment mechanism, or by using a hand tool.
The solution was a unique combination of drive components which is proprietary to our customer.
In addition to the mechanical design, we also conducted Finite Element Analysis of various components.
The first image is a SolidWorks rendering of the steam heater’s solid model. Images used by permission of ProSonix LLC
Upender Table
The challenge was to design a table that tips a large components from vertical to horizontal (upender) with enough strength to support the loads.
The solution was created using SolidWorks to design a heavy duty tilt mechanism and then analyzing the stresses using the SolidWorks simulation (finite element analysis) software.
Images used courtesy of Lift Products Inc.
Modular Assembly / Test Fixture
The challenge was to design a modular fixture that would allow multiple products to be assembled and tested within the same assembly cell.
The solution was a series of small modular fixtures based on die stamping components that allowed various parts to be assembled and tested. The various fixtures were easily exchanged as both electrical and pneumatic connections were made through modular connectors.
Fuel Tank Leak Test
The challenge was to design a system to leak test a fuel tank, by dunking the pressurized tank under water, with the ability to easily locate the source of the leak.
The solution was a mechanism that lowered the fuel tank into the dunk tank and then rotated the tank so all sides were visible under water.
We completed the mechanical design of the system.
Boom Pin Press
The challenge was to press a large pivot pin into the large boom of an excavator.
The solution was a large tool balancer that supported a floating frame, which included a press cylinder, that would pull the pivot into the boom and frame.
Innalytical Solutions completed the mechanical design of this system. Images used courtesy of Titan Systems.
Hydraulic Valve Test Stand
The challenge was to test a wide variety of hydraulic valve packs in a single test stand.
The solution was a test stand with modular fixtures that adapted the different valve packs to the test stand.
Innalytical Solutions completed the mechanical design of this system. Images used courtesy of Titan Systems.
Innalytical Solutions also completed a Finite Element Analysis on the machine base to insure it could withstand the large forces generated by the hydraulic pressure applied to the valve packs.
Pump Test Stand
The challenge was to test a wide variety of hydraulic pumps in a single test stand.
The solution was test stand with modular mounting hardware that adapted to the different pumps.
Innalytical Solutions completed the mechanical design of this system. Images used courtesy of Titan Systems.
When customers wanted to use the test stands in test rooms with lower ceilings a system was needed with a lower profile. A new guard was developed that greatly reduced the system height.
Plasma Cutter CNC Controller Replacement
The challenge was to keep old machines, with obsolete CNC controllers, running for its owner.
The solution was replace the entire control system including CNC controller, servo drives, and servo motors. The new control system was customized to be as familiar as possible for the operators while adding several new features.
3 Axis Plasma Cutter / Punch Press
2 Axis Punch Press
Cutting Tool Engineering Article
Hydraulic Suspension Component Assembly & Test #2
The challenge was to design a system that could safely assemble and test several different sizes of the suspension components. In addition the machine had to contain the 1,300,000 pounds of force produced during the functional test of the assembly.
The solution was a seven axes, servo operated machine that assembled the various components into the main housing and then rotated the assembly vertical for functional testing. A 12” bore hydraulic cylinder backed up the assembly as it was tested.
In addition to the mechanical design, we also conducted Finite Element Analysis of the structure and programmed all the servo axes.
Hydraulic Suspension Component Assembly & Test #1
The challenge was to design a system that could safely assemble and test suspension components that weighed up to 4 tons each. In addition there were seven different sizes of the completed assembly.
The solution was a ten axes, servo operated machine that assembled the various components into the main housing and then rotated the assembly vertical for functional testing. In addition to the mechanical design, we also programmed all the servo axes.
Cycle Time Simulation
The challenge was to create an estimate of the time required to complete a programmed cutting cycle on a commercial finishing system. The system consisted of a cutting head mounted on a two axis gantry. The path was created using a graphical program and exported as an HPGL file. The primary concerns were achieving an error of less than 10% and ease of use.
The solution was to create an Excel spreadsheet to complete the calculations and macros to automate the process. The path data was created by importing the HPGL file and converting each line into the appropriate motion. (Arcs were converted into a series of small linear moves.) The spreadsheet calculated the time required for each move and generated a total cutting time.
The image on the left shows a sample cut pattern that was used to test the accuracy of the spreadsheet.
The video on the right shows a flatbed cutter similar to the one being simulated by the spreadsheet.
Cycle Time Simulation
The challenge was to analyze various design alternatives for a sophisticated assembly system.
The solution was to create a SolidWorks animation where each step of the assembly process could be simulated and optimized. The video shows the animation created for this study.
Collet Design
The challenge was to design a replacement collet for a two piece retractable rod that would eliminate the rattling created when the two tubes contacted each other. The concern was applying adequate pressure on the thin tube while keeping the stress on the nylon collet at a safe level.
The solution was created using SolidWorks to design an attractive collet and then analyzing the stresses using the SolidWorks finite element analysis software module. Finally a rapid prototype part was created from the 3D model so the fit could be verified on the actual assembly.
Breach of Contract – Automated Assembly System
In 2004 our founder was deposed during arbitration between his former employer, a division of Thyssen Krupp, and their customer. As he had been the Director of Research & Development during the development of the assembly system in dispute, he was questioned about the product development process and the associated testing process for a product that was used extensively in the construction of the assembly system at issue in the arbitration. The case was settled before his deposition was to occur.
Hole Gauging with Vision
The challenge was to gauge the diameters of critical holes (orifices) in cylindrical parts as it was rotated. The tolerances were as low as 0.0002″.
The solution was a system utilizing a vision inspection system triggered by a micro PLC. The micro PLC also operated the motor rotating the part and verified that the proper number of good holes were detected in each part. In tight tolerance parts a special inside-out illumination system was devised that provided a lighted plates tip inside the cylindrical part. This provide the consistent lighting required to reach such tight tolerances.
Laser Pierce
The challenge, presented by a large supplier of automobile frame assemblies, was to gain a understanding of what combination of 13 separate parameters created the optimum laser pierced hold in steel. These holes were required for mounting holes and passages in hydro-formed frame rails. Because of the nature of the hydro-forming process these holes had to be added after the rails were formed. The laser pierce process, however, had a large number of parameters (such as focal distance, laser power, oxygen purity, etc.) that needed to be adjusted to provide the optimal results. The criteria for judging the best cut was the surface finish of the hole produced. Because of the large number of parameters that needed to be adjusted a huge number of sample cuts would be required to provide the best hole.
The solution was to create a Design of Experiments matrix utilizing an Excel spreadsheet that allowed the optimum settings to be determined with only a few dozen samples. The result was a huge savings of both time and money as the samples were taken more quickly and the project was completed much faster. Obviously, a test stand was also required to create these sample holes. A laser, laser cutting head, and robot were leased for three months so the entire test process had to be completed within the strict deadline.
Our founder created the test stand with two separate fixtures, as well as programs for the robot, cutting head and laser.
Breach of Contract – Driver Simulation System
In 2014 our founder provided an expert opinion report for litigation between a technical college and a manufacturer of portable driver simulation systems. The case related to the ability of the driver simulation (training) system provided to met expected levels of performance and reliability. The case was settled before his deposition was to occur.
Linear-Circular Assembly System
The challenge was to pick up series of trapezoidal parts cut from a coil and place them in a circular pattern for assembly. The process had to handle over eight trapezoidal parts per second. As the parts were created by making angled cuts across the strip of material the left hand and right hand parts also had to be separated.
The solution was to create a tooling head that utilized segmented tooling – very much like a chain. When the chain was straightened the parts could be picked up from the cutting station. The chain was then coiled up in order to place the parts into the circular pattern that was required. One tooling head was used for the left hand parts while a second tooling head was used for the right hand parts. The two head dictated a mirror image assembly system. One assembly station for the left hand parts and another for the right hand parts.
This video shows a SolidWorks animation of a time study for an alternative assembly process.
Torque Converter Blade Insertion System
The challenge was to create a modern replacement for a very old, totally mechanical machine that inserted blades into torque converter shells. The primary concern was the ability to operate on more than one model of torque converter in the same machine. The original machines required many weeks to convert from one model to another.
The solution proposed was to mount the shell on a Stewart Platform robot and actually push the shell onto the blade which was held stationery by a feeding mechanism. As the shell is toroidal and the blade is spherical the six degrees of freedom allowed the blade to be twisted and turned the the assembly operation occurred.
Unfortunately this machine was never constructed.
Click image to view U.S. Patent.
These images show the original blade loader machines and their mechanisms.
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Picture8
Picture2
Picture3
Picture4
Picture5
Picture6
Picture7
Programmable Part Handler
The challenge was to create a programmable pick & place device which could load and unload parts from automated assembly machines within a X-Z plane. The device needed to be less expensive than commercial robots and have a payload of at least 15 pounds. The standard approach to this type of device a combination of two linear axes mounted perpendicular to each other. The problem with this solution is that the horizontal axis must be considerably larger due the fact that it must carry the extra mass of the vertical axis. The larger size of the horizontal axis increases the system cost. In addition, system performance is greatly reduced due to the large mass reducing the rate of acceleration and increasing settling time.
The solution was to place the two carriages in parallel on a linear servo motor stage. The two axis are connected by a linkage that provides a horizontal motion when the two axis when the two axes operate in the same direction and a vertical motion when the two axes operate in opposite directions. With this configuration each axis carries only one half of the payload mass plus the weight of two links. Extremely high velocities and accelerations can be achieved with this system and the linear servo motors provide excellent reliability as the only wear parts are linear bearings, rotary ball bearings, and cables. In addition, the linear servos can be constructed in almost any length desired thus providing a longer work envelope than would be possible with ball screw stages.
First installed unit:
225mm x 2.5m work envelope
120 different pick-up points
2 m/sec
22.5 hrs/day operation
Second installed unit
0.1m x 2.5m work envelope
17 drop off points
3 m/sec
9 sec cylce time –
including 5 sec for gauging
One of twelve modules constructed utilizing 80 part handling units to assemble diesel fuel injectors.
The system incorporated:
250 servos
over 100 vision cameras
laser etched bar codes
78 vibratory feeder bowls
Click image to view U.S. Patent.
Gantry Tool Changer
The challenge was to create a tool changer for a machine tool (planer mill) that utilized cutting tools up to 16 inches in diameter and weighing up to 125 pounds. The customer also required that these cutting tools to be exchanged in banks, or groups, that were pre-configured for the part being manufactured as well as minimal tool exchange time. In addition, tools needed to be loaded to the machine tool in either a vertical or horizontal attitude.
The solution was to a large gantry (X, Y, Z) robot capable of handling two of the large cutting tools. The robot’s tooling was capable of rotating each cutting tool taper up or taper horizontal, for loading into the machine tool, as well as taper down, for storage. In addition, the tooling rotated 90 degrees about the vertical axis to provide access to the tool storage racks. Interchangeable tool storage racks were also created that provided a stair-step configuration that allowed different length tools to be stored at different levels without limiting access to the cutting tools on other levels. When the machine tool called for a new cutting tool, the robot would move to the proper storage rack and retrieve the proper cutting tool. It would then move to the machine tool and remove the old cutting tool from the machine tool spindle and place the new cutting tool into the spindle. The old cutting tool was then placed into proper storage rack. An RF tag was imbedded into each cutting tool and each storage rack to insure that the right cutting tool was used at all times.
Modular Conveyor Corner
The challenge, presented by a large automobile engine plant, was to create a heavy duty conveyor that could be operated even if electrical power and the source of compressed air was lost. A reduced production rate was acceptable but production had to continue. In common heavy duty conveyors the fixtures, often weighing up to 1000 pounds, were lifted above the conveyor side rail and then transferred off in a perpendicular path to make corners or to divert fixtures off the main line to repair spurs or parallel operations. The fixture was also lifted when it was necessary to rotate the fixture for various assembly processes that might require a different face of the engine to be presented. The modular conveyor described in “Modular Conveyor System” already satisfied this requirement but a new design was required for corners and fixture rotate stations.
The solution was to place four rollers, mounted at 45 degree angles to the normal conveyor path, at the same elevation as the straight conveyor rollers. By rotating the rollers in a direction that was at a 45 degree angle to the required path the applied forces offset each other and the fixture traveled in the desired direction. For example if the desired direction is to the right all the rollers are operated so the motion is to the right. The lower left and upper right rollers rotate toward the lower right corner. The upper left and lower right rollers rotate toward the upper right corner. If the desired direction is upward all the rollers are operated so the motion was upward. The lower left and upper right rollers rotate toward the upper left corner. The upper left and lower right rollers rotate toward the upper right corner. If the fixture needs to be rotated about its center all the rollers rotate in the same direction. Pneumatically operated guides help guide the fixture during these motions.
Admittedly, it takes a good amount of effort to manually push a fixture through such a corner unit but the customer was extremely happy. This conveyor module proved to be extremely reliable. It also allowed corner modules, lift & transfer modules, and lift & rotate modules to be replaced with just one module providing great flexibility. This flexibility was improved by making it interchangeable with the straight conveyor section described in Case #7. Major system changes were completed over a weekend due to this modular construction.
Awards
Magazine Articles
Click on image to read full article.
Patent
Click on image to view full patent.
Custom Components
Several custom components were developed specifically for this new conveyor. First of all the motors were created by combining a standard gearbox with a special version of a torque motor. It was literally impossible to burn out the motor as it dissipated as much heat as it could generate.
A special I/O module was also developed to operate this conveyor. The single block turned on and off two sets of three phase motors , changed the direction of the motor, monitored the motor current, and protected the motors with onboard fuses. It also monitored two inputs, and monitored the sensors for short circuits or open circuits. The module was controlled using a DeviceNet network. Both in and out ports were provided for the network, as well as the three phase power supply, so that the cables could be daisy chained from one block to the next.
Another special DeviceNet block was created by InterLink based on our requests. The block provided bidirectional I/O so that one network could communicate with another. This allowed each conveyor module to communicate with its neighbors so that a pallet was not transferred into a module that was not ready to receive it. The block shown below is the current version of this product. It was given to our founder by Interlink in appreciation for suggesting the idea for the product.
Ruggedness
In spite of setting efficiency and uptime records for assembly lines within the corporation, the two assembly lines were dismantled when the plant was closed. After transporting millions of V8 engines the systems were brutally ripped up and trucked to Mexico where the modules were stacked like firewood, (mostly uncovered) in the parking lot of the plant. The modules were stored like this for many months until the floor space was available for reassembly. Castings and electric motors were literally broken in half during the transport and stacking.
After this “less than ideal” treatment the modules were reassembled to create one “new” assembly line. Many bearings had to be replaced and rust had to be manually removed from many, many parts but the system was brought back to life and operated for more than ten years after it was first installed.
This story is not only a testament to the ruggedness of conveyor itself but also the many components that made it up. Even the PLC’s and operator interface screens survived the ordeal.
Modular Conveyor System
The challenge was to create a heavy duty roller conveyor that did not require the ongoing maintenance and adjustment of friction rollers or clutches normally encountered. An additional challenge was reduce the ongoing maintenance or pallet stops that take a continuous beating as 700 – 1000 pound pallet slammed into them.
The solution was to eliminate the clutch altogether! By using a unique electric motor to drive just one or two rollers an “electric clutch” was provided that eliminated all mechanical clutches. By adding a series of sensors and the required controls the conveyor was able to stop the pallet by reversing the electric motors – eliminating the mechanical stops altogether. This conveyor was extremely reliable as nearly all wear items were removed.
It set a new standard for up-time within the customer’s plants.
Conveyor maintenance dropped from two full time employees to 15 minutes per month.
Awards
Magazine Articles
Click on image to read full article.
Patent
Click on image to view full patent.
Custom Components
Several custom components were developed specifically for this new conveyor. First of all the motors were created by combining a standard gearbox with a special version of a torque motor. It was literally impossible to burn out the motor as it dissipated as much heat as it could generate.
A special I/O module was also developed to operate this conveyor. The single block turned on and off two sets of three phase motors , changed the direction of the motor, monitored the motor current, and protected the motors with onboard fuses. It also monitored two inputs, and monitored the sensors for short circuits or open circuits. The module was controlled using a DeviceNet network. Both in and out ports were provided for the network, as well as the three phase power supply, so that the cables could be daisy chained from one block to the next.
Another special DeviceNet block was created by InterLink based on our requests. The block provided bidirectional I/O so that one network could communicate with another. This allowed each conveyor module to communicate with its neighbors so that a pallet was not transferred into a module that was not ready to receive it. The block shown below is the current version of this product. It was given to our founder by Interlink in appreciation for suggesting the idea for the product.
Ruggedness
In spite of setting efficiency and uptime records for assembly lines within the corporation, the two assembly lines were dismantled when the plant was closed. After transporting millions of V8 engines the systems were brutally ripped up and trucked to Mexico where the modules were stacked like firewood, (mostly uncovered) in the parking lot of the plant. The modules were stored like this for many months until the floor space was available for reassembly. Castings and electric motors were literally broken in half during the transport and stacking.
After this “less than ideal” treatment the modules were reassembled to create one “new” assembly line. Many bearings had to be replaced and rust had to be manually removed from many, many parts but the system was brought back to life and operated for more than ten years after it was first installed.
This story is not only a testament to the ruggedness of conveyor itself but also the many components that made it up. Even the PLC’s and operator interface screens survived the ordeal.
Assembly System Simulation
The challenge was to create a user friendly computer simulation of manufacturing systems back in the days before Windows. The simulation itself was generated by a software package that used a C-like language to create the simulations. The engineers needing the simulations, however, were not programmers.
The solution was a front end created in C that prompted a user for the vital data that described the manufacturing system (such as cycle time, transfer time, uptime, and efficiencies) and created the code the the simulation package required. In addition, code was created that modified the generic graphic output of the simulation package to model the actual manufacturing system. Nearly 6000 lines of code were required for the front-end in addition to the basic simulation code that was then modified to create the final simulation.
Dash Assembly
The challenge was to design a system to install the instrument cluster, heater control panel, and the radio into the automobile dash being carried by an Automated Guided Vehicle (AGV).
The solution was a fixture that rode on top of the AGV along with a robotic cell that located the assembly fixture and installed the three components.
Our found completed the mechanical design of both systems.
Master Fixture Calibration
The challenge was to make fine adjustments to a master fixture that was used to machine a mini-van space frame. The master was the same size as the actual mini-van and had 57 locating pads that needed to be located to better than 0.001″. A giant coordinate measuring machine was used to measure the position of the locating pads in X, Y, and Z but what adjustments were required to each pad in order to accomplish the final 0.001″ tolerance?
The solution was a large spreadsheet that created a best fit linear regression center line for the master fixture and calculated the adjustment required for each of the 57 locating pads. After the calculations were completed and new, corrected pads were installed the measurement process was completed again with a very small number of readjustments required. It is unlikely the tolerance would have ever been achieved without the best fit calculations done by this spreadsheet. Thousands of dollars were saved by reducing the number of iterations required to achieve the tolerance levels.
This massive spreadsheet was created using a very rudimentary, very early version of Lotus 123.
Floating Locating Pin
The solution was a locating pin that could float with the movement of the table and then be locked into position.
As the table was raised hardened still bushing mounted to the table engaged these floating locking pins which could translate freely in the X&Y direction. The pin was mounted to a large disk that was supported by spring loaded ball rollers. Once the table was positioned large air cylinders would force the ball rollers down compressing the spring supports until the disk rested on brake pads. There was also a brake mounted to the air cylinder piston thus lock the pin in position.
This machine ran continuously for over five years before the model was discontinued.
XYZ Table
The challenge was to raise an entire vehicle body off of a conveyor system and located it in the X, Y, Z and Theta axes. The Z axis was required to raise 36 inches in order to lift the body off the carrier. The body also had to be located to less than 0.001″ with a plus or minus 0.500″ range in both the X and Y axes and at the same time be able to skew the body to align the center line of the body with the center line of the machine structure. The front of the body had to be able to be at +0.005″ while the rear was at -0.005″.
The solution was a servo operated table that was nearly 8 foot wide and over 16 foot long that raised the required 36 inches on a set of six large ball screws. The ball nuts were driven by a series of large timing belts and driven by a common (very large) servo motor. A hardened ball nose pin was pressed into the end of each ball screw and the screw was kept from rotating by a ball link. A spherical roller bearing was used between the ball nut and the table itself. This design allowed the ball screw to be be tipped from vertical once the table had been raised. Servo driven ball screw actuators moved the entire table in the X axis and each end of the table independently in the Y axis. Fine adjustments to the Z position were made as the X and Y axis were being positioned. All these motions were based on a special three axis locating device the proved gauging holes on the body. The body was located to better than 0.002″.
This machine ran continuously for over five years before the model was discontinued.
Electric Motor Assembly
The challenge was to maintain the the air gap between the stator and rotor of an electric motor while the end plates were clinched to the stator assembly.
The solution was to create a shim pack assembly that was attached to the rotor before it was inserted into the stator. The shims maintained the air gap during the clinching process. Small cam lobes opened the shim arms as the assembly was inserted through the motor end plate. A square cam block was designed to open the shim pack at the proper time and then close them again to clamp onto the end plate. After the assembly process was complete the entire shim pack was then automatically removed from the completed motor and transferred upstream on a conveyor system to be used once again. The shim pack assembly was able accommodate different size motors by using different length
shims.
This equipment ran for over 18 years!
Circuit Breaker Test
The challenge was to replace a manual test station for circuit breakers. Operators were manually loading and unloading circuit breakers into sockets of a test stand and then sort the good and reject units based on a series of lights. Repetitive motion was a constant concern and operator mistakes led to high warranty costs.The solution was to robotically load the circuit breakers into the test stand and then sorted the complete units between good and three different types of rejects.
The circuit breakers were fed automatically by a vibratory feeder and presented two at a time to the robot. They were then placed into one of four sets of two test sockets and a defined amperage is applied. The extension of the reset button is checked with a photoelectric sensor. After the breaker opens, or times out, the robot removes the units, drops any failed units and places good units into a shipping tray. The shipping trays are automatically stacked and an empty is loaded automatically so that the system can run over an hour’s production without operator intervention. The tray stackers were unique in that they each were operated using only one pneumatic cylinder. The testing cost was drastically reduced, repetitive motion was no longer an issue and warranty issues were reduced significantly.
The mechanic design, electrical design, PLC programming, and robot programming were all completed by our founder early in his career.
