Motion Index Drives, Inc. has moved the location of this blog to its website: www.motionindexdrives.com/blog. Future posts about the innovative cam-driven solutions we provide can be found there, and we encourage any comments to be directed to this new URL.

Thank you for following our posts so closely, we hope to continue to provide interesting material for readers of all knowledge levels about the precision and strength of cam-driven indexing systems.

1. Conveyor Drive: Although Motion Index Drives produces its own LF Series Precision Link Conveyors (industry-leading quality and pricing!), our parallel indexers are excellent drives for conveyors of all configurations and brands. Conveyors that often utilize stepping process (e.g. belt, chain, link, etc.) benefit greatly from the reliability of Motion’s cam-driven drive solutions.
2. Pivot Arm: Motion Index Drives’ Parallel Indexers are particularly well suited to act as pivot arms. Throughout the world, this configuration is used for sorting packages on shipping conveyors and chutes. Pivot arms are used in a variety of other industries as a simple mechanism for directing or enabling the flow of a product through assembly.
3. Producing Linear Movement: As depicted, Parallel Indexers can be utilized to produce oscillating linear movement while the indexer operates in a continuous mode. A Parallel Indexer operating in continuous mode will provide significantly better accuracy and lifespan than many other options for producing the oscillating linear motion depicted.
4. Part Rotation: With the addition of a small dial plate, a Parallel Indexer can act as a rotary surface for small parts. This option is often utilized for customers seeking a rotating surface smaller than our RT Series is capable of providing. With a Parallel Indexer such as an XP050, a significant amount of space and cost can be saved for these smaller applications.
5. Manipulation and Isolation: In the depicted example, a Parallel Indexer equipped with the proper tooling and system interaction removes part A and places it in a new configuration, A’. In assembly, this may be a necessary action in order for the part to be completed in additional assembly stages.

Motion's Lobby Display with a RT250 Drive

Differences

Trunnion Indexers are vertically mounted Rotary Index Tables designed for the unique purpose of creating a plane of rotation perpendicular to the floor. With this system, large sets of tooling can be mounted to simple box frames and rotated above the floor. This allows for multiple sets of tooling to be in place on a single frame (one set for each side), and turned in precise increments for use. Where a process may have previously required multiple stations, a trunnion can place all the necessary tooling in one place, saving significant amounts of floor space.

The physics behind a trunnion indexer are inherently different from those behind a standard configuration rotary table. Rather than the load capacity being dependent on the inertial loading and bearing capacities, a trunnion indexer’s capacity is usually dependent on its static torque output limitations. Here is a list of permissible static output torque values [Nm] for our line of rotary index tables:

A properly designed, well balanced trunnion system is capable of moving significant weights at remarkable speeds. Since inertia in a trunnion configuration is exponentially dependent upon system balance, a properly engineered system is necessary for an efficient end product.

Applications

Trunnions can be applied to any number of applications, but they are most commonly used for mounting welding equipment, rotary positioning and the mounting and rotation of parts for assembly purposes. The same custom design elements that can be applied to Motion Index Drives’ RT Series can be applied to the indexer used in a trunnion configuration. Special coatings; continuous, oscillating or flexible modes of operation; custom index times and dwell periods; as well as reinforced cam followers for increased static torque capacities.

Benefits

Several benefits have already been outlined, such as the saved floor space and potential for managed high load capacities in a well engineered system. In addition to these, manufacturing costs of a trunnion system tend to be lower than a standard configuration rotary table. In a properly balanced system, trunnions can allow for drives and frames to be sized down when compared to standard configuration counterparts. As an added note, trunnion drives offer significantly higher accessibility for maintenance purposes, giving owners and operators the opportunity to perform easier maintenance checks and potentially extend the life of the indexer.

To find out if a trunnion is the proper solution for your application needs, contact Motion Index Drives, Inc. at 877-866-1677 or fill out an application inquiry form online here.

One of Several E-Stop Buttons on this Custom Application

Safety Standards

Affects: How quickly a fully loaded indexer can safely be brought to a full stop, visibility

Options: Motion addresses this issue in table and motor sizing. Other indexer-related safety options include light screens, emergency stop buttons, colors and various others.

Description: Safety standards vary widely from company to company and even more from country to country. Safety is one of the most heavily regulated factors in most industrial processes and many technologies are available to meet these standards. Motion does not provide safety fixtures outside of those directly related to the indexing drive such as light screens or rubber mats. Solutions provided by Motion typically call for motors with enough braking power to bring a fully loaded indexer to a complete stop within a set time, as well as an indexer designed to withstand multiple e-stops without degradation of performance.

Nickel Plated Display Indexer

Surfaces/Coatings

Affects: Air Quality (via VOCs and surface exposure), Corrosion Resistance, Visibility, Range of items that can contact surface

Options: Various Colors, Low VOC and Water-Based Paints, Nickel Plating

Description: An indexer’s surface impacts several items of concern for safety, environmental and production. Visibility of heavy machinery such as an indexer is of importance for relevant safety standards. Low VOC paints may also be required for certain air quality standards or LEED facilities. Additionally, the surface coating is an indexer’s first line of protection against corrosion, which is a common issue – many indexers Motion has serviced have been found in up to a foot of standing water, oils and other various fluids. Nickel plating is the standard solution for many clean room indexer applications because of its reliable resistance to corrosion.

Not exactly standard, but a good visual of oil not leaving an indexer

Seals

Affects: Oil Leakage/Loss, Longevity, Air Quality

Options: Multi-Lip Seals, Different Materials, Spring Loaded (Mechanical), Coatings, Labyrinth Sealing

Description: Depending on the model, you will find multiple snap rings, O-rings and two-lip rubber seals on an RT Series indexer. These seals are tight enough to remain in use for decades (in standard climates) and need to be physically damaged in order to be removed. These, however, can crack under particularly harsh conditions, and don’t create a completely air tight system. Seals utilized for creating air tight systems can vary widely and will range from multi lip rubber seals and metal coatings to spring loaded units. Labyrinth sealing is utilized on indexers in industries where heavy washdowns of equipment are performed on a routine basis.

Yes, you are looking at a photo of some random oil waiting to be disposed of

Oil

Affects: Flammability, Longevity, Accuracy

Options: Oils vary as widely as the plant and wildlife Earth has to offer

Description: Motion Index Drives, Inc. recently placed indexers for fire door operation in a facility that handles weapons grade radioactive materials. As you can imagine, the oil placed in the indexer had to be particularly non-flammable and resistant to high radiation levels. Although extremely costly, this oil serves as an example of how widely the chemical properties of oil can vary. More commonly, oils that can be safely exposed in environments that perform food process or medical manufacturing tasks serve as an example of non-standard oils. Motion completely immerses the internal components of its indexers in an oil bath; many models will never require an oil change.

The Motor

Affects: Speed, Torque, Braking, Power Consumption

Options: Single and Two Speed, RPM and Torque values

Description: Key distinctions in motors can be found in two vs. single speed and varying RPM and torque capabilities. Motion manufactures tables with low-friction internal components; it is common for a Motion indexer to require a considerably smaller, more efficient and cost effective motor than leading competitors.

The Cam

Affects: Station Count, Indexing Speed, Longevity, Precision, Strength

Options: Barrel, Globoidal, Disc Various Laws of Motion, Physical Dimensions

Description: The heart of an indexer is its cam. It directly drives the dial plate/output shaft via the mechanical interaction between cam and cam followers (fixed to output). The indexer’s precision is entirely dependent on the quality of the cam’s surfaces; high-precision machining is necessary for the cam’s surface(s) to ensure an accurate dwell. The longevity of an indexer is first addressed at the hardening process of the cam and cam followers, which creates wear resistance and resilience to unnatural impacts (such as e-stops). Station count and indexing speed are both determined by the cam’s physical qualities.*

* Note that the Motion Flex line of servo-powered flexible indexers do not have a physically determined dwell, acceleration or deceleration. These constant lead cams are different from those used in fix indexers.

The Dial Plate

Affects: Applicable Tooling Configurations, Precision at Tooling Interface Points

Options: Custom Dimensions, Hole Configurations, Surfaces, Material

Description: The dial plate (aka indexing head) is the part of the indexer most processes interact with. It is a mounting surface fixed to the indexer’s top dial with machined holes at various points for tooling. Whether you are mounting large sets of robotic welding equipment or fine fixtures to hold toothbrushes while bristles are inserted, the dial plate is where it is all attached. Dial plates and structural frames can come in almost any shape and size… provided of course it is physically possible for the table to handle it.

Here is a list of some common myths… and their corresponding truths:

constant lead cam inside rotary table

Myth #1: Barrel cam indexers cannot be flexible

Fact #1: Flexible (constant lead) cams are machined to allow 100% flexibility utilizing a servo motor or encoder device. The best of both worlds is realized with the strength of barrel cam and cam follower design along with complete flexibility.

Myth #2: Barrel cam indexers lose accuracy after only a few years

Fact #2: Barrel cam indexers that have been in use for 20+ years are quite capable of holding accuracies and repeatability as they did from day one of their production lives. Internal components are designed and constructed to be wear-free in many cases, and others will not show signs of wear as long as they are properly maintained.

Myth #3: Flexible turntables are a new technology

flexible table built for Ford in 1971

Fact #3: Flexible turntables are not a new technology on the market – Motion Index Drives has built flexible rotary index devices dating back to 1971 (fexible turntable built in 1971 for FORD Motor Company).

Myth #4: Gear rack servo drives have faster rotational index times

Fact #4: All rotational devices are limited to laws of motion – what we bring to the customer is 40 years of manufacturing, designing, engineering to offer stronger more reliable turntables based on real world applications. You can be assured that we will offer the best index times on the market with the peace of mind that your customers will have many years of maintenance-free operation.

Myth #5: Barrel cam indexers are more expensive to maintain

table that required refurb... after a long and difficult life

Fact #5: We have had barrel cam indexing devices operating for 15 to 20 years in high production dirty environments without one minute of downtime. Automotive OEMs and tier one suppliers constantly reuse our equipment for multiple programs without one component being changed out.

Myth #6: Barrel cam indexers are not programmable

Fact#6: With the flexible constant lead cam our Motion Flex Line is 100% programmable to run in clockwise, counter-clockwise, and oscillating modes. The Flex line can also be changed from month-to-month, day-to-day, shift-to-shift or minute-to-minute.

Myth #7: Barrel cam indexers are more expensive to install

Fact #7: Motion Flex programmable ring turntables are no more expensive than gear-driven servo turntables to install and, in many cases, are found to be more cost effective.

Myth #8: Flexible barrel cam indexers are less accurate than gear rack and pinion turntables or planetary gear devices

Fact #8: Our highly engineered flexible constant lead cam is designed and manufactured to operate in a preload condition on our cam followers, offering absolute zero backlash. This allows our programmable turntables to increase the accuracy and repeatability of the input transmission gear up to 18 times! The customer will realize accuracy and repeatability far beyond a rack and pinion or planetary gear device.

Check with Motion Index Drives, Inc. next time you need a solution for your factory automation project. Our staff of experienced engineers is ready to match the appropriate cam-driven device to your specific needs. Call 248-743-9999 or visit www.motionindexdrives.com.

The RT Series is Motion’s flagship product line. Following in the footsteps of the I Series, it is engineered to maintain accuracy and speed for decades in a multitude of environments. But, what exactly makes the RT Series stand out among its competitors?

1. Low Friction Internal Components

Many companies will lay claim to the fact that their internal components are “low friction.” In all honesty, it is an absolute necessity when it comes to constructing an indexer. Motion Index Drives’ RT Series is above and beyond the rest. As a result of our low friction components, our indexers require up to 50% less input power than a competitor’s indexer for the same task.

2. Pre-Loading in Dwell

This distinction may not be one to be drawn directly to other cam-driven devices, but in comparison to any gear-driven mechanism it becomes a large difference. By pre-loading the indexer’s cam followers, the RT Series achieves zero backlash in dwell. Gear locking isn’t possible with cam-driven systems – a fact our engineers have taken advantage of.

3. Flame-Hardened Cams and Cam Followers

In a previous blog post, we touched on the value of our cam manufacturing process. Motion spends the time and resources to maintain excellence in each of the units we ship. Just as we put in the time to produce a better indexer, our indexer will help you manufacture better products.

4. Unparalleled Track Record

Motion I Series rotary tables, originally produced over 40 years ago, are still in operation in several factories. Over four decades of performance on a single unit is something to be proud of. We hope to continue to share this quality with our customers today, and we continue to improve on performance.

5. Available NANO Indexer Technology

In addition to all the remarkable qualities of our standard line of RT indexers, the RT Series can also be outfitted with Motion’s patented NANO Indexer Technology – making them the most accurate barrel cam tables in the world.

Side-by-Side Comparison

The following numbers are a direct comparison between project quotes made by Motion and a leading competitor:ø

*Motion’s indexer required an SEW Eurodrive DT100L8/4; the competitor’s required an SEW Eurodrive DV132M8/4.

For more information about the RT Series, visit Motion’s website or call us at 248-743-9999. New project inquiries and quote requests can be submitted online here.

In a cam-driven system, timing and precision are both dependent on the quality of the engineering and machining behind the components.

The Power of Flexibility: A Common Misconception

Many businesses searching for a high speed assembly system (or indexer in general) feel they have to choose between the reliability of a cam-driven mechanical system and the flexibility of a programmable one. Motion Index Drives offers the reliability of a fixed cam-driven indexer and the flexibility of a programmable unit in a single place with the Motion Flex line of indexers.

What is Motion Flex?

Motion Flex equipped indexers are cam-driven devices with programmable servo motors. A unique cam profile with a constant lead gives devices the smooth movement and reliable in-station accuracy of a mechanical system. Rather than run a direct-drive motor with a number of complex moving parts and the lack of a quality union between drive and application, a Motion Flex device places precision-machined cams and cam followers where they can impact the quality of your end product.

Backlash-Free Engineering

Cams and cam followers go through Motion’s unparalleled cam production process, giving buyers the same strength and reliability of Motion’s fixed cam-driven devices. The use of a gear reducer results in zero backlash, and accuracies of ±0.01 mm are still achieved.

Backlash, caused by empty space between two gears, causes drives to oscillate upon stopping. With a unique cam profile and exceptional machining behind both cam and cam followers, Motion Flex indexers produce zero backlash. The combination of a low backlash gear reducer and pre-loaded cam followers make this indexer’s flexibility and accuracy the perfect solution for factory automation processes.

Repurposability

As products change, so do production processes. The Motion Flex line allows users to repurpose their indexing equipment for new applications. By reprogramming the servo logic, someone could alter speed, station counts and rotation patterns, as opposed to single-purpose fixed indexers (which are often better suited for extensive use with extreme loads over long periods of time in abusive environments).

Keep in mind the value of a flexible cam-driven system next time you make a purchasing decision for your automation processes. Motion Index Drives’ experienced staff is ready to assist you in properly selecting the right indexer to suit your needs.

Visit www.motionindexdrives.com for more information about the Motion Flex line of indexers.

XP Series Parallel Indexer

Motion Index Drives recently installed four parallel indexers with unique cam profiles as drives for multiple conveyor systems at a battery manufacturer’s facility. The unique element exists in the cams’ dwell, which has been extended to abnormal lengths for a customized process.

The battery manufacturer was having significant trouble synchronizing stop phases with tooling equipment for each of the conveyor systems. The previous systems, each driven directly by AC brake motors, were governed by an irreplaceable optical PLC system.

Although the optical PLC system was causing the stop delay problems with the present motors, it was necessary for it to remain in place. To solve the problem, engineers recommended replacing the AC brake motors with specially designed cam-driven indexers with an extended dwell.

Motion’s XP Series Parallel Index Drive fit the profile well, and Motion’s capability to design and machine custom cam profiles led to a unique 12-inch single-stroke dwell phase. The single index station was built for an extended period to allow the optical PLC to continue to operate as it previously had. The varying time between receiving the data, processing it and sending the stop signal was compensated for by the extended dwell.

This battery manufacturer now has a completely operative and accurate conveying system. Each of the conveyors has been fitted with a custom XP Series Parallel Index Drive, allowing the manufacturer to retain their existing optical PLC logic and conveyors.

Motion Index Drives has provided numerous custom-built indexers and cam profiles in the past. If your business requires a custom-built automation solution, contact us at 248-743-9999 or fill out a project inquiry form at www.motionindexdrives.com.

Researchers designed the C-SPECT prototype with concern for functionality, patient comfort, generating accurate images, ease of use and reliability. As a result, an innovate platform that contours to the patient’s body and holds multiple sets of collimator slits was constructed utilizing a specially designed Precision Link Conveyor from Motion Index Drives, Inc.

The prototype C-SPECT relies heavily on repeatability and accuracy. Specifications on the conveyor are found in the project’s published paper:

Together with Motion Index Drives, Inc. of Troy, MI, we designed and built a prototype. It consists of 113 aluminum links, with 31.75 mm pitch. Each of the conveyor’s links is tightly constrained by means of three cam followers following tightly machined hardened steel tracks. The conveyor is driven by an SEW Eurodrive servo motor… through a 20:1 anti-backlash reducer. The motor is controlled by an SEW Movidrive Servo Drive Unit by feeding back on a single angular encoder on the motor shaft. A full revolution of the conveyor chain corresponds to 272,263 encoder pulses, with steps down to a single encoder pulse to length response.

Quality engineering and components are key aspects of the C-SPECT prototype conveyor. In order to stand up to the rigorous and constant use of imaging devices in medicine, the C-SPECT prototype was constructed with the highest quality precision and components.

Hardened steel tracks and cam followers were produced through Motion Index Drives, Inc.’s high quality steel hardening process. The resulting followers and track will not show signs of wear after significant use. The prototype ran through 100,000 revolutions (twice the estimated revolutions required of a production unit) and experienced no degradation of the conveyor.

Extensive studies of the conveyor’s repeatable precision concluded that the conveyor remained within medical standards for SPECT equipment. Precision remained within 0.1 mm, a large portion of which was concluded to result from variations in the measurement method.

C-SPECT is now in its second generation of development at Rush University in Chicago, IL.

Reference: Rozler, Mike, Liang, Haoning and Wei Change. “Collimator interchange system for adaptive cardiac imaging in C-SPECT”