Backlash Free Indexing

Posted on December 6, 2011 by motionindex

Motion Index Drives is becoming well known for “backlash-free” indexing equipment, so much so that we get repeated inquiries that get hung up on this fact that they believe it to be impossible: ALL gears have backlash, they tell us. A critical point to consider, however, is that Motion’s cam-driven indexers are not gears.

Backlash is the oscillating motion that occurs when a mass is brought to a stop. Caused by the space between the teeth of gears, backlash is an unavoidable reality when the teeth of gears are mated, and a necessary element to prevent jamming and allow for misalignment. A cam-driven indexer from Motion, however, is constructed with precision parts under a pre-load condition, completely eliminating backlash (granted, we have had several applications where backlash was necessary or desired by our customers). Contact is constantly established between cam followers and the cam while in dwell. This relationship applies a force to the followers (thus “pre-loaded”) and ensures that there is absolutely no room for play between followers and the walls of the cam.

Cam & Dial for Rotary Table

But what if the backlash in the gear causes the table to move?

In a fixed indexer, gear backlash would never affect the position of the output, even if it provided enough force to rotate the cam. Since dwell typically comprises at least 30 degrees of the cam’s profile, even if the cam is rotated there will not be enough motion generated for the cam followers to reach either edge of dwell. So, even if the gear backlash were to cause the input/output shaft to rotate, the degree of rotation would never be enough for the cam followers to exit dwell.

And in the case of a constant lead cam?

In the case of a programmable system, such as the FLEX series, one may argue that if any backlash exists in the gear assembly, it would translate directly into the output as a result of the cam’s constant lead (FLEX indexers also place followers under pre-load, making backlash between cam and cam follower impossible). FLEX indexers as a whole have a considerable amount of static inertia (larger than the force generated by the backlash in any gear motor by SEVERAL orders of magnitude). Therefore, even the FLEX Series’ constant lead cams manage zero backlash.

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Announcing the All New TMF Series Rotary Table

Posted on September 8, 2011 by motionindex

The new TMF Series is an innovative new line of 100% flexible rotary tables. These tables are built to maximize the potential of Motion’s FLEX technology with a streamlined housing and dial plate to maximize the potential of our constant-lead cam design. The design utilizes the full potential of the constant lead cam currently used in the FLEX tables.

The cam design, developed to give the cam-driven market a flexible, utilizes either a servo drive or AC motor with encoder to achieve the same precision, strength and reliability of a fixed cam table with the added benefit of a reprogrammable drive. Depending on the application, the TMF Series may provide significantly more strength that a fixed barrel cam solution.

The TMF design differs from the RT Series in several ways:

  1. A lower housing profile
  2. A larger center thru-hole
  3. A new output design to accommodate more cam followers. As a result, TMF Series indexers engage four cam followers at a time
  4. A new design that allows users to remove cam followers from the top

The new TMF Series from Motion Index Drives, Inc. is an innovative new series engineered to maximize the potential in cam-driven flexible indexing. Coupled with Motion’s state-of-the-art machining process and induction hardened components, the TMF Series design promises to be the world leader in flexible cam-driven indexing.

Contact Motion Index Drives, Inc. at 877-866-1677 or visit www.motionindexdrives.com for more information.

Posted in Compact Precision, Flexible Weld Cell Positioners, Motion Index Drives, Motion's Flexible Solution, TMF Series | Tagged , , , , , | Leave a comment

Custom Stroke LF Conveyors

Posted on August 8, 2011 by motionindex

Motion Index Drives’ LF Series Precision Link Conveyors are quickly gaining a reputation as the most cost effective indexing conveyor on the market. The LF Series design utilizes the highest quality components to achieve unprecedented precision and strength in a conveyor, as well as a design well suited for adaptability in new configurations or dimensional adjustments.

The LF Series comes in five standard sizes (measured by the length of work carriers in millimeters): 50, 080, 100, 125 and 150. Standard stroke lengths include one, two or three work carriers at a time (an LF050 will have a standard stroke of 50, 100 or 150mm); however, the modern design allows for easy adaptation for new carrier dimensions and stroke lengths.

A Custom LF051 (Link Width 78.5mm)

A Custom LF076 (Link Width 155m)

New stroke lengths are achieved by altering the work carrier’s length. Although these special orders will require some design work, Motion Index Drives’ efficient design and manufacturing processes allow us to complete this task at a minimum cost. Motion Index Drives has produced LF051s, LF076s, 142s and a number of other unique models for customers that require these lengths. In addition, link width can also be adjusted if necessary.

The images above show a couple of the unique LF Series Conveyors Motion has produced in the past. You can also see how the LF Series was adapted to act as a prototype cardiac imaging unit for Rush University in Chicago, IL in a previous blog post.

Links are produced from high quality wrought aluminum AlZnMgCu1.5. This compound provides a remarkably strong and lightweight modern alternative to fragile plastic or cumbersome steel links. All LF Series conveyors are rated for accuracies of ±0.04mm at the drive and ±0.07mm opposite the drive.

Additional custom solutions can include sealed units for use in clean room or highly abrasive airborne environments.

If your automation process requires a precision conveyor, Motion Index Drives’ LF Series is a cost-effective and robust solution. Call Motion Index Drives at 248-743-9999 or visit our website at www.motionindexdrives.com to inquire about your project.

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A Top Five: Applications for Parallel Indexers

Posted on July 15, 2011 by Motion Index Drives

Parallel Indexers are incredibly versatile automation machines capable of moving in clockwise, counter-clockwise or oscillating modes of operation. The reliability and accuracy provided by Motion Index Drives, Inc. indexers has improved process and product quality worldwide. Here are the top five applications for parallel indexers:

  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.
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Points to be Made and Money to be Saved: Trunnion Indexers

Posted on June 15, 2011 by Motion Index Drives

The Differences, Applications and Benefits of Trunnion Indexers

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:

RT160 RT200 RT250 RT400 RT500 RT630 TT315
400 620 890 3250 7500 12600 2030

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.

Posted in Flexible Weld Cell Positioners, Motion Index Drives, Motion's Flexible Solution, Trunnions | Tagged , , , , , | Leave a comment

Customizing and Indexer Part II – Environmental Specifications

Posted on May 26, 2011 by Motion Index Drives

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.

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Customizing an Indexer Part I – Technical Specifications

Posted on May 23, 2011 by Motion Index Drives

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.

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Common Cam-Related Myths and Their Corresponding Truths

Posted on April 20, 2011 by motionindex

Cam-driven machinery enjoys a relatively simplistic design: a series of mechanical components interact to transform a uniform input into an intermittent output. Unfortunately, in a world of increasingly complex technologies, cam-driven machinery’s simplicity appears almost deceptive. As a result, it is not uncommon for several misconceptions regarding the capability of cam-driven devices to exist in the mind of an individual.

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 OEM’s 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.

Posted in Components, Motion Index Drives, Motion's Flexible Solution, Remanufactured Turntables, Uncategorized | Tagged , , , , , , , | Leave a comment

Rotary Indexers: Motion’s Value

Posted on April 5, 2011 by motionindex

An indexer is, generally speaking, the central component to any factory automation process. It is an indexer that moves the product into position for other equipment (or people); it is an indexer’s timing that determines the rate at which a job is completed; and it is an indexer’s precision that determines the accuracy of interfacing and, therefore, the quality of a product at the end of the line.

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 Competitor
Horsepower* 1.2 3.0
Amperage (230V/460V/575V)* 6.3/3.15/2.52 12.2/6.1/4.90
Index Period Angle 320˚ 270˚
Internal Inertia (kgm2) 0.8 5.4

*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.

Posted in Components, Motion Index Drives, NANO Index Technology, Value Added | Tagged , , , , , , | 3 Comments

Flexible Cam-Driven Indexers

Posted on March 23, 2011 by motionindex

Several methods of governing a system’s timing and accuracy are available, but one thing is agreed upon by consumers and engineers alike: cam-driven systems provide the best results. Another thought equally agreed upon but misconceived is this: cam-driven systems are fixed, meaning station counts, timing and rotational patterns can never be adjusted.

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.

[youtube http://www.youtube.com/watch?v=3s3UfAe1RqY&w=425&h=349]

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 pre-loaded cam followers results in zero backlash, and accuracies of ±0.01 mm.

Backlash, caused by empty space between two gears, causes drives to oscillate upon stopping. With cam-driven indexing, backlash is completely eliminated. High precision machining gives our constant lead cams and high-quality cam followers a relationship that results in zero backlash.

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.

Posted in Motion Index Drives, Motion's Flexible Solution, Uncategorized | Tagged , , , , | Leave a comment