Category Archive: Balancing

Test Devices 2018 Year in Review

2018 has been a banner year for Test Devices, with expansions in both our facilities and our services, allowing us to better serve our customers as a “dependable partner” and a convenient “one stop shop”. Some of our new and expanded service offerings include in-house machining, eDrive spin testing, and expanded balancing capabilities – thanks to the acquisition of a new Schenck balancing machine.

Facility Updates 

Test Devices’ latest facility upgrade brought significant improvements to our shipping and receiving departments and upgrades to our climate-controlled precision inspection room, which includes the expansion of our Quality Inspection team and the acquisition of a new larger CMM (coordinate measuring machine).

The redesigned facility layout, added floor space, and new equipment allowed us to streamline our workflow and enables us to work more efficiently than ever before. The new shipping and receiving departments are now located to the front of the building with an expanded floor space, and optimally equipped handling areas with additional cranes and staged operations. This new layout minimizes unnecessary movement, creates easier access and an unobstructed flow of materials.

We have also expanded our equipment build area and relocated it to a new section of our facility. This move allowed for a more efficient staging of equipment builds and assembly operations capable of preparing three to four machines simultaneously.

Semi-Finish Machining

As of June, Test Devices now offers in-house semi-finish machining services for aerospace turbine disks. For over a decade, TDI has served leading jet engine OEMs who require forging pre-spinning services—a vital part of producing nascent engine disks that offer the highest performance. While a seemingly simple process, this service is deeply specialized, demanding the highest knowledge and skill level to produce a seamless operation. This newly added machining capability will vertically integrate operational steps and allow TDI to offer more expeditious and higher quality services. By the end of 2018, TDI is on track to ship over 100 semi-finished forgings.

Expanding Aerospace Grade Balancing Services

In 2018, Test Devices grew our balancing capabilities by acquiring a new HM 20 Schenck Horizontal Balancing Machine to support the growing demand for these operations. This high precision, state-of-the-art machine allows TDI to service a broader range of customers with varying rotor balancing needs.

Among the primary benefits of the HM 20 is its hard-mounted bearing design, ensuring rapid changeovers between rotors, which allows Test Devices handle significantly higher volumes of balancing jobs and increase the efficiency of our operational capabilities. The HM 20’s modular design also allows it to be easily modified.

Growth in eDrive Spin Testing Systems

The successful completion of an increasing number of proof and burst tests and 130,000 LCF cycles in 2018 attests to the growing demand for eDrive testing.

We are continuing to enhance our testing and engineering offerings to support eDrive customers in 2018, including advanced rotor growth mapping, high-resolution, high-speed video imaging, expedited fatigue, LCF tests (with RT-CDS and growth mapping), heated spin tests, unbalance budgeting and rotor design engineering support.

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2019 and Beyond

Test Devices Inc. continues to build our services and capabilities in 2019 and we look forward to offering better services for new and existing clients in the aerospace, automotive, and other highly technical industries. We will keep leading the industry by offering the latest services and technology.

To learn how our spin testing, balancing, and other services can help your R&D efforts, prototyping, or manufacturing operation, contact us or request a quote.

TDI Expanding Balancing Services with New Schenck Machine

For the past four decades, Test Devices Inc. has provided our customers with an extensive range of rotational services, including balancing troubleshooting, diagnostics, and calibration. In an effort to meet growing consumer demands and reinforce our commitment to providing the best and most accurate rotor balancing services, we are expanding our balancing capabilities by acquiring a new HM 20 Schenck Horizontal Balancing Machine to support our existing fleet of equipment.

This state-of-the-art machine represents the latest in rotor balancing technology. One of the main benefits of the HM 20 is its hard mounted bearing design, which ensures rapid changeovers between rotors. This feature gives us the ability to handle significantly higher volumes of balancing jobs and increase the efficiency of our operational capabilities.

Additionally, the HM 20 is easily modifiable due to its modular design. A wide range of components and attachments can be added to the unit, increasing its flexibility and allowing us to meet the unique demands of customers regardless of industry or application.

Why Balancing Matters

Rotor balancing is essential to ensure the even distribution of mass in rotating components. Unbalance due to eccentricities between the center of gravity of the rotor and the axis of rotation causes the heavier side of the rotor to exert more centrifugal load. The unbalance in the rotor ultimately leads to excessive noise, vibration, wear, and significantly reduced service life. In some applications, unbalanced rotors are even considered to be a safety hazard if machinery failure can result in personal injury or property damage.

Balancing Services at TDI

At Test Devices Inc., we offer a broad range of timely and cost-effective balancing of virtually any size rotor. Our advanced equipment (including our newly acquired HM 20 Schenck Horizontal Balancing Machine) is capable of providing balancing services for the most complex parts the aerospace industry.

Our services also include the design and manufacture of customized balance tooling for the production of unique and precisely balanced components.

Our staff of highly qualified and experienced industry experts, engineers, technicians, and consultants have provided rotary and balancing solutions in hundreds of challenging applications for many world-renowned clients. As a partner to Schenck, the experts in balancing, we are able to leverage their advanced technology and knowledge base with specific expertise and software support focused on the requirements most important to the aerospace industry. We also work closely with our customers, analyzing each specific case to determine the best methods and strategies for balancing.

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Proper balancing of rotors and other rotating components are essential to ensuring the efficiency, longevity, and safety of your machinery or equipment. Furthermore, balancing can have the added benefit of reduced maintenance, which can eliminate the costs associated with frequent repairs and part replacement.

Although the diagnosis of an imbalanced part is relatively simple, careful selection of a balancing service provider is crucial to guarantee optimum results. At Test Devices Inc., our technical staff have seen it all and are willing to assist you with your balancing needs.

Download Our Balancing 101 eBook

If you would like to learn more about the risks of improper balancing and how you can avoid them, download our comprehensive eBook, Balancing 101, or contact our team today.

Keep Your Machinery Performing Optimally: Static and Dynamic Balancing

Rotating machinery is omnipresent in industrial use and seen in different fields all across the spectrum. Rotational systems and components are critical to the overall efficiency of businesses in industries such as aerospace, energy storage, automotive, electronics, and medical devices to name a few.

Not sure what to look for in a balancing provider? Read our ebook below:


As the world continues to turn, industry experts rely more and more on rotating machinery to deliver fast, high-level and reliable results.

These sorts of turbomachinery include pumps, compressors, fans, blowers, bearings, engines, motors, and more. An essential to keeping these machine types in optimal condition is awareness and maintenance of its balance.

Understanding Unbalance

Unbalance is known to be one of the most common sources of failure in rotating components and is caused by an uneven distribution of mass around the axis of rotation.

When a system continues to rotate while unbalanced, it generates periodic forces perpendicular to the axis of rotation resulting in a vibration.

Static and Dynamic Balancing

This vibration becomes noisy and apparent as the severity of the unbalancing increases.

Often, such a defect can be mistaken for a simple machine repair or bearing replacement; however, if noise and vibration continue after repairs then the machine is likely signaling that it needs to be balanced.

If unbalance is detected in a rotational system, a balancing service is required to avoid structural defects and in extreme cases, catastrophic failure.

Imbalanced rotational parts can result in excess wear and tear along with structural cracks that could massively affect long-run costs.

A well-balanced turbomachine extends the bearing life and improves overall usage, quality, and accuracy of the machinery, which can be achieved through balancing services.

Static vs. Dynamic

Balancing services evaluate the components and provide a balance correction on materials like plastics or aerospace alloys. Based the type of machine or part, two balancing options can accurately restructure the assembly: Static and Dynamic.

  • Static Balancing is appropriate when an unbalance occurs at a single axial point on a disk-like rotor. In other words, the center of gravity of the object is on the axis of rotation allowing it to remain stationary with a horizontal axis and no braking force. The heavy point here is typically measured in relation to the component centerline.
  • Dynamic Balancing is appropriate for a dual plane unbalance with significant axial length and multi-rotor assemblies. In such a case, the rotation does not produce any resultant centrifugal force or couple and will rotate without application of an external force. Here, the two or more heavy points act independently on the mass centerline and unbalance must be corrected in two planes.

Balance Correction

Upon identifying the balancing service necessary, balance corrections can be done to bring rotational machines back to optimal performance levels. Balance corrections are mainly performed through material removal or mass addition at appropriate locations.

The most commonly used material removal methods are drilling/milling and abrasive material removal. Drills or milling equipment are used to control depth and arch of material removal.

For abrasive material removal, mass is removed through grinding or air-powered sanding equipment. Contrary to a removal process, a mass addition process can be implemented with epoxy, welding metal strips, or mechanical hardware.

Balancing providers are not all created equal. Read our ebook below to find out what to look for:


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Experts in rotational test systems and services are available to assure your machine’s success. These professionals are equipped with quality tools and systems to work with customer specifications for unparallelled spin testing and balancing services that can deliver results for the machinery’s optimal performance.

Two Ways Improper Balancing Can Affect Your Profits

Unbalance is a naturally occurring, and expected phenomenon with all rotating components. It can occur suddenly, or build up over time, and is caused by any number of factors.  Distortions due to stress, uneven thermal distribution, or deposit build-up on the part are a few of the most common causes for unbalance in rotating machinery. Every rotating part will need to be balanced at some point within its lifespan, and it’s vital that the unbalance correction is performed properly.

If you are unfamiliar with the balancing process, there is the possibility that your service provider can incorrectly “correct” the unbalance in your rotating component. This will occur when balance tooling and set-up are not properly developed, or the service provider’s personnel is not fully knowledgeable about the balance process required for the particular rotating component. An improperly balanced part (or batch of parts) can lead to severe consequences to your bottom line.

Delays & Missed Deadlines

As with all manufacturing processes, project schedules are extraordinarily sensitive. However, balancing services for the manufacturing industry usually occur at the very end of the component’s build process, right before delivery to the customer.

If improper balancing occurs and is detected, there’s a high possibility that the delays will directly affect your client’s revenue for the month. So not only will you be paying for the rebalancing, but you run the risk of losing future contracts with your customer. However, the more realistic possibility is that the incorrect balancing is not caught in time, and the rotating components are shipped directly to your customer (which leads to the next potential hit to your bottom line).

Non-Conformance & Part Failures

When improper balancing occurs, it is close to impossible to detect immediately. This means that there is a high probability that non-conforming parts are entering the field. In a best case scenario, the unbalance is detected by your client when assembled into the final product, but before full product launch. You will not only incur the costs of transporting parts back and forth and the second round of balance correction, but you will also incur the metaphoric cost of lost faith from your client. It is also possible that the initial improper unbalance correction will be so severe that the parts will need to be scrapped – a catastrophic scenario for any profit margin. In the worst case scenario, total part failure will occur in the field as a result of an improperly balanced part. The costs of part failure in the field can be ruinous.

The key to avoiding profit loss and potential part failures due to unbalance in your rotating components is in understanding what a good balance provider looks like and fully understanding the process.

For more information on Test Devices Inc’s balancing services, please feel free to request a quote or contact us with any specific questions.

Three Major Ways Your Manufactured Rotating Component Can Become Unbalanced

Unbalance in your rotating component is simply defined as the unequal distribution of weight along your rotor. It is a tricky problem that can sneak up on you unexpectedly. But with the proper knowledge, you can keep an eye out for the major causes of unbalance, and be prepared to address them quickly.

Distortion from Stress

Distortion can occur as a direct result of the manufacturing process and is often the result of a part “adjusting” to relieve stress. Manufacturing processes such as drawing, forging, pressing, etc. will yield internal stresses on parts. If stress relief is not built into the manufacturing process, the rotor will eventually distort to adjust to that residual, internal stress.

Thermal Distortion 

Change in temperature or uneven temperature distribution can also cause major distortions on a rotating part.  Most metals have the capacity to expand when exposed to heat, so when components operate within environments with elevated temperatures, there is the inherent possibility of expansion. If the heat exposure doesn’t happen uniformly over the entire part, certain sections will expand and distortion will occur.

Thermal distortion is a common and natural occurrence with machines that are exposed to (or operate within) elevated temperatures, so components within machines like motors, compressors, turbines,  etc should be regularly evaluated for unbalance.

Deposits & Oil Buildup

If a rotating component is involved in any sort of material handling, it is almost inevitable that buildups of deposits will occur. Minerals (like lime), dirt or dust will begin to build up on rotating parts, cause an initial uneven distribution of weight, and vibrations will begin to occur.

Rotating components that are exposed to oil (ie: lubricated compressors) are also highly susceptible to distortion. Oil has the ability to seep deep into components if left unchecked, and the liquid will accumulate until the buildup causes unbalance, vibrations, and sometimes part failure.

(In the case of deposits and build-up, distortion CAN be avoided before unbalance occurs, if there is a stringent maintenance routine and/or inspection process implemented.)

For more information on the balancing services that Test Devices Inc. provides check our Balancing Services Page or contact us directly.

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