‘Sorry: Your Part Is No Longer Available’

How do you respond when you hear that statement? Here are ways to address the unavailability of critical equipment-system components.

By Jane Alexander, Managing Editor

The phrase “no longer available” sends chills down the spine of even the most hardened maintenance pro. A production line goes down, and a crucial part must be replaced to get it back up. When you call the distributor or manufacturer to procure the needed item, you are informed that it can’t be had. The situation may seem dire, but because vendors want to retain customers, they’ve likely discussed about how to deal with such instances involving their products.

According to Greg Cober of Altra Industrial Motion, as manufacturers update and improve their offerings to take advantage of new materials, new processes and/or design improvements, they must be sensitive to the needs of end-users who still rely on their existing products. “Backwards compatibility is a key consideration,” he emphasizes, “but not the only one.”

Crucial replacement-part considerations

Cober points to several factors that need to be considered in situations where a part has become obsolete and must be replaced with a different component. In explaining them, he references several of his company’s own products:

Fig. 1. The Warner Electric Gen2 UniModule (left) retains the drivetrain performance of its Gen1 predecessor (right).

1. Footprint: Will the new unit fit in space allotted for the old unit?

In many situations, the manufacturer will have been able to upgrade its design while maintaining the approximate size and identical mounting interface as the prior generation. For example, the Warner Electric UniModule product line mounts to NEMA C-face motors and reducers. In 2007, Warner upgraded to the Gen 2 version of this product family and replaced nearly 250 end-item part numbers. Since the new product still had to be compatible with NEMA standards, it retained the same bolt circles, bore sizes and pilot diameters. It also retained the same overall lengths and lead wire configurations. Customers could replace Gen 1 product with Gen 2 units (Fig. 1) easily while retaining drivetrain performance.

Fig. 2. The footprint, shaft locations and overall envelope size of Boston Gear’s SS700 stainless steel worm gearbox (left) match those of the older design it replaces (right).

Similarly, when Boston Gear released its new SS700 stainless steel worm gearbox (Fig. 2), pains were taken to ensure that the footprint, shaft locations and overall envelope size matched the previous generation of stainless gearbox. While the new unit is very different overall, customers can remove the prior generation and replace it with the newer model without changing the machine.

Fig. 3. Bauer Gear Motor’s IE4 PMSM units consume less energy than older inverter-driven squirrel-cage designs, and often can mount into the gearing of an originally installed motor.

2. Efficiency: Is the new product more energy-efficient than the old?

Achieving higher operational energy efficiencies is a goal of every facility manager. Cober notes that it’s always wise to inquire about the energy ratings of any replacement component candidates. He cites Bauer Gear Motor’s recent introduction of a range of PMS (permanent magnet synchronous) units (Fig. 3) that meet the IE4 (Super Premium Efficiency) classification, as evidenced by their potential to achieve greater energy savings than IE2 inverter-driven squirrel-cage motors. In some instances, replacing a worn geared motor with a PMS model requires little more than mounting the new unit into the gearing of the originally installed unit.

3. Functional compatibility: Is the new product compatible with adjacent components?

It’s not uncommon for a new generation of products to perform similarly to an older generation, but reflect differences in mounting. After a brief hiatus, Warner Linear re-entered the linear actuator market in 2007 with its B-Track product offering. While capable of meeting the key criteria of providing a specific force and stroke length, there might be minor differences in unit speed, and the overall unit height and length may be slightly different (usually 0.250 in. or less). In many cases, Cober says these minor differences won’t have any impact, yet it can’t be said the units are the ‘same as’ the previous model. “With electronics,” he continues, “a new-design, variable-speed drive might control the motor speed and torque as well as, or better than, the previous model, but the wiring, mounting and programming may be different to reflect changes in microprocessor capabilities.”

Fig. 4. Newer Warner Electric capping headsets perform better and have a lower cost of ownership than the models they were designed to replace.

4. Upgrades and cost of ownership: Have new functions or features been added that will improve performance or maintenance? Will the new solution provide equivalent or reduced cost of operation over its service life?

According to Cober, manufacturers will sometimes make changes to an existing product, but won’t be able to promote the upgraded unit as “fully-compatible” with previous models given the fact that the internals have greatly changed. He uses the capping clutch headsets (Fig. 4) developed by Warner Electric at the end of the last decade to illustrate his point. These products were designed to match the footprint of many of the existing capping clutches used by the beverage industry so that retrofitting to existing systems would be easy. Still, the new models aren’t the same as the older designs. “While the footprint is the same,” Cober says, “the new units will typically last twice as long or more.” Among other things, he says they also provide a higher level of performance in a process where consistency is crucial; and the cost to rebuild them after their longer life is realized, has proven to be less than that of rebuilding the older units.

Trade-offs and other solutions

Cober agrees that trade-offs are sometimes necessary when selecting a replacement component. He describes advances in design, materials and machining capabilities that have enabled improvements in gearbox efficiency over the past dozen years, “but at a price.”

Most enhancements to gearbox efficiencies have been possible while maintaining shaft centerline dimensions. “Unfortunately,” Cober laments, “in many cases, the gearbox housing has changed in ways that might require new bolt-hole locations for base-mounting. The unit can mount at the same height, but it would be necessary to drill and tap new mounting holes.” On the other hand, this inconvenience brings with it a 3-5% improvement in unit efficiency, allowing the process involved to run better as a result of the change. “Given the long-term savings,” says Cober, “minor inconveniences like this one usually seem reasonable. “

Be flexible

When faced with “no longer available” scenarios, Cober urges end-users to remain flexible: You may need to educate suppliers on your processes so they can advise you of how changes in their products will impact your operations. Thus, keeping an open mind and focusing on results should get you closer to what you need. “The time constraints of having a high-value process shut down,” he says, “may not allow for a lengthy history lesson, but understanding why a product was changed may help you better evaluate how to make the new solution work.“

From time to time, “no longer available” does, in fact, mean “dead end.” The part you need is no longer manufactured. Those with machines that use obsolete parts have several options, Cober says:

• Fabricate or reverse-engineer the worn components.
• Find a functional replacement that may require re-engineering of the process.
• Contact the product manufacturer for help. The manufacturer may no longer have a  product for you, but may be able to guide you to how their other customers have solved this problem.

Finally, Cober cautions that the demise of a key component could, at some point, signal the demise of the machine with which it is associated. If a process using such equipment is operation-critical, it may be time to consider alternate courses of action. “Change is inevitable,” he stresses. “Understanding why and how manufacturers have changed their products can help smooth the process of integrating new designs into your operation.” MT

Greg Cober is Product Training Manager for Altra Industrial Motion.