SOLUTIONS MATERIAL HANDLING By Eric Hassen
Seven shortcomings of commodity casters The right application-specific casters and wheels can help optimize workflow
“I
f it ain’t broke, don’t fix it.” But if it is broke, don’t keep replacing it with the same inferior part. That logic applies to “commodity casters,” the wheel systems on the undersides of the material handling carts and platform trucks plant floor associates use every day. Original equipment manufacturer (OEM) cart manufacturers often specify inferior-quality casters and wheels that aren’t built to last so they can keep purchasing costs down for end users. Too often these commodity casters quickly show signs of wear, if not completely fall into disrepair, within six to 12 months of service. This, in turn, can result in issues like unplanned downtime, excessive noise and even workplace injuries (see Figure 1). In manufacturing and distribution center environments, more forethought is warranted about the wheels and casters on carts. To specify the right casters, it’s prudent to consider factors like load requirements: how far, at what speed and for how long the cart will be moved; flooring surfaces; and
more. There are many things to consider rather than just making a go at it with the default caster and wheel that comes with the cart. Commodity casters aren’t designed to address specific applications, whereas advances in application-specific casters and wheels can provide custom solutions to match precisely how they’ll be used on the floor. There are several inherent shortcomings in OEM casters that can lead to tangible, measurable issues in a plant’s operations. The following is a breakdown of the top seven:
1. Reliability
Many OEM carts have poor quality casters that fail prematurely. Most commodity casters use a standard kingpin design, the most common point of failure in a caster. The kingpin will likely stretch out over time, causing the housing to come loose, bearings to fall out and push-pull actions to require more effort. Failed casters directly result in lost productivity when carts and trucks are taken out of commission.
2. Ergonomics Figure 1: Typical cost of unplanned downtime. Courtesy: Caster Connection
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• April 2021
PLANT ENGINEERING
Casters with a high rolling resistance cause physical overexertion by associates, the primary cause of workplace injuries. If it takes more effort to push or pull, it increases the chance for injury. The U.S. National Safety Council pins the average insurance claim per workplace incident at $60,000 to $80,000. Lower back strain caused from pushing and pulling carts is a leading workers’ compensation claim in the United States. It happens regularly due to repetitive motion and overexertion from associates. These behaviors account for nearly 20% of injuries and illnesses in the workplace. Only the common cold accounts for more lost days at work. Commodity casters typically have standard swivel leads, which are harder to push, pull and maneuver. A standard swivel lead has a short distance roughly straight up and down from the center point of the kingpin to the center point of the www.plantengineering.com
