Steerable wheel tables are gaining momentum as alternatives to pop-up diverter modules for sorting applications. Many original equipment manufacturers (OEMs) have started to incorporate them into their systems over the last 5 years or are considering doing so soon.
Several advantages can be gained from utilizing steerable wheel tables, which are powered by electric motors, over pneumatically-powered pop-up diverters which is leading many OEMs to consider them for their operations.
But are they a temporary trend or a long-term replacement technology? There are signs that steerable wheel tables are just getting started and are here to stay. In this article, we’ll explore the new capabilities they offer and the benefits that are attracting attention to this versatile technology.
Pop-up Diverts vs. Steerable Wheel Tables: What’s the Difference?
Pop-up diverters are a long-established sortation technology. Modules of angled wheels or lateral conveyor belts are interspersed between rollers, “popping up” when an item needs to be diverted — most commonly at a fixed angle of 30, 45, or 90 degrees.
Steerable wheel technology is a more recent development that replaces rollers and pop-ups with an array of motorized wheels. Unlike pop-up modules, which tend to support only one fixed angle, the wheels can typically rotate up to 90 degrees in either direction from the main line. As a result, a wider range of diverting functions becomes possible — often with more compact units.
Some steerable wheel tables also feature more flexible and modular designs than traditional pop-ups. In such cases, they can be scaled to virtually any size the end user requires. Parcel weights and the customer’s available floor space define the upper limit.
What’s Driving Interest in Steerable Wheel Tables?
The high-level explanation for the popularity of steerable tables is their versatility. They can do everything pop-up diverter modules do, and more, while providing unique productivity and efficiency benefits.
There are several advantages generating significant industry interest in steerable tables.
Robust Package Handling
Imagine trying to move a stepladder, rolled-up carpet, or mattress on a conveyance line. Most operations won’t even attempt this because they have no way to divert these items. Yet approximately 10% of all e-commerce orders involve large, irregular objects or parcels like these.
Until recently, irregular parcels needed to be handled manually by scarce and expensive labor. Steerable tables create new options for automating the handling and diverting of these items.
At the other end of the spectrum, modern sortation systems need to process a greater variety of smaller, non-rigid items. As recently as 10-15 years ago, most shipments went into boxes or totes that could be managed with high-speed shoe sorters. Since then, direct-to-consumer e-commerce has dramatically increased the number of smaller parcels containing just a few individual items.
Dimensional weight (DIM) pricing models, introduced by major carriers in 2015, led to wider use of bubble packs, polybags, jiffy bags, and other packaging formats that can catch or fall through the gaps in conventional pop-up diverters, especially if they’re small or have flexible contents like apparel.
These items often required special equipment or hand-sorting before steerable tables became available. Today, steerable tables can handle items as small as 4 x 3 in. (100 x 76 mm).
Higher Throughput
Diverters matter to throughput because they’re typically the slowest components in the system. As a result, the worst-case scenario for the least efficient divert point often limits the guaranteed throughput of the entire line.
Pop-up modules aren’t built for high-speed applications. They’re usually powered by pneumatic systems, which limit their maximum actuation speed. To make matters worse, compressed air systems have multiple potential points of failure and deliver notoriously inconsistent performance, even when running properly.
By contrast, steerable tables are powered by electric motors capable of actuating much faster, with reliable consistency. The higher the throughput of the table, the higher the throughput of the entire system.
Easier Installation and Maintenance
Although higher throughput is one of the key advantages of steerable tables, electrification delivers other benefits by eliminating the hassles of pneumatic systems. Installation is greatly simplified — it’s essentially plug-and-play. There are no compressors, air lines, or belts to mess with, which simplifies installation and maintenance.
The failure of any pop-up component almost invariably leads to a complete shutdown of the line. Even though the modules can be lifted out and replaced, the trays are typically very heavy, requiring multiple people or a hoist to remove and install. A well-trained crew familiar with this process might be able to manage a replacement in about 30 minutes, but it can easily take much longer if your team is inexperienced or uncomfortable with the task.
In well-designed steerable tables, individual wheels fail in a safe mode that allows them to spin freely, keeping the line running until a more convenient shutdown window. For example, VersaSort tables from Johnson Electric are easy to service because they’re built from simple and lightweight modules that can be swapped in less than 5 minutes by a single operator, with no special tools required.
Improved Safety
Pop-up sorters have multiple pinch points, which not only make them challenging to maintain but potentially dangerous to operators. Steerable tables eliminate these hazards, along with O-belts and other components that could trap fingers or loose clothing.
Steering a Course for the Future
The advantages of steerable wheel tables are likely to ensure their ongoing popularity, making them more than a short-term diversion. This will be especially true for models that provide precise individual control of each wheel, enabling the system to divert, singulate, and manipulate items with the same unit. It also enables tighter spacing between items, resulting in higher throughput without increasing machine speed.
Emerging tables also feature intelligent predictive maintenance capabilities that can provide detailed advanced warnings of performance losses or other indicators of potential failure long before they impact the system.
This article was written and contributed by Vincent Sallé, Vice President of Business Development, Johnson Electric.
