Is the 2-axis delta robot replacing the tried-and-true gantry?

Two comparable technologies

In recent years, delta robots have been gaining popularity in the secondary packaging industry, trending at large-scale shows like Interpack and PackExpo. 3-axis deltas specifically have earned attention for their ability to handle relatively small products and provide precision placement at high rates of speed.

Equally notable, but far less recognized is the 2-axis delta. In terms of general capabilities, this up-and-coming technology threatens to rival the time-tested gantry robot – a solution that has become widely accepted in the industry after years of proven performance.  

Both the 2-axis delta and gantry top loaders are servo-controlled, using a parallel link (Delta) and Cartesian robot respectively. With dual-axis pick and place functions, end-of-arm tooling moves forward and backward, up and down (X and Z axis) - picking and placing products, rotating them as needed and placing them into cases.

Ideal for retail-ready packaging, both solutions are flexible in accommodating a wide range of product types and case styles – whether it’s loading cartons, rigid, or flexible products into regular or half slotted containers (RSCs or HSCs), bliss boxes, or trays. A wide range of pack patterns, including horizontal or vertical product orientations, can also be supported. 

So which option is better?

Comparable in terms of function and cost, the 2-axis delta is smaller, potentially faster and easier to maintain. However, for applications with extremely heavy products or large case sizes (requiring greater horizontal and vertical motion), the gantry may be the better-suited option. Understanding the benefits and limitations of each technology and consulting with your equipment manufacturer will help determine the option best-suited to your needs. 

Machine footprint vs. work envelope

Arguably the most differentiating characteristic of the 2-axis delta is its compact footprint, which allows for more flexible introduction into existing automated system layouts. Unlike the gantry, which requires overhead clearance to accommodate the vertically-moving gantry Z axis mechanism, the 2-axis delta is well-suited for placement under mezzanines or in facilities with height limitations.

Larger by comparison, the gantry’s size may be an attribute in its own right - enabling a larger work envelope. A wider range of horizontal and vertical movement allows the gantry top loader to accommodate wider and deeper case sizes compared to the 2-axis delta.

Payload vs. pick rate

Both the 2-axis delta and gantry have a high payload capacity compared to other top load technologies. The 2-axis delta is capable of lifting most packable products, with a max payload of 40kg. The gantry’s payload capacity is even more impressive at upwards of 100kgs, although the need to pack products of such extreme size and weight is relatively uncommon.

The 2-axis delta does provide a faster pick rate of up to 40 cycles per minute – twice that of the gantry. Depending on factors like product type, size and pack pattern, this can translate to a faster pack speed, fitting for high output applications. 

Maintenance & energy requirements

By design, gantry loaders are comprised of more moving parts than deltas, increasing the risk of mechanical malfunction or failure that could lead to machine downtime. Furthermore, the gantry has a higher wear parts count, including belts and linear bearings that eventually require replacement. To ensure machines are functioning at optimal efficiency levels, maintenance technicians can anticipate a higher frequency and cost of ongoing maintenance on gantry loaders.

Typically, 2-axis deltas require less energy than gantry packers, running on smaller servo motors. And while the energy savings aren’t significant enough to be a deal-maker, they do contribute to a lower TCO (total cost of ownership) over the lifetime of the machine.

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Identifying the best option

While unusually heavy products or large case sizes may require the robust gantry top loader to get the job done, the 2-axis Delta is comparable in many respects and the obvious solution for facilities with limited floor space or for high-speed applications. Reduced maintenance and energy costs further contribute to the delta’s appeal, making it a superior technology in more ways than one.  

In addition to 2-axis Delta and Gantry top load solutions, Pearson offers other top load case packers including 3-axis deltas, articulated arm robots and drop loaders. Taking factors like product size, shape and weight, pack patterns, desired output, machine footprint and cost into consideration, Pearson’s Applications Engineering team can help determine the best solution to fulfill your packing needs now and in the future.