Global agricultural equipment manufacturer implemented 88 Automatic Guided Carts
A global leader in agricultural equipment, John Deere (headquartered at Moline, Illinois, USA) is one of the oldest industrial companies in the U.S. It sells approximately 300 types of tractors (mainly lawn mowers and operates in 160 countries with over 40,000 employees and its net sales for fiscal 2007 reached $21,489 million.
John Deere has used a variety of material handling equipment over the years, including roller conveyors, Automatic Guided Vehicles, and power & free conveyor systems. The company introduced Jervis B. Webb’s SmartCart, or Automatic Guide Cart (AGC) in the Horicon, Wisconsin plant in 2005. This move consolidated three previously separate production lines into one allowing mixed flow production and significantly improved efficiency.
Formed a team to investigate magnetic tape-guided AGV
Prior to implementing the SmartCarts, the Horicon plant had been using a fleet of approx. 50 wire-guided AGVs (automatic guided vehicles) to manufacture lawn tractors for 20 years. For a number of reasons including the fact that the equipment had been in service beyond its normal life span, the additional costs of maintenance and the steep price of newer replacement units. Deere formed a production engineering team to investigate SmartCart technology as an alternative.
The Deere team responsible for alternative conveyors for use in the Horicon plant developed a matrix to compare the benefits and liabilities of various systems. It also considered cost. After reviewing its options, Deere selected and installed Webb’s new SmartCart AGC.
The team was impressed with flexibility of the units, which are guided by removable magnetic tape affixed to the floor. Given the unique configuration of some of Deere’s production lines, which had to accommodate L-shaped lines, right angle comers, pallet returns and other difficulties, SmarCart seemed to offer the right solution.
According to Dave Wekheiser, a manufacturing engineer at Horicon, “The SmartCart’s magnetic tape flexibility in overcoming layout obstacles was dramatic. We can just pick up the magnetic tape and change the layout in a matter of minutes.” With the system in place, Deere can reroute an entire line over a weekend.
AGC, the “best automatic transport system” with hydraulic lift and in-line automatic charging
Deere uses 88 SmartCarts to build its lawn mowers from start (1) to finish (2). For ergonomic reasons, the company mandated top-down assembly. Unlike the earlier AGVs that had trunnions to rotate tractor bodies for access, the SmartCart’s hydraulic lift capabilities make it possible for operators to tailor the cart height for individual operations, raising or lowering the tractor bodies to the proper height for optimum assembly operations. Ergonomic concerns have been minimized. In addition to the cart’s flexibility in making line modifications and the extreme ease of its installation. Deere benefited from cost savings in time and money with the SmartCart’s high “uptime.” By using a short, in-line automatic “opportunity charge” during every production cycle, a cart’s battery recharging time can be significantly reduced.
As Dave Werkheiser explains, “The magnetic tape flexibility has peaked interest throughout the company. Many of the plants are looking for alternative solutions for their material handling systems, including those in our agricultural division. When you look at the bang for the buck, you can’t beat these SmartCarts.”
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