Once you've decided to add hands-free steering to a tractor, your decision about what automated steering solution to buy boils down to a choice between two system types. The first type directly drives the steering valve. The second option turns the steering wheel or steering column.
In the first case, you maximize steering accuracy, but at a higher price. Steering-wheel-based systems are inherently less accurate because they transmit the steering effort along the entire steering linkage, but they are more affordable.
Your final decision about what to buy may be driven by the age of your tractor or, when you're buying a new tractor, whether it comes steering-ready from the factory, says Brian Verkuehlen, precision product manager for RDO Equipment Company, Fargo, ND, which is one of the largest retailers of John Deere steering systems in North America.
New tractors that are wired for steering from the factory, and those for which steering kits are available, typically are outfitted with high-end steering systems, Verkuehlen says. Steering-wheel-based steering systems predominate on older tractors.
“We have been putting the AutoTrac Universal (ATU) steering kit (Deere's steering-wheel-mounted system) on every platform out there,” says Verkuehlen, who notes that ATU sales represent 40% or more of steering system unit sales for RDO Equipment. “It is a less expensive solution. Guys have been getting excellent performance. And they can move the unit from their tractor to their combine.
“If you get into rough conditions, ATU steering is less optimal, but it is still very accurate,” he adds. “I have seen older tractors with ATUs that steer just as well as the new 8030 series tractors with integrated steering in the right field conditions.”
Making a head-to-head cost comparison between steering-wheel systems and hydraulic systems (which typically only require plugging in electronic harnesses in factory-ready units) or wire-based systems (available on many tracked vehicles) can be challenging. Often, wheel-based systems are specified with low-end GPS receivers. This results in a lower cost but doesn't provide an apples-to-apples comparison with steer-by-wire and hydraulic systems, which often are specified with high-end GPS receivers and other components.
That said, you can expect to pay $1,000 to as much as $8,000 more for a steer-by-wire or hydraulic system compared to wheel steering, assuming all other features are equal and that the manufacturer sells an identical system in both versions.
If you are looking for an entry-level system, a steering-wheel-based system with a Wide Area Augmentation System (WAAS) GPS receiver costs about $5,500 to $8,000. At the other end of the spectrum, high-end steer-by-wire and hydraulic systems with sub-1-in. real-time kinematic (RTK) accuracy are priced in the $20,000 to $25,000 range, plus $6,500 to $12,000 for an RTK base station, if there's no RTK subscription network operating in your area. Such 24/7 services generally cost about $1,200 to $2,000 per year per equipped machine.
Both steering-wheel-based and steer-by-wire or hydraulic systems are available from major tractor manufacturers, including AGCO, Case IH, John Deere and New Holland, as well as aftermarket providers Ag Leader, AutoFarm, Raven Industries and Trimble Navigation. Hemisphere GPS, TeeJet Technologies and Topcon Positioning Systems offer steer-by-wire solutions but not steering-wheel-mounted systems.
For a look at the range of automated steering systems, including prices, see “Guidance at the right price” in the April 2007 issue of Farm Industry News or at www.farmindustrynews.com. Or contact manufacturers (or your local equipment dealer) using the information at the end of this story.
Matching steering to needs
On new equipment, steer-by-wire systems are the most popular for row-crop equipment. In the Plains states, where broad-acreage crops dominate, wheel-based systems, such as Trimble's EZ-Steer, are often the system of choice even for new equipment, says Sid Siefken, sales channel manager for Trimble Navigation.
Sprayers, and tractors used primarily for tillage, also are often outfitted with steering-wheel-based systems. “You don't need a 1-in. level of precision for some field operations, like knocking cornstalks down in the fall,” Siefken says.
But steering-wheel-based systems may become less popular in the future as more tractors, sprayers and combines are wired at the factory for steer-by-wire systems.
“The autosteer systems that go on the steering wheel are pretty cost-effective right now,” says Scott Shearer, an agricultural engineer at the University of Kentucky. “What will win out in the future? Tractors will be wired for steering at the factory.”
Steeering system contacts
AGCO: contact your AGCO dealer; AutoFarm: call 877/947-7327 or visit www.gpsfarm.com; Case IH: contact your Case IH dealer; Hemisphere GPS: call 800/247-3808 or visit www.outbackguidance.com; John Deere: contact your John Deere dealer; New Holland: contact your New Holland dealer; Raven Industries: call 800/243-5435 or visit www.ravenprecision.com; TeeJet Technologies: call 217/753-8424 or visit www.teejet.com; Topcon Positioning Systems: call 925/245-8300 or visit www.topconpositioning.com; Trimble Navigation: call 800/865-7438 or visit www.trimble.com or www.ez-guide.com.