WINNIPEG – Spraying in hilly and rough fields can wreak havoc on booms. The bigger the boom, the more frequent and severe the damage.
Electronic boom height control devices prevent these problems, but the cost, along with operator training and programming requirements, prevent many farmers from buying them.
Ag Shield is ready to release a new type of boom height control system that uses no electronics or computers. The Ground Following System, or GFS, is a hydro-mechanical device that inserts two new valves into the existing boom hydraulics, said Ag Shield’s Gary McCrea.
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“We’ve sold computer-based boom height controllers for many years, so we know they work and they do the job they’re intended to do. But, because we sell them and use them ourselves, we also know the drawbacks.
“Cost is one factor. You’ll pay between $7,500 and $9,000 for a computer style boom height controller. Our new hydro-mechanical Ground Following System sells for $3,200. And it’s a very simple system. I don’t think anyone could build a simpler system.”
McCrea said the company’s move away from electronics was deliberate.
“The trend is toward greater use of electronics, sensors and computers. But we’re bucking the trend because we’re not convinced that electronics is always the way to go in the rough, dusty, pounding agricultural setting Ð especially on sprayers because of their speed.
“In our business, we see firsthand all the problems with electrical connections, sensors and delicate electronic pieces that can’t take the beating.”
McCrea said a cab might have three or four computers running at once.
“We also see a lot of the problems people have learning how to program and operate all these devices. It’s sometimes impossible for a farmer to find a good operator who can handle the machine properly and still master all the electronics. Farmers tell us the more electronics they have in the cab, the more difficult it is to find a competent operator.”
McCrea said Ag Shield’s GFS answers these concerns with a single on-off switch in the cab.
“There’s nothing for the operator to program or memorize. There is no wiring harness. There’s only one wire running up to the cab for the on-off switch and that’s it. Out on the boom itself, we have no switches, sensors or valves. Just that suspended tire.”
He said the ATV tire mounted on each boom serves as the sensor. The tires hang below the boom with little ground pressure.
“All the tire really does is gently roll along the surface, allowing the boom to move up and down with the terrain. As the boom moves, the GFS control box feels the change in hydraulic pressure and makes minor pressure adjustments within the existing hydraulic system so the boom stays at the correct height. The GFS valve lifts the boom up to prevent the tips from digging in or lowers the boom if it’s running through a low spot.
“You’d get the same feedback to the control box if you eliminated the tire and let the outer tip skid support the boom, but that would rip out so many plants.”
He said the non-load bearing ATV tire is gentle on the crop.
The two valves plumbed into the sprayer’s boom lift system are engineered to provide gentle pressure changes without the hammer effect. The valves and the hydro-mechanical control box are unique devices.
“These sensitive hydraulic valves are the key. Nobody has seen anything like this before. That’s why we’re having them patented.”
McCrea said the GFS has been tested on 120-foot booms, giving excellent height control. Ag Shield is testing the GFS on open centre boom control systems.
The first 50 GFS systems are being built this winter and will be available in the spring for pull-type and self-propelled sprayers.
McCrea said farmers have been enthusiastic about the innovation.
“Producers look at this very simple idea and they see reduced maintenance, no training or programming problems for operators, no breakdowns in the field and a much lower cost.”