Groundbreaking SynchroStacker

Innovative in every component, the R300’s SynchroStackerTM stacks turf with unmatched durability, quality, efficiency, and productivity.

Perhaps one of the most dramatic innovations of the R300 is the revolutionary stacker head, including its exclusive helical pick-up screws.

We selected a corkscrew-type mechanism because of its extremely high vertical holding force—much stronger than something like a spear or a hook. This means we can pick up even the most tender of grass rolls with amazing security, as well as penetrate very stiff clay soils—even rocky soils. The center stake provides additional stability of the roll as the counter-rotating screws go into it, so the stacker can hold rolls that would typically fall off any other machine. At the same time, they hold the roll in a way that also provides a lot of horizontal holding force and can therefore press down on the pallet, compressing the layers together for more stability.

Corkscrews, however, pose a little bit of a challenge. Anybody that’s ever tried to drill a hole and tap it for threads knows you must be perfectly synchronized going in with the vertical and rotational movement. This challenge is solved with FireFly’s electrically driven mechanisms. In fact, because the R300 has the highest performance, most technologically advanced control computer on any harvester in the industry, it does this reliably and effortlessly. We can precisely synchronize the pitch of that screw with the vertical movement of the stacker head, so it doesn’t disturb the roll at all and goes into the roll very cleanly.

The screws are made from high-strength spring steel, which is about ten times stronger than the regular steel commonly used. If you were to hit a big rock, they usually just bend and spring right back, so they’re exceptionally durable.

It’s actually difficult to apply down pressure with hooks. Spears can apply lots of down pressure because they use the top of the stacker to push on the rolls.

The R300’s mechanism uses the horizontal holding force of the screws to apply down pressure to the stacker, and we can apply a lot of pressure on that stack—well over a thousand pounds per stack—or the equivalent to a ton over the whole layer.

Everything in the R300’s stacker is electrically driven. There aren’t any hydraulics on the stacker at all. This is technology that FireFly pioneered with our slab machine, and we’ve been perfecting it now for over twelve years. We have logged many hundreds of thousands of hours of stacking time and refined this technology for use in sod harvesting machines.

Slab harvesters have a particularly challenging situation. Unlike a roll machine, where we’re picking up 50 square feet of sod at a time, on a slab machine, you’re maybe picking up eight square feet at a time, and so that stacker is moving back and forth literally over a million times a year. In an equivalent roll machine, cutting the same amount of sod, it’s moving something like 150,000 times.

In engineering and mechanical design, when you start getting mechanisms with over the magic number of a million, all kinds of new design considerations for fatigue come into play. We needed the stacker on our slab machine to hold up to millions and millions of cycles. Using an electric stacker gives us the ability to move very smoothly. Fast is important, of course, but also, the accelerations and decelerations have to be very tightly controlled to avoid high stresses in the system.

Electrification has other benefits beyond durability, including higher productivity, consistent rolls, and much lower fuel consumption and power requirements. The electrically driven stacker is also completely immune to temperature changes. It does the same move, time after time, whether it’s hot or cold.

FireFly harvesters have two important features that allow them to perform exceptionally well on all kinds of hilly fields. The first is outstanding chassis stability. Our wide stance front axle, along with great weight balance, keeps your cutterhead stable and square with the ground, even on side slopes.

The second is our electric stacker. Traditional hydraulically-controlled harvesters have difficulty holding the stacker steady along hills and slopes. All FireFly harvesters use electro servo motors to move the stacker. Electric motors give a smooth, accurate, efficient, and repeatable operation, and they also hold the stacker in exact position in sloping fields.

FireFly’s exclusive scissor vertical axis is another unique feature of the R300. This mechanism has the best rigidity and very low maintenance. All the stacker’s movements ride on smooth glide polyurethane rollers. As the machine gets thousands of hours on it, it will stay stiff. In addition, its wear components are replaceable, with nothing welded onto the chassis.

The R300’s gantry style stacker has many advantages over a robotic arm style: first and foremost are strength and rigidity. The fully supported gantry of the R300’s stacker is structurally superior, is able to move much faster with less power, and overall is much more simple and lower cost to maintain.

FireFly R300 side view