provided by: Construction EquipmentThe newest generation of big skid steers is capable of shaking off its utility-machine mantle and competing aggressively for production tasks with electronic-over-hydraulic joysticks and steadily more-refined cockpits. Most sophisticated features are optional, though, and buyers looking to save money on big loaders can still get simpler machines for utility work.
Options may come into play when outfitting large-frame loaders for production. But fundamentals such as the distribution of weight between front axle and rear and the choice of radial- or vertical-lift-path still determine the best machine for a given job.
All skid steers come from the factory weighted disproportionately on the rear axle. The machine is more maneuverable and tire wear slows when the front and rear are unequally weighted. Manufacturers' designs vary, but the basic objective is for the skid steer to pivot around the rear wheels when it is unladen, and the front wheels when the loader is handling rated capacity.
Carrying half of a skid steer's gross vehicle weight on the front axle and half on the rear will make it hard to steer, and tire wear will accelerate. Shifting too much unladen weight to the rear axles reduces the down pressure the machine can generate when digging and using attachments like a dozer blade or landscape rake.
Most Bobcats carry about 70 percent of their weight on the rear wheels, although longer-wheelbase, vertical-lift-path machines shift more toward 65/35. Caterpillar and Case tend to design with similar weight distributions. John Deere and New Holland build machines with weight distribution more in the 60/40, front-to-rear, range.
Variations in design offer buyers balance choices to suit their specific applications. If tire wear or precise maneuvering is a problem for users of machines with 60/40 weight distribution, it may be worth trying one that carries 70 percent of its weight on the rear wheels. If inadequate down force is a challenge to users of machines with 70/30 weight distribution, there may be benefits in machines that put more of their load on the front.
Choosing a vertical-lift-path machine will influence how much the loader can lift.
"No matter how you slice it, a machine with vertical lift path will have higher rated operating (ROC) capacity than a similar machine with radial lift path," says Mike Fitzgerald, Bobcat loader specialist. "Our S220 compares to an S250 when you go with the vertical lift path configuration. It's a 300-pound gain in ROC."
For about an $1,800 premium (adding vertical lift to the roughly $34,000 purchase of a Bobcat S220), vertical lift linkage frees the loader arm from a fixed rear pivot and mounts it in a four-link scissor configuration. Manufacturers mount stabilizer links and cylinders differently, but the object remains: Convert the radius lift path ? where the load rises in an arc and is farthest from the skid steer's center of gravity at mid lift, right where the operator needs maximum stability for loading pallets on flat-bed trailers ? to a straight vertical lift.
Electro-hydraulic controls, currently available as an option on Bobcat, Cat, and John Deere skid steers, also promise refinement in how the loader lifts loads. But initial advantages of the technology have been more limited to improving travel. Electronic-over-hydraulic controls convert joystick movement into digital signals received by an on-board computer that communicates with the hydraulic system.
The power of the computer, mysterious as it may seem to some, is prodigious. Bobcat and Caterpillar offer speed management with their electronically controlled machines. The operator can select a maximum speed setting on a dial and the machine will not exceed that speed no matter how far the operator moves the ground-drive lever. The operator no longer has to hold the joystick at a precise intermediate angle to move at a desired speed.
Trying to crowd too much asphalt into a cold planer or cut too much trench by traveling too fast can stall the engine and damage the tool. "Speed Management allows you to set the loader's maximum travel speed to achieve the sweet spot ? the speed where both the attachment and the loader perform most efficiently," says Fitzgerald.
Bobcat's Speed Management mode offers a choice of settings that represents a percentage of the skid steer's 7-mile-per-hour top speed. If you choose 50 on the dial, "no matter how far you move the joystick, the loader won't travel faster than around 3.5 miles per hour, which is about 50 percent of full speed," Fitzgerald says. "This allows you to maintain maximum driveline torque to power the wheels or tracks and full hydraulic power to operate your attachment."
In Speed-Management mode, moving the joystick a given distance results in a smaller speed change than throwing the lever the same distance in standard mode. Precise control of machine movements becomes much easier, which can add fine control for loading the machine on a trailer, hooking up attachments, working in confined areas, or other such jobs.
Caterpillar's Selectable Work Speed Control comes with the Advanced Machine Information Control System (AMICS). Another AMICS feature is the Selectable Implement Control. The system offers three levels of loader control, giving the operator the ability to adjust how quickly loader functions respond to joystick movement. Control can be tailored to match the operator's preferences.
Cat's Speed Sensitive Ride Control (SSL) is another option made possible by AMICS. It is a ride-control system much like that used on Cat's large wheel loaders, applying the lift cylinders to cushion the load, prevent spillage, and give the operator a smoother ride.
Of course, other skid steers are available with the hydraulic ride-control, but because SSL is an electronic system, its performance can easily adapt to changing ground speed. At high speeds, Cat's ride control automatically engages and allows the loader arms to float. The system turns off at low speed so the boom is rigid for digging and load-placing stability. The end result is faster cycle times.
John Deere is relatively new to using electronic joysticks in skid steers, announcing availability of E-H controls on its large-framed loaders and compact track loaders in January of 2008. But Gregg Zupancic, skid steer product manager with John Deere, promises the company will quickly match feature offerings of the technology's earliest adopters.
One great advantage of electronic controls is that systems already in the field can be upgraded with new features simply by changing software. A service technician can plug a portable computer into the machine's on-board computer and download a programming change. Machine owners get the latest features without paying for new hardware.
Making electronic controls optional features allows buyers who prize simplicity, such as rental fleets, to continue to save money on simpler hydraulic controls. Manufacturers such as Case and New Holland, Gehl/Mustang, Volvo, and JCB continue to offer manual controls (levers connected directly to the spools on hydraulic valves that regulate main-system flow) as standard equipment, with the option to upgrade to pilot-hydraulic controls to reduce lever effort. Pilot hydraulics employ a low-pressure hydraulic circuit between the control lever and valve. The pilot circuit acts on the valve's spools, assisting the operator's lever pressure.
All manufacturers are racing to market skid-steer cockpits that will offer operators a uniquely comfortable place to work. Size of the entry, and expanse of clear glass or grid to look through on the sides and top of ROPS continue to grow. Suspension seats are becoming standard equipment in many lines, and even heated air-ride seats are now offered as options in a couple of makes' enclosed cabs. This generation of operator-restraint bars is becoming ergonomic, with wider bars designed to offer operators more room and arm rests.
"Operator comfort is a big factor in productivity," said Jim Hughes, marketing manager with Case. The goal is not to coddle operators, but to keep them fresh and productive over more time in the seat. "That's why Case is always striving to improve the operator's platform when designing and upgrading models."
Manufacturers aren't neglecting reliability as they focus on skid steer productivity. Case's new Tier-3 skid steers come with oversized, wide-fin radiator and oil cooler (sized for high-flow auxiliary hydraulics) mounted side by side rather than stacked to improve air flow. Bobcat's largest Model S330 (introduced in January 2007) incorporates what the company calls SmartFan ? a thermostatically controlled, variable-speed cooling fan driven by a hydraulic motor that only turns as fast as necessary to maintain optimum coolant temperature. Noise and horsepower drain are both reduced.
As skid-steer capacity creeps up, a refined evaluation of large-frame loaders can help buyers carve new revenue streams with machines rated to handle 2,200 pounds or more. Nine machine models (from Bobcat, Case, John Deere, Caterpillar, Gehl and Mustang) can work with loads from 3,000 to 3,850 pounds. They will reach over sideboards 125 to 142 inches high, and drive hydraulic attachments with auxiliary flow rates of 33 to 41 gallons per minute. These big machines can compete with small wheel loaders for some production work. Buyers who want to wring productivity out of their over-$50,000 loaders can maximize their investments with any number of high-end options.
Big Skid-Steer Costs | Size | List Price | Hourly Rate |
|---|
| 2,201 to 2,500 lb. | $33,401 | $30.41 |
| $39,810 | $35.20 | |
Big Skid-Steer Specifications | Model | Rated load, standard (lb.) | Bucket breakout (lbf) | Net horse-power | Pump flow (gpm) standard/optional | Operating weight (lb.) |
|---|
| Mustang 2076 | 2,200 | 5,820 | 84 | 21.5/36 | 7,480 |
| New Holland L180 | 2,200 | 6,034 | 59 | 19.3/34.7 | 7,095 |
| Bobcat S220 K-Series | 2,200 | 6,550 | 74.9 | 20.7/40.5 | 7,470 |
| Case 440 | 2,200 | 6,198 | 82 | 21/31 | 6,980 |
| Gehl 5640E Turbo | 2,200 | 5,900 | 82 | 23/36 | 7,380 |
| Bulldog B8250 | 2,204 | -- | 80 | 28/na | 8,267 |
| Doosan 460 Plus | 2,250 | 4,678 | 65 | 21.7/32.3 | 7,174 |
| Case 435 | 2,300 | 6,000 | 72 | 21/32.1 | 6,830 |
| Caterpillar 256C | 2,350 | 7,328 | 82 | 22/33 | 7,566 |
| Volvo MC110B | 2,400 | 6,460 | 80.5 | 20.3/27.4 | 7,480 |
| JCB 1110 Wheel Robot | 2,425 | 4,630 | 82 | 20/32 | 8,214 |
| Case 450 | 2,450 | 6,200 | 82 | 22.1/37.2 | 8,830 |
| Caterpillar 252B Series 2 | 2,500 | 5,508 | 70 | 22/na | 7,861 |
| John Deere 325 | 2,500 | 7,500 | 70 | 22/34 | 8,390 |
| New Holland L185 | 2,500 | 7,670 | 72 | 19.3/34.7 | 7,100 |
| Case 445 | 2,500 | 5,100 | 74 | 21/33.7 | 7,677 |
| Bobcat S250 K-Series | 2,500 | 6,840 | 74.9 | 20.7/41.4 | 7,723 |
| Thomas 250 | 2,500 | 4,450 | 83 | 21/40 | 8,000 |
| Thomas 255 | 2,500 | 7,000 | 83 | 21/40 | 8,000 |
| Mustang 2086 | 2,600 | 5,640 | 84 | 21.5/36 | 7,860 |
| Gehl 6640E | 2,600 | 5,900 | 82 | 23/36 | 7,800 |
| Komatsu SK1026-5 | 2,650 | 5,400 | 84 | 21/34 | 8,068 |
| Caterpillar 262C | 2,700 | 7,315 | 82 | 22/33 | 7,968 |
| John Deere 328 | 2,750 | 10,500 | 76 | 22/36 | 8,580 |
| New Holland L190 | 2,800 | 7,670 | 74 | 21.9/37.3 | 7,755 |
| Bobcat S300 K-Series | 3,000 | 6,840 | 81 | 20.7/40.5 | 8,140 |
| Bobcat A300 K-Series | 3,000 | 7,150 | 81 | 20.7/37 | 8,673 |
| Case 465 | 3,000 | 6,175 | 82 | 22.1/37.2 | 8,910 |
| John Deere 332 | 3,175 | 11,600 | 85 | 24/41 | 9,160 |
| Caterpillar 272C | 3,250 | 7,315 | 90 | 22/33 | 8,292 |
| Bobcat S330 | 3,300 | 5,800 | 83.7 | 20.7/36.7 | 9,185 |
| Gehl 7810E | 3,850 | 8,340 | 99 | 29/41 | 10,520 |
| Mustang 2109 | 3,850 | 8,340 | 99 | 29/41 | 10,520 |
- CaseLarry Stewart
Power and Comfort Boost Performance
At January's World of Concrete, Case unveiled its new 400 Series 3 line of skid steer loaders with Tier 3 engines, a redesigned cab and improved service ability. Engine horsepower and torque increased on each model, including the 435, 440, 445, 450 and 465 large loaders, with Case engines ranging from 72 to 82 horsepower. A 7-percent increase in cab headroom allows installation of a standard suspension seat. Side lighting provides full visibility along the sides of the machine during night operation.
Number of models: 5
New models: 435, 440, 445, 450, and 465
Product-line features: The wide-fin side-by-side radiator and oil cooler are sized for high-flow auxiliary hydraulics and operating in extreme temperatures. A no-maintenance fan belt on the 435 and 445 Series 3 models is a plus, while an automatic belt tensioner on the 440, 450 and 465 eliminates the need for belt adjustments. Improved oil and fuel-filter access and remote oil drain help avoid spills and speed service.
- CaterpillarLarry Stewart
New Top Cat Offers Computer Control
Cat refined the positioning of hydraulic cylinders to improve lift and tilt forces of all its large skid steers compared to the equivalent B-Series models, and added the 256C and 272C to the range. At 90 net horsepower, the 272C (3,250 pounds rated capacity) is the most powerful Caterpillar skid steer. Electronic torque management maximizes power to the ground and prevents the engine from stalling in tough digging and heavy lifting.
Number of models: 5
New models: 246C, 252B Series 2, 256C, 262C and 272C
Product-line features: C-Series skid steers offer an optional performance package that includes a speed-sensitive ride control. At high speeds, ride control automatically engages and allows the loader arms to float. Loader arms act like a shock absorber, allowing for higher operating speeds with better load retention and more comfortable operation.
- BobcatLarry Stewart
New Biggest of the Bobcats
The newest model in Bobcat's K-Series large-framed loaders is its top-of-the-line S330 introduced in January 2007. With rated operating capacity of 3,300 pounds, it moved Bobcat over the 3,000-pound mark and placed a model within reasonably competitive range (550 pounds) of the behemoth Gehl 7810E/Mustang 2109. Perhaps more importantly, its 6,720-pound tipping load is larger than anything except the Gehl/Mustang monster.
Number of models: 4
New models: S330
Product-line features: All Bobcat K-Series skid steers with rated capacity of 2,200 pounds and more now come with a variable speed, hydraulically driven cooling fan that senses engine temperature and can be 30 percent quieter. Bobcat upgraded large-frame loaders' drive chains size to 120 HSOC (high strength oval chain) from 100 HSOC on K-Series, making the bowtie-style drive chains 38-percent stronger.
- MustangLarry Stewart
Proportional Auxiliary-Hydraulic Control
Mustang swapped the Cummins engine in the 2076 and 2086 skid steer loaders for the Tier-3 Yanmar turbo-diesel engines, moving up from 80 to 84 net horsepower. Conventional hand-and-foot controls are improved with pilot-hydraulic foot pedals and a new proportional auxiliary-hydraulic control. The joystick pilot control option remains with built-in proportional control, as well as a ride control feature. Customers who prefer the dual-hands control pattern can change the joysticks to provide for that control pattern.
Number of models: 3
New models: 2076, 2086, and 2109
Product-line features: Mustang and Gehl segregate their 2,200- and 2,600-pound-rated-capacity skid steers by engine choice. Mustang's Yanmars contrast with the Deutz engines Gehl chooses. All the engines are rated at 82 or 84 horsepower.
- VolvoLarry Stewart
Big Power in a Light Package
The B Series increased room in Volvo's skid-steer cockpit, and brought with it a deluxe, high-back standard seat and one of the largest entry and exit openings in the industry. There's only one skid steer lighter than the Volvo MC110B in the range from 2,300 pounds to 2,500 pounds rated operating capacity, yet Volvo's 2,400-pound machine delivers more bucket breakout force than half of the 2,500-pound units in the market. Volvo offers a choice of pilot operated joysticks or mechanical hand-and-foot controls.
Number of models: 1
New models: MC110B
Product-line features: Volvo builds the 16-valve D3.4A turbo diesel that delivers 80.5 net horsepower to the MC110B skid steer. The oil cooler tilts away from the radiator for easy cleaning.
- GehlLarry Stewart
Pilot Controls Manage More Capacity
Gehl increased the operating capacities of its large-framed skid steers with introduction of the E-Series, taking the 5640E to 2,200 pounds (from 2,000 pounds), the 6640E to 2,600 pounds (from 2,400 pounds), and the 7810E to 3,875 pounds (from 3,675 pounds). The company claims enhanced reliability and drive performance from Poclain's refined radial-piston drive motors, while reducing sound levels. The new models got pilot-operated joystick controls and finger-tip, proportional control of auxiliary hydraulics.
Number of models: 3
New models: 5640E, 6640E, 7810E
Product-line features: The low-profile Power View lift arm improves operator views to the left and right over the lift arm and lifts loads in a nearly vertical path. Gehl boosted rated operating capacity of the industry's largest skid steer, the 7810E (and Mustang 2109), to 3,850 pounds.
- Thomas EquipmentLarry Stewart
Fast Powerhouse
Thomas uses the Kubota V3300-T turbo-diesel rated at 83 horsepower in its 250 and 255 skid-steer models, which is at least 10 percent more power than any other skid steer rated at 2,500 pounds operating capacity. The 250 moves briskly around jobsites at 7.5 mph ? faster than any other 2,500-pound skid steers. The two-speed-equipped 255 fairly sprints at 12.3 mph ? 2 mph faster than any other large-framed loader.
Number of models: 2
Product-line features: Only two skid steers with rated capacities under 3,000 pounds ? Bobcat's S220 and S250 ? offer as much auxiliary hydraulic flow as the 40 gpm delivered by the high-flow 250 and 255.
- John DeereLarry Stewart
Digital Joysticks Extend Control Choice
John Deere made electro-hydraulic joysticks an optional control choice on its large-framed 325, 328 and 332 skid steers. With addition of the drive-by-wire option, which Deere calls E-H controls, the company now offers the most skid-steer control patterns on the market, including hand-and-foot controls; Case-style H hand controls or ISO pattern using pilot hydaulics; and the new E-H, ISO-pattern hand controls. About two years ago, Deere applied an electrical motor to its optional Power Quik-Tatch, taking advantage of the relatively easy-moving, patented system for retaining attachments.
Number of models: 3
Product-line features: Deere added a few notable standard features to its large-framed loaders in the past few years, including an anti-theft system, a 12-volt receptacle and storage, interior dome lighting, a cup holder, and enhanced engine and hydraulic sound deadening.
- KomatsuLarry Stewart
Anti-Stall Comes Standard
Komatsu strives to distinguish its SK1026-5 skid steer with a few standard features that are commonly options on large-frame loaders. Two speed travel motors with a top speed of 10 mph, self leveling bucket, two-way auxiliary hydraulics, and anti stall Automatic Power Control are all standard equipment. It delivers the greatest height to the bucket pin (128.3 inches) and dump reach (36.8 inches) of any skid steer from 2,500 to 2,700 pounds rated operating capacity. In fact, you have to go up to a machine with 3,250 pounds rated capacity to get more load-over height, and all the way to 3,850 pounds capacity to get more dump reach.
Number of models: 1
Product-line features: Komatsu eases maintenance with special bronze bushings and dust seals in the loader linkage that stretch the pin-greasing interval to 250 hours. Komatsu allows the same grade of multi-viscosity oil to serve as engine oil, hydraulic oil and chain-case.
- New HollandLarry Stewart
Bigger Engines and Better Cooling
The list of updates to New Holland's large-framed loaders reads much like that of their Case counterparts in the CNH family. In 2008, New Holland Construction will finish reintroducing its Super Boom skid steers with a new Tier-3 certified FPT (Fiat Power Technology) engine that will boost horsepower. More-powerful batteries (30 percent more cold cranking amps), starters and standard grid heaters will improve cold starts. Larger cabs with convex glass door, more headroom and elbow support, and standard suspension seat were introduced last June.
Number of models: 3
New models: Super Boom L180, L185, L190
Product-line features: New Holland continues to distinguish its skid steers from Case, and most other models on the market with longer wheelbase ? putting the 2,800-pound ROC L190 within range of Cat's 3,250-pound 272C, and its scissor-style vertical-lift boom.
- JCBLarry Stewart
Lower Boom, Better View
JCB recently lowered the single, right-side loader arm of its Robot 1110 skid steer to improve the operator's view over the boom. Side-door entry remains an exclusive JCB feature in skid steers, eliminating the need for operators to climb over attachments to enter the loader.
Number of models: 1
Product-line features: The Robot 1110 skid steer is powered by JCB's 82 net horsepower 1104C-44T diesel engine. Hydraulic self-leveling is an available option for pallet work.
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author: By Larry Stewart, Executive Editor
Construction Equipment. Copyright © 2008 Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.