Couplers that allow excavator attachments to tilt and/or rotate can dramatically increase jobsite efficiency when used in the right applications. While there are certain trade-offs in excavator performance, these are often eclipsed by the increased versatility and time savings.
“One of the biggest advantages of using tilting couplers with excavator attachments is the machine’s increased range of motion,” says Adam Bell, attachment product specialist, Doosan Construction Equipment. “Doosan excavator operators have up to 180° of tilt on our two mini-excavators (DX63-3 and DX85R-3) or 134° total tilt from the larger DX140LC-5 to the DX225LC-5 crawler models. The increased range of motion helps operators work more efficiently around utilities and minimize machine repositioning. Less repositioning improves operator productivity, which has a direct impact on the company’s bottom line.”
CaterpillarGreater range of motion directly translates to jobsite efficiency. “An excavator with a standard coupler or pin-on bucket is only able to work in parallel with the direction of the boom and stick,” says Rick Verstegen, product application specialist, Caterpillar. “Adding tilting and 360° rotating functions to the end of the stick increases the mobility of the excavator front structure, enabling the possibility to work in all directions, with different angles. Tilt-rotators eliminate the need to constantly reposition the excavator, which increases not only productivity and fuel efficiency, but also safety on the jobsite.”
Excavators used in a wide variety of applications will benefit from a tilt-rotator, says Verstegen. “Tilt-rotators bring big advantages compared to standard couplers in underground sewer, water and utility applications, where accurate digging around pipes, cables or concrete structures is required,” he notes. “The Cat Tilt Rotator System (TRS) can be equipped with an integrated grapple module, enabling the possibility to pick and place materials (e.g., pipes) without changing the attachment, making the excavator more versatile.”
Grading and finishing are also very popular tasks for tilting and rotating couplers. “Tilt-rotators offer productivity advantages compared to standard couplers when used in grading, leveling and finishing applications, especially when creating multi-angle slopes and used in combination with GPS,” says Verstegen. “The Cat TRS can be optionally equipped with RPS sensors, which provide precise positioning data to the grade control systems and in-cab monitor.”
The increased dig depth due to the additional coupler length — as much as 18 in. depending on the size of the machine and the size of the tilting coupler — may also be a benefit. “This may occasionally allow a company to use a smaller crawler excavator such as a 14-metric-ton model with the additional reach without moving up a machine size for additional dig depth,” Bell points out. “While the smaller crawler excavator will not permanently replace a larger model, if a contractor is working on a utility project in an area with limited space, a smaller model with additional dig depth may make the job much easier to complete.”
There are safety benefits in certain applications, as well. “Tilting couplers can eliminate having a worker in the trench if an operator is digging around or under buried utilities,” says Bell. “That worker can be freed up to do other tasks on a jobsite.”
“Excavators with tilt-rotators are 20% to 35% more productive (depending on the application) compared to an excavator with a standard coupler,” Verstegen states. “On top of that, there is less need for personnel around the machine. The lower need to constantly reposition the excavator makes the solution very suitable for working in confined areas where safety is important, like in city centers with high-density traffic or between or beside roads, buildings or other obstacles.”
For some applications, such as hydraulic breakers, make sure you check with the coupler supplier first. “Using a hammer with the PowerTilt is acceptable for intermittent use, unless it has been upsized specifically for a hammer application,” says Ron Hurst, product sales manager, Parker Hannifin Corp., Helac. “Some tilt-rotator brands do not recommend using hammers.”
Similarly, Rototilt’s Gerry Mallory recommends keeping hammer use intermittent. “If a hammer is to be used for a long period, it would be best to remove the Rototilt,” he advises.
A deciding factor in determining whether a tilt/rotator makes economic sense is how often you will rely on the enhanced range of motion.
“When determining whether a tilting coupler is a financial benefit on a jobsite, a contractor should consider how frequently the company will be working around utilities and how often the machine needs to be repositioned,” says Bell. “If the contractor is working in tight areas, having to reposition the machine can be difficult.”
Factor in how your excavator is currently being used. “If you spend much time repositioning the excavator to get at the work and/or find that a lot of hand digging/raking is being performed, then you can save money by using a tilting coupler or tilt-rotator,” says Hurst. “To perform an ROI, take the cost of the tilt coupler or tilt-rotator including installation and divide by the average charge-out rate for the excavators to determine the number of hours that need to be saved to pay for the attachment. Figure a minimum of an hour savings per day. Most customers estimate they can save 25% to 50%, but some claim 100%. It does not take long to pay for the attachment with this kind of time savings.”
“A Rototilt tilt-rotator will provide significant time and labor savings in any type of excavator work,” adds Mallory. “It can also expand the type of work that an excavator contractor can perform that would otherwise require multiple machines.”
DoosanFor those unable to justify the investment in a tilting and/or rotating coupler, there are options. “Some manufacturers, such as Doosan, offer an angle-tilt bucket if contractors have an occasional need to tilt a bucket but don’t need a tilting coupler,” says Bell. “Angle-tilt buckets are a versatile, cost-effective grading and land-clearing attachment that can tilt 45° in either direction.”
There are different types of tilting and rotating couplers offered by suppliers. “There are two types of tilting and tilt-rotating couplers available. One type uses linear actuators (cylinders) for tilting and the other type, like the Parker-Helac PowerTilt, uses a helical rotary actuator,” says Hurst.
According to Parker-Helac, the helical actuators provide a compact configuration that fits in a narrow trench with a narrow bucket. This type typically tilts up to 180° as compared to 90° for the cylinder type. In addition, there is no exposed cylinder rod to get damaged. The helical actuators are typically taller due to the clearance needed for the added rotation. Both types typically use worm drives for the continuous 360° rotation.
Werk-Brau’s coupler system offers an integrated, precision-built actuator to ensure trouble-free operation. “Many competitors offer a tilting coupler where they incorporate one or more cylinders, which increases the risk of coupler failure due to the cylinders not being enclosed,” says Alex Andrews, regional account manager, Werk-Brau. “This coupler is featured in a variety of coupler styles: John Deere Wedge, Kubota Bantam, mechanical pin grabber and hydraulic variable pin center pin grabber.”
But there are also advantages to the configuration that incorporates hydraulic cylinders. “Tilt-rotators without cylinders have a small fraction of the tilting torque compared to tilt-rotators with cylinders,” says Mallory.
The worm gear rotator systems have proven reliable. “The Cat TRS is equipped with a worm gear drive that provides broad bearing surfaces that distribute and resist excavation forces in all directions,” says Verstegen. “The gear group is in a constant oil bath to keep the worm gear lubricated in any condition for long-lasting reliability.”
Plumb It Properly
Tilting and rotating couplers are commonly used in trenching applications with narrow buckets and in grading applications with wide buckets.
“The Cat trenching and grading buckets have been designed with optimal dump and curl angles to enhance the ability of the operator to retain material for loading applications — but also to provide optimal vertical wall positioning for trenching or when working against walls when used with the TRS,” says Verstegen. “The full range of dedicated trenching and grading buckets are designed with a reduced tip radius and conical sides in order to ensure proper fit and superior performance on the Cat TRS.”
Tilting couplers are powered by the machine’s auxiliary hydraulics. “The excavator needs to have two sets of auxiliary hydraulics to operate additional hydraulic attachments, such as breakers, with tilting couplers,” Bell points out. “Excavator operators can use the tilting coupler with a hydraulic breaker to get a desired angle when demolishing a structure.”
You must account for the additional plumbing requirements when selecting a tilting and/or rotating coupler. “A tilt coupler requires a two-way auxiliary hydraulic circuit to operate,” says Hurst. “If a hydraulic quick coupler is used on the lower end of the tilting coupler, then a hydraulic circuit is required for it, as well.
“Requirements to run the tilt-rotators largely depend on the hydraulic package purchased with the unit,” he continues. “Many are available with proportional controls, in which case only one auxiliary hydraulic circuit is required to feed a bank of proportional control valves on the tilt-rotator that operate the tilt, rotate, auxiliary circuit and hydraulic quick coupler.”
HelacIn order to operate a tilt-rotator, the minimum requirement is for the excavator to be equipped with both a medium- and a high-pressure circuit. “The Cat TRS can optionally be equipped with a high-flow swivel in order to maximize productivity when used with hammers, compactors and demolition/sorting grapples,” says Verstegen.
Adding weight to the end of an excavator stick does decrease available lifting forces. “When construction companies add a tilting coupler to the end of the arm, depending upon the size of the machine, the coupler will add additional weight,” says Bell. “As a result, the operator will lose some lift capacity. That’s one of the trade-offs the contractor should be willing to accept when using a tilting coupler.”
“Tilt-rotators add more weight to the end of the stick compared to a standard coupler, and the bucket capacity needs to be adjusted to compensate for that,” says Verstegen. “In order to maximize the lifetime of the excavator front and the tilt-rotator, there are some limitations in the maximum bucket width. The maximum bucket width depends on the excavator size, tilt-rotator size and the application.”
Any weight added to the end of the boom should be taken into consideration. “This not only can add a tipping hazard, but also take into consideration the reduction of breakout force,” says Andrews. “The closer the attachment is to the end of the stick, the better your breakout force will be. In addition, when using heavy vibration attachments, this will increase wear from a normal day-to-day use of a non-movement attachment (digging bucket).”
Tilting couplers do change the geometry; the added length translates to a larger bucket tip radius from the stick pivot point. “The reduction in breakout forces is proportional to the percentage of increase in the bucket tip radius,” Hurst notes. “If you look at the increase in radius from the stick pin to the bucket tooth, the increase is maybe 20% to 30% depending upon the bucket. However, the added bucket tip radius from the arm pivot point is a significantly smaller percentage, maybe 5% to 10%. Trenching is generally done with the arm in long strokes, not with the bucket curl, so loss of breakout force is not really noticed.”
It’s all about whether the trade-offs in lifting and breakout force will be offset by the efficiency increase. “There is some marginal loss in breakout force, but it is far outweighed with all of the other operational benefits and efficiencies,” Mallory asserts.