Tiltrotator Q&A: Caterpillar Answers All Our Questions on These Twisty Mini Excavator Attachment Adaptors

Tiltrotators give excavators dexterity. These coupler systems attach to the end of the boom and allow an excavator’s attachment to twirl 360 degrees or tilt to odd angles for exacting excavation or implement work. Over the last couple of years, tiltrotator systems have not only been growing in popularity in America (they are big in Europe), but they also have been shrinking in size to fit on compact excavators. These systems add awesome maneuverability to your attachment, but they do initially present a learning curve in order to use them efficiently, and they ain’t cheap either.

But, a tiltrotator-equipped excavator offers enhanced value for customers, especially those working in tight, challenging jobsites or tackling applications that require precision and versatility such as site development, underground work, landscaping and grade control operations. Versatility and saving time are the tiltrotator’s biggest advantages. For example, the additional degrees of freedom from tilting and rotating your bucket or attachment can boost backfilling and grading operation. Tiltrotators can even be used with grade control system for the ultimate precision diggin’ combo.

To learn more about tiltrotating systems for compact excavators, we reached out to Daniel Cohen, product application specialist at Caterpillar for attachments, to discuss these flexible coupler systems.

CE: Daniel, first off, thanks for taking the time. We really appreciate your help learning about tiltrotators for compact excavators. They can be complex. Now, what tiltrotator products does Cat offer specifically for compact excavators? Can you give us a brief description of your products? How many are geared toward compact excavators, which we’ll categorize as 10-metric-tons and below?

Cohen: Caterpillar offers seven models of tiltrotators to fit machines from 2.7- to 35-ton machines. In the compact equipment space, there are three models: TRS4, TRS6 and TRS8. The TRS4 fits 2.7- to 4-ton machines. The TRS6 fits 5- to 6-ton machines, and the TRS8 fits 7- to 10-ton machines. Each model of TRS can be configured with S-type or Cat pin-grabber coupler interfaces. They can also be fitted with an integrated grapple when the TRS is configured with the S-type lower coupler interface.

How much do tiltrotator systems typically cost? Can we get a range? Basic to a tiltrotator/safety coupler combo with the grapple option and advanced controls.

The cost of an installed tiltrotate system will depend a lot on the machine it is being installed on and what options are selected. The TRS plus the components needed for installation will range from $25,000 to $40,000. Adding an optional grapple module will add to that. Most of the cost difference will lie in the TRS model itself. The labor to install the tiltrotator on the host machine should also be considered when comparing brands. It takes more work to install some tiltrotators than others.

What machine contractors and operators gravitate toward using a tiltrotator on small excavators? What applications are popular? What sectors do you see buying this equipment?

The range of contractors that are starting to adopt tiltrotators is broad. They can be a game-changing addition to a machine no matter what type of work a contractor primarily does. If I had to say which contractors have been early adopters, I would say landscapers and hardscapers. Many of them quickly saw the advantages of adding two more degrees of freedom to their excavator. They are able to take advantage of this when grading contours or working in tight spaces where repositioning the machine is a difficult task. That is not to say that utility contractors and others have yet to find unique ways to incorporate tiltrotators into their fleets. Tiltrotators are handy tools for installing pipes, manipulating poles and handling scrap or recycling.

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What attachments can be used with a tiltrotator? Buckets? Grapples? Anything else popular? What kind of buckets or grapples? Is it specific?

There is a wide range of tools available for tiltrotators. The most common attachment is a bucket, but not the standard excavator digging/trenching bucket. The buckets used with tiltrotators, sometimes called Nordic-style buckets, tend to be short and wide with very long floors. This makes them more useful when spreading and grading material. They also tend to taper inwards at the rear of the bucket. This limits the amount of “tail swing” when rotating the bucket around corners.

Grading beams are another very popular attachment. Although they are commonly called grading beams, they are more like grading boxes. They allow the operator to quickly spread and level material. Their length and width provide a stable platform, and their high sides allow material to be carried like a box blade. Some have a roller on one side to compact and smooth material.

Then there are the grapples. If a contractor is doing any material handling (pipes, poles, stone, etc.) with their excavator and tiltrotator, then a grapple is a must-have. The grapples commonly used with tiltrotators are bypass-style grapples, meaning the grapple arms move past each other. This allows the grapple to grip a wide range of material sizes. 

How does a thumb attachment interact with a tiltrotator? Can they still work together? Is there interference or hydraulic limitations?

Although it is possible to have a thumb installed on the stick of an excavator and run a tiltrotator, it is not recommended. There are several reasons why. First off, the thumb cannot be operated with the tiltrotator installed. The tines would not come close to reaching the edge of the bucket. Secondly, it adds additional weight, which decreases machine stability. And lastly, the tiltrotator can be positioned in ways that the attachment being used can crash into the thumb, even when it is fully retracted. If the customer understands the trade-offs and limitations, they could keep the thumb on the machine, which could be used when the tiltrotator is removed.

What equipment and hardware needs to be added to a compact excavator when installing a tiltrotator? New joysticks? New hydraulic plumbing? How long can this installation process take? Once installed, does it ever come off?

The equipment that must be added to install a tiltrotator fully will vary depending on the brand of machine and the brand of tiltrototator. One of the major benefits of using a Cat TRS on a Cat excavator is that there are very few required additions to the machine. The only hardware components that need to be installed are upgraded joysticks and a wiring harness for the TRS to plug into. The brains of the TRS are built into the machine ECM, and the user interface is done through the existing machine display. The TRS runs off the existing first auxiliary circuit, so there are no hydraulic components that need to be added. When installing an aftermarket TRS, it is very likely that an additional ECM and display will need to be added to the machine.

How difficult is a tiltrotator system to master? How long does it normally take?

There is a learning curve when mastering a tiltrotator, but an experienced excavator operator will likely start to get comfortable with the new controls within a day or two and become proficient soon after. Cat dealers have certified delivery instructors that will come out and train operators on their new equipment. There is also a growing community of operators sharing their tiltrotate experience online via YouTube, forums and Facebook groups.

What operator advice can you share about using a tiltrotator? What techniques are important to implement when employing a tiltrotator?

One of the biggest benefits of using a tiltrotator is that doing so reduces the number of times the machine needs to be repositioned to complete a task. A great example is digging for a septic tank installation. By using the tilt and rotation functions, the task can be completed without having to move the machine more than a couple of times. This reduces damage to the surrounding area and wear and tear on the machine. Tiltrotators are also a great tool for digging and grading along foundation walls. When paired with a Nordic-style bucket, an operator can grade inside 90-degree corners without the heel of the bucket hitting the wall.

The information shown in the machine display can also be a useful tool to the operator. When cutting ditches, the angles shown in the display can help the operator maintain even slopes on both sides of the ditch. One technique that can be useful when truck loading material is to rotate the bucket 180 degrees and use it like a front shovel. This is especially useful as the spoil pile moves closer to the machine. When trenching and installing utilities, the integrated grapple module can be used to pick and place pipe. When it is time to backfill the trench, the bucket shake feature can be used to evenly spread the backfill material.

One of the most beneficial things about running a tiltrotator is the ability of the machine operator to perform tasks from the cab of the machine that would have traditionally required a helper on the ground. Keeping that in mind when running the tiltrotator will help an operator see new opportunities to take advantage of the increased flexibility that the attachment offers.

What is the most popular sizes of compact excavators being outfitted with tiltrotators? 6 metric tons and above?

The 5- to 6-ton size class machines seem to be very popular hosts for tiltrotators. This size class of machines is the do-all size machine, so it is not surprising that we see many tiltrotators on them. I expect to see quite a bit of growth in tiltrotators for 3- to 4-ton size machines in the next few years. Caterpillar recently released the TRS4 just for smaller machines.

Can your tiltrotator systems work with grade control? How does that integration occur?

Yes, the Cat TRS is compatible with both 2D and 3D grade control systems. The process to upfit a TRS with grade control is similar to equipping any other piece of equipment with grade control. There is a kit that is purchased through the Cat dealer. The kit includes brackets for mounting additional sensors, adapter harnesses and software licensing. There may be additional hardware and software that will need to be purchased depending on what grade control system is being used.

How popular is the tiltrotator/safety quick-coupler combo? What options are available when it comes to safety quick-couplers and your tiltrotators?

Using the TRS in a “sandwich” configuration is very popular. What this means is that there is a coupler fitted to the stick of the excavator that can pick up the TRS. The TRS has a coupler on the bottom side to pick up attachments. This basically sandwiches the TRS between the stick coupler and the attachment being used. Caterpillar offers a Locking Control System, or LCS, on the TRS units. This system uses a sensor in the coupler itself to determine if the attachment is securely coupled. The operator will see a message on the machine display to communicate the status of the coupler. 

All TRS units have this feature on the lower coupler interface, whether a pin grabber style or an S-type coupler. Caterpillar also offers S-type machine-mounted couplers that have the LCS feature.

What auxiliary hydraulic requirements are needed to run your tiltrotators? GPM? PSI? Does it take much power?

The Cat TRS only requires first auxiliary hydraulics to operate. The flow requirement varies depending on the TRS model but is well aligned with the host machine that the TRS is designed to be used on. For example, the Cat TRS6 has an optimal flow range suitable for 5- to 6-ton machines. They aren’t power-hungry attachments like a mulcher or mower would be. Even when giving multifunction commands, there won’t be a noticeable reduction in speed.

What options are available with your tiltrotators? Advanced control systems? Grapples? Double or single acting cylinders? Lubrication systems? Do tell.

The biggest decision a customer will have to make with the Cat TRS is what interfaces best suit their needs. There are two interfaces on a tiltrotator. The top interface connects the tiltrotator to the host machine, and the bottom interface connects an attachment to the tiltrotator. Customers can opt for three different interface options:

  • Pin on top interface — pin grabber coupler lower interface: This configuration allows the TRS to either be pinned directly to the stick of the machine or picked up using a Cat pin grabber coupler. The pin grabber coupler on the bottom of the TRS can pick up the same attachments that the machine-mounted coupler can.
    • Pro: This setup will be compatible with any Cat attachments the customer already has for their machine.
    • Con: The integrated grapple module is not compatible with the pin grabber lower interface
  • Pin on top interface — S-type lower interface: This configuration uses the same top interface as above but with an S-type coupler on the bottom side. The S-type coupler is common in the tiltrotator world and is the coupler of choice in the European market.
    • Pro: It offers a lower height offset than the pin grabber coupler, which helps retain breakout forces. It is also compatible with the integrated grapple module.
  • S-type top interface — S-type lower interface: This version of the TRS uses an S-type interface on the top and an S-type coupler on the bottom of the unit. This is a good option if the customer is already using S-type attachments. The S-type interface is an industry standard interface, which means that S-type attachments from all manufacturers are interchangeable. It also has the benefit of having a lower stack height than a TRS that is used with the Cat pin-grabber coupler.

The only other option on the Cat TRS systems is whether to install the integrated grapple unit. The grapple unit can be added to any TRS with an S-type lower interface. The Cat TRS uses single-point greasing for the pin joints and gear oil lubrication for the rotator. The single point greasing reduces daily maintenance time, and the gear oil lubrication helps reduce heat buildup in the rotator.

What advice would you give a buyer when choosing a tiltrotator system for compact excavator operations?

There are quite a few good options out there for tiltrotators on mini excavators, and they are all going to have similar performance. The two pieces of advice I would give are this.

  1. How well does the tiltrotator you are looking at match up to your machine? Is the unit that you are looking at really the best size, or are you going to install a unit that is too large or too small simply because it is what a certain manufacturer offers? Is the tiltrotator you are looking at going to integrate well with your machine, or are you going to end up with a bunch of extra hardware added to your machine to run the unit?
  2. What service support will be available for the unit you choose? Some manufacturers have great service support, and some will leave you hanging at the worst possible time.

What makes your tiltrotator systems unique? What brand differentiators can you share? Do you have a unique technology, size or option?

Cat TRS8 tilt rotator

The thing that sets the Cat TRS apart from competitive units is the integration into the machine. The Next Gen Cat mini excavators have about all the goodies needed to run a TRS already built into the machine. The brain for the TRS is integrated into the machine ECM, and all the user interface to the TRS settings are done through the existing machine display. Both the basic and advanced versions of the machine display are compatible with the Cat TRS. Much of the wiring is also already present on the machine, which makes for a tidy installation. These things add up to a tiltrotator and a machine that was designed to work together. The Cat TRS is also covered by a standard two-year warranty. 

Anything else you’d like to mention, Daniel? You sure know your stuff.

Thank you for the opportunity to contribute! Caterpillar is committed to the tiltrotator business, and we continue to bring new products to the market for this segment. In 2022 we launched the TRS4 for 302.7-304 machines, and in 2023 we will launch two new grapples to go with the TRS6 and TRS8. 

Keith Gribbins is publisher of Compact Equipment.