When a bucket alone can’t handle the job, look for a thumb, a grapple, or a hybrid attachment to help you seize the moment.
When it comes
to digging, loading, and piling dirt, nothing beats a bucket. But what if you
want to use your excavator to handle other tasks, such as lifting logs, placing
boulders, clearing brush, or even tearing down a small building? That’s where
you need—if not an extra hand or two—at least a thumb to get a better grip on
irregular-shaped objects.
Manufacturers
offer a variety of mechanical and hydraulic clamps, which work like a human
thumb, to pinch an object between the thumb and the bucket, enabling you to use
your excavator or backhoe, to handle unwieldy material faster, easier, and more
safely.
“Just like
using your hand to hold material against shovel or rake, a thumb allows a
machine operator to grasp and manipulate objects or loose material much easier,
maximizing a backhoe or excavator’s versatility in a range of applications,”
explains Mark Elliott, sales manager for Amulet Manufacturing Co., which makes a
line of thumbs. “A thumb creates a positive gripping profile to significantly
increase the capability of a backhoe or excavator. It’s just the same as trying
to reach down and grasp rocks or material, such as dirt, with your hand without
using your thumb. You may get some, but not as much as using your thumb.”
That, in turn,
opens the door to more ways of making money.
“Customers
often tell us that, since purchasing a thumb for their machine, they’ve taken on
projects that they would have never considered before,” Elliott says. “Many of
those same customers had previously lost out on bids to competitors with thumbs
on their machines who could do the same job in half the time. Time is money, and
thumb owners know it.”
A
Multipurpose Tool
Before buying
an excavator, land-clearing contractor Jimmy Harris had rented excavators with
thumbs. So when the owner of the Greenville, NC–based Harris Land Development
bought his first excavator in 2004, a Hyundai R210, he wasted no time equipping
it with a Werk-Brau hydraulic E-Z Grip Material Handler thumb.
“I wanted to be
able to multitask,” says Harris, who also equipped his second excavator, a
Hyundai R160, with another of these thumbs.
 |
Photo: Kenco
The Brush Grapple and the Hardrock Grapple, both made by Kenco, can be used with direct pin-on or pin-grabber. For quick, easy attachment changes, either grapple can be used with the Wedgebolt coupler. |
He uses the
thumb on his land-clearing projects for picking up logs. “I couldn’t do what I
do without my thumb,” he says. “It’s my main tool for these projects. I could
pick up a log with just a bucket, but it would be a very slow process and it
wouldn’t be safe, because I would have no control over it.”
Harris also
uses his thumb on excavating jobs for handling and laying plastic and concrete
pipe.
“If I’m digging
and run across debris, it’s very easy to pick it up with the thumb and move it
out of the way.”
The thumb has
also proved handy when working with plastic or concrete pipe, he adds.
“I can use the
thumb to apply a minimal amount of squeeze pressure to carry and place pipe in a
ditch,” he says. “Because of the weight, I don’t pick up concrete pipe larger
than about 24-inches diameter. However, I can pick up 20-foot sticks of 36- to
48-inch diameter plastic pipe without any problems.”
The thumbs on
the excavators that Harris used to rent were mounted in a fixed position at
about a 45-degree angle to the stick. His E-Z Grip thumb, on the other hand,
folds up tight against the stick when not in use. “I load a lot of dump trucks,
and a rigid thumb can really get in the way in that kind of work,” Harris says.
“My thumb folds out of the way to provide the truck clearance I need when
loading trucks, especially when the excavator is working at or below ground
level.”
Another
contractor saving time and money with a thumb is Terry Dykstra of Dykstra
Excavating Inc. in Orange City, IA. He uses a Kenco Hardrock hydraulic thumb.
“It’s a very useful tool when working with loose debris, trees, and even large
pieces of concrete foundation,” he says. “The thumb allows me to work faster and
more efficiently compared to my old method of using a track-loader.”
Thumb
Versus Grapple
Another
time-and-money-saving attachment for handling various types of materials is the
grapple. Instead of a bucket, it features two sets of finger-like tines that let
you efficiently clutch and load bulky land-clearing debris, chunks of concrete,
and tangled rebar from demolition projects, boosting productivity.
Generally,
grapples are used for more specialized applications, such as handling brush,
demolition material, or scrap metal, where no digging is required. By contrast,
thumbs offer more versatility. “A thumb is great when the job requires going
back and forth between digging and material handling, because the bucket can
still be used for excavation work without having to remove the thumb,” says
Chris Nichols, general manager of Aim Attachments.
The thumb is
something of “a poor man’s grapple,” according to Tracy Black, operations
manager for Kenco. “It’s significantly cheaper than a grapple, and it doesn’t
take a lot of work to install. However, you can’t pick up as much material with
a thumb as you can with a grapple. Some guys who do light demolition, like a
garage or a house, prefer the thumb because it’s quick and easy to mount in its
bracket. For tearing down larger buildings, though, a grapple is usually a
better way to go, because it can handle more material faster. Other operators
will dedicate one machine for use with a grapple on demolition jobs and use
buckets and thumbs on their other machines for the rest of their work.”
 |
Photo Helac
Helac's multipurpose Power Grip fits excavators and backhoes with extendable dipper sticks. |
Peter Baumann,
sales manager for Weldco-Beales Manufacturing Corp., reports regional
differences in popularity between these two types of attachments depending.
“Grapples are pretty much used throughout North America,” he says. “However, use
of thumbs is much higher west of the Rockies than to the east, where many
equipment owners and operators aren’t aware of the benefits of thumbs in saving
time and labor. For example, one operator can use a compact excavator, bucket,
and thumb to set rock for building a retaining wall in about half the time it
would take another operator using the same machine and bucket without thumb and
two or three guys on the ground to move the rocks around.”
Thumb
Styles
Thumbs are
available in several styles that differ in terms of ease of use, size of opening
between the thumb and the bucket, and price.
A rigid or
stiff-arm thumb is normally welded to the underside of the dipper with an
independent main pin. The lowest in price, it offers two or three working
positions. Typically, they’re mounted at an angle between about 90 degrees and
120 degrees to the stick. This angle can be adjusted manually by sliding one end
of the thumb along a bar or mounting bracket welded to the stick and pinning it
to the bar through one of several holes. Some require removing the thumb from
the bracket when not in use. Others are designed so that the thumb folds back
and is secured out the way against the stick.
In the case of
a hydraulic thumb, the hydraulic cylinder is pinned directly to the thumb. This
allows the thumb to rotate from about 135 degrees to 160 degrees, depending on
manufacturer, to offer more options for clamping onto an object and folding back
much farther than a rigid thumb.
“This style is
very easy to install,” says Bo Pratt, sales manger for Rockland Manufacturing.
“It gives you more precision than a rigid thumb for handling objects like large
stones to minimize any scarring. Also, unlike a rigid thumb, you can use it at
maximum reach of the machine.”
In addition to
a higher price tag, a hydraulic thumb requires spending another $2,500 or so to
add a separate hydraulic circuit to the machine for controlling the opening and
closing of the thumb from the cab with foot or hand controls.
The
highest-priced style, the hydraulic thumb with progressive link, does not pin
onto the end of the stick. Instead, it has a mechanical linkage that hangs down
about 12 to 14 inches from the end of the stick. This allows the thumb to rotate
up to about 180 degrees. By providing the widest opening between the bucket
teeth and thumb, it offers the most versatility for picking and placing
objects.
Either type of
hydraulic thumb can also be used with a quick-coupler for changing between other
attachments quickly and easily.
“We are
experiencing much more interest in hydraulic thumbs compared with manual
thumbs,” says David Jenkins, president of Solesbee’s Equipment and Attachments
in Douglasville, GA. “Contractors are beginning to understand how much more
productive the hydraulic thumbs can be. The costs of adding auxiliary hydraulics
are minimal compared to the increase in productivity.”
 |
Photo: Stanley LaBounty
LaBounty offers seven series of grapples with 33 different models, from fixed-time to rotating grapples with synchronized halves for positive placement. |
Thumb styles
also differ in width. Originally, a thumb consisted of a single tine, about a
foot wide. Over the past several years, wider thumbs with three or four tines
that close in between the teeth of the bucket, have increased in popularity,
reports Dale DeWeese, sales manager for Werk-Brau Co. Inc. “Multi-tine thumbs
are designed to handle more and looser material,” he says. “Because of the way
the tines mesh with the bucket teeth, they also reduce spillage from the
bucket.
Another
difference in styles is the profile of the thumb. Some are smooth-edged. Others
have a serrated edge for better gripping. Still others have more curvature to
provide a little extra capacity for picking up groups of smaller-diameter logs
or larger-diameter individual logs.
Grapple Choices
Much wider than
a thumb, a grapple offers more material-handling capacity. The selection
includes grapples designed specifically for such duties as demolition, brush,
stump removal, rock, or light material work.
On most
grapples, one jaw remains stationary while the other, operated by a hydraulic
cylinder, closes and opens. In the case of grapples, which rotate 360-degrees
for maximum versatility, both halves open and close together hydraulically. This
type requires two additional hydraulic circuits—one to rotate the grapple and
another to open and close the jaws.
Those designed
for heavy-duty demolition, rock handling, or severe land-clearing applications
typically feature a two-tine clamp and a three-tine frame for maximum clamping,
prying, and digging forces. Grapples built for less-demanding land-clearing work
and for handling heavy, bulky material usually have a three-tine clamp and a
four-tine frame. Grapples designed for working with lighter, bulky materials,
trash, or light scrap normally have a clamp with four tines and a frame with
five tines.
Depending on
manufacturer and model, grapples are made with solid tines or with tines
constructed in a box design for added strength and rigidity.
Some grapples
have mounting brackets and pivot points that are independent of the bucket pins.
When the attachment is unhooked, the two halves stay together, eliminating the
need to re-assemble the grapple when remounting them on the machine.
In addition to
grapples that are mounted in a fixed position on the end of the dipper stick, a
grapple that rotates 360-degrees offers added versatility.
“It allows you
to place the grapple in the best position to pick up a rock, pole, log, or other
object regardless of the position of the excavator boom and dipper stick in
relation to the object,” says Mark Shukla, director of marketing for Rotobec
Inc., which makes a line of grapples and hydraulic rotator systems for these
machines. “This type is extremely useful for saving time and effort in complex
material handling situations.”
Choices include
two styles of rotating grapples. The positioned-type of rotating grapple can be
mounted directly on the bucket pins, the most common option. “It provides the
ultimate material handling attachment solution,” Shukla says. Other
positioned-type models can be mounted using either a pin-grabbing coupler or a
wedge-type coupler.
The dangling
style rotation grapple offers excellent operating versatility, he notes.
“This style of
grapple hangs off a yoke on the dipper stick to move freely forward and backward
and side to side, giving you a great deal of control in picking up and placing
objects,” Shukla explains. “Either style of grapple will handle jobs like
placing rocks for a retaining wall or loading logs into a truck,” he says.
“However, in cases where you need to control the attitude or pitch of the
grapple in addition to its height above ground, such as a demolition project,
the positioned style lets you tilt the grapple to get a better grip on an object
the first time.”
Durability Difference
Much of the
durability of a thumb or a grapple reflects the quality of materials used to
build the attachment. The better ones are made of higher-grade steel, like AR400
or T1, which offer more strength and wear resistance than a lighter grade, such
as A36. Other keys to longer life and lower maintenance costs are heavy-duty
cylinders; large-diameter, case-hardened pins and bushings; and heavy
gussets.
In assessing
quality, don’t assume that heavier is better, cautions Black.
“For example, a
well-designed grapple made of high-quality steel may weigh less than another
grapple but offer more durability along with a higher payload than a heavier one
made of milder, less-expensive steel.”
If you’re
planning to use a grapple with a quick-coupler, he advises, make sure the two
are compatible. “Not all pin-on type grapples work properly with a
quick-coupler,” he says. “The quick-coupler will change the geometry and can
adversely affect the grapple’s performance. When used with a pin-on grapple, the
attachment may not squeeze as tightly or open more slowly than it should.”
What style and
which features are best for your operations? “Talk with your dealer’s attachment
specialist,” suggests DeWeese. “They’ll ask you questions about the kind of jobs
you’ll be doing and types of material you’ll be handling to help guide you to
making the best buying decision.”
A
Hybrid Option
The PowerGrip
attachment, a multipurpose jaw bucket made by Helac Corp., can be used as a
trenching, grading, or clamshell bucket or as a grapple or hydraulic thumb with
excavators and with backhoes with extendable dipper sticks. Unlike
cylinder-style hydraulic thumbs, this attachment is powered by a helical
hydraulic rotary actuator. “Because all moving parts of the actuator are
enclosed inside a single cylindrical hinge, this technology eliminates the
exposed cylinder and rod of a hydraulic thumb and threat of any damage to these
components,” says Mike Peil, the company’s attachment sales manager.
This pin-on
attachment, which requires an auxiliary hydraulic circuit, offers 120 degrees of
jaw movement. It weighs less than a hydraulic thumb and provides slightly less
crushing force but more holding force, he notes. “You can use this attachment
with a 20-ton excavator to pick up a four-by-four piece of wood without breaking
it,” Peil says. “But, if you were to use it to grab a concrete pier to pull it
up out of the ground, you’d stall the excavator before the attachment would lose
its grip.” The jaw of the PowerGrip is driven equally on both sides of the
actuator. This design resists twisting forces associated with grabbing objects
on either side of the bucket and prevents bending and cracking that can occur
with competitive product designs, he explains.
For added
positioning versatility, the PowerGrip can be used with Helac’s PowerTilt Swing
attachment. It gives operators both swing and grab capabilities. PowerGrip and
PowerTilt can be used with or without quick-couplers.
Ken Williams of
Williams Loaders Service in Charlottesville, VA, comments on his experience with
the attachment. “The weight savings and overall versatility of the PowerGrip put
it so far ahead of a thumb,” he says. “When used with the PowerTilt, I can clear
lots, dig basements, cut a swale, rip trees apart, separate materials, and even
pick up brittle soapstone without breaking it. For certain jobs this combination
can be 30% quicker than a conventional bucket/thumb combination. There’s no tool
that can do my work as efficiently and with as much precision.”
More
information is available at www.helac.com