Install a fence. Plant shrubs. Put in a new street sign. Different projects with one common link – each requires the proper hole to be dug in order to complete the task properly. But how tough is it to dig a suitable hole? While the process is far from rocket science, it’s not quite as simple as one would expect either.
All hole digging projects may appear to be the same on the surface, but it’s often what’s below the surface that really matters. Additionally, the available equipment and accessory options – while great for enhancing productivity – can make things a bit more complicated for public works professionals.
These days, it’s more than just grabbing a shovel or hand posthole diggers and hitting the dirt; sophisticated, productive earth drilling equipment exists. And though they all achieve the same basic end result – a hole – all one-man earth drills are not the same. No longer “just a hole digger”, designs and features have advanced and improved over the years – the industry has come a long way from the simple hand method of digging. With many models and accessories available, units are now able to match specific applications and cut through virtually any type of ground. Whether the project calls for several, identical holes in typical lawn soil, or a single, large hole in rocky soil, there is a model and appropriate accessories available to achieve the best results safely and efficiently.
Because each machine will perform better in certain situations, and offer features and options to further enhance the process, it’s important to consider the entire scope of the digging project when selecting a drill. All aspects, from the soil structure and project location to the hole depth, diameter and frequency will come into play. But despite differences in projects, the bottom line remains the same – choosing the proper drill will complete the job fast and effectively, and even help to dig up some ROI along the way.
Style Is An Option
Engine-powered, one-man earth drills are typically available in two common styles: hydraulic and mechanical. While often similar in appearance in their most basic configurations, these two styles operate differently and are built with distinct features and options to make them better-suited for certain projects.
Built rugged and powerful, hydraulic drills are designed for the most challenging digging projects, including those in more complex soil conditions and even frozen ground. These hydraulically-powered units offer very controlled, precise operation at a lower speed and higher torque, allowing them to drill accurately in even the most difficult applications. Additionally, hydraulic models are ideally suited for rougher terrain and rocky conditions, as they incorporate a reverse auger operation function. Should the auger become lodged under an object, such as a rock or tree root, it can be removed safely and easily by running the auger in reverse.
Generally accepting of larger-diameter augers, these units are ideal for single-hole projects such as sign installation. Additionally, most hydraulic drills are compatible with smaller augers as well, opening them up to a variety of lawn and landscape projects.
Though very versatile, hydraulic drills do pose one distinct drawback – speed. Because they offer controlled operation at a higher torque, the tradeoff with hydraulic units is slower operation. Projects requiring multiple holes wouldn’t be the ideal setting for a hydraulic unit to shine, as efficiency would not be maximized. For those types of projects, a better choice exists.
Compact, lightweight, and still packing a powerful punch, mechanical drills are transmission-powered units that offer high-speed rotation for superior productivity and clean holes. These drills are best suited for use with smaller-diameter augers and, due to their high speed, are ideal for projects calling for several, narrow holes, such as in fence and deck installations, and decorative plantings.
Unlike hydraulic models, mechanical units aren’t equipped with a reverse feature. The lack of reverse operation can present a problem if the auger were to become caught under an obstruction, making it necessary for the operator to remove the auger manually, using a pipe wrench in a counter-clockwise motion.
Ultimately, the drilling task is the best indicator of which drill is best suited for the project. It will also dictate the required auger size. Based on the project specification for hole diameter, the right size auger can easily be paired with the selected drill, and most manufacturers will offer several options, from the smallest model used for applications like soil nursery work, up to the largest augers commonly used in foundation repair or soil sampling.
The next factor that will affect the selection process requires a bit of digging to get the info – literally. Just as important as why a hole is being drilled is the soil being dug. As mentioned previously, mechanical drills are best suited for loam-type soil conditions, while hydraulic units are better in tougher, rocky soils or even frozen ground. But the decision doesn’t end there – the appropriate auger model, point and blade must be properly selected to handle the soil conditions.
Below The Surface
The auger’s point and blade (also commonly referred to as its tip) does the actual cutting as the unit rotates, and helps to protect the auger’s flighting from excessive wear. As important as the tip is to drilling success, it’s imperative to know the available options and in what soil each will perform best.
A standard, general-purpose point with a side-mount cutting blade will work well in most conditions, but is particularly suited for sandy, loam-type soils and softer clays. These general-purpose tips will be compatible with most standard augers, in varying lengths and diameters.
When drilling in more solid, dense material such as limestone or sandstone, or hard clay and frozen ground, a carbide blade will offer the best performance. Rather than digging into the material, a carbide blade will cut the clay or ground into small pieces, allowing the operator to drill much faster. This blade mounts to the bottom of most standard augers and will replace both a general-purpose point and cutting blade.
If the drilling task includes loose, gravely soil or even rocky conditions, a heavy-duty auger, point and blade combination will tackle it best. Most effective when attached to lower speed drills like hydraulic units, a heavy-duty auger is recommended for challenging soil conditions. It features a larger, more rugged and aggressive flighting than standard augers, and also incorporates a special dirt-tooth blade in addition to a heavy-duty point.
Jobsite conditions, particularly soil, play an important role in proper unit selection, and location may present additional challenges – most notably, transporting the auger to the desired work area. The good news is both mechanical and hydraulic augers aren’t just designed for easy operation by one person – they’re intended for simple, one-man transport as well. While the most basic designs are compact and easy to move, some manufacturers offer a variety of design options for various methods of transport.
Oh The Places You’ll Go
When choosing an earth drill, mobility needs must be assessed. Most models are designed for easy transport, some also incorporating both front and rear handles for convenient loading and unloading. Mechanical units are generally the easiest to move, with the ability to be loaded in a car trunk, the back of an SUV or in the bed of a pickup truck. Because they are typically a bit larger than mechanicals, hydraulic units are a bit less convenient to move from site to site. But on the flip side, they offer a variety of transport modes, allowing operators flexibility to match their vehicle and space needs.
The smallest hydraulic models are best moved with a pickup truck or small trailer. In cases where truck and trailer space is minimal, consider a model designed to be towed behind the vehicle, as it frees up valuable room for jobsite tools and other equipment. For those looking for yet another alternative, a new style has emerged recently that takes portability options even further.
A hydraulic unit is now being offered that separates into two pieces, making the entire unit lighter and much more manageable. The power pack can be placed in the vehicle, while the rest of the drill is transported behind the vehicle, off the ground – eliminating common towing hassles. The unit features a special hitch design, compatible with even small SUVs and pickups, that allows it sit up and off the ground. This provides an option for those lacking a vehicle large enough to meet typical towing requirements, while still offering the benefit of freeing up precious vehicle space.
A drill that is easy to move from point A to point B provides greater efficiency and saves both time and energy. But once the unit is onsite, safety becomes a top priority and must be taken into consideration.
Play It Safe
It’s a widely understood rule that digging into the ground can be extremely dangerous. One-call phone numbers have been established for every area across the country to help protect operators and let them know what’s below the surface before digging. But the drill itself can pose a safety threat to the operator too, making it imperative to look for units designed with added safety features.
Certain models incorporate the engine and auger into one piece, while some manufacturers offer a configuration that places the engine on a wheeled chassis, which sits back a few feet from the operation point. Compared to models that mount the engine right on the operator’s handle, a separate mounting keeps harmful exhaust emissions at a distance. Even in well-ventilated areas, carbon monoxide poisoning is serious, and minimizing its likelihood of occurring in any way will greatly increase operator safety. This style may also protect the operator in additional ways.
Some models with a separate engine chassis utilize a steel torque tube that protects operators from potential harm by transferring digging torque from the drill head to the engine carriage. This allows operators to use larger diameter augers without fear of dangerous kickback. Additionally, the torque tube enhances drilling ease and reduces operator fatigue, effectively improving overall drilling safety. A more alert, less fatigued operator will be more likely to pay attention and handle the drill properly. And as an added benefit, easier operation will reduce physical stress on the operator, including back problems and muscle strains.
A pressure relief valve is another safety feature to look for, and one that is often incorporated on hydraulic units. If the auger becomes overworked and the drill reaches a certain hydraulic pressure, the valve will release, stopping the auger’s rotation. This halts the drill before it reaches a point where it stops the engine or causes damage to the machine.
Mechanical units are also built with unique safety features, one in particular is a centrifugal clutch. If a buried object is encountered or the auger is overloaded, the clutch automatically slips, protecting the operator from serious injury. Additionally, this eliminates potential damage to the drive cable and transmission gears, reducing the likelihood of expensive repairs or full replacement.
When the crucial considerations have been identified, and the drill choice and accessories have been narrowed down, the final decision rests in the details. From ergonomic designs and the unit’s engine, to reduced maintenance and enhanced portability features, these extra features play a major role in finding a productive solution that will maximize overall drilling efficiency and safety.
Whether an experienced operator or first-time hole digger, all ultimately desire a machine that’s easy to use. An ergonomically designed piece of equipment will provide a more comfortable, user-friendly experience, further enhancing operation ease.
First, a unit with large, easy-to-grip handles will allow for better control and more comfortable operation. Additionally, look for a model that places operator controls right on, or in close proximity to the handle. Certain functions, such as a hydraulic unit’s forward/reverse switch should be adjacent to the machine’s on/off switch for added convenience.
Choosing a unit with a high-quality engine is a must, as a drill’s operation is greatly dependent on its engine. Look for one from a reputable manufacturer that includes a warranty and adequate service network. For portable units offering the engine on a separate chassis, one that includes a durable, steel frame will help protect the engine and its components.
To ensure the machine is safe for even the most delicate lawns and turfs, consider a unit with large, pneumatic or semi-pneumatic tires. The benefit will be two-fold, as quality tires won’t damage turf, and will also allow the unit to easily traverse a variety of terrain conditions.
Beyond providing multiple auger tips, look for a manufacturer that also offers augers in multiple lengths and diameters. Some manufacturers offer snap-on augers, making the change-out process quick and easy, and eliminating the need for extra tools. Snap-on auger extensions offer the ability to achieve various digging depths without requiring multiple augers, adding versatility and saving money.
Finally, just like any piece of jobsite equipment, an earth drill that’s easy to care for is ideal. In the event the machine becomes damaged, a unit that can be serviced in the field, and doesn’t require special tools to do so, will be most convenient. As an added bonus, a drill that’s easy to maintain will encourage the operator to stick to a routine maintenance schedule, preventing future issues, enhancing longevity and, ultimately, maximizing the drill’s ROI potential.
Thanks to the advancements in drill designs, as well as the available features and accessories, what was once a simple hole digger is now much more – it’s a complete solution to any digging project, simple or complex. Taking the time to learn about the available options prior to selection will ensure the success of a project on all levels – from safety and productivity to quality and equipment ROI.