Understanding Power Tool Features and Functions to Improve Efficiency
Understanding jobsite needs, as well as tool features and functions, put greater efficiency in the hands of technicians
Managers specifying power tools for technicians might assume that tools are similar and likely to function about the same. There are major differences among power tools, and one important difference lies in their features and functions. These elements make a major difference in achieving productivity goals: quality, quantity, safety, timeliness, and cost.
One example involves features and functions for fastener assembly using low- versus high-productivity methods. One low-productivity method to insert a wood screw is starting a hole with the tip of the screw, then driving the screw with a hand screwdriver.
The higher-productivity method is hand-drilling a pilot hole, then using a screwdriver to insert the screw, or using a one-chuck power drill to drill the hole and a driver to fasten the screw. The technician achieves highest productivity using a two-chuck, quick-switching combination on the same tool to drill the pilot hole and drive the screw.
The latter method is four times faster than the manual method and twice as fast as using separate drill-and-drive steps with one chuck. Therefore, it requires one-fourth of the labor cost of the first method at the same pay rate. Add to this the savings in setup time of a standard, one-size-fits-all hex chuck, cordless drill compared to a screwed chuck, corded drill and the productivity improvement is even better – very little setup time and 400 percent faster with the two-chuck than the manual screwdriver method.
Spotlight on saws
Portable power saws have become workhorses of many maintenance departments. They perform a variety of tasks and come in a number of different styles: circular, reciprocating, miter, band, and chain.
Managers first should take a close look at saws’ shared features — power capacity, weight, corded or cordless, ergonomics, and safety. If all of a department’s power tools are the same make and powered by a common battery pack, technicians will need only one charger and a few battery packs to power all tools.
Depending on the work technicians will do, other common considerations include: weight; cut depth and width at 90 degrees; a long battery run time and short charge time; power management; a brushless motor for longer motor life; training; and warranty duration, inclusions, and exclusions.
Circular saw features to consider include:
• Weight. A 4½-inch-diameter saw weighs one-half as much as 7¼-inch-diameter model and still can make a 2-inch cut in one stroke.
• Blades. Thin blades reduce load, deliver higher-speed performance, and reduce cut time. A left-sided blade provides higher visibility and is safer.
• Quick depth and bevel adjustments.
• Ergonomic grips. They provide balance, grip for comfort and power, and better control with two-handed gripping.
• Power capacity. It has to meet job needs from 4 to 17 amps and voltage selection with an eye to available power sources. Doubling the voltage to 220 volts (V) from 110 V halves the amp draw, reducing power cost proportionately.
Technicians can achieve flexibility and cut speed with portable abrasive cutoff saws, which cut pipe, tube, bar stock, brick, block, sheet metal, and wire mesh or rebar. Technicians can make blade changes quickly without removing the base. They tend to be noisy, so ear protection is a must. If dark workplaces are a factor, a built-in LED light focused on the cut path yields better control and cut accuracy, as well as safety.
Reciprocating saws, with their push-pull action and the right features, can perform plunge cuts and curved cuts that other saws cannot. Plunge cuts can quickly make an electric box cutout in wall board or a pipe or conduit hole in wallboard or a wood floor.
Other key features of reciprocating saws include: a trigger-adjustable blade speed for more efficient, quicker cuts; a trigger lock; toolless blade and pivoting shoe changes; a cut line dust blower; lightweight; extended battery life; a brushless motor for cooler operation and longer motor life; and power capacity adequate for light-duty work.
Chainsaws and electric loppers — whether electric corded, cordless, or gasoline-powered portable — can handle most tree-trimming jobs. Features managers should consider for most efficient operation start with safety. Studies show that 28,000 chainsaw injuries occur annually, so clearly, safety features and personal protective equipment, such as hard hat, hard toed shoes, goggles, gloves, and tight clothes are a must.
Most chainsaws exceed the permissible noise limit of 85 decibels, so ear protection is a must. Electric models can handle light-duty tasks, while gasoline models are suited for heavy-duty jobs. Workers can use electric loppers for small branch trimming.
Making a match
Before specification managers should perform a survey of recently completed jobs that involved power tools in order to identify the power, versatility, and durability factors that technicians need for high-productivity performance.
Did the tools used perform well? What were the shortfalls, if any? What characteristics would have enabled the technician to improve job quantity and quality and lower cost while still working safely? Three factors – job preparation, setup and tool change at the job site, and tool use during the job — are important considerations.
The more multi-tasking capability a power tool offers, the better tool utilization will be and the fewer tools technicians will require. In the wood screw assembly example above, one driver performs both drilling and driving. Coupled with quick chuck rotation from one driver to the other, the result is a high-productivity system that gets a quality job done fast with less labor at lower cost. By using a predetermined time system, managers and technicians can make a side-by-side comparison of several method times to identify the best time before making a purchase.
Thomas A. Westerkamp is a maintenance and engineering management consultant and president of the work management division of Westerkamp Group LLC.