Popular Woodworking 2000-11 № 118, страница 25
PW the handle extends down from the rearmost position of the motor housing) or center handle (also known as T-handle) with the handle mounted at the middle of the motor housing. There are benefits to each design, though the center handle design is more popular. Pistol grip handles offer more concentrated pressure in line with the drill bit or driver. This allows more physical force to be brought to bear on demanding tasks such as drilling large holes, driving lag bolts or when using a hole saw. The center-mount handles provide better balance, which makes the drill feel easier to control and feel lighter. Variations on the center-handle, such as rear-angling and contoured grips, are making the difference in handle benefits less dramatic. Try both handles on for size and see which models appeal to your needs and grip. Power Cordless drills are available in many power configurations ranging from 7.2 volts to 24 volts with 1.4- to 2.6-amp hour (with 3.0 to come) capacities. Then there's the questions of Nickel Cadmium versus Nickel Metal Hydride batteries. So what does all this mean, and what do you need? We talked to our technical advisers from Makita and Bosch and distilled their explanations for you. In simplistic terms, the higher the voltage the more torque you produce. The higher the amp-hour rating, the longer the run-time capability of the battery pack. Torque is the amount of force applied by the bit or driver to the work. The higher the torque, the easier you can drive 2" screws into wood and use a 1V4" Forstner bit without it bogging down. The improvement gained through Nickel-Metal Hydride technology is the ability to put more run time into the same size battery cell. So without increasing the size or weight, the battery has a larger gas tank. The other factor is that NiMH batteries are also more environmentally friendly, whereas the cadmium in NiCad bat teries must be disposed of in a controlled manner. OK, so you want to buy a 24-volt, 2.6-amp hour drill then, right? No. You trade off weight and balance for all the power and run-time. While you may need that kind of power for a cordless circular saw, a drill/driver is a different story. When it comes to the amp hours, get the most you can afford (and price is affected by that ability). As for voltage, we recommend 9.6 volt as a choice for lighter applications and 14.4 volt for heavier use, such as drilling a lot of holes with spade bits. But in most applications 12 volts is plenty for most woodshop applications. If you're on a job-site, 14.4 and 18 volts makes better sense for use with hole saws and lag bolts. Speeds All but the least expensive (and lightest duty) drill/drivers offer a pretty impressive array of features to make work easier. Some features are more valuable than others, but you should understand why each one is available, nonetheless. Many drills are available with both variable speed and two-speed capability. They're different features that work together. Variable speed is the ability to control infinitely the rotations per minute (rpm) of the chuck by increasing or decreasing the pressure on the trigger. This allows better control over your work, to keep a drill bit from wandering off the mark, or to start a screw in just the right spot. The two-speed capability allows the drill to be switched from one speed range to another, much like switching from first to second gear in your car. Torque in low speed is higher, but the top rpms are lower. This is best for large-diameter drill bits. In high speed the rpms are increased, but with less torque. This is best for small diameter drill bits. Having the option of variable speed and a high and low speed settings makes a drill more versatile and allows finesse. Clutches Another finesse feature is the clutch, some-continued on page 40 The cordless drill category is the easiest to make recommendations in because there are so many good choices. Rather than choose individual drills, we've recommended drills by brand.Those recommended have been tested or used by the editors of Popular Woodworking. Occasional User An occasional user has a number of good choices in the cordless drill category these days. Manufacturers are offering many of their best features on entry-level drills at great savings.We recommend a 9.6-volt drill for most uses, with 12- or 14.4-volt drill for more strenuous work.We have found that both Black & Decker and Ryobi are making good quality low priced models that will perform well for the occasional user Serious Home Woodworker & Advanced Woodworker or Professional We've broken the mold for this section, combining the serious and advanced categories. During our discussions we realized that the drills we would recommend for the serious home woodworker would likely see good duty in a professional setting as well.We recommend a 12-volt tool for everyday woodworking use for both categories, but recommend a 14.4-volt for the all-day applications and 18-volt for the high-torque needs of a professional shop.While there are a great number of quality drill/drivers available today we feel a little more strongly about those available from Porter-Cable, Makita, Metabo or Milwaukee, and recommend their models for most pros and serious woodworkers alike. We will take one step further and recommend drills from Panasonic slightly ahead of those previously mentioned for the professional.The engineering and reliablility found in these quality drills have made them a workplace favorite for years. |
