DIY Cordless Drill/Driver Guide
A cordless drill/driver can make short work of most fastening jobs. The quick bit changes possible with a keyless chuck shave tons of time off of any project that requires boring holes and driving screws. With a keyless chuck, an eighth inch drill bit and a phillips/slotted screw driver bit, installing curtain rods, towel bars, door and window hardware, cabinets or just about any installation requiring pilot holes and screw fasteners, is suddenly quick and easy.
A basic 9.6 volt cordless drill/driver, starting at around $100.00, is more than adequate for any task around the house and even tougher jobs like hanging drywall and remodeling projects.
There are two classes of cordless tools based on the type of rechargeable battery they use. See Cordless Tool Batteries for details. The first class of cordless tools has been around for some time. These use either Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH) battery packs. Voltage ratings for these battery packs start at about 9 volts and top out at about 18. Because of weigh constraints higher voltage is not possible with NiCd and NiMH technology.
This lead tool makers to develop a second class of cordless tools which use Lithium-ion (Li-Ion) battery packs. The main advantage of Li-Ion batteries over NiCd and NiMH is lighter weight. This allows for more voltage per battery pack, up to 36 volts for some cordless tools on the market today.
This increased voltage translates to increased torque making it possible to build a cordless tool with as much or more torque than its corded counterpart. These high torque tools are really overkill for most average users. Lithium-ion powered tools were developed to meet the needs of the construction industry for a cordless tool that can standup to heavy–duty demands.
Cordless Drill/Driver Features Virtually all cordless drill/drivers include a variable clutch, usually with at least a dozen settings. The clutch disengages the drive motor at a preset torque level. Set the clutch by turning the collar just behind the chuck. A graduated scale on the collar allows for precise torque settings every time. Use this feature for countersinking screws in wood or drywall. Avoid stripping brass screw heads and other delicate fasteners by setting the clutch to disengage before any damage is done. A setting at the end of the clutch scale allows for instant switching from clutch control to full torque for boring holes.
A ratcheting keyless chuck is a standard feature for most cordless drill/drivers. The chuck consist of a collar that turns to tighten a metal sleeve around a drill bit shank. The collar can be turned by hand to loosen and tighten the chuck, eliminating the need for a chuck wrench. The ratchet feature keeps the chuck tight around the shank for less slipping as the bit meets resistance.
Chuck size will be either three eighths or half inch for most cordless drills. A 3|8's chuck may limit the choices for drill bits and other attachments although many attachments will have a reduced shank to fit the smaller chuck.
Variable speeds are another standard feature on these drill/drivers. Speed is varied by depressing the trigger switch to varying degrees. Usually there will be two speed settings averaging 0-400rpms and 0-1,400rpms. A slide switch on the back or side of the tool switches between the two.
Use low drill speeds for boring holes in metal, ceramics and plastic and for starting screws or using large attachment. Also use low speeds when high torque is needed and whenever boring large holes or holes in hard materials. Use high speeds for soft materials like wood and whenever using small drill bits. High speeds should also be used for sanding and polishing attachments.
Although variable speeds are a standard feature, drill manufacturers recommend limiting the use of low speeds for extend periods because of the heat build–up in the motor which will shorten tool life.
Torque ratings for NiCd and NiMH powered drill/drivers start at about 200in.-lbs. for a 12 volt tool and up to about 500in.-lbs. for the larger models. All these drill/drivers are reversible to spin clockwise and counter–clockwise. Use the reverse direction to remove screws and for backing a drill bit out of a jamb. This can be a life saver for small bits that can break easily when binding becomes a problem.
Choosing a Cordless Drill/Driver Choose the smaller 9.6 to 12 volt model drill/driver for most do-it-yourself and home uses. A cordless drill/driver of this size will have a 3|8's chuck and can handle most requirements around the house. Drive 3 inch screws and bore holes in 2x4's easily. Hanging drywall will be no problem for this tool.
The next step up the power scale is the mid-range 14 or 15 volt model. These larger models may have a 3|8 or 1|2 inch chuck. These will hold their own on most construction jobs. With increased torque over the smaller drill, drilling thru framing and concrete, driving long screws and other more difficult tasks are made easy.
High torque, 18volt cordless drill/drivers and hammer drills are the top of the heap when it comes to power for NiCd and NiMH powered tools. Chuck size for these tools is half inch as opposed to the three eighths of the smaller sized models. These tools are the best choice for serious construction projects where boring large holes and driving lots of screws is typical.
Weight and balance should be a consideration when choosing a cordless drill/driver. Because of the weight of the battery packs for these tools the design and placement of the power source will have an impact on ease of handling. Hand fatigue can become a problem if the battery weight pulls on the user. Most manufacturers deal with this problem well using the battery weight to counter the weight of the motor and other drill parts.
Look for a battery pack that is streamlined in design to avoid problems when working in tight spaces. Most manufacturers consider this issue in their tool design, however a large 18 volt drill/driver may require a battery pack that is simply too large for tight spaces.
It can be very helpful to have a compact 9.6 or 12 volt model in addition the larger one if you plan to do many and various projects using your cordless drill/driver.
