Take the hard work out of DO-IT-YOURSELF with a good drill.
It could be on of the most diverse and very useful tools you buy.
Proper drill will save time during your work and make easy drilling holes into metal, wood, concrete etc., as well as drive screws and bolts.
It is useful getting acquaint with a drill’s main feature before you buy, so you could choose the best one.
I. Types
- Standard Drills
- Hammer Drills
- Screw Guns
II. Cordless drills
- Cord or Cordless? Pros and Cons
- The main features
- Power and Battery
III. Drill Shapes
IV. Variable speed
V. Torque
VI. Other features to look out for
VII. Power rating
VIII. Hammer action
IX. Chuck type
TYPES
Standard Drills
Standard electric rotary drills designed for drilling metal and wood. This type of drill is normally small and compact. Motor sizes range from around 500 watts. The lower wattage motors are OK for drilling small holes or minimal use, the more powerful motored machines will cope with larger size holes and more frequent use. The chuck size is another thing to check, the smaller drills have a chuck which will only accept drill bits up to 10mm diameter the larger chuck size is 13mm.
Hammer Drills
The hammer drill is similar to a standard electric drill, with the exception that it is provided with a hammer action for drilling masonry. The hammer action may be engaged or disengaged as required.
The hammer action is cheap but delicate. It uses two cam plates to make the chuck accelerate towards the work. However because of the relative masses of the chuck+bit and the remainder of the drill the energy transfer is inefficient and will fail to penetrate harder materials and vibrates the operators hand. The cams wear quickly.
Compare this to a rotary/pneumatic hammer drill where just the bit is accelerated to the work. They have relatively little vibration and penetrate most building materials. It feels as though the work is sucking the bit inwards.
Large cam hammer drills, especially transverse motor, are crude in their action. The energy delivered in each stroke is highly variable. The cheaper drill will smash its way through the work and vibrate the surroundings, this can cause lots of collateral damage. A good SDS drill will gently pulverize the work material just in front of the bit and glide into the hole without any “fuss”.
However there is a big difference in cost. In the UK typically £12-40 for a cam hammer and £100 up for a rotary/pneumatic. For light DIY use they are fine.
Screw Guns
These Electric Screwdrivers are made specifically for applying screws and hexagon headed Tek Screw to plasterboard and metal cladding. The drywall screws are designed purely for plasterboard fixing. The electric screwdriver uses a specially designed chuck to self guide the specifically designed fixings that feature widely spaced threads to ensure good grip. This is achieved by the unique collar on this type of electric screwdriver.
Some electric screwdrivers are able to use Collated Screws which provides auto-loading of screws which are loaded into the tool on a strip which is then fed onto the bit.
Drill press
A drill press (also known as pedestal drill, pillar drill, or bench drill) is a fixed style of drill that may be mounted on a stand or bolted to the floor or workbench. A drill press consists of a base, column (or pillar), table, spindle (or quill), and drill head, usually driven by an induction motor. The head has a set of handles (usually 3) radiating from a central hub that, when turned, move the spindle and chuck vertically, parallel to the axis of the column. The table can be adjusted vertically and is generally moved by a rack and pinion; however, some older models rely on the operator to lift and re-clamp the table in position. The table may also be offset from the spindle’s axis and in some cases rotated to a position perpendicular to the column. The size of a drill press is typically measured in terms of swing. Swing is defined as twice the throat distance, which is the distance from the center of the spindle to the closest edge of the pillar. For example, a 16-inch drill press will have an 8-inch throat distance.
A drill press has a number of advantages over a hand-held drill:
less effort is required to apply the drill to the workpiece. The movement of the chuck and spindle is by a lever working on a rack and pinion, which gives the operator considerable mechanical advantage.
the table allows a vise or clamp to position and lock the work in place making the operation secure.
the angle of the spindle is fixed in relation to the table, allowing holes to be drilled accurately and repetitively.
Speed change is achieved by manually moving a belt across a stepped pulley arrangement. Some drill presses add a third stepped pulley to increase the speed range. Modern drill presses can, however, use a variable-speed motor in conjunction with the stepped-pulley system; a few older drill presses, on the other hand, have a sort of traction-based continuously variable transmission for wide ranges of chuck speeds instead, which can be changed while the machine is running.
CORDLESS DRILLS
A cordless drill is a type of electric drill which uses rechargeable batteries. These drills are available with similar features to an AC mains-powered drill. They are available in the hammer drill configuration and most also have a clutch setting which allows them to be used for driving screws.
For continuous use, a worker will have one or more spare battery packs charging while drilling, so that he or she can quickly swap them, instead of having to wait several hours during recharges.
Early cordless drills started with interchangeable 7.2V battery packs, and over the years the battery voltage has been increased to 18V, and higher, allowing these tools to produce as much torque as many mains-powered drills. The drawback of most current models is the use of nickel-cadmium (NiCd) batteries, which develop a memory effect or internal short circuits due to dendrite growth, severely limiting their useful life, and posing a hazardous materials disposal problem. Drill manufacturers are now introducing lithium ion batteries, most notably DEWALT.
The main advantages are lack of memory effect and very short charging time. Instead of charging a tool for an hour to get 20 minutes of use, 20 minutes of charge can run the tool for an hour. Lithium-ion batteries also have a constant discharge rate. The power output remains constant until the battery is depleted, something that nickel-cadmium batteries also lack, and which makes the tool much more versatile. Lithium-ion batteries also hold a charge for a significantly longer time than nickel-cadmium batteries, about 2 years if not used, vs. around 4 months for a nickel-cadmium battery.
CORD OR CORDLESS. Pros and Cons
I. Corded Drills
- Pack the most power
- Most durable
- Can handle mixing mud, boring holes, and drilling concrete
- Usually unnecessary for most homeowners
II. Cordless Power Drills
- Easily transported and used
- Less power and run time restricted by battery life
- Recharging may take several hours
- Higher voltage means more power, but also more weight
- Newer technology has improved cordless drills; most are now strong enough for many tasks previously out of their league
Cordless drill:
Corded drill:
THE MAIN FEATURES
Top 10 points to look for:
Speed-range switch, generally 2 ratios, both high and low, normally selected by changing mechanical gearing. High is for drilling applications whilst low range is reserved for driving screws. Look out for the widest range between the two settings
Look for a reliable motor, some models have external brushes for easy changing – when the brushes wear down you can easily change them for new ones, some bosch models have this feature ,it is only of use if you are uning your cordless drill on a daily basis.
Forward/reverse switch: This should be easy to operate with either your thumb or trigger finger – again this is a standard feature but look for one which is easy to operate.
Hand grip: Texture and contoured, should aid your grip, some Porter and Cable cordless drills have padded grips which you can choose to match your hand size – useful after an 8 hour shift.
Voltage: a higher voltage means more drilling power but it can also mean more weight – don’t buy a drill you won’t need, 12 volt drills are powerful enough for most DIY users, bigger models just weigh more so think carefully about what you will be using the drill for.
Batteries: Two are better than one. New NiMH batteries tend to be better because they deliver more charge and last longer.
Trigger: Make sure your index finger fits around it comfortably when gripping the drill, Variable speed offers the greatest control.
Chuck jaws: The maximum chuck capacity on most drills is 3/8 inches. Although some 14.4 and 18V drills can handle 1/2-inch-diameter bits, these have a 1/2inch chuck.
Keyless chuck: Virtually a standard fitting today, hand-turn it to open and close the chuck jaws. The keyless chuck can grip any screwdriver bit or drill bit securely.
Clutch: Setting the clutch gives you greater control of the depth to which screws are driven.
POWER AND BATTERY
Batteries: A cordless drill is only as good as its battery. Make sure the battery has enough run time to help you power through all your tasks. For more demanding applications, look for a drill that comes with a second battery or purchase an additional one. Chargers can take several hours to fully recharge a battery, so bear that in mind when planning your work schedule. If you need a faster recharge, look for a “smart” charger. Smart chargers work quickly and often reduce charge as the battery becomes full to avoid overcharging to extend the life of the battery. Look for nickel-metal-hydride (NiMH) and lithium-ion batteries, as they are slightly smaller and tend to have a longer run time.
Charge a second battery as you work to avoid mid-job downtime
Smart chargers use fans to reduce heat and decrease recharging time
NiMH batteries are easier and less hazardous to dispose of than other types
First thing when you look at a good cordless drill will be Volts of the the battery pack. To simplify it – the more Volts your cordless drill has – the faster the motor spins – the more torque you will get. Unfortunately – the more volts your cordless drills have – the heavier they get (if you ever worked with a 18 Volt drill over a longer period of time – you will know what I am talking about).
Similar important as the Volts of your battery are the Ampere. Measured in Ah (Ampere per hour) it gives you an idea of how long a battery will last. You can have a 12 Volts battery with 1.8 Ah and with 2.4 Ah. Obviously both batteries should give you the same power initially, but the 2.4 Ah will last 30% longer. Important if you use cordless drills for heavy duty work.
Looking at Volts and Ampere, you should also understand the basic types of battery packs currently available on the market. The (older) Standard Nickel Cadmium (Ni-Cd) battery packs are cheaper but do not give you much Ah as the newer Nickel Metal Hydride (Ni-MH) battery packs. The Ni-MH packs also give you an additional advantage in recharging, as the do not loose power after being recharged many many times (no-memory effect). Nickel Metal Hydride (Ni-MH) battery packs are usually more expensive, but definitely worth it’s money.
As batteries changed improved over the past years most manufacturers offer a wide range of power packs. Finding the right Dewalt or Makita batteries can therefore sometimes be a bit of a challenge.
The higher the voltage, the more power (9.6-28V) and weight (3-10 lb) the drill will possess. Most household jobs will be fine with a 13.2 volt or 14.4 volt battery, but an 18 volt couldn’t hurt. Most 9.6V drills might be sufficient for home jobs, but may lack the needed torque you find in a 14.4V drill — which is usually not significantly more in price. Go with at least a 14.4V. For tough jobs and doing masonry, a more powerful 24 or 28 volt battery is recommended.
Rechargeable drill batteries should last you about five years, or roughly 500 charges, though with frequent use you might need to replace it sooner. They can be pricey ($50-$80) so if your drill was only $100 or less, you might want to consider just buying a brand new drill. If you have a higher end drill, it’s probably more economical to buy a replacement battery.
DRILL SHAPES
Pistol Grip Drills
Are held like a pistol.
Doesn’t that feel powerful?
T-Handle Drills
Are most popular.
Shaped like a T for best balance.
Right Angle Drills
Are barrel-less.
The bit extends from the base at a right angle.
TORQUE
Drill price reflects a number of features, including torque. Torque, which is measured in foot-pounds, is the drill’s maximum amount of turning force. Some drills have an adjustable clutch with different torque settings for different applications.
Common features you’ll want in a cordless or corded drill are electric brakes, which stops the drill chuck as soon as you release the trigger, and keyless chucks.
OTHER FEATURES TO LOOK OUT FOR
Keyless Chuck: The chuck holds the drill bit in place, and keyless chucks allow you to conveniently change bits without having to use a separate key to unlock and replace.
Auxiliary Handle: Drills with side handles provide greater control and two-handed operation. These auxiliary handles rotate, enabling you to find the ideal angle and position from which to work.
Multiple Clutch Settings: Cordless drills often feature a clutch adjustment ring, which may have anywhere from two to twenty-four settings. Once you know the depth and torque needed on a particular surface, set the clutch accordingly to ensure consistent results and reduce the instance of wrist snap.
Electronic Brake: This feature causes the drill to stop immediately when you stop squeezing the trigger, preventing you from overdriving or stripping screws.
Variable Speed and Reversing: Many drills offer multiple speed settings, allowing you to choose the right one for the job at hand, and most have a reverse feature that allows you to remove screws and other fasteners.
Heat Shields and Cooling Fans: These features protect the drill from overheating, enabling longer, more efficient periods of use.