Drill
A drill is a tool with a rotating drill bit used for drilling holes in various materials.
Electric handheld drill
The drill bit is gripped by a chuck at one end of the drill, and is pressed against the target material and rotated. The tip of the drill bit does the work of cutting into the target material, slicing off thin shavings (twist drills or auger bits) or grinding off small particles (oil drilling).
Electric drill
Hand-held electric drills are ubiquitous. They usually look like a pistol, with a trigger-like switch. They are also used for driving screws. These drills typically employ a universal motor with brushes. Modern variable speed drills contain solid state phase control circuits that limit their use to AC power only. As a tradeoff, the electronics now give them variable speed, reversibility and torque control. Many drills are also cordless and use rechargeable batteries.
Drill press
A drill press is a fixed style of drill, which may be mounted on a stand or bolted to the floor or workbench. It 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 which, when turned, move the drill 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 reclamp it in position. The table may also be off-set from the spindle’s axis and in some cases rotated perpendicular to the column.
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, this 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 types introduce a third stepped pulley to increase the speed range. This makes selecting the correct spindle speed more likely.
Safety
- Always wear eye protection
- Keep loose clothing away from the spinning parts
- Be mindful of hands and body parts, as the drill bit goes through hands as well as aluminum