What Is Drilling Machine? Its Parts, Diagram, Types, Specifications, And How It Works, Advantages, And Disadvantages.
A drilling machine, also known as a drill press, uses drill bits to cut circular holes in solid materials like metal, plastic, wood, and rocks. The drill bit rotates at hundreds to thousands of revolutions per minute, causing the cutting edge to cut off chips from the workpiece with force applied.
A drilling machine is a crucial tool in woodworking, metalworking, construction, and utility projects, equipped with a drill bit to create cylindrical holes of specified depth and diameter on a workpiece.
The drill bit is held in the drill press by a chuck and fed into the work at variable speeds. Drilling operations are performed on wood and metal, making it one of the most important machine tools.
The first handheld portable drilling machine was developed by Wilhelm and Carl Fein in 1895, while the first pistol-grip portable drill with a trigger switch was patented by Black & Decker in 1917.
Today, drilling machines are widely used in various operations, including plane drilling, step drilling, core drilling, boring, counterboring, reaming, countersinking, spot facing, tapping, and trenching.
A drilling machine is a powerful tool used for drilling large-scale projects. It comprises several key components, including the base, column, upper arm, worktable, drill head, feed mechanism, spindle, chuck, electric motor, and pulley.
The base is made of cast iron or steel, with slots for supporting big jobs and a radial column on one side. The column is designed to carry the load of the arm and drill head, with a sliding head table mounted on it for up and down motion.
The upper arm carries the drill head and the driving mechanism, which is made of the same material as the base. Some manufacturers provide a guideway for the drill head to slide over the upper arm.
The worktable, mounted on the column, is made of cast iron and can be adjusted manually or using electrical mechanisms.
The drill head is mounted on one side of the drill arm and has various driving mechanisms, such as a V belt that transfers power from the motor to the pulley and mechanical power from the pulley to the drill head. Different speeds are generated by cone pulley and gear-train mechanisms.
The feed mechanism receives power from the electric motor to the V belt and pulley, allowing the drill head to move up and down automatically or manually. Rack and pinion can also convert rotational movement from an electrical motor or by hand to straight-line movement.
The spindle is a circular taper shaft used to hold the drill chuck, made of high-carbon chromium steel, stainless steel, or steel alloys. The rotary motion is transferred from the drill head to the drill jigs, and a keyhole is provided on the spindle for changing the drill chuck.
The rack and pinion mechanism also helps in the up-and-down movement of the spindle. The drill chuck is mounted on the lower end of the spindle, holding the drill jig. A keyhole is provided for changing the drill jigs, and a three-jaw chuck is used.
An electric motor is used in a drilling machine, with a single-phase AC motor running at 600 to 5000 rpm. Pulleys or gears transmit power and generate different speeds, with a bevel gear being the most common type.
A drilling machine is a crucial tool for various operations, and its specifications include power source, motor capacity, drill chuck size, spindle speed, drill depth capacity, feed rate, and drill bit compatibility.
Power sources, such as electricity, are essential for reliable and consistent performance. Modern portable drilling machines are equipped with batteries for remote usage, while some advanced models incorporate hydraulic systems for specialised applications.
Motor capacity is measured in horsepower (HP) or kW, indicating the machine’s power output. Drill chuck size determines the maximum diameter of the drill bit, with sizes ranging from 1/2 inch to 1 inch.
Spindle speed, measured in revolutions per minute (RPM), indicates the rotational speed of the drill bit. Drill depth capacity is the maximum depth a machine drill bit can penetrate into a workpiece material, crucial for precise and efficient operations.
Feed rate is the speed at which the drill bit makes into the material during operations. Drilling machines with adjustable feed rates allow operators to control drilling speed according to the material’s requirements, determining the project outcome.
Drill bit compatibility is another important aspect of a drilling machine, as it is designed to be compatible with different types and sizes of drill bits. Chuck size and machine configurations determine the compactibility of the drill bits with the drilling machine.
Drilling machines are essential tools for various tasks, including drilling holes in rocks, wood, and metal. There are various types of drilling machines, such as portable, sensitive, upright, radial, gang, multiple spindle, and deep mole.
Portable drilling machines are small, portable, and can be carried to any work location. They work with a universal motor and can drill from 12mm to 18mm in diameter.
Sensitive drilling machines, also known as bench drilling machines, are used for making small holes at high speeds. They come with a base, table, spindle, drill head, and driving mechanism.
Upright drilling machines are designed for handling small to medium-sized workpieces but are heavier than normal machines. They come with a spindle feed and speed, making them suitable for different types of work.
Radial drilling machines are designed for large and heavy workspaces and support a radial arm in the column. They can drill workpieces of different heights and are used in construction companies.
Gang drilling machines have a long common table and base, containing 4-6 drill heads placed side by side. They are used for operations like drilling, reaming, counterboring, and tapping.
Multiple spindle drilling machines are designed to drill multiple holes in a workpiece or drill identical pieces. These machines drill all at the same time and alter the distance between axles to manage the holes in the drill.
Deep mole drilling machines are designed to drill deep holes in connecting rods, spindles, and barrels of the gun. They achieve high cutting speeds and require less feed and coolant during the process.
Drilling works by carrying the swarf away from the tip of the drill bit by fluting it, producing more chips that continue the movement outwards from the hole. Cutting fluid or coolant is applied to prolong the tool’s life by cooling and lubricating the tip and chip flow.
Gun drill coolant is used for aluminium drilling, ensuring smooth and accurate cutting and preventing metal from grabbing the drill bit. For soft metals like brass, 1-2 mm can be ground on the cutting edge to create an obtuse angle of 91 to 93 degrees, preventing chatter and cutting the metal.
Oil-hole drills are used for heavy feeds and deep holes, with a lubricant pump supplying the drill head through a small hole in the bit and flowing out along the fluting. Conventional drill presses can be used in oil-hole drilling, but automatic drilling machinery is more common.
Peck drilling, also known as interrupted cut drilling in computer numerical control (CNC), is used to prevent swarf buildup in deep holes by plunging the drill partway through the material and retracting it to the surface.
Drilling machines are essential tools for various tasks, including workpieces. Hand-feed machines are portable, light-duty machines that can be bench or floor-mounted and are driven by electric motors.
These machines are designed for small workpieces and have a hole drill size of ½ inch or smaller. They can move up and down on the column by losing and locking the chuck, allowing the drilling machine to drill different heights of work.
Power-feed drills are used in maintenance workshops for medium-duty work or work that requires large drills. They are larger and heavier than hand-feed machines and can feed the cutting tool into the work automatically.
They are designed for drills or cutting tools over ½ inch in diameter and require more force to make the hole than hand-fed drills.
Power-feed drills have a speed ranging from 50 rpm to 1,800 rpm, and special operations like counterboring, countersinking, and reaming are achieved with slower sleep.
Machines range from 17-inch to 22-inch centre drilling capacity and are usually floor-mounted. They can be up to 2 inches long and mounted into tapered Morse sockets.
Power transmission in drilling machines is supplied from the electric motor through a V belt and pulley stacks, with adjustments in the mechanism generating different speeds for the spindle.
A drilling machine’s operation relies on the feed, cutting speed, and machining time to achieve the desired result. Feed rate, measured in millimetres, is the distance a drill bit travels into the workpiece with each rotation.
The cutting speed, which is the rate at which the edge tool travels through rotation, is crucial for maintaining the drill bit’s performance. The cutting speed typically ranges from 10 m/min to 90 m/min, depending on the material.
The machining time, the total time taken by the drilling machine to achieve the desired hole on the workpiece, is calculated using the formula T=LN×f.
Drilling machines are essential tools for drilling, as they require careful maintenance to prevent damage to moving parts. Lubricating between the drill bit and workpiece helps dissolve heat and friction generated by moving parts.
Proper cleaning and lubrication are essential to prevent rust on machine parts. Drilling larger holes requires special care to avoid operator injuries. The machine should operate at slow speeds and lubricate more frequently.
In extremely cold conditions, work at a slow speed and allow parts and lubricants to warm up before increasing speed.
Safety precautions are crucial in drilling operations, involving power equipment and proper working tools. Proper working tools and holding devices are essential to prevent damage.
Drilling machines are capable of making large holes with consistent side, shape, and depth, making them faster and more precise than manual drills. They are used in various industries and materials like plastics, wood, metal, and composites.
However, they can be noisy, have limited depth, expose operators to injury, and be expensive to purchase and maintain. Regular maintenance is necessary to prevent breakdowns and ensure the machine’s longevity.
FAQs
What is a drilling machine?
Drilling machines function as machine tools to create clean holes in various materials. They rotate a drill bit at high speeds, applying pressure to drive it into the workpiece, resulting in precise results.
What are the three types of drilling machines?
Drilling machines, categorised into broad categories like upright sensitive, upright, radial, and special purpose, are used for various purposes in drilling operations.
What are the five uses of a drilling machine?
Drill machines are essential tools for drilling holes in hard materials, used in various industries such as manufacturing, metallurgy, woodworking, masonry, and construction. They can also be used for tapping, spot facing, reaming, counter sinking, and counter boring.
What is the definition of drilling?
Drilling is the process of cutting holes in a solid material using a rotating tool, with the indentation serving as a starting point. This process involves using a drill bit to enlarge or cut holes in the material.
Related: Drilling Explained!
Source: Mechlesson.com/drilling-machine