Anyone who has spent a fair amount of time working in shops will have seen many different types of drilling machines. There is an alarming range of shapes and sizes (including complexity!) of devices, so we present a summary of the types available as well as how you may use them.
There are conventional handheld drills, as well as turret- and gang drills, all with their pluses, minuses, oddities and uses will be reviewed.
This article is meant for us to share our experiences in making holes in various ways, using machines ranging from simple to more exotic in different shops. We hope it helps to clarify the complexities of what can be a very simple operation!
What is a Drilling Machine?
A drill is a tool utilized for creating round holes or driving fasteners and is equipped with a bit that can either be a drill or driver chuck. While types operated by hand have experienced a noted decrease in popularity, cordless battery-powered types have been proliferating.
A drill machine, or drill press, is a tool used to cut a round hole into, or through metal, plastic, wood or other solid materials, by turning and advancing rotary drill bits into a workpiece by using one or several of several common functions.
This drilling cutting tool, drill bit, is held in the drill press by a chuck and is fed into the work, at variable speeds. The speed and feed are set properly, and the heated portion of the work reamed as cooling for the desired finished part.
A drilling machine cannot only be applied in the drilling process but is also advantageous for many other machining operations.
Operations that can be performed on a drilling machine, are plane drilling, step drilling, core drilling, boring, counterboring, reaming, countersinking, spot facing, tapping, and trepanning.
Drills are used commonly in woodworking, metalworking, construction, machine tool fabrication, construction and utility projects. Specially designed types are made for miniature applications.
Parts of a Drilling Machine
A drilling machine is usually composed of several or all of the following parts.
- Base: generally bolted to the ground to support the weight of the drilling machine.
- Column: located on one side of the base, can carry the load of the arm and drill head, with a sliding table mounted on it.
- Arm: at the top of the column, carries the drill head and the housing of the driving mechanism.
- Drill head: mounted on one side of the arm, consists of feed and driving mechanism. It can slide up and down.
- Worktable: mounted on the column, can move vertically and horizontally.
- Feed mechanism: hand and automatic feed by an electrical motor.
- Spindle: holds the drill or cutting tool and revolves in a fixed position in a sleeve.
- Chuck: situated on the spindle, holds the drill jig.
- Electric Motor
Working of the Drilling Machine
When the power is given to the motor, the spindle rotates, and thereby the stepped pulley attached to it also rotates. On the other end, one more stepped pulley is attached and that is inverted to increase or decrease the speed of the rotational motion.
Now, a V-belt is placed in between the stepped pulleys so as to drive the power transmission. Here a V-belt is used instead of a flat belt, in order to increase the power efficiency.
Now the drill bit also rotates which was placed in the chuck and which was in connection with the spindle. As the Pulleys rotate, the spindle also rotates which can rotate the drill bit.
Now, by the rotation of the hand wheel, the spindle moves up and down in the vertical direction in order to give the necessary amount of feed to the work, and this drill bit is used to make the holes in the component placed in the machine vice.
Types of Drilling Machines
There are many different types of drilling machines:
- Radial drilling machine
- Upright drilling machine
- Automatic drilling machine
- Multiple Spindle Drilling Machine
- Deep hole drilling machine
- Sensitive drilling machine
- Portable drilling machine
- Gang drilling machine
Here are some different types of drilling machines with their construction, characteristics, and uses.
- Portable drilling machine (Hand drilling machine): generally small in size and contains a universal motor, used for drilling holes in rocks or any rigid surface, suitable for any location. The piece to be drilled is held in a vice.
- Sensitive drilling machine (Bench drilling machine): perfect for producing small holes at high speeds, usually consists of a base, worktable, spindle, drill head, driving mechanism and column. The work is started from the drill fed into the piece by hand.
- Radial drilling machine: mainly for drilling large and heavy workspaces, the table can be adjusted to suit different heights. It allows the operator to make the spindle directly over the workpiece rather than move the part to the tool, and also capable to create intersecting or angular holds in one setup.
- Upright drilling machine: larger and stronger than sensitive drilling machine, designed for handling medium to large-sized holes.
- Gang drilling machine: can be used for drilling, reaming, counterboring and tapping, just need to move the machine back and forth.
- Deep mole drilling machine: special type that is designed to drill deep holes in the connecting rods, spindles and others, with high cutting speed and less feed.
- Multiple spindle drilling machine: with several spindles, perfect for drilling a large number of holes into a part and drilling same holes on identical workpieces.
- CNC drilling machine: computer numerical control drilling machine can automatically change tooling with a turret or automatic tool changer. The program controls the speeds, feeds and table position.
- Micro drill press: extremely accurate, high spindle speed, used to handle tiny or very small parts.
- Turret type drilling machine: equipped with several drilling heads mounted on a turret, the tool can be quickly indexed into position.
How to Choose a Basic Drill Bit?
A pile of twist drill bits and a drill sit on a wooden table.
When you’re ready to learn how to use a drill, start with the bit. The drill bit you use will depend on the task at hand. Keeping a drill bit set in your toolbox means you’re prepared for many projects.
- If you’re drilling a hole, you’ll need a pointy drill bit. It’s called a twist drill bit.
There are bits that fit whatever you’re drilling: wood, metal, ceramic or other surfaces. Choose a bit that matches your project. It’s smart to drill a slightly smaller hole than the screw you’re using. That way, the screw can bite into the material firmly.
- If you’re driving a screw in with a drill, go with a drill bit that fits the screw. These are called screwdriver bits.
You’ll have drill bits with Phillips and flat head options. It doesn’t have to be an exact match to the screw. As long as the bit fits into the slots on the screw, it works.
How to Change a Drill Bit?
Once you’ve chosen your drill bit, it’s time to insert it. It’s not tough to learn how to put a bit in a drill. In fact, changing a bit is a big part of knowing how to use a drill.
Note: If you’ve just used your power drill, the bit will be hot from friction. Let it cool or use work gloves to remove it.
Follow these steps to change or insert a drill bit:
- Disconnect the drill from the power source. That means remove the battery or unplug it.
- Open the chuck. Unless you have a heavy-duty drill, just unscrew the chuck. It’ll be a circular piece with the bit in the middle. Rotate it until you see the chuck open. If you need a key, use the chuck key that came with the drill to open it.
- Pull out the bit. If it’s stuck, open the chuck more so you can remove the bit.
- Put the old bit in a case or off to the side. You don’t want it getting stepped on.
- Insert the new bit into the chuck as far as it can go. Make sure it’s centered and not angled.
- Twist the chuck to tightly close it around the drill bit. Again, if you need the key, use it here.
- Assure your drill bit is snugly held. It should be evenly inserted so it won’t wiggle.
How to Use a Drill?
To save time once you’re ready to drill, figure out where you need screws. Finish all your measuring and assure any straight lines are level. Then, mark with a pencil where you want to drill each hole. Use a tiny X or make a dot with a pencil.
Note: Always wear protective glasses or goggles when using power tools. Secure all loose clothing and hair before working. You want to avoid anything getting tangled or wrapped around the drill bit.
To use a drill for drilling a hole, follow these steps:
- Power up your drill. Plug it in or insert the battery.
- Adjust the torque to suit the material you’re drilling. For example, drilling wood will require more torque than drilling drywall. In general, harder surfaces need more torque.
- Find the Xs or dots you made to mark where to drill.
- Get at the correct level to drill the hole. If you need a ladder, assure it’s opened and secured properly.
- Stabilize your drill vertically. You want the hole to be perfectly straight.
- Gently pull the trigger. Start drilling with a low speed. As you get further into the material, you can speed up.
- Once you’ve drilled as far as you need, put the drill in reverse.
- Pull the trigger and back out the drill bit. Take care not to yank on the drill or pull at an angle.
To use a drill for inserting a screw into a pilot hole, follow these steps:
- Power up the drill.
- Adjust the torque so it’s low. Drilling in screws that have pilot holes doesn’t require a lot of force.
- Fit the screw into the slot on the drill bit.
- Line up the screw with the hole.
- Make sure the drill is vertical.
- Pull the trigger on the drill and press gently into the screw. This should keep the screw in place.
- Make sure you’re not drilling at an angle.
- Once the screw is inserted, stop drilling.
If you’re concerned about over-screwing, stop before the screw is completely inserted. Finish with a screwdriver.