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Black & Decker Drill Dissection

Figure 1: Black & Decker Drill Before Disassembly

Figure 2: Black & Decker Drill Control Top

Function

The function of the Black & Decker Light Weight Cordless Drill is to drill screws. The advantage of this battery powered tool is to offer more power than manual screw drivers. Furthermore, the toold is hand-held and lightweight for ease in use and storage.

User Requirements

• Motors strong enough to create enough torque to drill screw
• Small and handheld for ease of use
• Efficient battery use so the battery life will be long enough
• Ergonomic design for long use
• Noise Control

Possible Engineering Specifications

• Powered by 6V (4 AA batteries) – long battery life
• Maximum Torque for Battery Power, high torque rating
• Powerful motor
• How the planetary gears are set up as well as the material they are made of
• Low Cost maximizes manufacturer profit, use plastic frame and gears, only using metal for parts that needed to be the strongest
• Lightweight --- due to utilization of plastic materials
• Using lube – minimize noise control

How It Drills

The motor uses the energy from four 1.5V AA batteries to generate power. This power turns the drive shaft of the drill. This drive shaft is then connected to two planetary gear systems. The second of these gear systems powers and turns the end drill bit shaft. The drill bit shaft is what rotates the inserted drill bit and consequently the screw.

1) The motor is powered by four 1.5V AA batteries.

Figure 3: AA Alkaline Battery

Figure 4: Four AA Alkaline Batteries in Casing

2) The motor then turns the drive shaft of the drill.

Figure 5: Motor of the Black & Decker Drill

Figure 6: Drive Shaft of the Motor

3) The drive shaft is connected to the first of two planetary gear sets. These planetary gears are used to decrease the angular velocity created by the rotating motor shaft. This therefore increases the amount of torque that will be exerted by the drill bit.

Figure 7: One of Two Planetary Gear Systems Connected to Arm

Figure 8: Planetary Gears Outside of Shaft and Arm Connection

4) Finally, the torque created by the rotating drill shaft is transferred to screw through the rotating drill shaft and bit.

Figure 9: Casing of Drill Shaft

Figure 10: Drillbit Rotated by Drill Shaft

Parts

The table belows lists the components for the Black & Decker Drill:

Table 1: Black & Decker Drill Component List

Part #	Part Name	Category	Function	Material	Picture
1	Batteries	Power	Supply Power	4 AA Batteries in Battery Carried - Alkaline Batteries
2	Motor	Power	Converts energy necessary to rotate shaft	Low grade steel and plastic
3	Exterior Casing	Frame	Ergonomic design to protect interior components and to conform to users hand; controls readily available for pinky and thumb use	Plastic with rubber grips
4	Motor Shaft	Power	Turns planetary gears as well as acts as teh conversion between the motor power and the torque created by the shaft	Hardened steel
5	Planetary gear system (double)	Torque	First set of three is powered by the motor shaft - this set is then connected to a second set of three gears that power the actual drill shaft	Both sets of gears are made of plastic - gears closed to drill bit are made of a higher strength plastic - gears further from drill bit are made of lesser quality plastic
6	Arm	Torque	Convert torque created by the first set of planetary gears to the shaft that goes through the second set of planetary gears	Metal
7	The Drill Shaft	Drilling	Turns the actual drill bit	Metal
8	Drill Bit	Drilling	Drills	Metal
9	Outer Gear	Setting change	Allows user to lock gears and use the drill manually	Lower grade plastic