Group 1 - Black & Decker Drill/CDR

Purpose

Gate 4 is the final project review in which the reassembly process is documented and analyzed. Additionally, recommendations are made to increase the ease and success rate of reassembling the product.

Product Reassembly Plan

The product's reassembly is best approached by first reconstructing each predefined assembly, combining these sub assemblies into the whole internal assembly, and then seating the internal assembly inside of the drill housing. Below details a step-by-step process for reassembling the drill.

It is recommended that photographs of parts, assemblies and step photographs be used as aides during the reassembly process.

Tools required:

Torx #15 screw driver
Flat-head screwdriver
Needle-nose pliers

Diagram 10

Armature Reassembly Steps
Step	Description	Tool Required	Time Required	Difficulty (1-3)	Step Photograph
1	Slide red washer over rear end of the armature.	Hands	0:15	1	Red washer replaced
2	Slide heat sink over rear end of the armature. The fin side of the heat sink should be closest to the armature core.	Hands	0:15	1	Smooth side of the heat sink Fin side of the heat sink Heat sink replaced
3	Slide small metallic washer over read end of the armature.	Hands	0:15	1	Metallic washer
4	Replace retaining ring to secure all of the components on the end of the armature. Note: The retaining ring is easily replaced by positioning the open side of the "C" shaped clamp against the armature and then squeezing the ring into place with pliers.	Hands and pliers	0:15	1	Completed armature reassembly

Diagram 11

Motor Reassembly Steps
Step	Description	Tool Required	Time Required	Difficulty (1-3)	Step Photograph
1	Slide reverse ring and field together and then secure the two pieces with the 1 7/8" torx screws. Note: The reverse ring can be combined with the field in two ways. To easily identify the proper orientation hold the field in one hand with the serial numbers on top and slide the reverse ring into position from the left such that the "B" is further away.	Hands and torx 15	1:15	2	View of field serial numbers View of the "B" on the reverse ring Field and reverse ring reassembly
2	Slide retaining brushes into place ensuring that the flat spring fits into rear end of the brushes.	Hands	0:15	1	Retaining brushes orientation
3	Compress retaining brushes with a flat-head screwdriver and slide the armature inside.	Flat-head screwdriver	:20	1	Completed motor assembly

Diagram 12

Gearbox Reassembly Steps
Step	Description	Tool Required	Time Required	Difficulty (1-3)	Step Photograph
1	Slide pinion into the front bearing, meshing it with the gear.	Hands	0:15	1	Front bearing assembly Pinion and front bearing assembly
2	Slide rear bearing onto the rear of the pinion and gear prongs.	Hands	0:15	1	Completed gearbox assembly

Diagram 13

Internal Assembly Reconstruction Steps
Step	Description	Tool Required	Time Required	Difficulty (1-3)	Step Photograph
1	Slide the geared end of the motor assembly into the center of the rear bearing.	Hands	0:15	1	Motor assembly and rear bearing reassembly Combined motor assembly with gearbox assembly
2	Reconnect power wires into the rear of the reverse ring. Note: The black wire enters the reverse ring terminal marked with a "B" and the white wire enters the unmarked terminal.	Hands	0:15	1	Completed internal assembly

Diagram 14

Housing Reassembly Steps
Step	Description	Tool Required	Time Required	Difficulty (1-3)	Step Photograph
1	Seat internal assembly into the grooves of the drill housing. Note: Ensure that the serial numbers on the field are towards the top of the drill housing and that the retaining brushes on the armature are still on the copper track. The internal assembly should slide into place with minimal effort.	Hands	2:45	2	Internal assembly seated inside of drill housing (Front View) Internal assembly seated inside of drill housing (Top View)
2	Replace VS control unit. Note: The triangular locking mechanism should slide freely into the hole on the drill housing.	Hands	0:15	1	Triangular locking mechanism VS control unit replaced
3	Slide cord protector into its location at the base of the drill housing.	Hands	0:15	1	Cord protector replaced
4	Secure power cord with cord clamp and two 3/4" screws.	Hands and Trox 15	0:15	1	Power cord secured with cord clamp
5	Slide cap and bit holder into place on the top of the drill.	Hands	0:45	1	Cap replaced (Side View) Cap replaced (Side Top) Bit holder replaced (Side View) Bit holder replaced (Top View)
6	Replace housing cover and secure with nine 3/4" screws.	Hands and Trox 15	2:45	1	Completed drill assembly

Total reassembly time: 10 minutes, 50 seconds.
*Note: The break down for the difficulty levels are as follows:

1 = easy; requiring little effort.
2 = medium; some prior thinking required.
3 = hard; required multiple attempts; two people recommended.

Post-Reassembly Analysis

Below are a few sample questions that address the final condition of the product, disassembly/reassembly differences and further product recommendations:

- Does your product run the same as it did before you disassembled it?

The product runs the same as it did before the disassembly process. We attribute the successful disassembly and reassembly of the process to the detailed notes and photography, making it easy to retrace the steps.

- What were the differences between the disassembly/reassembly processes?

The main differences between the disassembly and the reassembly processes were the attention to detail needed. For example, it's easy to remove all of the small washers, the heat sink, and the red washer, but when returning the armature to its original form, the person doing the reassembly needs to know the order and the orientation of the heat sink so that the product will fit into the drill housing properly. similarly, when combining the field and the reverse ring, there are many opportunities for mistakes such as in wire placement and the proper orientation of the reverse ring on the field itself.

Taking good notes and paying close attention to each piece prior to removing it allowed the group to reassemble the entire product.

Different tools used:

Needle-nose pliers

- What additional recommendations would the group make at the product level?

The only area of the drill that the group felt could benefit from modification was the field and reverse ring. The first modification that could be made would be to implement a notch into the field and a protrusion on the reverse ring such that the two could only fit together one way. This would prevent the two from being reassembled improperly. The second modification would be to replace the current system of connecting the wires individually into the reverse ring with a single plug-in system which would further reduce faulty reconstruction of the motor assembly.

Main Page

Return to main page