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A Quick Power Point Presentation
Project Objective

This purpose of this project is to analyze the cost and product structure of a basic hair dryer. Using DFA~Design For Assembly software, and AutoCAD release 14, an estimated cost of manually assembling a small hair dryer and the view of the product’s structure can be created.

Procedure

Start the Program

Select the Start icon.
Scroll up to the Programs icon.
Select the Engineering Software icon.
Scroll down to Dfma.
Open the DFA 7.1 icon and click OK on the license box.
The DFA Structure Chart is shown. Select List entries in Assembly order from the Subassembly on the Menu bar.
Type in the name The Basic Hair Dryer.
Click on Change Settings.
A Settings menu pops up. These default settings are acceptable. Click OK.
Click OK again.
DFA Worksheet pops up empty with the name The Basic Hair Dryer in the Title Bar.

Adding and naming all components

Open the DFA Worksheet by double clicking on the Title Box named The Basic Hair Dryer.
Find the word Part on the screen. This is called the item type drop-down list box. Click on the down arrow and select Subassembly.
Select secured on insertion from the upper right box.
Select threaded fastening from the lower right box. Click the ADD icon.
Double-click on the number 1 in the No. column.
Type in the name Front Cover.
Click on Shape class & size. This is a nonrotational item. Click on Nonrotational. Enter the dimensions for this item – 6"x 2.5"x 3.0".
Click on the Symmetry Box. This item is entirely asymmetrical, so both symmetry fields can remain at the default settings of alpha=360° and beta=360° . Click OK.
Click OK again.
Select DFA Structure Chart from Window menu on the Menu bar.
Double-click on the box named Front Cover.
Select Part from the upper left box.
Select secured on insertion from the upper-right box.
Select push fit from the lower right box. Click ADD.
Double-click on the number 1 in the No. column.
Type in the item name Front Grill.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions for this item, 1.75" x 1.75" x 0.125."
Click on the Symmetry box. Enter alpha=180° and beta=0-60° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select push fit from the lower right operation box. Click ADD.
Double-click on the number 2 in the No. column.
Type in the item name Switch.
Click on Shape class & size.
Click on Nonrotational. Enter the dimension 1.5" x 0.5" x 0.125".
Click on the Symmetry box. Enter alpha=360° and beta=360° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select push fit from the lower right operation box, then Click ADD.
Double click on the number 3 in the No. column.
Type in the item name Insulator.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions – 6.0" x 1.75" x 0.02".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again.
Select Subassembly from the item type drop-down list box.
Select secured on insertion from the upper right box.
Double click on the number 4 in the No. column.
Type in the item name Fan Assembly.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions – 2.0" x 2.0" x 3.0".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select push fit from the lower right operation box then Click ADD.
Double click on the number 5 in the No. column.
Type in the item name Electrical Cord.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions – 30.0" x 0.250" x 0.250".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again.
Select item added but not secured from the upper right drop-down box.
Click ADD. Double click on the number 6 in the No. column.
Type in the item name Cord Retainer.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions – .625" x 0.625" x 0.125".
Click on the Symmetry box. Enter alpha=0-60° and beta=0-60° . Click OK.
Click OK again.
Select DFA Structure Chart from the Window menu on the Menu bar.
Double-click on the box named Fan Assembly.
Select Part from upper left box.
Select secured on insertion from the upper-right drop-down box.
Select riveting from the lower right operation box.
Click ADD.
Double click in the number 1 in the No. column.
Type in item name Heating Coil.
Click on Tool Type.
Select Hand Tool and Click OK.
Click on Shape class & size.
Click on Nonrotational. Enter the dimensions – 25.0" x 0.125" x 0.125".
Click on the Symmetry box. Enter alpha=360° and beta=360° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select push fit from the lower right box.
Click ADD.
Double click on the number 2 in the No. column.
Type in the item name Coil Spline.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 2.0" x 1.5" x 1.5".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select snap fit from the lower right box.
Click ADD.
Double click on the number 3 in the No. column.
Type in the item name Motor.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 1.0" x 1.0" x 1.0".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again.
Select secured on insertion from the upper right box.
Select press fit from the lower right box.
Click ADD.
Double click on the number 4 in the No. column.
Type in the item name Fan Blade.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 1.5" x 1.5" x 0.5".
Click on the Symmetry box. Enter alpha=360° and beta=0-60° . Click OK.
Click OK again. Select secured on insertion from the upper right box.
Select push fit from the lower right box.
Click ADD.
Double click on the number 5 in the No. column.
Type in the item name Blade Housing.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 2.0" x 2.0" x 0.5".
Click on the Symmetry box. Enter alpha=360° and beta=360° . Click OK.
Click OK again.
Select DFA Structure Chart from the Window menu on the Menu bar.
Double-click on the name The Basic Hair Dryer.
Select Subassembly from the item type drop-down list box.
Select secured on insertion from the upper right box.
Select threaded fastening from the lower right box.
Click ADD.
Double click on the number 2 in the No. column.
Type in the item name Back Cover.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 6.0" x 2.5" x 3.0".
Click on the Symmetry box. Enter alpha=360° and beta=360° . Click OK.
Click OK again.
Select DFA Structure Chart Window menu on the Menu bar.
Double-click on the box named Back Cover.
Select Part form the upper left box.
Select secured on insertion from the upper right box.
Select push fit from the lower right box.
Click ADD.
Double click on the number 1 in the No. column.
Type in the item name Safety Screen.
Click on Shape class & size.
Click Nonrotational. Enter the dimensions – 2.75" x 2.75" x .25".
Click on the Symmetry box. Enter alpha=90-120° and beta=90-120° .Click OK.
Click OK again.
Select DFA Structure Chart from the Window menu on the Menu bar.
Select Library Item from the upper left box.
Select Machine Screws from the box right underneath.
Select Screw ¼-20 1 from the middle right box.
Click ADD.
Double-click on the number 3 in the No. column.
Click on the Handling Difficulties Box.
Check the box other grasping tools.
Click OK.
Click on the Operation Characteristics box.
Select Hand Tool – nut driver, screwdriver, or ratchet wrench. Click OK.
Click OK again.

Analysis

The dryer consists of the following parts:

Front Cover

Front Grill

Switch

Insulator

Fan Assembly

Heating Coil

Coil Spline

Motor

Fan Blade

Blade Housing

Electrical Cord

Cord Retainer Ring

Back Cover

Safety Screen

Screw ¼-20 1
Qty =2

Total Assembly Time – 130.8 seconds

Total Assembly Cost - $1.09

The total assembly cost is based on hourly labor cost of $30.00/hr and the component costs for each part of the dryer.

The Design Efficiency is 2.3%.

This shows that there is definitely room for improvement in the design. In viewing the individual component assembly time, any part that take longer than 3 or 4 seconds to assemble needs to be improved on. This aspect will be taken into consideration when developing recommendations for the re-design of this product.

Re-Design Recommendations

Using a snap fit to attach the heating coil, instead of rivets, would improve the design.

Eliminate the safety screen. Since the back cover is simply a plastic injection molded part, the redesign could have vents in the area where the safety screen is currently located. This will eliminate the need of adding the safety screen during assembly, which takes 6.1 seconds.

Eliminate and replace the front grill similar to the safety screen. However, there is one safety precaution that must be addressed. The current front grill is made of material that can withstand the high temperature of the heat coming out of the dryer. Incorporating the new front grill into the plastic injection molded front cover would mean that the plastic material used to make the front cover would have to be able to withstand the heat exiting the dryer. If this could be accomplished, the design efficiency of the hair dryer would improve tremendously.

Replace the threaded fasteners, used to join the front and back cover of the dryer, with a snap fit. Currently it takes 8.4 seconds to assembly, individually, the front and back covers. Using a snap fit would decrease the assembly time and improve the design efficiency of the dryer.

By combining the blade housing, which takes 6.9 seconds to assemble with the coil spline, which takes 6.5 seconds to assemble, into one part will definitely improve the design efficiency of the dryer.

AutoCAD View of Hair Dryer

Front Cover
	Front Grill
	Switch
	Insulator
	Fan Assembly
		Heating Coil
		Coil Spline
		Motor
		Fan Blade
		Blade Housing
	Electrical Cord
	Cord Retainer Ring
Back Cover
	Safety Screen
Screw ¼-20 1 Qty =2