Bathroom scale
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Current revision (11:36, 23 January 2007) (view source) |
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- | This page contains information from an in-class study of a bathroom scale as an example for the spring semester 2007 of the [[24-441 Engineering Design Course | + | This page contains information from an in-class study of a bathroom scale as an example for the spring semester 2007 of the [[24-441 Engineering Design Course]]. The information is incomplete and should not be viewed as an example of a complete report. |
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+ | {{incomplete}} | ||
=Product Dissection= | =Product Dissection= | ||
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==Use:== | ==Use:== | ||
1. Scale moved to where weighing takes place (ground) - NOTE: Shaking – noise made | 1. Scale moved to where weighing takes place (ground) - NOTE: Shaking – noise made | ||
- | 2. Observed zero reading of dial (does it need calibrating) | + | <br>2. Observed zero reading of dial (does it need calibrating) |
- | 3. Calibration – locate calibration dial, turn dial until zero lines up with red line | + | <br>3. Calibration – locate calibration dial, turn dial until zero lines up with red line |
- | 4. Steping on the scale | + | <br>4. Steping on the scale |
* Orientation of the feet around the dial window | * Orientation of the feet around the dial window | ||
* Even distribution of weight | * Even distribution of weight | ||
* One foot first, then the full weight | * One foot first, then the full weight | ||
- | 5. Wait for dial to reach equilibrium | + | <br>5. Wait for dial to reach equilibrium |
- | 6. Read the number that lines up with the red line | + | <br>6. Read the number that lines up with the red line |
==Different Users / Use Scenarios== | ==Different Users / Use Scenarios== | ||
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==Functional Operation:== | ==Functional Operation:== | ||
1. Force applied to cover | 1. Force applied to cover | ||
- | 2. Angle brackets transfer force to levers | + | <br>2. Angle brackets transfer force to levers |
- | 3. Levers amplify the force and transfer to the spring plate | + | <br>3. Levers amplify the force and transfer to the spring plate |
- | 4. Spring compresses proportionally to the force applied | + | <br>4. Spring compresses proportionally to the force applied |
- | 5. Pivot transfers vertical motion of the spring plate to the horizontal motion of the rack (amplifies as well) | + | <br>5. Pivot transfers vertical motion of the spring plate to the horizontal motion of the rack (amplifies as well) |
- | 6. Rack and pinion translates linear motion into rotational motion | + | <br>6. Rack and pinion translates linear motion into rotational motion |
- | 7. Rotational motion is read out on the dial | + | <br>7. Rotational motion is read out on the dial |
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! Part # !! Part name !! QTY !! Function | ! Part # !! Part name !! QTY !! Function | ||
|- | |- | ||
- | | 001 || | + | | 001 || Angle bracket || 4 || |
+ | * Transfer force to the levers | ||
+ | * Provide support for applied force | ||
+ | * Locate cover on base assembly | ||
|- | |- | ||
- | | 002 || | + | | 002 || Cover plate || 1 || |
+ | * Provide surface for stepping | ||
+ | * Enclose/protect mechanical components | ||
+ | * Allow unobstructed view of dial | ||
+ | * Provide aesthetic definition | ||
+ | * Distribute applied force to angle brackets | ||
+ | * Provide anchor points for window, bracket, and springs | ||
+ | |- | ||
+ | | 003 || Lower lever || 2 || | ||
+ | * Amplify and translate force from the angle bracket | ||
+ | * Locate cover (angle brackets) on base assembly | ||
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Current revision
This page contains information from an in-class study of a bathroom scale as an example for the spring semester 2007 of the 24-441 Engineering Design Course. The information is incomplete and should not be viewed as an example of a complete report.
Contents |
Product Dissection
The following notes were taken prior to and during product dissection.
Function/Purpose:
Measures weight of user (or item) placed on top
- Measurement of health
- Weigh an item (self + item – self)
- Measure progress – achieving goal
- Building muscle mass (bodybuilding)
- Losing weight (aesthetic cultural, health)
- Medical issues
- Meet requirements – sports, military
Inputs/Outputs:
- INPUTS: Force pushing down
- INPUTS: (reaction force / support force)
- OUTPUTS: dial turn
Use:
1. Scale moved to where weighing takes place (ground) - NOTE: Shaking – noise made
2. Observed zero reading of dial (does it need calibrating)
3. Calibration – locate calibration dial, turn dial until zero lines up with red line
4. Steping on the scale
- Orientation of the feet around the dial window
- Even distribution of weight
- One foot first, then the full weight
5. Wait for dial to reach equilibrium
6. Read the number that lines up with the red line
Different Users / Use Scenarios
- Weighing objects
- Balance difficult in stepping
- Weight beyond capacity
- Body shape in the line of vision
- Different eyesight
- Lighting
- Flat surface
- Calibration tasks, difficult for Parkinsons, limited hand-eye coordination
Functional Operation:
1. Force applied to cover
2. Angle brackets transfer force to levers
3. Levers amplify the force and transfer to the spring plate
4. Spring compresses proportionally to the force applied
5. Pivot transfers vertical motion of the spring plate to the horizontal motion of the rack (amplifies as well)
6. Rack and pinion translates linear motion into rotational motion
7. Rotational motion is read out on the dial
Part # | Part name | QTY | Function |
---|---|---|---|
001 | Angle bracket | 4 |
|
002 | Cover plate | 1 |
|
003 | Lower lever | 2 |
|