Design of the U-tube

We come up in Two Plans – Plan A and Plan B.
Plan A is inserting an aluminum part inside the tube.
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Plan B is covering an aluminum part outside the tube.
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We start Plan A first. After we purchase the aluminum rod, we decide to manufacture two parts with different diameter (3mm and 5mm). However, we find that the temperature of the water output is not so high. Also, the insertion will break the interior structure.
We choose Plan B. First, we choose to build the 3mm diameter part. We cover the part on the edge of the tube. Lastly, we add the hot melt plastic at the end of the part to prevent the water leakage. We found that there is a significant change. So, we continue to try the 2.5mm diameter part. The 2.5mm diameter part cannot show the high temperature. Hence, we try to step back to build the 4mm diameter part. It cannot show the significant changes. We try to build the 3.5mm diameter part. The result displays the similar performance of the 3mm diameter part.


Procedure
We order the aluminum rod first.


Number

Items

Quantities

1.

Ф10 x 20 aluminum

4

2.

Ф20 x 40 aluminum

4

After that we collect all the data and want to find out the optimum diameter to get the high temperature. We plot the graph and conclude that 3mm diameter of the Plan B valve is the best solution. So, we use it and use the epoxy to the final connection.

 

Results


Diameter of Valve (mm)

Average Temperature Reached (⁰C)

Special Situation

2.5

92.33

So many stream came out

3

92.67

/

3.5

89.50

/

4

84.50

No observable changes

4.5

84.33

No observable changes

Design – The Retractable Ball Pen System

Principles of using the ball pen and steam iron were applied

as

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In this coffee maker, the pin serves as a function of hindering the coffee going down to the carafe

 

The testing results of the different diameter of the pin used:

3mm

2.9mm

2.8mm

2.7mm

Time

Water level

Time

Water level

Time

Water level

Time

Water level

0 s

0

0 s

0

0 s

0

0 s

0

31 s

100

39 s

100

31 s

100

54 s

100

69 s

200

84 s

200

104 s

200

106 s

150

110 s

300

120 s

300

156 s

300

150 s

200

134 s

400

150 s

400

170 s

350

195 s

240

193 s

520

302 s

300

195 s

300

222 s

200

702 s

400

385 s

200

261 s

200

292 s

100

997 s

300

472 s

100

338 s

100

351 s

0

1292 s

200

560 s

0

408 s

0

1570 s

100

1850 s

0

 

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The 2.8mm pin can immerse all the coffee powder and requires less time to complete the whole process

Design – Inner Filter

Coffee will pass through the inner filter to the carafe
Not to use filter paper as it will absorb the flavor of coffee
s
Problem: Not all the water can pass through the filter as the holes are too small
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The diameter of the holes has been widen to 0.273mm
Testing with this diameter, the water can pass through the filter freely

Design – Water Outlet

  1. aThe aim of creating the new outlet is to

   1) Let the water contacts with most of the coffee powder
2) Let the pin easily pass through the filter holder and the cover

  1. New features of the design:

     - Y – shape of the outlet

     - Two positions to let the water coming out

 

Design – Filter Holder

  1. Basically, the aim of changing shape is about the product appearance
  2. aFrom a cone shape to an ellipse-circle one
  3. A piece of silicon rubber was inserted

   - Users can see through the filter to observe the water level

 

Design – Cover

    • Changed from one cover to two covers
    • Compared with the old one, we just need to rotate the filter holder and can easily take out the pin
    • Users can be more flexible to use the coffee maker as they can control the cover in a different way
    a

The Complete Design

s

Design Comparison

Comparing the new coffee maker design with the original design, we concluded the following comparison table to show the changes of the designs.

Parts

Original Design

New Design

Cover

  • One piece
  • Two pieces

Water Outlet

  • One output
  • Triangular shape
  • Two outputs
  • Y shape

Swing out filter holder

  • Cone shape
  • Without window
  • Ellipse – Circle
  • With window

Filter

  • Silk
  • Filter paper needed
  • Stainless Steel
  • No filter paper

Water Output Initiation

  • By switch
  • By pin

Filter Holder

  • One part
  • Two parts
Design downloaded from free website templates.