Wednesday, 17 February 2010

Play Critique

The time has come to present my current findings to my lectures. The two areas that have always been important to me is water temperature and brew time. I will show my Galileo thermometer working and how you judge brew time from the colour of the tea (this came from user testing). After displaying how to make the tea I am going to justify the choices to the materials I have chosen for my cups.
So basically I am presenting the tea set all the cups and my temperature method. Below is a 3D model displaying the materials and giving an idea of the aesthetics.

Monday, 15 February 2010

Galileo Thermometer

After the testing of my galileo thermometer and nothing going wrong with the bulbs being boiled, I went ahead and ordered bulbs to be made by Scott Glass. These are the bulbs I got back.


The bulb has washers hanging from it giving it a total weight of 12.4 grams with a diameter of 30 mm and wall thickness of 0.3mm (these are rough sizes)
With these sizes and weight the bulb would sink and boiling and float a around 84 C

Sunday, 7 February 2010

Cast Iron

For one of the cups I will be using cast iron. So I spent a lot of time trying to find a place that casts with iron. I tried powder hall in edinburgh first. Powder hall mainly casts in bronze, they do use other metals but iron is not one of them. The next company I tried was Ballantine Boness, this company specialises in cast iron perfect for my cup. After contacting the company they informed me that to make the cup it will cost me £800.... a bit out of my price range.

Plan B for the cup was to source Iron myself and have the cup lathed as much as possible to my design and have the cup finished by a cnc lathe.

So more to come on the progress of this cup.

Dead Ends

As my time runs out and my electronic skills do not seem to be growing I have been forced to look towards other alternatives of telling your tea is ready.
I have mentioned before that a tea company Suki tea gave me there tea bible and inside it tells the reader how to judge your tea is ready by the colour it produces. This method was also mentioned to me by my tea tasters, we should be keeping an eye out for the water changing colour.
To do this with a glass cup would be easy as you can see the tea clearly and easily. From my pictures I posted up about my form you can see a few cups have a white interior and this white interior will show the colour of the tea a lot better.

For time the user will judge the tea and its colour to tell when the tea is ready instead of using a timer.

Cup Testing

After previously testing my cups and choosing a form the heat retention was between 2:52 and 2:45 but to up that heat time I found an old tea preparation method known as Gong Fu which can be seen here.

The idea of this method is too pour boiling water in to all your cups to heat them. While the hot water in your kettle cools the cup heats. When the kettle water reaches the temperature required the water heating the cup is poured away and water from the kettle is used to fill the cup again with the tea for brewing.

This method increased the cup heat time up to .....

Porcelain cups

After playing with my form using engineering foam on the lathe I was able to take one of my models and use it to make a mould for producing porcelain cups. Below are pictures following roughly the stages of the process.

First thing to do for producing a mould is to have a sheet of set plaster to section off the top and bottom halves of the model. The to halves will be separately casted to complete the mould. The sheet of plaster was held up by clay and the plaster was boxed in and sealed using clay so the the liquid plaster does not run out.

The top of the model was cast in plaster first and left to set for 15 min. The same process was copied for the bottom half of the model to produce a complete mould.
The mould takes four days to dry out then will be ready to have porcelain poured in.

Heat Solution

Identified earlier when testing my clay cups there was a problem with picking up the hot cups without handles.

Tuesday, 2 February 2010

The beginnings of the prototyping

For the prototype of my model I have been using engineering foam to explore the form and give a visual of my product.These are some images of me using the lathe and below are images of the results. I have explored different shapes and an alternative to the handle for stopping the hands from being burned whilst touching the cups. More images will follow and with the cups finished better.

Tea Tasting

As a back up to my knowledge on tea taste being affected by water temperature and brew time, I held a tasting session to see what other people thought.

Green Dragon well tea brewing. Good tea leaves should hang in the water vertically as they brew shown here (knowledge I picked up from some tasters that came to the session)

The session consisted of three teas being tasted gunpowder deluxe green tea, dragon well green tea and jade sword green tea. Each tea was made perfectly and then ruined by the tea being over brewed with the water being too hot or under brewed with the water being to cold. The first two teas were down with the tasters knowing which tea was perfect and which was ruined. The final tea was done with out the tasters knowing which tea was perfect and which was ruined..... and the tasters guessed correctly. They could distinguish between the good and bad teas so water and time clearly affects the tea.

Galileo Thermometer Update - testing

With Scott Glass suggesting that my glass bulbs would explode I decided to test the method before I continued. So I bought a Galileo thermometer smashed it open and boiled the bulbs, repeatedly and NONE EXPLODED!! so everything is now back on track.

Monday, 1 February 2010

Cup Testing

To help more with form the cups were tested for how well they retained heat. Each cup had boiling water poured in to it and timed to see how long it took for the temperature to fall below 69C.
The first cups tested have the smallest openings and times for the looked like this
Thickest 4:00 min
Medium 3:43 min (averages)
Thinest 3:32 min

The second cups to be tested were the ones with the second biggest openings on top and there times are as followed
Thickest 2:52 min
Medium 2:50 min (averages)
Thinest 2:45 min

The final cups being tested had the biggest openings on top and the times are as follows
Thickest 2:00 min
Medium 1:58 min (averages)
Thinest 1:55 min

For ease with drinking and heat retention I will be using the second form for my final prototype.

One thing high lighted from this testing was that the cups with out handles were unbearable to hold from the heat. This will need to be sorted as I prefer cups without handles. Shown below is a cup with a handle and another without.
Without does look better.

Galileo Thermometer Update - getting glass made

I am going with a company used by previous designers from the course. The company is known as Scott Glass in stirling.
I phoned the company with the figures and shapes of what I wanted to do and they flagged a serious problem I could incur. The average Galileo thermometer has bulbs on the inside and these bulbs have a fluid on the inside. The people at Scott Glass believed that this fluid on the inside will boil when I boiled the bulbs. This boiling fluid on the inside of the bulb will expand shattering the bulb.......... this puts a serious hole n my idea!

Galileo Thermometer Update

With the galileo thermometer working on the principles of changing densities in water I needed to figure out how to calculate a few things.
How to calculate the shape of the bulb, the size it must be?
What is the density of water and glass?
To do this I got some help from a physicist Mervin Rose.

From my chat with Mervin I got this little A4 sheet on it was basically how I need to calculate the bulb. The bulb must be a shape that dispenses the water evenly (circular would be easiest) as for sizes the bulb must be made to two parts air one part glass. This basically means that the volume of the air on the inside must be double that of the volume of the glass on the outside to make it buoyant.

clay play

Since one of my cups will be of clay I decided to play with the material to get use to it and discover a little form.
While I played with the clay a technician known as Sean spun some clay for me taking three of my designs and for each design he made three cups each of different thickness to experience heat loss through thickness.

As you can see the cups design have different openings on top, this was to experiment with heat loss out of the cup as well.