Assignment Questions

1. Choose 2 machines that you used in the fabrication of your desk tidy. With these machines in mind, outline WPH&S considerations that must be adhered to when using these machines. Include photographs of your chosen machines (OnGuard may be an excellent resource for this question).


Band saw
• Long hair must be tied back.
• Safety goggles must be worn to prevent small pieces of objects from flying into your eyes.
• Never leave the machine operating when it is unattended.
• Use two hands at all times.
• Don’t have too many people near the machine.
• Always rest the material you are cutting on the table – do not hold it above the table.
• Keep hands away from the blade.
• Closed in shoes must be worn when using the machine.
• Material smaller than 3cm should not be cut using this machine.


Belt sander/disc sander
• Long hair must be tied back.
• Safety goggles must be worn to prevent small pieces of objects from flying into your eyes.
• Never leave the machine operating when it is unattended.
• Use two hands at all times.
• Closed in shoes must be worn when using the machine
• Material smaller than 3cm should not be sanded using this machine.


2. The material you are using for your desk tidy is called Polymethylmethacrylate (ACRYLIC). It has specific properties and uses. Choose 2 other common polymers and in table form give their industrial name, common name, properties and uses.



3. Extrusion, injection moulding, compression moulding, vacuum forming and laminating are examples of common manufacturing processes used with polymers (Plastics). Choose one process and with the use of diagrams and bullet points outline the process.

Vacuum Forming:
-Firstly, a mould is made using a material such as wood of cardboard. The edges are made at an angle that will make it easy to remove the plastic after it is formed.
-This mould is then placed in the vacuum former.
-A sheet of plastic is clamped above the mould.
-A heater gradually melts the plastic so it becomes pliable. After a few minutes it is ready for forming.
-The heater is then turned off and a lever is used to lift the plastic until it is in position.
-The vacuum is the turned on, which pumps the air out from beneath the plastic sheet, causing it to form around the mould.
-After the sheet has cooled down and become solid again, the vacuum is turned off and the sheet and mould are removed from the vacuum. The sheet would have taken the shape of the mould.

4. Extension Work - Using processes acquired from your maths lessons, calculate the amount of acrylic sheet that your FINAL desk tidy represents. Show all calculations; answer needs to be in square metres.





Therefore, the amount of acrylic used in my desk tidy is 0.1096 square metres.

Desk Tidy Evaluation

Aesthetics
The design of my desk tidy is simple, but looks nice. It is simple enough that it isn’t crowded, but at the same time isn’t boring either. The only thing I would change about the aesthetics of my desk tidy is the colours. Originally I planned on using lack for the base and the cylinders, and red for the stand. However, when I started making it I realised I had accidentally used a transparent black sheet instead of a solid black one for the base. I kept it as this, as it looked fine, but later I found out that there were only clear cylinders. Due to this, there are many colours on my desk tidy that don’t really match, but also don’t look too bad. In my opinion, my desk tidy looks nice, but if I were to do it again I would change the colours.

Ergonomics
My desk tidy is easy and comfortable to use, as it is small enough to not get in the way when it is on a desk and easily holds the items it is meant to. It is small so it doesn’t take up much space. The ergonomics of my desk tidy could be improved if the cylinders had a larger diameter. This would make it easier to get items out of them, and they would be able to hold more things.

Economics
The economics for my desk tidy are very good. Seeing as the average price for a sheet of acrylic is $95.7 for 3 square metres and my desk tidy only uses up 0.1096 square metres, the materials for my desk tidy only cost $3.50. This is a lot cheaper than it would cost if it was purchased from a shop. The acrylic sheets were also shared between classes, so not much of it was wasted.

Function
My desk tidy solves the problem that was presented. It works effectively as a desk tidy that caters to my own needs and is smaller than 200mm x 200mm. It can be used to organize my desk, and holds pens, pencils, my keys, my phone and other small items. The function could be improved if the cylinders had a larger diameter, or if there were more of them because then they would be able to hold more things.