Assignment 3: Reflection
Introduction
Over one semester of studying BEIL0014 on metal shaping techniques, some computer modelling as well as laser cutting techniques have gained me some knowledge and practical experience in understand handcrafting and how metal behaves under pressure.
Five products have been produced starting with the bowl:
Technique learnt:
For the first product I produce, I have gain a strong concept from lecturers that I should have visualize the finished the product before starting any work. Having the final shape in the mind, helps me to set the appropriate bowl radius and develop strategy to hammer the product evenly in circle and planishing it smoothly.
I also learnt that the aluminium metal is very easy to modify its shape, so that I could put a curved wooden panel below the metal and shape it right away. Given its easy shape property, it is so important to be aware of hammering evenly.
For this project, I prefer to work from outer circle of the metal because it will be easier to start from edge and to expect two other side of the metal to shrink together causing a bent when I work on new are of the metal. The circled area is an example of bent caused by shrinking.
I also learnt the power of English wheel, "It is like working with hammer but single roll is 100 times hammering on a straight line." However, it is all about experience when looking at which wheel to be chosen. Since the wheel only covers a line of flattening, orientation has to change regularly and uniformly to produce smooth result. Last, planishing hammer is used to flatten last bit of the product. To give a shine metal finish,polish with Brasso is recommended.
What I will do if I start this project again is to start from the outer circle and switch into the center on the half way to make sure the metal's center position is aligned and the shrinking would not be too great. For equipment, I would recommend UNSW to purchase a pneumatic hammer.
A pneumatic planishing hammer is a stationary tool that facilitates smoothing a hammerformed sheetmetal part with relative speed and ease. The work piece can be held in both hands and moved carefully and accurately relative to the dies while a foot operated switch controls the machine. Silicone lubricant such as WD-40 would also be very helpful when planishing.
For this project, I prefer to work from outer circle of the metal because it will be easier to start from edge and to expect two other side of the metal to shrink together causing a bent when I work on new are of the metal. The circled area is an example of bent caused by shrinking.
I also learnt the power of English wheel, "It is like working with hammer but single roll is 100 times hammering on a straight line." However, it is all about experience when looking at which wheel to be chosen. Since the wheel only covers a line of flattening, orientation has to change regularly and uniformly to produce smooth result. Last, planishing hammer is used to flatten last bit of the product. To give a shine metal finish,polish with Brasso is recommended.
Things I could improve:
This project I worked from outer circle into inner circle, the weakness for this approach is I could have offset of the center of the metal if I have worked from the outer circle with uneven force. I could have started from the center of the circle to make sure I have the best center position aligned with circular sheet itself. However,I expect this approach will create even greater shrink of metal.What I will do if I start this project again is to start from the outer circle and switch into the center on the half way to make sure the metal's center position is aligned and the shrinking would not be too great. For equipment, I would recommend UNSW to purchase a pneumatic hammer.
A pneumatic planishing hammer is a stationary tool that facilitates smoothing a hammerformed sheetmetal part with relative speed and ease. The work piece can be held in both hands and moved carefully and accurately relative to the dies while a foot operated switch controls the machine. Silicone lubricant such as WD-40 would also be very helpful when planishing.
2nd project is reversed curve:
Technique learnt:
To make a reserve curve, my approach is to attach the sheet metal on to a circular plank of wood to create a primary curve.
and hammer the middle part of the metal where the plank of wood has a slight depression curve on it to create the shape of secondary curve.
Then the thin curve shaped tool is being used to help create the peaks of the reverse curve. Using the line which I drawn previously, I was able to precisely hammer the 2 identical peaks from the left and right section of the sheet.
Things I could improve:
I could put the finish product into the English wheel to have a smooth finish, however this could result in the primary curve being flatterned, serveral attempt should be made.
On the other hand, this project could be done 100% on an English wheel, I came across another way of making the reverse curve with only English wheel.
Using only English wheel approach would give a a smooth finishes however the curve would be less significant.
3rd project is the tray:
Technique learnt:
Cooperation is the main theme for this project as it seem to be impossible to finish this project by oneself. In order to achieve a symmetric shaped tray, I measured the length of the plank and the sheet metal and draw markings on the sheet metal so that the plank of wood sit exactly in the middle of the metal.
Laser tool has been used by the lecturer to help cutting out wooden circles for edges.
Again, same as the bowl project metal folding is expected however the scale of folding is smaller meaning it would be tougher to handle smaller fold.
I have developed a technique to minimize metal fold is by adding a support (such as a screwdriver) underneath the corner while hammering. I have noticed the difficulties while working on smaller part of metal is much harder than working on bigger metal projects, especially the metal would be hardened after cold worked
Things I could improve:
To get a better finishing product, I have grinded out a lot of metal to make the edge look even and smooth, what I could do is to reserve more metal of the edge which can make the hammering process easier and I could cut the extra part out at last.
4th project is the blister
Technique learnt:
In my opinion, this is the easiest project but doesn't mean I could not learn anything from it. 
I have done some research on this and found out I should test out the "ultimate tensile strength" of the metal. I have developed a plan by hammering the metal with constant force, so that the metal will get thinner and thinner as well as harder on the other hand. Up to a point where the metal stopped stretching is where I know it reaches its ultimate strength. Any force beyond this could result in creating a hole in the middle.
I have also created a wooden tool to help shaping my metal.
By focusing the edge of the blister, I could create a defined shape of the metal. The whole process I used plastic head hammer to give a smooth surface. Then hammer it with constant strength until is nearly reaches its ultimate strength.
Things I could improve:
What I could do to improve is to try out with different "constant forces" on different sheet metals, I could potentially make a hole in the blister but it could be a good experiment on whether how much force should I apply on the metal before it break to achieve the deepest blister I could create.
The last project is Fuel tank:
Technique learnt:
This project has infused some modern technology into it before metal work which is worth learning, Autodesk Recap, Fusion 360 slicer and illustrator have been used.
The metal work part summaries the technique I learn from bowl, tray and reverse curve. I found out it could be a challenge to work on a large individual part. As a small group of three, we have divide the metal work into three part, 2 side part and 1 top plate.
For the side part, due to the elastic property of metal, the end edge keep sticking out whenever we tried to get it in place. Eventually I decide to "over-bend "the metal using English wheel and after few attempts it finally fits.
For top plate, the problem I encounter when working on it mainly is when I hammer the top part perfectly after finishing the bottom part, the bottom part start to deform and change. This means meaning I have to work on the whole part simultaneously.What I did there to solve this problem is to ask my teammate to hold tight the other part of the top plate when I working on one part. This approach is similar to the tray project I did previously while the face of the plate is being hold by two wood planks with large clamp. Without the clamp, the face of tray would have deform while I was working on the edge.
Things I could improve:
Due to symmetrical property of the wooden template itself, the finished aluminium product is tilted on one side as well but it is perfectly matching the wooden template.
What I could have done is double check the wooden template before printing it out. having an asymmetrical template has increase the difficulties significantly.
Moreover, looking at the website of Bristish V8
http://www.britishv8.org/Articles/Hammerforming-and-Planishing.htm
They have created something similar to the top plate with a pneumatic hammer where it acts as a strong flattening tool to smooth the metal quickly with ease.
Moreover, looking at the website of Bristish V8
http://www.britishv8.org/Articles/Hammerforming-and-Planishing.htm
They have created something similar to the top plate with a pneumatic hammer where it acts as a strong flattening tool to smooth the metal quickly with ease.
Conclusion:
I have been feeling very grateful to choose this subject as my BEIL course, I have gained experience on handling metals at which it is a total new area for myself, I have develop my thought of creating these metals and I have learnt to appreciate hand made metals and also interpret the ways of creating metal work when I see products done by others.
