Project 4: The blister

Project 4: The blister

Introduction

This is the fourth project for BEIL0014 I have been working on, which is hammering out a blister on a sheet of aluminium with aid of a hollow double sided wood mold . My objective is to create a blister that has a clear edge with maximizing its depth. 

Theory

As I have been given a relatively big mold for this project, which means there is more metal available to be stretched out, my aim is to let the metal reaching its ultimate strength. The following shows a graph of metal behavior of stress vs strain. 

Before the sheet metal fracture, the metal will undergo strain hardening which become harder and harder as it stretches. My strategy was to apply this theory and hammer the metal evenly at constant strength so that the unstretched part will keep stretching and the fully stretched part will stop stretching. This will keep me from breaking the sheet metal. 

Procedure

To begin with, I place the sheet metal between two molds and drilled four holes in the corner. Then I add 4 screw each at the holes that I drilled before. This is used to stabilize the sheet metal as I hammer it. 

After that, I put two plank of wood on each side of the wood mold to increase the ground clearance,  next I clamp the whole thing to stabilize the set up as hammering will movement to the product.  

Next, I took a stick of wood and sharpen it at the grinder, then with aid of the stick I was able to hammer the edge to the mold to give a distinctive look of the blister.

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

The finish product are shown as follow:

Project 3: The Tray

Project 3: The Tray 

Introduction

This is the third project for BEIL0014 for making 2 identical trays with the cooperation of two people. For this project me (Louis) and Iverson formed a team of 2. 

Procedure

We start with 2 plank of wood and 2 sheets of metal. First I have chosen a suitable radius for the corner of the tray which is 50mm. I then draw lines around the plank of wood with the circle tool disturbed in class. 

Next, I bring the plank of wood to the grinder to grind out the extras

Until the wood perfectly matches with the circle tool. 

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. 

The marking are shown on the metal for both sides:

Next, again with the help of the circle tool, I was able to cut off the sharp edge of the metal and turn them into rounded corners. 

Then I place the metal in between two wood planks with the wood sit exactly in the marks I have created previously. I then place the whole thing in a large clamp which is directly attached to the working bench. The hammering process then begins. 

Metal fold is very common in the process of working on corners. The solution to avoid metal folding is to add a support underneath the corner while hammering. 

After the work has been nearly finished, it has been taken out from the mold to do some minor fix on the metal since the tray has been deformed a bit in the process of taking the wood out of the tray. 

Next, it is bring to coarse sand paper to grind the bottom and making the tray look even. And for the surface of the tray, different grades of sand paper has been applied from coarse to fine. This makes the finishing of the tray looks shiny. The process is being repeated for the second tray.

The finishing product is shown as below: