Main aim: to create the skin of the fuel tank which can perfectly fit the shape of the actual model.
There are 3 models which can be chosen as the model.
Below is the model we choose which is downloadable on blog, the total result of our mark equals to actual mark x 1.25.
1.25 ASSESSMENT MULTIPLICATION FACTOR!!!!!!!!!!!!!!!!!!!!
(Custom tank for a CB550: Andrew Wallace)
Step 1:
Use Rhino/Grasshopper techniques to create a 3D model of the chosen fuel tank. It is available for us to directly download the documentation from blog as shown above.
Note: the model being opened initially can be seen as several lines, it is supposed to use grasshopper command to turn lines into reticulated body.
Step 2:
Use Autodesk slicer for fusion 360 to prepare fuel tank template for laser cutting.Specific waffle body can be seen as below in image 0 and 1.
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| Image 1 |
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| Image 0 |
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| Image 2 |
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| Image 3 |
Note: Some parts of the printed items are very fragile just like part Y-13 in image 3. In order to prevent breakage, we delete the assembling mark on this item to keep it unbroken.
In order to make sure the components of model can be assembled, it is supposed to make sure every gap of the components is the same. And this should be modified and confirmed constantly to find the best result because big gap may make the model to be very loose (not stable) and small gap may make the model to be very tight(difficult to be assembled). We try several times by assembling 2 components with the same gap width. The width we use is 3 mm at last.
Step 3: Laser cutting.
(equipment provided by the campus lab)
It takes long time for waiting.
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| Image 4 |
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| Image 5 |
For long components of this model, there are many gaps on it. This also means the friction between gaps may be added as well. Thus, it is really difficult to assemble 2 long components of this model.
Step 5 : As it can be seen in the image 4 and 5, there is no surface skin for fuel tank model, it is just a skeleton or frame. It is supposed to create the surface of the model by tape as below.
Step 6: Divide the entire surface of the model into 3 parts ( left part, right part, top part) as below:
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| Image 6 |
My individual part is the left part of the model as can be shown in image 6
Shape analysis
This is the lateral view of the left part.
It can be roughly divided into 3 parts:
1 Curve being bent towards inner space of the model at top
2 Curve which is almost straight at middle
3 Curve being bent towards inner space of the model at bottom
Step 6: Get the rough shape of aluminum ( Pattern making)
As it can be seen in image 7, we stick 3 A4 papers together with tape then make the shape of paper to be the shape of the left part of the model by scissor.
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| Image 7 |
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| Image 8 |
It is supposed to draw the shape of paper on the aluminum. Then cut away needless area of aluminum by tin scissor.
Note: Actually, the aluminum may stretch after being hammered, so it is supposed to cut away needless area in latter step as well.
Step 7: Build the Curve which is almost straight at middle
Note: This is supposed to be the step which is in front of building top and bottom curve because most of the area is middle curve and it keeps the entire shape stable.
It is suggested to bend the aluminum so that it fit the horizontal curve of the model. Then we need to put it on the metal ball as shown in image 9 and hit it will mallet to make middle curve.
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| Image 9 |
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| Image 10 |
Image 10 shows it more specifically that how we build the middle curve..
Note: The middle curve may change its shape while hammering. Therefore, it is supposed to use timber model in step 4 to check the shape continually while doing this step.
Step 8:English whee
This is called English wheel in laboratory. It is used for smooth out the bumpy surface of the bowl. We need to choose one of the wheels on the top and assemble it on the equipment. Our aluminum strip should be placed and then moved or rubbed in between these 2 wheels.
Note: this is not done at last because English wheel can change middle curve easily.
Step 9: Build top and bottom curve
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| Image 11 |
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| Image 12 |
The metal horse shoe as shown in image 11 is used to make the edge of the torus. The red mallet in image 12 is used to hit the aluminum strip because the flat surface of the red mallet can make the edge perfectly fit the metal horse shoe.
Note: that it is supposed to make the edge by mallet
starting from the inner space of the torus to the outer side to make a regular shape.
Note: while doing this step, the middle curve may change its shape. Thus, it is supposed to do step 7 8 9 again and again to get the perfect shape.
Step 10: It is supposed to put left part on model then use mallet to hit it to get final shape.
Note: Do not hammer hard because our model is very fragile and easy to be broken
Step 11: Sanding and polishing
Finally!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
