When it came to designing the octopurse I kept buoyancy in mind, so the I made the base of the design as large as possible to help it float, I also made the internal body hollow to further provide buoyancy. To enable the design to hold money I added canister inside the octopus to contain the mass of coins. The legs of the octopus are separate to the main body as trying to print the design in one piece would have been difficult. The legs (tentacles) needed to be inserted in to the holes on the side of the octopus. The reason that I chose to design an octopus was that I wanted to design something associated with water. I designed the model using 3D CAD software. This is my first design uploaded to Thingiverse.
The lid is separate and allows you to insert the coins inside the octopurse. I then 3D printed my design to see if it worked. The reason that printed the legs separate to the main body was that the 3D printer created a lot of support material and the full model could not fit on to my 3D printer, so it was more beneficial make the main body as large as possible so that it could hold more coins and the print the legs separately. I added chamfers onto end of the legs to make it easyier to insert onto the main body of the octopurse. When it comes to 3D printing the model its best to lay legs to acheive the best quality and detail. The best shell thickness that I found to use was 1.6 mm making it still structurally sound and light weight. Setting your 3D printer speed to 50 mm per second should work well.
Test one - Total weight held = 800 Grams of coins
To improve the weight held I went back to the drawing board to find a way of adding more buoyancy to the design. I came up with adding two floats either side of the octopus, I designed the floats to look like toxic oil drums!
Test two - Total weight held = 1.218 KG of coins
My aim was to put as many coins on design without it sinking , which I accomplished in test two, plus the barrels assisted in balancing the octopus.
I designed the model using 3D CAD software and then 3D printed it to test it.