3D printing

 During the holiday, we were tasked to design an object that could not be made subtractively. Subtractive means can be cut (like using laser cutter), carve out (using milling or CNC machine). I had consulted Dr noel about my initial design which was a chip clip but realised it could be made subtractively. He then gave me some examples of what I could do instead. In the end, I decided to make a ball inside an open box. the ball would have the same diameter as the length of the open cube, therefore the ball could not have been placed there, instead be built in it.

Steps in fusion360

I first created a 50x50 square and a 40x40 square inside the first sketch on the horizontal plane. 

I then repeat the first step for the other two planes making sure the sketches form a cube.

choosing a single plane, I extruded the 50x50 square by 50mm, creating a solid cube.

enabling the 40x40 sketches, I un-extrude the square, this creates an open cube with just its corners.

I then added a sphere with a radius of 25mm.

I moved the sphere into the open cube, making sure it was centred in the open cube. 

I have added a video of me creating the design from scratch below.

https://drive.google.com/file/d/1A9v9Py7lH4kzoG118SuGWWwye8EA4Ztx/view?usp=sharing

After that, I saved the design file as mesh, this would then open the Ultimaker Cura, a slicer program with the design file embedded. I made an outline and added support (support placement: everywhere) (adhesion type: raft). Because the ball will be inside the box, support is required. the ball must be on a platform inside the box. after the print, the platform will be removed. I used 5% infill as I didn't want the product to be hollow and I didn't want the print time to be too long. everything else is left alone. After slicing it, I realised the estimated print time is nearly 9 hours. Fortunately, there was a scaling feature in cura, I lowered the scale from 100% to 40% which brought the print time to slightly longer than 1 hour.

Here is the Hero shot of me and my final product.

Reflection:

It was my first time 3D printing and I was expecting it to go smoothly but there were many bumps along the way. I had to return to campus multiple times. firstly, the design I created in fusion beforehand was way too complicated. the structure was too thin and it required way too much support. the print time without the support was less than 30mins, with the support it was more than 4hour. the material required for the support was 10 times the material required for the product itself. I did not realise this until I was on campus. Here was my initial design.

After this incident. I simplified my design and thought about how the 3d print can easily print a product without trouble. I then created a chip clip. this was coming to the end of the holiday already and I had forgotten that a chip clip could be made subtractively. At this point, I thought I was screwed as all the slots were booked up. Thankfully the workshop technician allowed me to come back on a separate date to print my final attempt and it was a success.  Here is my chip clip design.

The 3D printing process itself is really simple. it was the planning and design of the product that I was struggling with. After this experience, I had become much more fluent in fusion360 and learnt many more of the features in fusion360 through experimentation and looking up fusion360 guides.