3D Printing

3D Printing

For this week's blog, I will be talking about my experience with the term break assignment. For this assignment, I was tasked with creating a model in Fusion360 that could be 3D printed with the help of the slicing software Ultimaker Cura. At first, I was quite confused with what I should model as I did not fully understand what they meant with the requirement " Design in Fusion360 and 3D print an object that could not be easily made subtractively". From my understanding at the time, I assumed that I could make pretty much anything that would not be possible to make via subtractive methods that I had learnt previously such as laser cutting. Hence, I had decided to try and model my favourite Pokémon, Ditto and 3D print it as a tiny souvenir figure.

Figure 1: Ditto Reference Model

However, after about 3 hours of playing around with the form functions, I was unable to get the shape of ditto that I wanted. This was likely because using the form functions had not been taught to me in school and the videos that I had found of people using the form functions were of little help as the way you manipulate the form is hard to explain or replicate without prior experience. Thus, I had scraped the idea and decided to do something simpler that I had either leant before or is easy to plug and play via watching a quick tutorial or reading a guide.

Figure 2: Ditto Model Failed Attempt

When brainstorming on what my next attempt should be, I decided to try and think of an object that is made out of simple shapes that doesn't require the use of form functions and since I was already on the topic of Pokémon, I eventually landed on the idea of making a Pokéball. After deciding, I had proceeded to model the Pokéball in Fusion360 with reference to this video.

Figure 3: Pokéball Reference Model

Before I move on to the next section where I document the steps to make the Pokéball, I had faced another setback to this design. My friends who did their 3D printing the day prior to my slot had informed me that some of their designs had been rejected as they could technically be made via subtractive methods such as sculpting or carving and it just so happens that 1 of my friends had the same idea of making a Pokéball. This meant that I had to either redo my entire design which I had already completed or I could modify the existing design that can only be accomplished via additive methods such as 3D printing. After evaluating my options and looking through the 3D printing slides on blackboard, I decided to put the Pokéball in a box as ball in a box was one of designs that was given as a possible additive design.

How to Model Pokéball in a Box

Step 1: Create a sketch on any plane. I used the front plane for this step.

Step 2: Create a centre point circle with a diameter of 5cm at the origin

Note: Exact dimensions need not be followed but dimensions should be to scale i.e. If you halved the diameter of the circle, all dimensions in subsequent steps should also be halved and vice versa if you doubled etc.

Step 3: Draw a line through the middle of the circle

Note: Line can be as long as you wish, it just needs to be longer than the diameter of the circle

Step 4: Create a centre-point rectangle with a breadth of 0.4cm and any length that is longer than that of the diameter of the circle. I used 10cm for this step

Step 5: Finish the sketch and use the revolve function on either the left or right side of the circle with the centre line created in step 3 being the axis. I used the right side for this step

Step 6: Use the shell function on the 2 flat sides of the semicircle to create a 0.25cm shell

Step 7: Create another sketch on the same plane and create a centre-point circle with a diameter of 4.75cm at the origin

Step 8: Draw a line through the middle of the new circle

Note: Line can be as long as you wish, it just needs to be longer than the diameter of the new circle

Step 9: Finish the sketch and use the revolve function on either the left or right side of the circle with the line created in step 8 being the axis. I used the right side for this step

Note: Make sure the operation is set to "New Body"

Step 10: Show the origin plane and offset the origin plane such that it is located on the front surface of the Pokéball

Step 11: Create another sketch on the same plane and create a centre-point circle with a diameter of 1.5cm at the origin

Step 12: Create a centre-point circle with a diameter of 1cm at the origin

Step 13: Create a centre-point circle with a diameter of 0.75cm at the origin

Step 14: Create a centre-point circle with a diameter of 0.675cm at the origin

Step 15: Extrude the newly created circles by 1mm

Note: Make sure direction is two sides where the 1st side has extent type "Distance" while the 2nd side has extent type "To Object" where the object is the inner sphere and the operation is set to "New body"

Step 16: Colour/decorate the Pokéball to your liking

Step 17: Create a sketch on any plane and create a 6cm x 6cm square

Note: The dimensions of the square has to be 1cm longer than the diameter of your Pokéball

Step 18: Finish the sketch and extrude the square by 6cm so that you get a cube

Note: The extrusion length should be the same as the length used for the square in step 17

Step 19: Create a sketch on any face of the cube and create a 4 cm by 4cm square

Note: The dimensions of the inner square has to be 1cm shorter than the diameter of your

Step 20: Finish the sketch and extrude the inner square by 6cm and repeat steps 19 & 20 for the remaining sides of the cube.

Note: The extrusion length should be the same as the length of the cube and the operation should be set to "Cut"

Step 21: If done correctly, check that you have something that looks like this, if so, proceed to final step, if not, read through the preceding steps again and make changes where necessary

Step 22: Move the Pokéball into the box or vice versa and colour/decorate to your liking

Ultimaker Cura Settings

Once the model in Fusion360 is done, the model can be exported out as an .stl file which can then be imported into Ultimaker Cura where it will be sliced and converted into a format that is readable by the 3D printer. Within the Ultimake Cura Software, there are several settings that can be modified to suit your needs, for my print, I had kept most of the default settings. The settings that I had used are listed below, those in the picture are default while those written in yellow are edited.

Figure 4: Ultimake Cura Settings

By default, the Support option and Adhesion option are turned off. Since my Pokéball in a box design requires the Pokéball to "float" and not be connected to the floor or the box itself, Support is a must to ensure that the Pokéball is its separate entity and is not bound to anything, hence I turned on the Support setting. As for the Adhesion setting, I decided to turn it on as I wanted to make sure that the Pokéball sphere comes out nicely as slight movements can result in a non-perfect sphere. Finally, the Scale has to be decreased as after slicing with my original dimensions, the time required is 10 hours and 25 minutes which is way over the 1 hour limit that is given, hence I had to Scale down the dimensions to 35% such that the print time would be 1 hour and 4 minutes which is acceptable as it is just slightly over the 1 hour limit.

Why Can't This Design be Made Subtractively?

This is because although the original cube design itself has dimensions of 6cm x 6cm x 6cm, the holes in the cube are only 4cm x 4cm large while the Pokéball has a diameter of 5cm, hence it would be physically impossible to have the Pokéball inside the cube as the diameter of the Pokéball is larger than the holes in the cube.

Pokéball in a Box File Preview & Download

3D Print Process Gallery

Figure 4: 3D Print Mid Point

Figure 5: 3D Print Completed

Figure 6: Final Product with Adhesion and Support

Figure 7: Final Product

Reflection

I found this 3D printing assignment to be very fun and interesting and was actually surprised at how easy the 3D printing process actually is. Initially, I thought that 3D printing was a very complex process that would require a detailed SOP similar to that of my other practicals such as the laser cutter practical that I had done a few weeks back. But in reality, after a quick 2 minute rundown of the prerequisite steps, I was already competent and ready to operate the 3D printer. Operating a 3D printer only consists of these 5 simple steps.

1. Import the Gcode of your object into the 3D printer using the SD card provided in the 3D printer
2. Go to the "Prepare" section and preheat the PLA to the desired temperature of your print
3. Stay in the "Prepare" section and Disable the Stepper 
4. Stay in the "Prepare" section and Move the X, Y and Z coordinates of the print to 0, 0 and 25 respectively
5. Exit the "Prepare" section and Click Print while selecting your imported file

The hardest part of this practical and 3D printing in general in my opinion is making the 3D model you want using Fusion360. I feel this way as while I have definitely improved on my CAD skills using Fusion360 as compared to last semester, I still have a ways to go as I still need guidance in order to complete my desired 3D model. However, through this module, I will have the perfect opportunity to test and hone in on my skills as my group has been assigned to make a CO ventilation system and as a group, we have decided to use 3D printing to make the casing for all the components of the system. Since we will be coming up with the design ourselves, there will be no step by step tutorial available and hence we will have the perfect chance to improve on our CAD skills using Fusion360 as we have no other shortcut option.

Overall, I find that 3D printing is one of the most fun practicals that I have done in my poly life so far alongside laser cutting as I also found that to be extremely fun to carry out. Unlike with laser cutting however, the ceiling to what I can do is a lot higher, meaning that there are a myriad of other new possibilities that I can now accomplish with the help of 3D printing. I may also be able to use both these processes to either streamline or create an even better product in the future.