3D Printing

3D Print: Cat Figurine

The task assigned was to design in Fusion360 and 3D print an object that could not be easily made subtractively. There was a limit of a maximum of 1 hour in printing so the object had to be very small and so I decided to design a cat figurine because it was cute. The process to design the cat figurine in Fusion360, settings on Cura and how to set up the 3D Printer to print my object will be explained below. I watched a couple of videos to guide me on how to design a cat and import a picture onto Fusion360 on Youtube. 

Guided video resources:

1) How to import picture in Fusion360 - Peppa Pig Example

2) Sketching and creating bodies for the cat

1. Designing Cat Figurine in Fusion360

Step 1: Insert > Canvas > Insert from my computer and select the picture of cat

Step 2: Select face in BLUE, Canvas Opacity set to 64 and TICK Display Through > OK

Step 3: Create Form under Create tab > Select arrow on create tab > Quadball > Cancel

Step 4: Select Canvases on left side with the eye icons > Click on image file under Canvases > Right click on image > Calibrate > Take the highest and lowest point = 55 mm

Step 5: Quadball > Select face in white (pointed by red arrow) > Select middle of face

DESIGNING CAT'S FACE:

Step 6: Pull BLUE arrow (make sure the quadball touches the top and bottom of cat’s face) > Symmetry select mirror > Check Length Symmetry > OK > Click Select at the top > Drag mouse to the whole of quadball to form a selection (in YELLOW BOX), make sure all faces are selected > Press M to move

Step 7: Move object is bodies > Adjust blue ball to move at centre of cat’s face > OK

Step 8: Select any one face of the quadball and right click > Edit form > Pull the faces or edges needed to fit the cat’s faces (outside faces)

Note: Steps 6-8 requires a lot of adjustments; you may need to move the quadball after editing the form to fit the face of the cat. After the quadball fits the cat’s face, select OK on edit form.

Step 9: Adjust the BLUE edge on the right to make the line be in the centre of the cat’s eyes

Step 10: The final quadball should look like this 

Step 11: Go to the top view > Select a face from the top > Right click > Subdivide

Step 12: Select 4 faces from the top view and double check to see the faces selected is the ear using the front view

Step 13: Right click > Delete

Step 14: Adjust the lengths of the rectangle (hole sides) to fit the cat's ear 

Step 15: From the front view, double click a line from the rectangle to select the whole shape shown in BLUE > Right click edit form > Hold ALT to make a “block” then release and pull up while toggle in or out to mould the ear

Step 16: After moulding, move the ear to the left. Continue to hold ALT then release and pull up while moulding (Pull up > Move > Mould) until the ear look like the one in the picture 

Step 17: From top view, double click hole > Modify at the top > Fill hole > Fill hole mode is fill star > OK

Step 18: Right click > Edit form > Adjust the edges or faces or points by changing its angle, pulling in or out to form the inside ear. 

Note: make sure the lines are not intersecting each other 

Step 19: Create an indent on the ear by clicking 4 faces as shown in picture > Hold ALT key, pull left then release and toggle in > Edit the faces in the ear accordingly until you are satisfied with your cat's ear > OK 

DESIGNING CAT'S BODY:

Step 20: Create quadball > Front plane view > Check height summary > Press M to move and move body quadball to face  

Step 21: Adjust points or edges or faces to fit cat's body using edit form > OK 

Step 22: Stretch out 4 corners (point/edges/faces) of the lower body to form the arms and legs by using edit form > To make the hand, select the top face and right click and delete > Double click on edge > hold alt to make a “block” then release ALT key and pull up and move and mould until it fits the hand of the cat’s hands picture while toggling in and out to mould hand > Repeat > Modify > Fill hole > Fill hole mode is fill star > Repeat steps for the other arm and both legs > Finish form

Step 23: Making the tail: Create sketch > Draw the tail using line and 3-tangent arc to connect both lines > Finish sketch > Press M for Move > Move the arc near the cat's body to be touching the body

Step 24: Press E for extrude > Direction is symmetric > Operation is join > OK 

Step 25: Draw eye of cat using splint lines and 3-point arc by creating sketch and do the same for the other eye > Finish sketch 

Step 26: Press E for extrude > Extrude outer liner of eye and eye ball of both eyes > Direction is single distance > Operation is new body 

Step 27: Draw the nose using lines and use constraint, equal, to equalize the length of 2 whiskers. Press M to move the nose in between the eyes > Finish sketch

Step 28: Press E to extrude out nose > Direction is single distance > Operation is new body 

Step 29: Hold shift and press the edges of the nose and whiskers > Press F to fillet the whole nose and whiskers 

Step 30: Change the appearance of the cat to your preferences by right clicking > Appearances > Drag the colour/material to the body of the cat 

2. Cura Settings

After designing on fusion360, we can save it as an .STL file and open it in ultimaker cura for 3D printing to save as a .gcode file for the 3D printer machine. The 3D printer used is Creality Ender 3. The cura settings I used to ensure my design is within 1 hour are:

Time taken - 37 minutes

Layer Height - 0.2mm

Wall Thickness - 0.6mm

Infill Density and Pattern - 15%, Cubic

Print Speed - 90mm/s

Build Plate Adhesion Type - Raft

Bed Adhesion was needed as the cat's legs were not fully in contact with the bed's plate and it was to also ensure that the design can be printed smoothly without any movements. 

In addition, I scaled up the size of my cat uniformly to 25mm on the X axis as I have built it too small at 13.6445mm on the X axis which is the measurement of my design in fusion360.

Picture of the settings in Cura:

STL File: 3D_Printing_Cat_Figurine_Katrina_2B01

3. Setting up the 3D Printer

Steps to set up the 3D Printer are explained accordingly:

1. Use the knob to select by turning it and then pushing the knob to select

2. Preheat PLA > enter (note: check at the bottom of the display screen on the left side which indicates the nozzle hot end temperature and 200℃ is the set point, the right side is the bed end)

3. Angle cut the filament to about 45° 

4. Turn the box of the filament so that filament can be used

5. Select move > move Z > turn knob clockwise to 25mm (the bar will rise in the 3d printer machine)

6. Disable stepper

7. Use a brush to sweep filament leftovers on the printing bed

8. Insert the filament into the hole of the 3D printer machine located behind at the screw shedding when hot end is at 200℃ by pressing lever to insert filament so two gear will open and then insert into hole (aligned) > push the filament in while pressing the lever > check if filament is inserted from the bottom > use a cutter to cut the excess filament at the bottom

9. Transfer .gcode file in laptop to micro sd card and then insert it into the 3D printer with the gold facing on top > Print

Time-lapse of 3D printing process: 

Hero Shot with printed object: 

Picture of 3D Printed object:

Why it could not be easily made subtractively: 

The cat figurine meets the criteria of not being easily made subtractively because the shape of the cat's face and body are made up of a quadball which would be difficult to be trimmed from a bigger piece of material. This cat figurine can be done through additive manufacturing, or 3D printing, as the cat figurine is made by depositing the material in layers to give the cat figurine's shape, in this case, a quadball. Additionally, the cat's ear and its waist have a dent which is difficult to be made subtractively like laser cutting. Hence, this product meets the criteria of not being easily made subtractively.

Reflection:

This activity was exciting to me because it was my first time 3D printing and a new technology that I would be introduced as I didn't know how to use the 3D printer. I chose a cat figurine to design as I thought that it would be cute and it fits the criteria. Even though the steps to design the cat were long, I had fun designing it on Fusion360 as I got to learn new features such as importing a picture and creating a quadball and splint lines for the cat's eyes with the help from the guided Youtube video resources. Moreover, I learned new shortcuts such as holding the SHIFT or CTRL key on Fusion360 when you want to select more than 1 faces/edges/points and holding the ALT key to form the cat's ear to extend a new "block". If the ALT key was not pressed, the dent of the ear and the ear shape could not be formed.

Initially, I thought the process of setting up a 3D printer would take a lot longer but it was a lot faster than I expected. I enjoyed the process of 3D printing and doing it first hand made me understand how to use the 3D printer better and its limitations. I also understood and resolved the errors in my product designed in Fusion360 as it could not be easily seen in Cura when I used the slicer. The error I made was that initially I didn't include a bed adhesion as I thought the foot was flat on the bed plate of the printer. This error caused my cat figurine to move and thus, made it hard for the whole figurine to be 3D printed as the legs were not stable. I resolved this problem by adding a bed adhesion to ensure the cat figurine was stable to the ground. I did not remove the bed adhesion as the cat could not stand on ground with as one of the legs was not flat to the ground. To improve my product better, I would need to make the cat's legs be flat on ground by redesigning its legs on Fusion360 and ensuring both legs are wide enough to support the whole weight of the cat's body. With the legs wider and flat to the ground, the bed adhesion could be removed. Furthermore, the nose and the whiskers could not be seen on the 3D printed product, this would need to be improved on the design in Fusion360 by extruding out the nose and whiskers so it would be visible on the 3D printed object. The result of the error can be seen in the picture and video below: 

Despite the errors and mistakes made, I think it was a success as I was satisfied with my product and the major errors were resolved even though the minor details could not be seen properly. Moreover, it was a fruitful experience to learn how to set up the 3d printer in which I hope to bring forward in the subsequent weeks when my group and I will be using the 3D printer to design our chemical product and for our final year project. I also learnt how to navigate through Cura and adjust the settings to fit accordingly to my product needs and ensure that it meets the criteria of being printed within an hour. With all the new lessons I have learnt here, I hope to bring it forward to my future projects so I can become more competent with 3D printing and designing on Fusion360. Additionally, with the mistakes I have made such as making the legs flat to the ground, I would need to practice more on Fusion360 so that I would not repeat the same mistake.

References:

1. Gbtcdn.com. (2021). [online] Available at: https://gloimg.gbtcdn.com/soa/gb/pdm-product-pic/Electronic/2021/06/11/source-img/20210611153609_60c31269b358b.jpg [Accessed 22 Dec. 2021].

2. Staff, C.M. (n.d.). Additive Manufacturing vs Subtractive Manufacturing. [online] www.creativemechanisms.com. Available at: https://www.creativemechanisms.com/blog/additive-manufacturing-vs-subtractive-manufacturing. [Accessed 29 Dec. 2021].

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