Entry 4 (Practical 5)

 In this entry, I will be documenting my experience on the Egg Drop Challenge, fueled mainly by 3D Printing. 

The objective of this challenge is to create a device that can adequately protect a quail egg from a drop of 2m.

For this Challenge, I will be working with my teammate, Jun Hao.

Contents of this entry:

1. Ideation Process
2. Final Design created and Documentation of the Steps
3. How to Convert Fusion360 design to a 3D Printed Design
4. How to use the 3D Printer
5. Final Product and Egg Drop
6. Reflection + Alternative ideas/notable mentions

If only it were that easy ~~

Ideation Phase

After looking at the GrabCAD Community Designs for the Egg Drop Challenge, Jun Hao and I narrowed our scope down to a few options for inspiration. 

1. Egg-Ning

2. Ovoplex v2 

However, upon further consultations with Dr Noel, the designs would not have worked since the structure was weak and would easily break upon contact from even just a low height.

Ultimately, we settled on this design.

Synopsis of the Design

For this design to protect the egg adequately from the fall, there are 2 key considerations to be made.

1. Good fit of the egg within the inner case to reduce unwanted movement (shifting) which may cause the egg to break
2.  Good outer layer support structure to distribute the force from the drop throughout the structure and away from the egg.

Hence, the outer layer support's concept is based on the physics formula for Pressure, P = Force / Area. 

An outer layer with a greater surface area will decrease the pressure exerted on the device due to the drop.

A greater surface area will be in contact with the ground. This causes a lower pressure exerted on the case which protects the egg better.

How the Egg Case was designed in Fusion360 (Documentation)

Before designing, there have to be specifications for how large we want our product to be.

I searched online for the average size of a quail egg and added some additional length for offset allowance. (Since every egg is unique and not the same size)

Looking back, I could have bought the eggs first and measured them to get a better fit.

Diameter of avg egg: 27mm

Length of avg egg: 35mm

Alright, lo and behold...the steps to create Our rendition of the quail egg protector device.

There are 4 parts to this Design. This design was created by Jun Hao on Fusion 360 and later he taught me how to design it as well so that I could learn from his approach.

1. Inner Case (Top and Bottom)
2. Outer Case (Top and Bottom)

Inner Case

This is the Bottom piece of the Inner case.

Next is the Top piece of the inner case.

Now, the steps to replicate this model. 😆😆💻

Bottom

• First things first, select "create sketch", ensuring that the camera angle is panned to  "front-facing". 

(All of the designs from here on out are FRONT FACING. This process guide will not work on top or bottom faces.)

Step 1: Use the "Eclipse" function under the create tab and form a "55mm tall and 35mm wide" ovular shape at an angle of  "90 deg".

Step 2: Use the "Coincident" function in the constraints tab to centre the sketch on the Origin for easy navigation.

Step 3: Use the "Line" function and draw using the x and y axes to cut the shape into four equal pieces.

Step 4: Next, use the same "Line" function to draw a line at the bottom at your own discretion to make a flat surface.

Step 5: Use the "Trim" function under the modify tab to trim out all sections besides the bottom left corner of the sketch.

Step 6: You can go ahead and finish the sketch and use the revolve function under the create tab. Set the profile as the remaining portion of the sketch and the axis as the vertical line drawn in step 5.

•  Use the "Shell" function under the modify tab to make space for the quail egg. Set the inside thickness as "3mm" with the direction set as inside.

Top

• Steps 1 to 4 from the bottom section of the inner shell are repeated for this Top section as well

Step 1: Use the "Trim" function to cut out all but the top right section instead this time

Step 2: Use the "Revolve" function again in the same way as before.

Step 3: Use the same "Shell" function to create a space inside but the thickness is to be "4mm" this time.

Step 4: Next, create another sketch on the front plane and you may hide the bodies to be seen for ease of creation of the sketch.

Step 5: Create the same sketch as in step 6 of the bottom shell. Use the "Offset" function under the modify tab and set the offset position as "-3mm".

Step 6: At your own discretion of height, create a line using the "Line" function between the offset ovular shape and below the x-axis.

Step 7: Create another offset using the "Offset" function, "1mm" deeper within the initial sketch.

Step 8: Ensure that another line is created lying on the x-axis throughout the sketch. Then use the "Trim" function to trim all but the outlying protrusion of the shell case.

Step 9: Use the "Revolve" function on just one of the outer borders, for an angle of "360 deg".

Step 10: Lastly, you can use the "Move" function to turn it around until the tip is touching the Origin for ease of printing.

Alright, now that we are done with the Inner Case, let's move on to the Outer Layer Case.

Outer Layer Case

Here is the Bottom piece.

Next, the Top Piece to put it all together!

Now, I will show you the steps to recreate these 2 parts in a similar fashion.

Bottom

Step 1: Use the "Eclipse" function to create a "58mm tall and 36mm" wide shape at a "90 deg" angle.

Step 2: Create a "centre diameter circle" of a diameter of "58mm" and use the "Offset" function to offset that by "10mm".

Step 3: Create a rectangular shape of "7mm in height" and "68mm in width" having its bottom line lying on the x-axis.

Step 4: Form lines along the y and x axes.

Step 5: Trim out all of the excess portions until it looks like this:

Step 6: Use the "Revolve" function on these three profiles along the y-axis.

Step 7: Use the "Hole" function under the create tab to create a "7mm tall and 64 mm wide" space.

Step 8: Marvel at the finished product 🤯.

Top

Step 1: Create the same sketch as step 5 for the bottom layer, but without the top rectangular shape. Instead, create a "62mm wide and 7mm tall" rectangle that cuts into the sketch's bottom half. Then trim away all of the excesses to get the sketch below.

Step 2: Last but not least use the "Revolve" function again to form the shape.

Step 3: The piece is now complete.

Wow, that was a lot of trimming and revolving 😮‍💨😮‍💨 

With that, the Designing phase using Computer-Aided Design (CAD) is now complete. Next, we move on to converting the file and preparing it for a 3D Print.

3D Printing 🖨

Before we embark on 3D Printing, let's revisit the step process of creating an idea from a CAD Drawing, into a real 3D Printed product.

1. Create a Printable 3D Design in Fusion360 (CAD)
2. Convert the 3D Design into a 3D representable file (STL, 3MF or OBJ), however, for this, we will use the .stl file conversion
3. Slice the 3D Representable file (.stl) into layers using Cura Slicer software
4. Convert the layers into instructions for the 3D Printer (gcode)
5. The 3D Printer creates the 3D object

Before doing all of these, we have to download Ultimaker Cura Slicer software from the web.

Converting the 3D Design into STL format

Fun fact: STL stands for Standard Tessellation Language or Stereolithography; the original form of 3D Printing. 

STL format is hence commonly used for 3D Printing and CADD.

Once the design has been completed in Fusion360, we have to convert it into STL Format that can be transferrable into 3D Printer software.

There are 2 ways to do this, I will show both ways to do it.

Method 1

Note: Method 1 works only when the design consists of only 1 Body component, to the best of my knowledge. Hence, if there are multiple bodies, the "Combine" function can be used.

Here's a link to a video that teaches using the "Combine" function. 

This video actually provides insights into the use of the function and I find that it can also be a rather useful function for organising when there are multiple bodies to manage.

First, launch your Fusion360 application and go into the desired folder with the design.

• Select the "Bodies" tab and on the dropdown menu, select save as mesh for the desired Body to print.

• Next, the prompt options are shown. Ensure you have selected either of the STL formats (Binary or ASCII). Then select "ok".
• Saving the file into your documents will pop out as an option and we can name the document as whatever we want.
• The document will be saved as an STL file and we can open it up with our Cura Slicer software.

Method 2

Method 2 is my preferred method as it is much more convenient and works the same as well in my opinion. (However, there is some loading time)

• On the top left corner, go to "File" and on the dropdown menu, select "Export" and save the type as an STL file.

Slicing the STL file into layers using Cura Slicer software

The Slicer software changes the 3D model into a gcode file for the 3D Printer to read as instructional blueprints to turn the model into reality.

• Open the file after you have installed Cura Slicer software
• There will be many print settings to customise and input before slicing the file

First, add a printer that you will be using. For our Labs, we use Creality Ender-6, Creality Ender-3 and the Ultimaker S3. Next, select the Printer that you will be printing with. 

For this project, I am using the Creality Ender-6.

I found this video to be greatly useful for a beginner using the software.

It goes through the important printing parameters to modify. 

However, the steps are directed toward a user who has his own printer at home. For us DCHE Students, we are co-sharing the printers and should limit to a few hours/print.

Important Printing Parameters to customise.

• Profile (Quality)

Profile determines the print quality and use of filament. 

Staying with the default "Standard quality" is a safe bet.

• Infill

Here, you can customise the Infill Density and Infill Pattern. Both of which are very fun to play around with to achieve either a lighter or denser final product. 

Having a lower infill density and good infill pattern will result in a lower printing time as well which is definitely beneficial.

For Infill Density, a density of 5-15% will be good enough for the device to function as it shouldn't be hard or dense to protect the egg from the drop. Furthermore, having a lower infill density saves on filament use and ultimately time.

For Infill Pattern, based on trial and error, the Triangles or Tri-hexagonal are good options.

Tri-hexagonal infill pattern

• Material

Printing Nozzle Temperature: 200 deg Celcius

Printing Bed Temperature: 70 deg Celcius

• Speed

Print Speed can be set between "70-140mm/s" as a safe measure and for good print quality.

• Support (Important)

Support "Touching Buildplate" should be generated if the structure needs some scaffolding in place based on the type of Design, e.g. there is an Overhang (Red highlights). 

Since the printer cannot print on thin air, support is required.

Finally, when all parameters are set to desired, click "Slice" on the bottom right corner.

Cura slices the model into multiple layers and converts the model into a "gcode file" and shows the estimated time for printing the model.

Converting the layers into instructions for the 3D Printer (gcode)

At the workshop lab, there will be SD cards available with each of the 3D Printers. 

• Take an SD Card and insert the thumb drive together with the SD card into your laptop.

SD Card

Insert SD Card into Thumb drive

• Save the file's gcode into the removable drive

Remember to eject to allow for complete removal of the file from the computer into the thumb drive

Alright, with all the groundwork out of the picture, we are finally able to 3D Print!

3D Printing

Before printing, there is some pre-preparation to do. Remember to come at least an hour to 30mins before you want to print to do the background work. Mainly to preheat and dry the filament to remove moisture from it.

Startup

Remove the desired filament from the dry box. The filament we work with here is polylactic acid (PLA) polymer.

From this dry box, there are many filament colours and sizes to choose from.

Note: Ultimaker S3 uses 2.85mm filament while Creality Ender 3 and 6 use 1.75mm filament.

Hence, for my print, I am using the 1.75mm filament. This is an important step to check.

• Insert the filament roll into the heater box for the printer
• Allow it to heat for 30-60min

• Turn the Printer on using the Power Switch

• Take the filament and pull it out through the hole at the top of the heater box

• Use the pliers and angle it at a 45 deg angle and cut the filament. This allows a smooth entry of the filament into the feeder.

• Unlock the feeder by pressing on the spring latch and pushing the filament in until it enters the feed tube.

• Now you can heat the printer's extruder and hot-bed. We heated them to 200°C and 60°C respectively just for pre-heating purposes.

From here, there are 2 options:

1. Manually push the filament through all the way to the extrusion point. This method is physically taxing and a bit awkward to handle, but it is the faster way of feeding the filament into the printer.
2. Use the printer's feed function to pull the filament through. This method is very slow, but it is very easy to do and also allows for the filament to further dry inside of the heater. 

• Once hot filament comes out of the extruder, the filament is ready and the printer can be used for printing. (Similar fashion to a glue gun, just more complex 🤣🤣🤣)

• Insert the SD Card into the 3D Printer and wait for a short period for the files to load

SD Card Slot

• Select your file in the printer's print menu (it should be the top most one), and start the printing.
• Ensure there is at least 1 member in the room monitoring the 3D Printer for safety for the duration of the print.
• Occasionally look closely at the printer to ensure that filament is still coming out and printing well and at a correct rate.

Post Printing

• Once the printing is finished, the extruder will move to its original position at the back right corner of the bed.
• Take a scraper or pliers to remove the device quickly and carefully. This is because the bed is still hot but cooling down quickly, the easiest time to get the device off is while it is still hot.

A video of me using the scraper slice to remove my print from the Ender 3 before realising I can just remove the metal hotplate attachment and bend the metal sheet to remove my print 🤦🏻‍♀️🤦🏻‍♀️

• Once removed, conduct post-printing processing. This means the removal of supports and even filing or sanding to have a good finish of the product.
• In my team's case, we did filing to allow for the "Snap Fit" design of the egg case to work

Printer Shutdown

Whenever we had used the printers, we had never been the last to use them, hence, we do not have images of us shutting down the printer as we had always left it for others to use. 

Nevertheless, here is the shutdown procedure.

1. First, heat the extruder to 200°C. Then manually pull out the filament inside of the tube. Wind up the pulled filament around the wheel and lock the end. Place the filament back into the dry box.
2. Finally, turn off the printer and the heater, then shut off the power to them both
3. Ensure that there is no debris inside and around the printer and perform the cleanup in the room.

Egg Drop

By far, the most exciting part of this journey, the long-awaited egg drop...Will the device hold its own against the concrete drop or will it break together with the egg?

Well, unfortunately from the video, the egg did not survive the drop :( 😵😵😶

Nonetheless, there is much to learn from this egg drop journey. From the start all the way to the end. 

We can only learn when things go wrong.

Hero Shot of me with the device

Reflection

For me by far, the hardest part of the 3D Printing process is the Designing phase. Once you can get the design down, the rest are all a piece of cake. 🎂🎂

It was a struggle for me to be sitting on Fusion360 many late nights, grinding away and learning this new skill to try to turn my design on paper into a CADD. The process truly takes hours to master, even at a beginner level. This was especially tough to balance together with other school assignments, hence taught me the importance of starting a project early and ahead of time.

This was my first time using a 3D Printer and I had always dreamt of using one however felt that it was too complicated for me to understand. 

Coming into this course I never would have imagined I would learn how to use it and that the process would actually be manageable. This is something I am surprised with and I feel that we as humans are able to learn and do anything as long as we put our mind to it.

Another thing to note about learning is to always start small and slowly increase your skill level. This is something Dr Noel always preaches, "Don't climb Mt Kinabalu when you haven't even climbed Bukit Timah Hill." Then, learning won't be difficult, but a journey.

Here are a few notable mentions of designs that I had created and would have liked for them to be used in this challenge.

Ideation Sketches

Another way I feel that could have shifted the dynamics of the project was to try a different approach to the design, where the device sacrifices itself to save the egg, the reason being that the polymer used, PLA is actually rather brittle. Hence, it should break first and let the egg land safely.

I mentioned this in the project's report and here is the idea.

Lastly, I finally understand the importance of Independence, a value that has been reemphasised for me to internalise and understand. 

In the working world, seniors will not take to be kind and spoon-feed everything to me, there will be instances where I need to do and find things by myself.

However, lecturers and staff are more than willing to help and teach me if I need help.

Jun Hao and I with our finished product

That will be all for my Egg Drop Challenge Journey, stay tuned for more.