5. 3D Scanning and printing

Unit description

Task: 3D Scanning and Printing
Group assignment:
* Test the design rules for your 3D printer(s)
* Document your work on the group work page and reflect on your individual page what you learned about characteristics of your printer(s)
Individual assignment:
* Design, document and 3D print an object (small, few cm3, limited by printer time) that could not be easily made subtractively
* 3D scan an object (and optionally print it)

Learning outcomes

• Identify the advantages and limitations of 3D printing

• Apply design methods and production processes to show your understanding of 3D printing.

• Demonstrate how scanning technology can be used to digitize object(s)

Group Assignment

—> Go to Group Assignment

Individual Assignment

Research

I got several good footage shared by Rico during the Asian Review session;

• 3D Printing on the Moon and Beyond for NASA | Project Olympus - Off-world Construction

• Build a Moon 3D Printed Habitat | Designing for life on the Moon

Design, document and 3D print an object

Considering the parts for my Final Project, I selected a ball joint combined arm as an example to experience additive manufacturing. I tried this approach because I thought that fabricating the arm together with the ball joint as a single integrated part would be impossible using subtractive manufacturing, while additive manufacturing makes it achievable without any assembly.

Investigate existing 3D-Printed Ball Joint model

At first, I searched already existing several open source Ball Joint models.

I downloaded this model from Bambu Studio Library.

I downloaded this model made by Fusion from “Printables” site.

I chose the 1st model since it is designed totally additive way and the size of the model is close to what I am considering in my small scaled model.

I downloaded the STL model and opened by Fusion360.
Since the STL is made by Mesh modeling, I changed into MESH Mode.
Pulldown MODIFY menu and select “Convert Mesh” in order to convert a mesh body to a solid body.

What I wanted to refer from this model is the clearance between ball and case.
So I tried to see the cross section at middle by making middle plane of the case.

Pulldown INSPECT menu and select “Section Analysis” in order to see the cross section of the middle plane.

Select middle plane for Section Analysis.

Section Analysis

Created sketch with 3 pointed circle drawing in order to measure the precise diameter of the ball circle and case circle;
Ball circle diameter: 6.99mm Case circle diameter: 7.09mm Clearance: 7.09-6.99= 0.1mm in diameter

This clearance is too small in comparison with the Group Assignment “Clearance test” result which is 0.3mm in diameter.

With our 3D-Printer setting, it is obvious that the ball joint will never be able to move with this clearance 0.1mm.
I decided to design my ball joint with 0.3mm clearance in diameter.

Design Ball joint Parts for small scaled model of my Final Project

I started Ball Joint parts with parametric design.

Start drawing from Ball with sphere and Case with sphere.

Case outer wall diameter was designed.

Extruding for a cylinder drawing.

Drawing ball joint case

Boolean removal for case wall 0.3mm bigger in diameter from the ball.

Draw rod with the length parameter (30mm)

Combine rod and ball in one part.

Mirroring the model at half length to complete the 3D-Printing model.

Export data as STL file for 3D-Printing.

3D-Printing the Ball Joint Parts

Open the STL file by Bambu Studio.

Sliced and got warning telling that the model has floating regions.

Without carefully confirming the all condition of the setting, I made the file with this condition.
This was a mistake!!!
This setting shows that I am printing with “ABS” setting while I use “PLA”.
I don’t know why “ABS” setting ws chosen…

Sliced data transported to A-1 showing that it takes 1h to complete.

I was watching the process at the beginning, and recorded the preparation temperature.
This made us realize the fault that I did later.

The error printing was found…

While I was sharing the temperature it went, Daisuke thought 259C is too hight for PLA and there must be something wrong in my 3DP setting.
Then, I found that I happened to select “ABS” instead of “PLA” in the printing condition setting. I have no idea why “ABS” was selected…

It seems Filament must jammed in the the nozzle. Therefore, we have to remove the jammed filament from the nozzle. ] Thanks to Daisuke got certificate of “Bambu Lab treatment”, he proceeded following process;

First, unload the filament.

Then, cut the switch of 3D-Printer, and open the Nozzle part.

Took off the cover.

Uncover the nozzle.

Took off Nozzle cover.

Use tweezers to remove the jammed filament.

Set the nozzle cover.

Switch on the 3D-Printer, and operate “control” function to heat the nozzle.


Set Nozzle temperature as 50C for loading the filament again.

This is not ideal filament real condition.
So we decided to take off the real and rewind of the surface little bit jammed part.

Carefully set the rewound filament real into holder.

Slice the model again with “PLA” selected condition.

Double check if the “PLA” is selected as the filament.

Check that the operation time 48minutes is be much shorter than before “ABS setting”. It must be because of less heat at the nozzle.

With the correct filament print setting, the 3DP seems printing OK.

Filament is dropping at the top ball joint case area.

Here is the result of printing.

To show how clearance of the Ball Joint works, I placed it upside down.
You can see the Ball joint at the top has degree of freedom as ball joint.
This part was printed as the bottom area in process, while bottom one which was printed at the top area in process has no degree of freedom since outer case of ball is not established due to the filament falling.

Then, I decided to slice in lateral direction as the 3rd try.

The operation time 27minutes was indicated as much quicker than the 2nd try of 48minutes.

Here is the result of 3rd try.

It seems OK this time from the outside, but it does not have joint function.
Lateral direction printing will not achieve good clearance for revolutional direction.

Print vertical direction with full supports.

I used Prusa XL for this printing.
The Ball Joint file was imported to Prusa Slicer.

Middle part of rod infill structure by default Prusa Slicer is different from One by Bambu Studio.

Supports “Everywhere” was selected.

Printing with Supports Everywhere in Prusa XL.

Printed result with Supports Everywhere

By removing the supports, I could confirm that both joints are working!

Just in case, I tried lateral direction printing with PrusaXL as well.

These ball joint case edge part might fall…

Middle part of rod infill structure by default Prusa Slicer is very different from One by Bambu Studio.

Lateral direction print by PrusaXL result

After removing the supports, I confirmed that both Ball Joints don’t work whats so ever…

Note

• For the moment, I recommend to print Ball Joint Parts by setting rod vertical direction.

• Seeing the feeling the result of Ball joint 3DP working well at vertical direction printing but not at lateral printing direction, I had a discussion with my team mate {Daisuke](https://fabacademy.org/2026/labs/kamakura/students/daisuke-hanamido/). He mentioned it is understandable to have this result with this relatively small model requires the preciseness.
  In vertical direction, the ball joint and case are printed continuously in circular motion which might print smooth sphere surface.
  While in lateral direction, the call joint and case are printed with several steps of straight lines causing unevenness on the sphere surface.

I checked the Sliced result layer by layer in depth direction.
Beginning part of Ball at the bottom of lateral printing

It is printed as circle direction not straight line direction separately.

I suppose, this part might cause little bit drop of filament due to not having support.

Middle part of Ball printing path of lateral printing

The path shows continuous circle, not several steps of straight line.

Top part of Ball printing path of lateral printing

I suppose, this part might cause group of filament drop due to it’s path not connecting from the side wall…

Beginning part of Ball at the bottom of vertical printing

I suppose, this part might cause little bit drop of filament due to not having support.

Middle part of vertical printing

This path is not ideal for the rod strength.

Top part of vertical printing

I suppose there must be no filament drop due to it’s coss pilar like printing path.

My supposition for the moment;

• The reason why the ball joint clearance could not properly be made is that in lateral direction printing there are 2 or 3 floating parts causing filament drop in each ball joint. While vertical direction printing has only one floating part which causing filament drop.

• Considering the stiffness of the rod, lateral direction printing is preferable. There might be a possibility to solve the craps of the ceiling by changing the inside structure pattern.

Advice from Instructors;

After explaining what I did this week in the Asian Review session, I was instructed by Saheen Palayi that I have to follow the information of the Filament package indicates as follows.
Better to set the 3D-Printing filament setting with those information, and it will result much better 3D-Printed model.

3D scan an object

For 3D scanning trial, I decided to use my i-Phone with the software called ” Polycam” which I used during my Fabricademy assignment.
I used Photogrammetry mode of this software this time.
It also has LiDAR measurement function, but it is not relevant to 3D scan a small object.

This is the object that I scan with my i-Phone.

As I started “Object Scanning” mode, Polycam shows the following message;
To begin recording, aim the camera at the subject and tap the recording button. First, I tried by fixing i-phone and turning the object with motor, but Polycam never start to capture the picture.

Then, I decided to move camera around the object as Polycam is asking, and fix the object. Polycam started recording automatically as I move the camera.

When I make a sudden motion, it shows following message;
Return to the previous area to resume. or
Click “start over from the beginning” button

Select analysis method from “quick”, “default”, “detail”, “row”.
I chose this time “row”.

Process on going

Polycam analysis result with “row” condition.

In order to export to CAD data, I had three choice for Fusion; “OBJ”, “FBX”, “STL”.
It requires payment of 5000yen($32)/month to export the analyzed data.
Then, I had to accept this condition for this assignment…
I chose STL file for opening the data by Fusion.

Here is the 3D scanning analysis result with “Row” (highest resolution) condition opened by Fusion.

Face of Daibutsu by Row Analysis
This result is OK for the 3D scanned result in terms of statue structure.

I also tried with “Default” analysis condition and got following result.

Face of Daibutsu by Derault Analysis
This is not relevant condition if it comes to the stature structure.

Files

Ball Joint 3D CAD (Fusion)

Ball Joint Prusa Sliced G-Code