Skip to content

5. 3D Scanning and Printing

view Checklists *Checklist: personal*
- [x] DeepL check spelling, grammar
- [ ] GPTcheck for better markdown
- [ ] Test external Links

*Checklist: Nueval:*
- [x] Linked to the group assignment page
- [x] Explained what you learned from testing the 3D printers
- [x] Documented how you designed and 3D printed your object and explained why it could not be easily made subtractively
- [x] Documented how you scanned an object
- [x] Included your original design files for 3D printing
- [x] Included your hero shots

Group Assignment:

20.02.25
Link to Group Assignment - 05. 3D Scanning and Printing

This is the test file we printed: Print test (Thingiverse)

For this week's group assignment, Benedikt already printed a common printer test on our Prusa MK4 and Prusa XL printers in two different materials, PETG and PLA.
Jakob and Richard (that's me) then decided to select a few dimensions of the test object.
The measured dimensions are shown in the picture below.

group_printertest_measurements

We used digital calipers to take the measurements.
The measurements we took are not scientific in any way, but they are accurate enough to give us a good estimate of our dimensional accuracy.
I've created a small deviation table to be able to estimate the deviations from the original.
These are the results we got.

group_deviation_table

If you compare the deviation between the two printers, there aren't that many differences.
They are very close in the reproduction of 3D geometries.
The main difference could be seen between PLA and PETG, PETG produces less accurate prints and a more inconsistent surface than PLA, at least with the original Prusa filaments and their factory provided presets.

No matter what material or printer you choose for round diameters, it is recommended that you add approximately 0.15 or 0.2 mm to all diameters for accurate reproduction.

Individual Assignment:

3D Printing:

25.02.2025

After being back from my exams, a cold, and a short break, I first made an overview of the missing tasks.
I missed a lot and I have to catch up with all the other missing assignments.
But first, it was Tuesday again, the day I worked on most of my projects so far.
I decided to print the files I created in 02. Week (CAD Week) to see if my idea to improve the mounting system actually works or not.

Let's print some parts quickly - or so I thought.

error

I got a corrupted USB stick that crashed the Prusa MK4s printer with a "watchdog reset" error.
After some quick research, I found out that a corrupted USB stick could be the source of the problem.
After a quick reset with the reset button, everything was back to normal.

During this week's group assignment, I found that the shape reproduction and accuracy of PLA was superior to the precision of PETG, which I had previously used for most of my other prints.
For the improved mount, I used the following print settings:

print_mount_printsettings

For the Luedo lamp itself, I split the body in two halves to

  • reduce material loss in the support structure
  • improve the surface quality (without support contact points)
  • add sand to the filling structure

After splitting the body in two, I created an alignment lip using the sweep feature of Shapr3D (my favorite 3D modeling software).

cad_lip

26.02.2025

To create a part that could not be produced subtractively, I decided to stop my print halfway and fill some of it with sand.
Why do this? When a mockup is used to determine haptic usability aspects of a final prototype, it is useful to have an accurate weight representation of the part.
For this week's assignment, I will just do a test run of the process to see if it works for me or not.
- Spoiler: it was a big failure. But more on that later.

I started by using a scale to determine the amount of sand I needed and measured the exact amount needed (100g total weight).

(My reference for this was an existing bike light.)

weight_goal
sand_weight

Once everything was weighed correctly, I found that filling the infill was a slow and incredibly tedious process.

sand_weight

I then made sure that none of the sand touched the top layer to avoid contact with the printer's nozzle.
I imagined that the printer's acceleration and fan airflow might be a problem, so I decided to slow down the printing and rotate the fan.
And this was the result:

sand_chaos
sand_chaos_02

Loose sand near precision machinery is just not a good idea.
Due to the harsh acceleration changes of the printer, all the sand was spread all over the printer, and when I say all over the printer, I mean all over the printer.
The particles got into the linear rods and stepper motors.
(The printer is still working, I removed everything in a tedious cleaning process).

After removing all the visible sand with a vacuum, I successfully completed the print (with a small rock in the infill - so that part couldn't be subtracted).

print_stone

the finished print

Files

Here are the .stl files for the Mount.stl and Mockup.stl

3D Scanning:

25.02.2025

For the scanning process, I decided to scan a simple matte object with our Creality 3D scanner.
I chose a rubber eraser from my pencil case.
The software was already set up and configured by my team members.
I took the 3D-printed reflector markers, arranged them in a circle around the eraser, and did my first scan.

scan_rubber

The first scan was bad because the scanner couldn't find the reflectors, and sometimes I was too close or too far away from the object.

scan_first_try

The second scan turned out great, and I was pleased with how quickly I was able to create a simple scan.

scan_final
scan_final_cleanup

After exporting the files, I used my computer's built-in file viewer to check the files. The scan is not perfect but probably good enough to get some basic dimensions and angles of the model.

I expected the process to be much more difficult, but the software was intuitive and quite easy to use.

Files

I have exported the scans as .asc and .ply documents. They are hosted externally due to space limitations.