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Week X: Title

Table of Contents

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[[[summary 2 to 3 sentences]]]

This Week’s Tasks

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 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)

Introduction to 3D Printing & Scanning

In this week’s Lecture, Neil talked about 3D Printing and Scanning. We covered different printing techniques, materials, design rules for designing objects for 3D printing as well as more or less affordable options for scanning objects.

Ferdi added to the lecture by discussing early 3D printing projects, such as Popfab (portable printers that fit in a suitcase). He also hinted us at useful software like Codethread for generating G-code to print structures that you could hardly model in CAD and he talked briefly about the concept of topology optimization (TopOpt) for creating lightweight structures.

Types of Printers

There are the following types of 3D printing:
- fdm (fused deposition molding): stratusses was one of the market leaders together with 3d systems. there fdm name comes from
- fff (fused filament fabrication): open source version of it
  - pla, plant-based. more detailed. porous
  - petg, oil-based, recyclable, more robust
  - filament types
- sls (selective laser sintering)
  - you have powder and you laser the powder until it melts
- sla (selective laser …) same thing but using a projector
- stereolithography
- printing clay with metal and then remove clay in oven

Selected Issues with 3D Printing

look at the following points (from above article plus from fa website):
- over-extrusion
  - printer spits out too much of plastic resulting in visible horizontal lines and overall bad quality
  - ungleichmäßige schichten
  - not a problem here
- pid autotune & temperature settings. visible z lines -> incorrect bed pid tuning
  - ???
  - - symptom: gleichmäßig glänzend. wenn nicht: temperatur ändert sich. hier auch nicht der falln
- stringing
  - too much presure in extruder and melted plastic leaks. retraction, temperatiure, travel speed
  - not a problem for our prints
  - foto
  - mk4s petg
  - kömmer aber so lassen
- belt tension
  - spannung vom riemen. wie stark der gespannt ist.
  - wenn zu locker wirds ungenau. ist aber selten ein problem. sagt ferdi
andere parameter die man beachten muss:
- steps per millimeter kalibrieren: zylinder drucken und schauen ob das ganze rund ist
  - ferdi sagt: passt
- minimal layer time: wenn layer länger als sekunde braucht dann warte noch n bisschen
- layerhöhe vom ersten layer
- retraction length, retraction speed (um stringing zu vermeiden)
- randomize line where you lift the layer

How To Print

screenshot of benchmark

https://www.thingiverse.com/thing:2656594/files
by majda107, CC BY license
use the thing from 2018-02-25
open stl file in prusa slicer
init config:
- fff (fused filament fabrication or similar):
  - there is a thermoplast filament
  - that is made hot and extruded
- alternatively fdm (filament … …) name is proprietary
- sla (check …):
  - resin printer
only load prusa fff
only
choosing expert mode
filament presets can be added using settings gear
useful to note with prusa slicer
- always first choose printer and then adjust print settings and filament [image]
- reason: if you change printer you overwrite settings above
for xl two possible profiles:
- input shaper
  - see article
  - does a frequency test
- normal
disable whip e tower
- whipe tower is useful if you print with multiple materials and only one nozzle to remove the “trash” filament from the nozzle
- not the case here
different support options
- none
- support on build plate only
  - only support that stems on plate. i.e. holes above ground are not supported
- everywhere
- different support options:
  - snug
  - organic
  - grid
- infills
  - depends on how the thing is stressed in the end
  - cubic is fast and 3d stressable
  - gyroid similarly
  - ferdi recommends adaptive cubic. dont know what this is but i will watch this
    - https://www.youtube.com/watch?v=nV3GbN6hLjg
    - after printing benchmark.
    - for now cubic
- brim
  - helpful if you think you will have a momentum of the nozzle that might remove the thing from the bed
- draft
  - support under everything. like brim but everywhere
- warping is a problem when large contact area.
  - you can do brims at the corners
  - or print it in other directions
load object
- right click menu: nice if you want to set multiple number of instances
insert image for options
0.2mm is a good standard layer height
the thinner the layer the smoother the surface, the more instable
choose prusament pla filament
slice
export gcode
todos
- benchmarks drucken pro drucker
  - einmal für prusa xl
  - einmal prusa mk4s
- 2 modelle je drucker: einmal petg und einmal pla
- we also have tpu but we decided not to do benchmarks with it for time reasons as it is not a material that is critical.
welche druckparams?
- wir nehmen die einstellungen die für das entsprechende filament empfohlen sind.
- siehe prusa

TODO: benedikts bilder vom druck

Design Rules

every benchmark printed for two printers a two filaments:
printers
- mk4s
- xl
filaments
- pla
- petg

General Benchmark

https://www.thingiverse.com/thing:2656594/files
guide for this model: https://3dnation504795197.wordpress.com/guide/
guide for this model: https://3dnation504795197.wordpress.com/guide/
detail pictures
richard and i measured:
take dimension names from richards picture

Layer Height: 0.2mm All dimensions in mm ,,,,,,,,,,,,

Value (see photo)	target value	Prusa XL PLA	delta abs	delta percent	Prusa XL PETG	delta	delta percent	Prusa MK4S PLA	delta	delta percent	Prusa MK4S PETG	delta	delta percent
x1	100.00	99.87	0.13	0.13	99.83	0.17	0.17	100.13	0.13	0.13	99.72	0.28	0.28
x2	30.00	30.03	0.03	0.10	30.17	0.17	0.57	30.06	0.06	0.20	30.06	0.06	0.20
x3	10.00	10.04	0.04	0.40	10.16	0.16	1.60	10.04	0.04	0.40	10.04	0.04	0.40
x4	14.00	14.01	0.01	0.07	14.00	0.00	0.00	14.01	0.01	0.07	14.02	0.02	0.14
y1	100.00	99.91	0.09	0.09	99.82	0.18	0.18	100.25	0.25	0.25	99.77	0.23	0.23
y2	30.00	30.00	0.00	0.00	30.11	0.11	0.37	30.04	0.04	0.13	30.04	0.04	0.13
y3	10.00	10.03	0.03	0.30	10.12	0.12	1.20	10.16	0.16	1.60	10.14	0.14	1.40
y4	4.00	4.03	0.03	0.75	4.03	0.03	0.75	4.03	0.03	0.75	4.04	0.04	1.00
y5	2.00	2.00	0.00	0.00	2.03	0.03	1.50	2.00	0.00	0.00	2.02	0.02	1.00
di	8.00	7.83	0.17	2.13	7.61	0.39	4.88	7.81	0.19	2.38	7.78	0.22	2.75
do	10.00	9.85	0.15	1.50	9.83	0.17	1.70	9.86	0.14	1.40	9.81	0.19	1.90

now, deriving design rules
from general benchmark: discussing values & answering following questions (richard)
- real outer diameter given, how to dimension in design?
- real outer diameter given, how to dimension when designing?
- real length in x/y given, how to dimension?
questions to answer we do not need to be that precise for
- how steep is the steepest angle to be printed without support?
  - neil recommended 30deg.
  - following our prints it is 50deg (if you want to be precise)
  - and 60deg if you have some tolerance
  - starting from 70deg it clearly gets odd
- how long can bridges be without support?
  - we tried it up to 25mm and did not have any problems
- How does the surface finish look at which angle?
  - see picture
- warping
  - TODO: how to deal with this?

Overhang, Wall-Thickness, Clearance

printing
- print all three parts
- add organic support for easier removal of the clearance part
- remove support only from overhang and wall part.
- did not work for the group, so reimported and did everything again
- import part by part
- prusa xl: input shaper 0.4 nozzle, 0.2 structural modified. prussament pla, petg
- prusa mk4s: input shaper 0.4 nozzle, 0.2 structural modified. prusament pla, petg
- duplicate but without petg clearance bc we already printed that
deriving design rules
- what is the thinnest wall i can print?
  - TODO: measure. it is dependent on the print, on the machine, on filament
- how much overhang can i print without support?
  - nothing really, all overhangs with 90deg angle dont look good
- how much tolerance / clearance must be considered for joints?
  - TODO
TODO: print clearance test for one printers PETG, namely the one we do not have a clearance test for. we have clearance benchmarks for
- xl and mk4s pla
- an unknown printer: petg (the black print) (ask bene where this print came from to know what printer has to be benchmarked.)
TODO: make pictures of the clearance test and discuss it

Designing & Printing an Object

https://www.instructables.com/3D-Printed-Record/
codethread: library that generates gcode from tiago
https://www.youtube.com/watch?v=PUvCP1_2Gww

Galvanizing

kupfersulfat
lösung a (kupfersulfat)
lösung b
lösung c: natronlauge und formaldehyt

heizplatte

zu galvanisierendes mittel
monodestilliertes (einmal destilliert) wasser
wasser einfüllen
heizplatte drunter (mit magnetrührer)
thermometer (sensor) oben rein
50grad erhitzen
zutaten nach rezept in der reihenfolge hinzufügen.
todo: translate recipe

vorbehandlung von platte

hso entfetter
natronlauge und dinatriumetasylikat plus something like fit
- entfetten
dadurch bilden sich sehr kleineoxidschichten. diese wollen wir abspülen
spülen (mit wasser)
stück in lösung getan
wie dick soll schicht werden?
3 bis 8 μm pro stunde
bad ist auf langsam getrimmt. warum? weil bad ist dafür da um eselektive beschichtung zu machen. heißt man will einen teil beschichten und anderen nicht.
3d leiterplatten kann man damit auch basteln. kann man spritzgießen und dann in galvanik beschichten
3d kunststoff: kupferpartikel in kunststoff. mit nem laser freilegen und galvanisieren.
- 3d mid
prozess funktioniert nur weil ein bisschen kupfer auf der oberfläche drauf ist. das kupfer wirkt als katalysator.

wenn ich jetzt ein blatt galvanisieren möchte, dann muss ich es vorher in eine lösung tauchen damit sich eine metallschicht drauflegt.

folgende wären möglich:
- palladium, silber etc. frage ist nur wie man es auf die oberfläche bekommt
wir nehmen palladium weil das ein sehr guter katalysator ist. ist ein sehr guter katalysator weil der mit zinnpartikeln gut an der oberfläche festhaftet
irgendein palladiumteil
siehe praktikumsanleitung
kann ich alles beschichten was ich will
wenn ichs selber machen will: mit chemieprof reden

kollegen entwickeln pasten zum drucken auf silberbasis

Scanning

scan my hand (?)
introduce
- structured light scanning
- scanning with milk
- photogrammetry
- nerf

TODO

Embedded

datasheet reading
todo: check again what neil says for which ARM family is good when

Final Project

write down what is now in your journal
implement sound on esp

printing & scanning

print on fabric
scanning with milk
photogrammetry
model with topopt
do nerf
check powerpoint from sabine as resource!
- do not use for docu unless ask sabine
check recording for fpga vs microcontroller
check neils notes on applications for different microcontrollers at begin of class
write script that write stl files
learn design rules
dont too large, limited by time
ideas
- check nervous system
group assignment
- find out design rules
topopt
codethread: library that generates gcode from tiago
vinyl

analyze test print

question is what are the design rules. at least 20.

easiest: - mode cube, print it. inside the cube is a rubberduck - then you scan it - your done

non-subtractive:

in place printed joints
cavitated. something inside something
strings, fine structures. grids etc.

if you want to dive deeper

Reflections

What I Learned

when printing two separate things on the same bed with multiple filament types: also assign them to separate beds in the slicer. reason: prusa xl switches print head every (few?) layers. that costs time. rather it should print one thing to the end and then switch the filament once.

What Went Wrong

What Went Well

What I Would Do Differently

Digitial Files

Use of Language Models

During writing this report, I used the following prompts asking ChatGPT 4o mini to …