3D Printing

WHERE TO GET ASSETS

There are different option to get a printable Model. One way would be to use a modelling software and start building something from scratch. Another option would be to check one of the webpages specified for 3D-Print-Models. It might be, that your problem has been already solved by others. On websites like PRINTABLES.COM or THINGYVERSE.COM you can find thousands of printable 3D Modells, its always worth a visit even if its just for Inspiration.

Assets from the Web

PRINTABLES	THINGYVERSE
The oficial page for printable models launched from PRUSA the Brand of our 3D-Printers. The Database contains more than 500.000 objects for different Areas like “living”, “learning” and even “clothing”.	UltiMakers's Thingiverse is a thriving design community for discovering, making, and sharing 3D printable things. Thingiverse contains more than 2.5 million things, and that number is growing every day.
Get Models Here:
Printables	Thingyverse

Download and File Format
When you have chosen a model, you can observe the single parts by going on Files. Also you gonna find a Download Button for each of the Elements within your preferred Model. The Dataformat of the Parts will be a .stl file format. However, this file format can’t be transfered to the printer. The printers need a format which is called .gcode. To transfer the .stl files into .gcode we use a method called slicing. Therefore we need a tool which is called PRUSA SLICER.

DESIGN & CONSTRUCTION

If you can't find what you're looking for online, you could try to build your own 3D-model. There are various softwares to do this. Here is a short list with possible choices:

Software	Information	Download Link	Tutorials
	TinkerCAD is beginner friendly and free	Download TinkerCAD	TinkerCAD Learning Center
	Fusion360 is more advanced for percise construction and free for students. You can import models from TinkerCAD	Download Fusion360	Tutorial for absolute beginners
	Blender is an open source 3d modeling software and completely free	Download Blender	Blender modeling for beginners
	Maya is an industry standart, similar to Blender and free for students	Download Maya	Maya Tutorial

Exporting your model

When exporting a model from Blender, there are a few steps you need to take to make sure, that the model gets exported right. Here is a step-by-step guide on how to properly export your model from Blender:

Step	Description	Pictures
Step 1	Go to 'Preferences'
Step 2	Enable the 'Mesh: 3D-Print Toolbox' add-on
Step 3	Safe your Preferences
Step 4	Under 'Scene' change the 'Unit System' to Metric, the 'Unit Scale' to 0.001 and the 'Length' to Millimeters. Your model is now being displayed in millimeters
Step 5	In the '3D-Print' Tab, go to 'Clean Up' and select 'Make Manifold'. This makes the model watertight and makes sure, that the model doesn't habe any holes or missing faces
Step 6	Blender offers many modifiers. The ones you need for 3D-printing are Remesh, Decimate and Solidify. You can find tutorials on those modifiers right under this table
Step 7	To actually export your model, go to 'File', 'Export' and select 'Stl'
Step 8	When exporting, make sure that 'Scale' is set to 1 and that 'Apply Modifiers' is checked

Modifiers Tutorials

Blender offers many different modifiers. The three listed down below are the most important ones for 3D-printing.

Modifier	Tutorial
Remesh	Remesh Tutorial
Solidify	Solidify Tutorial
Decimate	Decimate Tutorial

MATERIAL

PLA

1 PLA-Basic
PLA is the most commonly used material, it is biodegradable and easy to print. It is suitable for large objects due to its low thermal expansion. Wet-sanding should be used for post-processing, as the plastic melts locally and is therefore difficult to control. Available in various basic colors.
Advantages	Disadvantages
easy to print high details in small prints hard, low flexibility odorless ( doesnt smell) cheap	brittle low temperature resistance difficult in post-processing not suitable for outdoor-use
When to use
Prototyping Toys Figures & Jewlery (high-details) Architectural models

2 PLA-Thermo
In the Prototyping-Lab we also have thermoactive PLA, a Material which changes its color based on ambient temperature. This special property makes Thermoactive PLA filament perfect for printing objects where temperature changes need to be visually perceived. This material is therefore suitable for: Educational projects Temperature sensors

PET/ PETG

1 PETG
PETG is well suited for printing mechanical components, as it is less brittle and therefore more flexible than PLA. It also has a higher temperature resistance. The material is waterproof and therefore suitable for outdoor use. It is also food-safe.
Advantages	Disadvantages
easy to print & post-proces (grinding) high tempreature-resistance & low thermal-expansion odorless (doesnt smell) water-proof recyclable food-safe	unsuitable for very small prints bridging is difficult high adhesion on the printing-plater
When to use
mechanical components keepers & boxes (cases) waterproof prints (outdoor)

PRINTER

LCD Display

1 Startscreen
The start screen of the LCD-Display contains the most important values about temperatures and Material.
Nozzle temperature (actual / desired temperature) Heatbed temperature (actual / desired temperature) Progress of printing in % - shown only during the printing Status bar (Prusa i3 MK3S ready. / Heating / file_name.gcode, etc.) Z-Axis position Printing speed Remaining time estimation

TUTORIALS

Slicing

First of all you need to install the app PRUSA SLICER on your device.

1 Getting started

1 Align Object
After opening the PRUSA SLICER you can drag and drop your downloaded .stl file in to the working space. The alignment of the 3d model on the stage is very important. The measurements of the printing surface are: 21×21x25×cm. You can't print in air. Floating areas must be supported. Rotate the model in a way so that there are as little floating parts as possible
To rotate the Modell you can either choose the rotation tool or the surface-tool. Both works, but the surface tool is a little easier to use. When you select the surface-tool Prusa Slicer will automatically highlight all plain surffaces. If you click on one of the marked areas, the model is automatically aligned so that this specific area is grounded.

2 Print Settings

On the right side of the window you find a menue containing various settings you have to determine before you can start the slicing process.

1 Print Settings

The first dropdown parameter determines two things: Layer-Height Speed-Property(UPPERCASE) The two Properties will influence two main properties of the Print: The vertical-resolution and the print-time. The layer height determines the vertical resolution! In the 3D-print-process the extruder stacks lines of material on top of each other. The thinner those lines are the better the resolution of the surface. However its recommended to not go less than 0.1mm because the improvement in level of detail is small compared to the increased printing time. Within a specific layer-height sometimes you can choose between the speed-propertys QUALITY and SPEED. This will primarily change the speed of the print head and affect both: resolution and layer-height

2 Filament
Select the material you prefer. In the Prototyping Lab we offer the following materials: PLA - the standart Material Hard, strong, but brittle. Low resistance to heat. PETG Resistance to humidity and chemicals. High transparency & Food safe

3 Printer
Here you need to select the right Printer. In our case its: Original Prusa i3 MK3S & MK3S+ Take care that the right NOZZLE SIZE is selected. The option without nozzle-specification within the name: => 0.4mm nozzle

4 Supports
Floating areas must be supported. It cant be printed in air. To automatically generate supports you can use two options. Support on build plate only. Everywhere Fast approach: supports everywhere Prusa-Slicer automatically calculates the Areas which need to be supported and builds supports. Keep in mind that supports need to be printed, meaning they will increase the print time. Moreover in the post-print-process it will take time to remove the supports. Avoid residue: supports on-build-plate only Keep in mind that supports might not be removable without residue. To not run in this problem you should always use the on-build-plate option if your model allows it.
More Information about custom-supports below

5 Infill
The infill determines how densely your model is filled with material and which structure is used. Inner supports are important for the stability of the model. Without inner fill the top layers would float. The infill influences: Print time Structural strength of the print Filament usage Filling density Most Modells can be print with 10 - 15% infill. If you need the model to be heavier, want more compression resistance or higher stiffness, you can increase the infill. More than 30% infill is super rare (100% infill would force the inner structure to be linear). Mesh-structure There are a lot of different mesh-types for infill. The Gyroid is one of the best infills. Its 3D which results in equal strength in all directions. It can be printed fairly quickly and it has a good strength/weight ratio.
To choose the Gyroid you need to do the following: In the top middle part of the working area choose Printsettings > Infill > Fill pattern.

3 Slicing & Exporting

1 Slice the model
Once you have defined all the print settings from above, you can “slice” the model. On the bottom right you find the slice now button.

2 Preview
After slicing, you automatically land in preview mode. By using the slider on the right side of the plater-view you have the possibility to check every single layer of your model. different areas are highlighted in color the legend on the left specifies the different areas and provides various information like the filament usage for single areas. You can then check whether you still have, for example, any floating parts.

3 Exporting
If you want to further edit the model, you can switch back to 3D editing. click the cube icon at the bottom left to toggle viewport. If the model is fine, you can export the file as g-code. g-code is the format the printer is working on. On the bottom right you find the export button. Take care that your file-name doesnt contain special character (printer cant handle them).
The g-code file now can be moved on an ssd card and put inside the printer.

Custom Supports

The most intuitiv way to add custom supports is the Paint on supports tool from Prusa Slicer. To use the Tool you need to be in either advanced- or expertmode In combination with support setting for support enforcers only, it allows you to paint on supported areas on where you need them to be. In combination with support setting everywhere, or on build-plate only (automatic supports) it allows you to block specific areas which you think dont need to be supported.

1 Basic Functionality
Paint On Supports	Block supports	Remove selection
Paint on Areas which you think should be enforced. holding the left mouse button	Define Areas which should not be enforced. holding the right mouse button. often used in combination with supports everywhere in the print settings, when you only want a specific area to not be supported.	Get rid of areas which already has been painted. holding Shift + left mouse button

2 Support-Placement

Highlight Overhangs: Realtime Visualisation of the overhangs of your model. This can be really helpfull to spot the areas which might need enforcers and support. By using the slider you are able to determine until which degree a specific area counts as overhang. By clicking on "enforce" the highlighted areas will be painted. After enforcing the painted areas are still editable. So you can remove parts which wont need to be supported.

Supports needed	Supports not needed
Bigger areas like the circled ones in the image must be supported.	Very small areas (circled) which are highlighted as overhangs, are propably fine and the printer can handle them without supports.

Bridging

1 Whats Bridging
Horizontally floating Areas (between two enforcers) can actually be printed, at least up to a certain distance. Bridging describes the ability of newer 3D printers to bridge the void between two supports. The floating part does not require any extra supports.
This provides two advantages: time savings material savings
On one hand the printer has to print less support-material (Time/Material). On the other hand the time for post-processing and cleanup is omitted(Time). Bridging works by cooling the extruded plastic directly via the extruder's fans. This requires the first layer of the bridge to be printed with a low material flow and reduced speed. This ensures that this first layer does not sag.

2 Bridge-Test
The Behaviour of the bridging is affected by two parameters. material flow printing speed
Those Paramters vary based on the material is used. It is therefore recommended that you carry out a bridge test to determine the best parameter settings for your printer and the respective material. bridge-test are printable models, which cover different distances by means of bridging. the test is carried out using various pairs of paramters (material flow/speed) to determine which length of distance can be covered without using supports.

3 Bridging Parameters
To be able to set these parameters, you must be in expert mode. This mode can be accessed by clicking on the Expert button on the workspace. The parameter settings can then be called up by right-clicking on the model.

Changing Filament

1 Unload Filament

Press the button on the LCD display to call up the menu. Select unload filament and choose the correct material. When you select remove filament, the printer heats up to the appropriate temperature. When the temperature is reached, the printer emits a beeping sound. After pressing the button on the LCD, the material can be removed. If a filament tube is used you need to remove the tube from the extruder by loosen the screw on top of the extruder.

2 Loading Filament
Autoloading Disabled (Load Manually)	Autoloading Enabled
Press the control knob on the LCD panel to enter the main menu. Choose the ​load-filament ​option in the menu and press the button to confirm. If the nozzle is not preheated, the preheat menu will be automatically shown. Select the filament type and confirm by pressing the control knob. Wait for the nozzle to preheat. Insert the filament into the extruder and confirm loading by pressing the control knob.	Preheat the printer and simply insert the filament into the extruder. The Z-axis will rise in case the current Z coordinate is less than 20mm from the print bed.

3 Insert Filament
take care that the tip of the filament you want to insert is cut nice and pointy. (you can use a side cutter) insert the material into the hole on top of the Extruder. the material will be drawn in automatically. when the extruded filament is visible and has reached the correct color the filament change has been completed successfully.

Start Printing

1 Start Printing

To print a model, the file format must be ".gcode". If you still have an .stl model, take a look at the slicing tutorial. If you got your sliced .gcode file ready: Drag your file onto an SD-card and insert it into the slot on the left of the LCD-display. Ensure that the printer is preheated (nozzle & bed) based on the material you wanna use. LCD-Display > preheat > preferred material Press the knob on the LCD-Display to enter the menu. LCD > Print from SD > your_file.gcode If you have forgotten to preheat, the printer will preheat automatically. The printing process will not start until the temperature has reached the required value. Watch the first printed layers to be sure filament has attached to the bed properly. (first 5 mins)

2 Remove Object
When the printing is finished, let both nozzle and heatbed cool down to room temperature before removing the printed object. When the bed still is hot, objects are very hard to remove. Remove the steel sheet from the printer and bend it slightly. prints should pop off.

ALREADY PRINTED