3D Printer Instructions
- 1 Safety
- 2 The Basics
- 3 Print Mats
- 4 Filaments
- 4.1 PLA
- 4.2 PETG
- 4.3 PLA vs. PETG
- 4.4 ASA/ABS
- 4.5 ASA vs. ABS
- 5 How to
- 6 Planning and Tolerancing your Prints
Safety
When using the 3D printers, there are some hazards to watch for. One of the main hazards is high heat. These temperatures could result in serious burns if the equipment is not handled properly. The three main areas that heat up are the tips of the extruders, the printing plate area, and the melted plastic. The extruding tip is the most hazardous area as it heats up to over 200 degrees Celsius. It is vital that you keep your hands and yourself away from the extruder when using the 3D printer. Additionally, the melted filament that comes out of the extruder can pose a hazard if handled before it hardens. Lastly, the printing plate is also heated to 80 degrees Celsius and above. Prolonged exposure to these temperatures can lead to burns. Do not place your hand on the build plate for long periods of time.
Other hazards include the moving motors and gears. These parts could potentially pinch or crush your hands. To avoid injuries, please keep a distance from the 3D printer when it is running.
The Basics
The ETIS Studio contains 3 Original Prusa i3 MK3S+ 3D Printers. Please read through this documentation to familiarize yourself with how these printers function. The Prusa website has more documentation and manuals available: https://help.prusa3d.com/product/mk3s
Controlling the LCD screen is done by a single control element: a rotational knob that you press to confirm the selection. By single-pressing the control button on the information screen, you enter the main menu. The Reset button is placed directly under the control knob. Pressing the reset button equates to quickly toggling the power switch. It is useful when the printer exhibits weird behaviour or you see a failed print that requires immediate cancellation.
Print Mats
There are two different types of 3D printing mats available: smooth (to the left) and rough (to the right).
More information on when to use which print mat can be found here: https://all3dp.com/2/prusa-pei-sheet-textured-powder-coated-steel/#google_vignette
Filaments
PLA
The perfect choice for printing large objects due to low thermal expansion (prints do not warp on the heat bed) and for printing small, detailed models. PLA is great for prototyping purposes.
Advantages
Easy to print
Detailed prints of small models
Trouble-free printing of large objects
Hard, low flexibility
Odorless
Affordable – cheaper than PETG filament
Wide color selection
Disadvantages
Brittle
Not suitable for outdoor use
Low temperature resistance (60 degrees)
Difficult to post process
Specifications
Nozzle Temperature: 215 °C
Bed Temperature 50 – 60 °C
Heated: Make sure the surface is clean
PETG
Best for printing mechanical components, cases, holders, and watertight prints such as pots. Generally stronger than PLA.
Advantages
Higher temperature resistance
Low thermal expansion
Ductility and strength
Easily sanded
Easy to print
Does not absorb water
Glossy surface
Disadvantages
Not suitable for small models
Bridging can occur
Possible stringing
Supports can be difficult to remove
Specifications
Nozzle Temperature: 240 °C
Bed Temperature 80 – 100 °C
Heat Bed: Make sure the surface is clean, isopropyl alcohol may cause the bed adhesion between PETG filament and the heat bed.
PLA vs. PETG
PETG is considered stronger and more resilient than PLA as it is more chemically stable and overall has a higher impact strength than PLA.
PLA requires a lower temperature to melt and therefore makes it more compatible with a wide range of different machines.
PLA is more amenable to hand finishing than PETG.
PLA is more prone to stringing than PETG. This requires tuning in some printer settings.
PLA can be sanded, painted and handled more easily than PETG making it easier to post process.
ASA/ABS
ASA and ABS are both strong and versatile materials for 3D printing. They have a higher melting point than PLA and great heat resistance, resulting in prints not showing any signs of deformation up to around 100 degrees Celsius. Most often used for printing covers, protective cases, prototypes, replacement parts, and toys and figures.
Advantages
Suitable for outdoor use – UV stable – Generally ASA
Very good temperature resistance.
High impact and wear resistance.
Disadvantages
Difficult material to print with
Tendency to warp while printing
Creates worse detail resolution
Produces an unpleasant odor when 3D printing
Specifications
Nozzle Temperature: 245 - 265 °C
Bed Temperature 90 – 110 °C
Heated: Make sure the surface is clean
ASA vs. ABS
ASA – Known for excelling in outdoor durability, providing warping resistance, and UV resistance.
ABS – Known for its strength, post processing ease and strong electrical insulation properties.
How to
Below you will find how-to guides for a variety of tasks related to 3D printing with our printers.
Find designs from online repositories
There are various sites where you are able to download 3D designs that other uses have made. Some commonly used websites include Printables and Thingiverse. This how to guide will walk through the process of finding and downloading models for 3D printing.
Go to Printables.com
Use the search bar to find a specific 3D model you want to print.
Click on the model thumbnail to open its page.
Look for the "Download" button or link.
You may have options to download different file formats (like STL, OBJ, etc.). Choose the one compatible with PrusaSlicer (typically STL). If you are working on a computer with PrusaSlicer installed, you may have the option to open the .3mf file directly in PrusaSlicer.
Save the file to a location on your computer where you can easily find it later.
Tips
Check Model Compatibility: Make sure the model is suitable for your printer's build volume and capabilities.
Read Model Instructions: Some models may have specific instructions regarding supports or orientation.
Modeling your own designs
If you are knowledgeable with 3D modeling software you may bring in your own designs. ETIS computers are equipped with Fusion 360. You are able to create free educational accounts through the Fusion webpage. These accounts may take a few days for student verification, please plan accordingly.
Use PrusaSlicer to Create a Printable File
Open the PrusaSlicer application on your computer.
Navigate to the location where you saved the downloaded or modeled file and select it to import.
Ensure you’ve selected the correct printer profile for your 3D printer.
Configure print settings like layer height, infill, supports, and filament type based on your preferences and the specific model requirements.
Support Settings: The most important thing to keep in mind while modeling for 3D printing is support material. 3D printers can’t print in mid-air, each layer has to be laid on top of the previous layer. When designing, try to avoid creating steep overhangs. If you print an object with a gradient lower than 45°, the resulting overhang would be preventing the object to be printed correctly. PrusaSlicer allows you to print such objects thanks to the ‘Printing with support’ function. In the print settings window supports can be selected and set to zero which lets the printer detect problematic parts automatically and print supports where needed. Make sure to review support material generated in the slicer before printing your part.
Infill Settings: 3D printed models are rarely printed solid (100% infill) or completely hollow. Instead, we use a method that fills the inside of an object with a sparse supporting structure. The typical infill selections for best density is 10-20%. This is the ideal balance between strength, print reliability, print time, and material consumption.
To learn more about infill types and properties click Here.
Slice the Model: Click the “Slice Now” button. This will generate the G-code needed for your 3D printer.
Preview: After slicing, you can preview the model to ensure everything looks correct.
Unloading filaments
Press the switch on the back of the 3D printer to power on the 3D printer.
Press the orange knob on the 3D printer and twist the knob clockwise until you reach the text “unload filament”.
Press the knob to select “unload filament” and select the type of filament (PLA, PETG, ABS Etc.) currently present on the 3D printer. You should be able to identity what filament is loaded by looking for the specification label on the spool of loaded filament.
Wait until the 3D printer has finished unloading the filament present and when prompted pull out the filament immediately.
Make sure that the old filament gets stored correctly and the loose end of the filament gets secured on the side of the spool.
Loading filaments
1.Take the filament that you wish to load and use scissors to cut the tip of the new filament as indicated in the image.
Take the new filament and insert the cut end in the small hole on the nozzle. Ensure that the new filament is taken in by the 3D printer and is extruding the same color as the filament that you are loading. If it is extruding the correct color press the knob on the 3D printer to select Yes, when prompted. If it is not extruding the correct color press No and wait until it is.
Ensure that the filament cannot be pulled out easily once it is finished loading. You should not be able to pull it out with a little bit of force.
Place the rest of the filament roll on the provided T shaped bracket.
Use the isopropyl alcohol spray bottle and cotton pads to thoroughly wipe down the mat of the 3D printer ensure that there is not any previous filament remaining on the 3D printer mat.
Press the knob on the 3D printer and twist the knob until you see “Preheat”
Press the knob to select “Preheat” and select the type of filament you wish to load. (PLA, PETG, ABS, Etc.)
Wait until the 3D printer has finished preheating and you are now ready to 3D print. You have successfully changed filaments on the 3D printer.
Printing from an SD Card
This how to guide will outline how to save a file from PrusaSlicer and open it in the 3D printer, below are step by step guides.
If you’re printing a complex design, consider doing a test print with lower quality settings to ensure everything works properly.
Insert a SD card into the computer.
In PrusaSlicer, after slicing, click the Export G-code button at the bottom right corner.
An export pop up will appear. Name the file, ensure you only change the text before the first underscore. Changing any other text may cause problems.
Click Save.
A small popup will appear at the bottom of the screen. Click the little export button.
Remove the SD card.
Insert the SD card into the 3D printer.
Scroll through the 3D printer menu, find the 'Print from SD' menu.
Scroll through the SD card and select your file.
The printer will begin to calibrate and printing will begin if filament is inserted.
Planning and Tolerancing your Prints
Scaling your print to fit on the print bed
When getting ready to print your part you will need to make sure it fits on the print bed.
The printers have a print bed size of 250 (x axis) x 200 (y axis) mm. Additionally, the working area of the print bed includes 210 mm in the z axis.
If your part is designed to be larger than the print bed size, you will need to scale it down to the proper dimensions if you wish to print it.
What to consider while scaling your part:
the units you are working in (mm, ft., inch, etc.)
how will this part function at a scaled size?
is printing the best method for producing the part or are there more suitable options available?
If you are working in units other than mm, make sure that you convert them to mm after scaling to make sure your part will fit on the print bed! Additionally, ensure that the new size of your part is accurate to the size you want.
Tolerancing
Tolerance is the amount of variation a dimension has from its exact value. When a part is designed using exact dimensions it will likely not fit properly with other parts. When designing a part, you will need to understand how to use tolerancing.
An example of tolerancing is with a hole and shaft.
If we want the shaft to fit within the hole, we will need tolerances. You may choose to either tolerance the shaft or the hole in your design. A tolerance will either make the dimensions of the hole slightly larger so that the shaft can fit, or it could make the dimensions of the shaft slightly smaller so it will fit through the hole.
For example, here we will add a tolerance of +0.3 mm to the hole to ensure that the shaft will fit. This tolerance makes the hole slightly larger. As the hole and shaft originally have the same diameters of 10mm without the tolerance they will not fit together.
Alternatively, we could also make the shaft smaller in diameter by 0.3mm and leave the hole size at 10mm. This is the same as the above example as there is still a 0.3mm tolerance so it does not matter if you choose to add a tolerance to the hole or shaft dimension as you will obtain the same outcome.
Another example of tolerancing is when making screw holes in your design. For example, below is a hole made for a 2.5 mm diameter screw. Here there is a tolerance of 0.2mm as the hole diameter is 2.7mm.
It is important to use tolerancing for any print that is going to fit with other parts or in tight spaces. You can use your own judgement to decide how large to make your tolerance based on how you want your parts to fit together. A tolerance will also depend on how large your components are in general.
You may look up online resources to help you decide how large your tolerances should be, but the Makerspace staff are always happy to help if necessary.
Here are some types of fits below.
Supports and print failure
Supports are necessary to prevent a print from failing. If your part has spots where there will be potential for the print to collapse supports will be required. The supports are just temporary material attached to the part while its printing and can be removed after the print has finished. However, for some parts using supports can create issues as they may be difficult remove, or the part can get damaged during the support removal and therefore the design may need to be adjusted to account for this.
Below is an example of a part printed with supports. The green part of the print represents the support material.
Print thickness
The thickness of a print is also important to consider. For prints with a wall thickness less than 2mm the print is likely to fail. Additionally, when the print has a small thickness is makes it difficult to remove supports without damaging the part. You must ensure that you make the thickness of your part to be larger than 2mm.
Below is an example with a wall thickness that is too thin and was not printed with supports.
As you can see the print failed due to the thin layer of material that was unable to support itself.
Therefore, to have a successful print it is important to consider wall thickness, tolerancing, and print bed size within your designs!
Final notes
It is important to note that the 3D printer may not print properly due to it being moved a lot or damaged. You may need to perform a first layer calibration to check the quality of how the filament is 3D printing.
It is always a good idea to check the specifications on the filament roll to ensure that you have the correct type of filament as they all look and feel similar, and it is hard to differentiate between filament types of the same color.
It is also a good idea to check the setting on the filament rolls so that you preheat the filament to the correct temperature. This can be found on the filament roll itself and is necessary when you are setting up your file on the PrusaSlicer app. This ensures that when the 3D printer is printing the filament prints correctly as the temperature matters.
If you have technical issues, Please submit a request to the ETIS Jira Queue. If you need help after hours or on the weekends, contact IST Service Desk.