Week 8 - 3D printing and scanning¶
What is 3D printing?¶
3D printing or as it called additive manufacturing is the process of transforming a 3D design from a digital file to a 3D object. Unlike CNC machines such as milling, lathe, and laser which are subtractive manufacturing processes, 3D printing is an additive process. In this kind of process, the objects are created by lying down layer upon layer of certain material until the object gets created.
How does 3D printing it work?¶
3D printing is accomplished through a 3D printer, where the printer takes a certain material ( the filament) and adds it in successive layers in accordance with the wanted design.
filament¶
There are different types of filament/materials that can be used in a 3D printer. Here as some:
As always, each type offer different properties and characteristics to suit different type of objects. However, PLA is known to be the most famous and used type of filament. Here a comparison between different types of filament depending on their properties:
3D printer¶
As mentioned above, there are different types of 3D printers some are large enough to build houses and some use resin to as a material. However, or focus here on the 3D printers that use filament as a material.
Those printer basically heat the filament to certain temperature until it reaches a state where it can be extruded through narrow nozzle.
Design¶
The printers accept design in STL form only. You can create the design in any 3D design software such as FFusion 360, SolidWorks, Tinkercad, or you can download these files from online sources such as thingiverse or any online source.
However, the design itself cannot be printed directly, there are few setting that need to be adjusted or set before starting.
Support¶
If your design contains overhanging angles more then 45 degree, it can not be printed without support.
Any overhanging that is above 45 degree require support. The same goes for roofs, let’s say you are creating a structure that is similar to a room where you have 4 walls and a roof in top, you cannot create the roof without a 100% support that fills the entity of the room below the roof. Let’s take the letters T, H, Y as an example:
As you can see, the letter H needs a support under its bridge as for the letter T where the letter Y does not need any support since its angle does not exceed 45 degree.
Furthermore, there two types of support (tree and normal):
Generally, tree support is preferred over the normal support for several reasons:
-
Consumes less material since the tree support does not have uniform shape, it can become smaller where it needed. Hence, lesser printing time.
-
Tree support is designs to have lesser contact points with the 3D model which will result in smother surface finish eventually.
-
Since it has lesser contact point with the model, it will provide easier removal whereas normal support bond strongly with the model making it hard to remove them without damaging the model.
Infill¶
The infill is material that occupies the the internal section of the model. Naturally, higher the percentage of the infill, the higher the strength of the model. Through the 3D printer, you can specify the percentage of the infill that ranges from 0% (hollow) to 100% (entirely solid). In addition to the amount of the fill, the infill comes in different shapes and sizes.
Group Test¶
To test the capacities and limits of each printer we downloaded a test model from thingiverse and printed on both printers.
You can download the model from here
The available printers are the Creality k1 and Ultimaker +2
Creality K1¶
From here you can download the Creality software.
As you install the software, this is the first window that will pop up immediately, demanding you to select the the model of your printer:
The printer we have in FabLab is the K1.
Firstly, import the design in in the Creality software. (Make sure the file is in STL form).
After importing the design, the software allows you to scale it. Note that the Printer bed is 220 x 220 x 250 mm so make sure that your model does not exceed those dimensions.
After adjusting your design, you have to adjust the printing settings such ass support, infill, quality, and brim.
On the right we have 5 settings to choose from, let’s start with first one - Process - This refers to the height of the the successive layers. The smaller the height of the layer is, the finer the surface finish wll be printed. The standard option is 0.2 mm and it is wat we go with most of the times to speed up the process.
The second option is - Strength - this option contain three main things (Wall loops, shells, and infill), those three option is responsible for the end strength of the object. From here you can control the how many walls the machine will put per layer, the pattern of the shells, number of layers for each shell (Top and bottom), and the pattern of the infill. For this test we left everything as it is with pre-set settings.
fourthly, is the support. As explained above, tree support is better that the normal. Therefore, we are choosing the tree (auto) to let the software generated automatically. The threshold angle will be put at 65 degree. Although the research said 45 degree, the instructor said to put it at 65 degree. However, for this test we are not gonna use support.
Here are other options such as brim, and spacial modes. For example, you can select the type of brim you want to use.
After finishing setting the options, hit Slice plate. Wait a few moment and it will give you a preview of the G-code, as you can see it will take 23 minutes to print and 3 meters of material. If you are satisfied with numbers click on LAN printing.
This window will appear, click on “send G-code” to send the the file to the printer.
After sending the G-code to the printer, it id now stored in the files of the 3D - printer. As you can see in the screen above, you can find it in the third icon of the vertical toolbar on the left =, here you woll find your file and the recently sent files. Click on it and hit “Print” to start printing.
You can see the the speed of the Creakity.
Ultimaker +2¶
Here are the key features of the Ultimaker +2.
From here you can download the Ultimaker +2 software.
In the software follow the same steps done in the creality software, from scaling to adding support. Howerver, there is one key difference between the two: the Ultimaker +2 does not have Wi-Fi; therefore you cannot sent the G-code. However, you must store the file in a SD card then insert it in the Ultimaker.
As we saw, the screen of the Creality was touch screen. In contrast, the screen is not touch here, you can control the printer using a single knob.
Here a speed difference between the Creality and the Ultimaker:
As you can see, it is quite noticeable how the Creality is much faster than the Ultimaker.
And the Creality surpasses the Ultimaker in speed it also surpasses it in Quality:
The one on the left is printed by the Creality and the one on the right is printed by the Ultimaker. As evident, the Creality surface finish is much cleaner and smother than the Ultimaker for the exact same settings and filament, in addition to being much faster.
In conclusion, the Creality is better than the Ultimaker in every aspect (faster, better quality, easier to connect, and easer to operate) and this due to the Creality being from a newer generation of 3-D printers where Ultimaker is an older version.