6. 3D Scanning and printing¶
The assignment this week required to design and print an object (using a 3D printer) that could not be done using other machines, for example laser cute. This task enforce to use and work with 3D printer that is a machine often used to create new creative projects. The second part of the assignment asked to scan an 3D object and if possible print it, to practice using scan tools and convertion into files that can be compiled by a 3D printer.
Start a sketch (CREATE > Create Sketch); draw a rectangule; define parameter width equal 60mm.
Create a extrude (CREATE > Extrude) with size width / 2; chamfer the extruder in 29.99 mm (using 30 mm creates a strange shape different from a pyramid);
Create another extrude using the same sketch with size width; it creates a cube.
In three distints sides of the cube create a new sketch; set parameter thickness equal to 10mm; create a square with exact distance (all sides) of thickness from the external square of the cube;
Create one extrude for each sketch with size -width (this will remove the internal part of the cube).
Move the cube for the top of the pyramid (use the right click of the mouse and move menu, it is easy to place the cube the position you want).
Join both parts (pyramid and cube) in one single object.
There are many machines available in our lab to perform this assignment. The machine chosen for this assignment was the one bellow because it is easy to operate and produces good quality objects.
The object designed before were converted to STL. Fusion has a menu to Export the object designed to diverse formats. One of them is STL. The STL file is imported to the software of the 3D printer, as shown bellow.
The parameters were adjusted like shown in the image.
Result o the object designed before after using 3D printer.
Some objects might be difficult to be replicated in a 3D software model and require a different technique to be printed for a creative project. A good technique to tackle the problem of printing complex and detailed objects is the 3D scanning. This technique allow you to replicate real objects into a 3D model that can be used in a 3D printer. After scanning the object, you can generate the STL file, and send it to a 3D printer. Depending of the size of the desired object, you might need a different printer. There are specifics machines to print detailed objects in miniature. It is even possible to scan human body for using in a 3D printer. Be aware that the state-of-the-art scan machine are not able to recognize well long human hair.
To show how does work this technique, I have scan the following object (bee doll) using the software EXScan.
But, before starting to scan, the machine needed to be calibrated. This was done using a plate containig several dots that is read by the two cameras of the machine and adjust the software to scan the object. After using this place, it is necessary to put a sheet of paper to finish the calibration.
The object was placed in the base reader and a new project was initialized in the software. The machine will turn the base and two cameras capture the faces of the object and translate into the 3D model. The property Turntable Steps determine the degree the base reader will turn to scan the object. The bigger, the more detailed the 3D model of the object will be. It was setup 25 parts to fully turn the base reader.
Then, it was clicked play in the software and the scan process started. The object scanned generated is not the final one that can be sent to a 3D printer, as you can see in the image. The object scanned is a little bit different from the original one because the machine has difficulties in read the black parts.
It is necessary to fill the object that will actually connect all the parts that was not perfectly scanned. By clicking in the menu Mesh Model, you have access to the following menu. The option Watertight Model will fill the entire object whereas Unwatertight Model will create the object internaly empty. I chose the former menu for this exercise.
This was the object resulted that can be sent to a 3D printer. As mentioned, the black parts of the object was not scanned very well and it results in a incomplete 3D model of the original object. This machine might not be ideal for objects containing black color. Another possibility is to scan a colorful object, but this option were not tested this time.
The 3D model can be exported as STL file and some properties can be adjusted.
Other scan softwares¶
There are different softwares and machines that do the 3D scan of real objects, for example qlone. This is a very simple software to scan real objects. You simple place the object in the printed square image (figure bellow) and use the smartphone to scan it. The software will use the squares from the image to identify the dimensions of the object and create its digital 3D model.
The softwate skanect is free and very easy to use. It enables to scan human body and large objects. It uses a different approach to recognize the dimensions of the object. And if you are looking for a precise scan software, take a look at einscan-SE. It can scan object with accuracy of milimeters.