3D Printing or additive manufacturing is a process of making three dimensional solid objects. Creating solid 3D objects based on additive manufacturing, and, it is the opposite of subtractive manufacturing process. Additive manufacturing is the process of making objects using the concept of adding layers of that material (E.g. PLA or ABS plastic) which combines to create the desired product. So, we can say that Additive manufacturing is "material joining process", and from 3D model it fabricates the product usually layer upon layer. This whole process requires a CAD software (E.g. SolidWorks, Rhino 3D, Fusion 360, InkScape, and many other CAD softwares) in which we design our own demand 3D object with different aspects. And, then give that CAD file to 3D printer (E.g. Ultimaker, Prusa i3. Available in our FabLab Khairpur ). While, subtractive manufacturing is a process to make, design, or construct 3D objects by cutting materials away from a block of solid object. It also done by cutting the material manually but, mostly it done with a CNC machine. (Examples of CNC machines: Epilog Laser Cutter Machine, Shopbot, and Roland SRM-20. Available in our FabLab Khairpur ). As "Additive Manufacturing" also known as 3D printing, in the same way "Subtractive Manufacturing" is known as CNC machining.

3D Scanning is a process of capturing shapes of an object using a 3D scanner, this technology allows us to create a 3 dimensional object. By using 3D scanning device we will be able to capture a digital copy of physical object, then the resulted file will be a 3D file on computer, which can be printed later, using 3D printer. For me, there are two relevant techniques of 3D scanning, "Photogrammetry" and "Light-based Scanning". Photogrammetry, This method is based on taking several 2D pictures around a particular object from different angles using a digital camera or camera of smartphone. Then combining these 2D images into a single 3 dimensional image using a specified software. Light-based Scanning also known as Laser Scanning, It is a device which measures the angle of the reflected lasers which translate into different coordinates of an object then into a 3D mesh, later on the resulted 3D mesh file feed to 3D printer.

Tasks of the week

Group Assignment:
• Test the design rules for your 3D printer(s)
Individual Assignment:
• Design and 3D print an object (small size, few centimeters) that could not be made subtractively
• 3D scan an object and print it (printing of the 3D scanned object is optional)

Testing the capabilities of 3D printer For this task, we printed an object on "ultimaker 2+ extended" and also on "Prusa i3". We downloaded standard test file from Thingiverse website ( Link for test file).

image of the test file object, taken from HERE

Printed on Ultimaker 2+ extended

Printed on Prusa i3

In both, Ultimaker 2+ extended and Prusa i3, the dimensions and settings were same. We set infill was 35% and layer height as 0.1 mm. But, above results show that the quality of printed object in Ultimaker is quite fascinating than Prusa i3. Generally it is considered that nozzle with smaller diameter is good, here smaller nozzle is of Prusa i3 that is 0.3 mm, and ultimaker has nozzle of 0.4 mm. From this statistic the quality result of Prusa i3 must be good comparatively. But, we did not set the dimensions of test file accordingly to Prusa.

Observations:

Nozzle with small diameter prints good in quality but takes more time comparatively, e.g. in "Prusa i3" with nozzle diameter of 0.3mm.

Nozzle with large size e.g. 0.4 mm in "Ultimaker 2+" results time saving, and with acceptable result but not that much satisfied.

Layer height with 0.1 mm (by-default) is very good for precise printed objects but one has to compromise with time.

Layer height with 0.2 mm or greater up to 1 mm is acceptable where there is no thin layers or line in 3D object which is being under print, but good thing is that it will reduce the printing time. So, normaly 0.2 mm is good, again I say that it depends on the nature of the printed object.

Printing with higher speed also reduces the quality of the object

3D printing of an object For this task, there was a limitation to do not design any object which easily be made in subtractive method. So, it gave me tough time to design such a model, especially when I have not much knowledge about CAD software like SolidWorks. I tried to design an eye catching vase with flowers. But, It took me much time and in last I encountered a problem in designing it, so I escaped this model, then started to design a perfect model which can not be made using subtractive manufacturing, that was a mobius bracelet, by the way I used SolidWorks software.

Here are snaps of uncompleted design on SolidWorks

I designed this bracelet on SolidWorks by getting help from different sites and following a video. Now, I am feeling bit handy with SolidWorks.

Print screens of the process of designing the bracelet are shown below:

I export .stl file from designed object on Solidworks

Then fed that .stl file to Cura, and from Cura I export .gcode file which is acceptable for 3D printing devices.

I print this object on Ultimaker 2+

Printed Object on Ultimaker 2+, it took about 3 and half hours

3D Scanning

For this task, I scanned myself using an interesting device, "X box 360 Kinetic". I am completely new in this type of activities, this task was really interesting for me. X box 360 kinetic module is used to get 3D scan of any object, here, I got scanned copy of myself. It needs an specialized software "Skanect", so I downloaded its 1.9.0-win64 version first then installed it on my laptop. It also requires the installation of KinectSDK and KinectDeveloperToolKit to run on a windows PC. I managed to connect the above said device on my PC on Skanect software. Then, next step was to get a scanned copy of myself. For this, I got the help of my colleagues as the were guided me to move or stop, so I followed their instructions to successfully finish the first step. Here, there are two options for getting Scanned any object, first is to move the X box Skanect device around the object, second one is to move the object while putting the device in static condition. Here in my case I was the object and I moved slowly around 360 degree while the device was in rest condition.

Here are few glimpse of my whole process of Scanning object using Skanect.

I saved the generated file in .STL formate then opened it in Cura

From Cura, I got the .gcode file of my scanned copy for 3D printing Fed the .gcode file to Prusa i3 by following the pre-requisite steps I set the layer height as 0.3 mm, this saves much time of printing, but it requires bit compromising on the quality of printing

Me in 3D form is ready to show It took hardly 2 hours to print the object

Download all files from here


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