06. 3D Scanning and printing¶

The best thing about this course is you get to make and experiment with your designs. This week was another such week which involved making with a process called 3d printing and scanning the real world objects into the virtual world.

3d Printing¶

3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file. In an additive process an object is created by laying down successive layers of material until the object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object.

3D printing enables you to produce complex (functional) shapes using less material than traditional manufacturing methods.

Source : 3dprinting.com

Materials¶

Process of 3d Printing¶

The main aim of the assignment was to make something which can be made only by additive process and not any other. Hence, I decided to make a rotatable sphere within a spherical form.

1. CAD Modelling :
   The first 3d printing requirement is having a 3d model. There are multiple ways of getting a model ready for 3d printing.

2. First is downloading an existing models from websites like Thingiverse.

3. Secondly, you can scan a physical object using one of the 3d scanning techniques.

4. Last is by making a 3d model using one of the 3d modelling CAD softwares. The one I’ve used here is AudoCAD 3d.

5. The size of the outer sphere is 60mm outer diameter, and the inner sphere is of 40mm diameter. The inner diameter of the outer sphere is 42mm hence, 1mm tolerance is kept on each side to allow movement.

• If you make your own model using CAD or 3d scanning, you’ll need to export the file in .stl extension. The online files for 3d printing are generally downloaded in this format.

• G-code Generation :
  For this, you need to open the .stl file in a slicing software. Each printer has its own software. In FabLab CEPT, we have ultimaker 2+ for which the software is Cura there is flashforge which uses the flashprint software. Since I used flashforge for this print, I opened the file in Flashprint.

        Ultimaker 2+                    FlashForge Dreamer

• Once you import your .stl file in one of these softwares and select the printer model, it will show the 3d placed in the 3d printer.

• Next is adding supports. For that, click on support options and select tree-like. Post diameter I kept at 3mm and base diameter at 6mm.

• Once these settings are in place, click on auto supports.

• Once these supports are generated, click on print. A print settings dialogue box should open up. Settings used here:
  Machine - Flashforge Dreamer
  Material - ABS(Only right extruder)
  Supports - Enable
  Raft - Enable
  Brim - Yes
  Resolution - Standard

Layer Height - 0.15mm
Fill Density :20%

Note: The model preferences are more customizable in the Cura software for ultimaker whereas the supports are customised better in Flashprint for Flashforge Dreamer.

1. 3d Printing :
   When you insert your SD Card in the 3D printer, it will show a list of all the G-codes for 3d printing in the folder and you can select yours to start the printing.

The process of 3D printing is a long one and hence, it is generally used only when the output is not possible by any other process. This particular model took almost 3 hours to complete. On completeion, carefully remove your object from the printing with its base.

1. Removing Supports :
   This step needs to be done very carefully. Since the printer cannot print in air, it created supports in certain areas which can later be removed. There are different types of supports that can be made depanding on the type of printer you’re using. Most common is linear supports which create straight lines from the base to support the overhanging areas. Second is tree-like supports wich create a tree shaped structure for support. These are comparitively bigger and hence more difficult to remove.

1. Finishing :
   Lastly, you need to finish the areas from where the supports are removed using a sand paper or washing the model where the support material is soluble.

   

3D Scanning¶

A process, exact opposite of 3D scanning, is used when you want to transfer a real world object into the virtual world. There are multiple methods of doing this, some which involve special equipment abnd some which can be done using regualar smartphones.

Here, I’ve tried out both these methods.

1. Using images clicked using Mobile Camera using Autodesk recap.

• Open Autodesk Recap and select ‘Photo Project’ and select all the images to make the 3d. On how to click these images, refer this link

• In this method, I tried out two environments:

• First, I tested in outdoor conditions. This was the output

• Second, in Indoor conditions. This was the output.

2. Using Kinect 3D scanner

In this method, you will need the Kinect 3D Scanner, which we had at our Lab.

To start with, get a person or an object that you wish to scan. Here, I’ve made my fellow FabAcademy Friend, Dhruv Patel, to sit aon a revolving chair and instead of moving the kinect, he is rotating.

• Once this is set, open Skanect Software which can be downloaded from here. Click on ‘New’ and select the below settings.

• Once the model is ready to start, click on Record.

• This should be the output once the scanning is done.

• Once the scanning is done, you need to make it watertight solid since there might be parts of the body that the scanner might now be able to reach.

• Export this 3d as .stl once this is done by clicking on export.

• This is the final output.

• Thus, this week we explored 3d printing and scanning. We’ll be using these processes for manufacturing parts of bigger systems in the coming weeks.

All the files for this week are attached here

Group Work¶

The Group Assignment was to test the design rules for your 3D printer. The group page can be found here