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6. 3D Scanning and printing

This Weeks’ Task:

Group Assignment

  1. Test the design rules for your 3D printers.

Individual Assignment

  1. Design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively.
  2. 3D scan an object (and optionally print it).

3D Printing

3D printing workshop

Fablab Bahrain organised a workshop about 3D printing to help us get started and prepared for printing. The following were the important information that we should know about 3D printing:

Model requirements

  • Water tight
  • A solid object
  • No floating objects
  • No internal overlapping
  • .stl format since it is the most required for 3D printing

Printer limitations

  • Bed size
  • Bed should be heated for printing
  • Nozzle size – the smaller, the better, which results in better quality. The bigger the nozzle, the higher the models will be printed.
  • Layer height – more layers, better quality but time consuming.
  • Printing temperature – different temperature should be set for each material.
  • Shell
  • Filling type
  • Orientation
  • Filament types
  • Finishing – sanding, resin coating, acetone bath, painting.

Adjusting the first layer

The first layer of the model should be printed properly in order to print the entire model in a good condition. To properly stick the first layer onto the bed, use: * Hair spray * Glue stick * Painter tape

How to clean the bed:

  • Water
  • Alcohol
  • Acetone

Issues in 3D printer

  • Warping

  • Solutions to avoid warping:

    1. Raft
    2. Brim
    3. Skirt

Uses of 3D printing

  • Prototypes
  • Medical field
  • Jewellery

Advantages of 3D printing:

  • Complex shapes
  • Easy to custom
  • Less material waste
  • More chances for creativity

Disadvantages of 3D printing:

  • Slow
  • Limited
  • Copy right issues - cannot print things which has copy rights.

When to 3D print

  • Custom items whic are not available
  • Moulds for casting
  • Prototyping

When not to 3d print

  • Creeping - when an object will be exposed to high temperature which will cause creeping.
  • When an object is exposed to high stress.
  • Mass production
  • Not always fastest solution
  • Contact with food

Group Assignment

Here is a link to the group assignment page.

Individual Assignment

I created my design using solidworks and then saved it as an .stl file. Below will be the steps of how I created the model and the final design image.

  1. I drew a hexagon using the polygon tool in the toolsbar.

  2. I used the extruded boss feature to create a 3D model out of it. I set the depth as 5 mm and the thickness of the hexagon as 8 mm.

  3. This is the 3D model.

  4. I opened an assembly file and imported two hexagons so that they will be placed this way and saved the file as STL to prepare it for 3D printing.

  5. This is a video showing the model getting printed.

  6. This is the model after being printed.

  7. A video showing the final outcome.

  8. This is the settings used.

Click here to download the solidworks file. Download file

3D Scanning

I used two different applications to scan an object. The first one was a mobile application called Qlone and the second was ReCap.

Qlone

My first attempt was to scan a mouse.

Below, is the picture of the mouse. I placed it at the centre of the mat. You can get the mat from the application itself.

To start scanning, ensure that all four corners of the mat is showing on your phone camera. Then, you will see a blue dome appearing on your object, this is an indication to start scanning. Start moving 360 degrees around your object until the dome transfers completely from blue colour to clear. While moving, ensure again that all four corners of the mat shows or else the dome will disappear. Once the dome is completely clear, it will automatically start scanning and the final result will be shown.

This is the final result after scanning.

Mouse by FatimaJ on Sketchfab

As it can be seen, the scanning of the mouse was not very successful. There were many parts in which it wasnt able to show clearly, and also included some rough surfaces, broken and damaged parts. Therefore, I tried to scan a much simpler object to test whether it will be able to obtain a similar image of the actual object.

The second attempt was to scan an object which was 3D printed before.

This is images of the object.

This is the final result after scanning.

Object by FatimaJ on Sketchfab

In comparison to my first attempt, this had a decent scan which looked almost the same as the actual object. Although, it wasnt able to scan the sides of the object clearly, but it gave a better scanning result that the previous one. Also, if you could notice, the first image of the object had a pointy tip. This is because the application doesnot have the ability to scan accurately from the top view. However, there was ‘Flatten top’ option, in which I turned on to flatten my image.

ReCap

This application works by taking plenty of pictures (atleast 20) of the object, from different angles and uploading it to the software. The software will then take its time to create the 3D scan. The more pictures you upload, the more accurate the scanning result will be.

Therefore, I wanted to test out the software by scanning a complex object. And so, I decided to scan my colleague by taking approximately 36 photos of her, by moving 360 degrees around her.

This was the final result.

This one had a very accurate scanning than the other application. Although it scanned a more complex thing, but it gave the best results. The colours and the texture of the scanning was also similar to the photos taken.