Hi guys,

For the 6th assignment the task was to 3D print a piece of our choice. The constraints for this project were:

• It can be printed on any of the 3D printers at the OEDK
• The part must fit within a 3x3x3 inch cube
• The part must be able to be manufactured (reasonably) using a 3D printer only. This could include interlocking parts, moving parts, embedded geometries, complex surfaces, etc.

First we need to understand how 3D printing work, in order to choose an adequate part. 3D printing, also known as additive manufacturing (AM), refers to various processes used to synthesize a three-dimensional object. In this manufacturing process, successive layers of material are formed under computer control to create an object. These objects can be of almost any shape or geometry and are produced from a 3D model or other electronic data source. Since the object is formed by adding successive layers, 3D printing allows for the fabrication of extremely complex geometries and interlocking parts. To learn more click here.

This assignment consisted of two steps:

1) Find an object to print using Thingiverse then modify it to print.

2) Produce your object with 3D printing.

The first part was not difficult, the major challenge was to choose one part between the wide variety of options available. After analyzing several objects I ended up choosing the Two-part Bagel (this link also contains 4 other pieces). This object matches all the requirements as it has a complex geometry and interlocking parts. It could be possibly made by cutting a bagel, but it would be an extremely difficult cut to be made. Below there is a picture of the 3D model used:

Then I downloaded the .stl file and took it to the 3D printer room. After reading each printer characteristics and specifications and talking to a lab assistant I decided to use the Fortus 250mc printer, because the FDM method was adequate for my piece, the printer had a soluble support material – required for my application – and the printing queue was not too long.

Next I opened the Insight software and following the Fortus Training Module I scaled my piece so it fits in a 3x3x3 inch cube, generated the support material and the layers, sent the file to the printer and started the job.

After 6 hours the job was done and my piece looked like this:

Then I put the piece in the sodium hydroxide bath to dissolve the support material. After 5 hours I pulled it out and my object was ready:

I am very happy with my piece, despite the layers being visible, the rigid ABS plastic worked really well, the piece can be mounted and dismounted very easily and it looks amazing.

Moreover, this assignment provided me the opportunity to learn a lot about the 3D printing process: how it works, its advantages, limitations and applications.

Thanks for reading. See you on the next post!