Week 1 - Journal

Task Description:
Prepare design files and fabricate models of your choice using 3D Printing and Laser Cutting.

Part I (3D Printing)
There are unlimited options when browsing CAD library on @thingreverse.com, a dedicated website for open-sourced models that can be digitally fabricated using 3D printers. 

The good thing is these models are categorized according to different product categories. Since printing time should not exceed 90 minutes, I aimed at picking a model from the accessories category including earrings or keychains that can be printed as a single-piece model. 

Part 2 (Laser Cutting)
@3axis.co where I was looking for an open-sourced DXF file to laser cut. Lots of fancy-looking designs but not necessarily the format I wanted so I had to lower my expectations a little bit for the sake of finding the right format. 

Besides the file format, I was really keen on applying the three different operations on the selected design; cut, engrave, and speed cut (pen).  

What was needed for 3D printing? 

• After downloading the file in STL format, slicing software was needed to turn it into a G-code file; we simply need to explain to the machine what we expect her to do so we translate the file into her (programming) language (G-code). 

• For this purpose, I used Cura software and I selected  PrusaMK2 3D printer in the printer profile. Turquoise PLA filaments stood out so I had to change the filament quickly before I run the machine. 

• Link to download the software: https://ultimaker.com/software/ultimaker-cura

What was needed for laser cutting? 

• The same reason why we used Cura, I had to download LaserWorkV6 software so the machine can support understanding and executing the design. 

• A three mm plywood sheet was used to implement the selected design on the newly delivered laser cut machine that I can not remember its name. 

The expectation from this week was about knowing how to slice an object that you already picked from an open-source CAD library. Unfortunately, I was too ambitious and I chose a model that does not tick all the boxes and can not be 3d printed as a single-piece model. I thought if it will be printed in one go what is the problem? I knew I was wrong when I received feedback that I have to choose another object as this one does not fulfill the requirements. 

I've to admit that I really enjoyed getting the support needed from the lab specialists and getting introduced to the term "horizontal expansion" which reduces the space between the rings in this case and allows more movement. 

More insights on the slicing process: 
As an attempt to decrease the printing time without reducing the size of the object, I tried to use zero-infill which was not a wise decision, and again I was advised by the lab specialists to at least increase it to five. I went back to the first approach that I was trying to avoid with is reducing the size by 70% and in order to compensate for the effect that happened to the clearance between the rings, I was advised again to reduce the horizontal expansion of the objects. 

Surprisingly, when the infill was adjusted the time of the printing did not take longer as I expected and the total printing time did not exceed 90 mins as stated in the requirements. 

The single-piece model I chose was the wing earnings so as not to give me too much headache like the previous model. It has one side flat which allowed perfect mounting on the machine bed without the need for any support.  I had the intention from the beginning to print two pieces so I have the complete set of earnings and I attached them to a hook so they can be wearable. 

The file was downloaded as an STL file from the open-source CAD library on Thingiverse: https://www.thingiverse.com/thing:5785411 

It consumed 5 grams and the printing time was less than one hour for the two earrings in total. The infill value was ten this time to preserve the surface quality while maintaining the light weight of the object. 

I was again fortunate enough to get the needed support from the lab specialists with setting the right power and speed for each operation which varies according to the material type and thickness.  

It was a really smooth process, however, I had the impression that I should have increased the speed of scanning as it took time more than I expected and I saw some of its traces on the back of the coaster which should not be happening with the right mix of speed and power, reducing the power is also a potential solution for such a problem.

For 3D Printing: 

• After saving the file as a g-code on the SD card, I inserted it into the machine and started the 3d printing process with a white PLA filament. 

• The machine started heating the bed to 220 C which is the standard heat required for printing with PLA. 

• I had to monitor the machine until the first layer was done to make sure the adhesion was enough and the object will stick on the bed during the printing process. 

• When the job was done, I waited ten mins till the bed cool down to avoid any warping of the model. 

For Laser-cutting: 

• After importing the DXF file to Laserworks software, I had to adjust the right speed and power for each operation. 

• Before making sure that the laser focus (distance between the lenses and the material used) is correct I had to use masking tape to make sure that the material will not move during the vibration of the machine and that the sheet is completely flat on the bed. 

• I connected the laptop to the machine with a USB cable and downloaded the file. 

• After closing the bed cover I did the following: 

1. Position the head in the right corner of my sheet and press on "origin so I communicate the start point to the machine. 

2.  Select "frame" from the control panel to make sure that my design fits in the sheet area.

3. Click start and see my design coming to life. 

The below-learned lessons are the conclusion of what I have experienced choosing an object that does not meet the requirements of the 3d printing task. 

• 3D printing is not a forgiving technique and it takes ages to finish printing an object! 

• To focus on the requirements so I avoid repeating work.

• There will be always room for experimentation just finish the necessary, and then take it from there and enhance. 

• Understanding the limitations of each machine and what is possible to be done and what is not possible to get the best result.

•  Thinking from a fabrication perspective and adjusting the concept based on this fact to make the project more doable for production. 

• Working with people from different backgrounds can be a very inspiring and enriching experience! Can't wait till I get the chance to work with more people from my group!!