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WEEK 5: 3D scanning and printing

This week's assignment was about 3D scanning and printing
For the group assignment we had to test the rules for our 3D printers
For the individual assignment the task was to design and 3D print an object that could not be made substractively and also to 3D scan an object

Group assignment:

To do the group assignment, we decided to assign one printer to each one of us and to agree in wich files and parameters we were going to use.
The files we decided to use to test the printers were the following:

The first one can be downloaded here: https://www.thingiverse.com/thing:1363023, and the second one here: https://www.thingiverse.com/thing:636363
With these test we were able to see some features of the machines, like overhangs, bridges, hole sizes, minimum distance of walls, minimum thickness...

We tested the following machines:

Prusa Mk2 & Mk3

With the following result:

And the following parameters:

RepRap 1:

Results:

Parameters:

RepRap 2:

Results:

Parameters:

Anycubic Kossel

Results:

Parameters:

Creality CR-10S5

Results:

Parameters:

Creality Ender 3

Results:

Parameters:

Anycubic Photon S

The first test was kind of a failure, because the orientation of the pieces with the bed was not okay

For the second test, we rotated the pieces and the result was way better:

Parameters:

Conclusions:

After testing all the printers and compare the results, the first thought is the big differences there are between the pieces we print in the different printers. Most of them were expected though, some because of the different nozzle size, others because the different materials, special mention requires the flexible one which is the most difficult to print. The RepRap printers had less resolution mainly because they are old and they are used to test stuff. At the end of the day, we achieved the best results in the Creality Ender 3 and in the Prusas. The resin printer yielded really good results in so tinny pieces. After all the tests, I realize that the software is also very important, because it makes a lot of decisions. Other important factors are the well known speed, layer height, proper temperature...

Individual assignment

3D scanning:

The 3D scanning assignment of this week was kind of frustrating. I decided to do some tests with photogrametry to scan some objects. I saw some examples made with Meshroom, so I decided to give it a try.
I did three different tests with different objects, different light, different cameras, but in the end I allways obtained nothing, just a mess of points but I was not able to achieve a decent mesh or something similar.
In the following pictures you can see all the tests and the final result in meshroom

First test:

Second test:

Third test:

Then, after achieving anything with Meshroom, I decided to test Recap Photo, just in case. It was a nice surprise to see how with the same photos I got really god results.

The first model is a little human figure made of wood

The second test, is a simple bucket in the rooftop of our Lab:

3D printing:

For the 3D printing, I decided to design a 3D model of my final project, in order to start testing also different shapes in different materials. I used Rhinoceros with grasshopper to create the 3d model. In this way, I was able to adjust all the dimmensions and parameters of it afterwards.
The final project is supposed to be in a candle shape, but it must integrate some sensors. I decided to make a base for the "candle" in order to place the sensors in a way that the air can pass through. The design for the candle itself is like a lamp shade that will cover the light inside.
The requirement of the assignment was that the object could not be made substractively. In this case, neither the base and the shade can be made substractively. About the shade, the first issue would be the transparent material, the second one the thin thickness of the wall and the third one the colissions if we do it with a CNC. About the base, we would need a 5 axis machine to mill it and even so it would be so complicated to make it, not to say impossible.

I also made a fast render of the design to se how it looks:

To print the base, I had to make the decision of separate it in two parts, because otherwise it would require a lot of supports. In this way, I was able to print without supports. To fit in the two parts together, I design also a insertion in one of them.
I printed both parts in the Prusa Mk3 with the following parameters:

The holes didn't need any kind of supports and the result was quite good.

To print the lamp shade, that has to be hollow inside, I decided to use the Creality CR-10S5 with the 1mm nozzle in order to print it with the spiralize funcion. Thereby, the wall is only one layer of 1mm thickness.

The parameter used were the following:

Where the thickness of the wall was 1mm (the diameter of the nozzle), and the bottom layers was set to three in order to match the same thickness as the wall.

The result was not the precise I wanted, probably because the fan to cool down the print was not working. Then I decided to slow a bit down the speed to let the print cool down a bit more before the next layer. It worked quite well an the result was considerably better. Here is the difference between the first test at 30 mm/s speed and the second one at 20 mm/s speed:

The final result with the base and the lamp shade mounted was good, although the lamp shade didn't fit in the insertion I made in the base to hold it, probably because of the rectraction of the material.

Files:

Dropbox folder with the ReCap files
Rhino file for the base and the shade
STL for the base of the lamp
STL for the lamp shade