Week 5 3D Scanning and Printing

This week we are going to explore reaches and using of 3D Scanning and Printing

To scan us, we used Sense 3D Systems Scanner; this scanner functions by capturing an image with an integrated camera and sensing the distance by a laser.


First we setted the scanner on Human>Head, then one by one we sat on a rotary chair in front of the scanner and turned slowly once. That was enough for the scanner to capture all the information to generate a virtual 3D model of us. When we checked that all was alright, we post-processed the information: Solidify the mesh and trim the unnecessary surfaces. Finally we exported into a STL file and now is ready to print.


For printing the previous ourselves scan file, we use a MakerBot Replicator 3D printer. The steps to print are the following:

Convert the OBJ file into STL to be able to insert it in MakerBot Print

Insert the STL file and scale it to 50 mm height (Z axis)

When we crop the model in SENSE it was not straight, so we had to orient to X plane, otherwise when printing, the MakerBot will print supports between the model and the printer plate.

Export the file using 0.2 mm resolution, 10% infill and number of shells 2.

When the export is done, you can see the estimated time and material to use in the printing process.

Save the exported file in a USB drive and plug it in the MakerBot, select the file to print and as soon as the printer reaches the right temperature, it will start printing.

Done!

Download 3Dme on Thingiverse

For this scanning we used an Aicon 3D Systems Scanner; this scanner functions by the triangulation of two cameras’s images, of different patterns of light beams projected on the surface of the object.


In this case, first we needed to get the room darker, because this scanner has its own light projector to catch only the information of the object we want to scan. When we start the software we have to create a project and decide what kind of scan process we are going to use: Contour scan, that take part of the same object as reference to merge the next scan; or Index points reference, that take circular sticker that we put on the object as reference to merge the next scan. Then we need to calibrate in the software the amount of light that the cameras are capturing, and when this is done we “take a picture”. For the following scans we need to move the object to a new are, respecting the parameters of references that we have chosen earlier, and repeat the last step. If we respect the references the software merge itself the surface. And finally we can export an STL file, but in this case, the solidify process is made in an external software.

Comparision

Parameter	Sense	Aicon
Color	Yes	No
Resolution	Low	Very high
Scanning Time	Very fast	Slow
Manipulating Mesh Software	Same	Third party
Manipulating Mesh Complexity	Easy	Very complex
Computing Resources	Considered	Special
Light presence	Helps	Affects
Object treatment	-	White flat surfaces
Applications	Quick scan, hobby, home projects	Industrial, medicine, inverse engineering

For this part I used a uPrint SE Plus, this 3D Printer let us print with 2 materials, Model and Support, model for the pieces and support to make a base over which the printer deposite the model material, it is also used for the support on complex geometry and temporarily fill free spaces on mobile assemblies.

CatalystEX is the slicer and control software for uPrint SE and here we change different settings as:

• Layer Resolution - That determines the thickness for the layer, and therefore, the quantity of layers
• 0.254mm
• 0.3302mm
• Model Interior - Establishes the fill for model material
• Solid - Fill completely the object which means more material, more mechanical resistence and more print time
• Sparse High Density - This is the intermediate parameter of material, time and resistence
• Sparse Low Density - The interior will be filled by a hatch or a honeycomb, reducing the time and material but also de strength
• Support Fill - Determine the quantity and the style for the support material
• Basic - Recommended for basic geometries
• SMART - This is the default choise and has an algorithm that optimize the distribution of the support material for a correct deposition of the modelling material to prevent the deformation of the piece during the print process
• Surround - Support material surround all the piece

For this comparison I will change the Model Interior parameter for the same object and see how this affect to the material quantity and printing time. I will use this model from a friend of mine.

Sparse Low Density

First I'm going to print with the lowest parameters and will be increasing. So I setted low density of modelling material and I get a calculation of the time and material, model and support, this is the information that I will use as reference.

• Model Material: 3.11cm3
• Support Material: 0.89cm3
• Time: 21min

Sparse High Density

For the second try I setted the model interior on high density

• Model Material: 3.71cm3
• Support Material: 0.89cm3
• Time: 23min

Solid

And finally I will set the infill as solid

• Model Material: 4.08cm3
• Support Material: 0.89cm3
• Time: 21min

After making the individual virtual comparision I printed the three models

via GIPHY

Having printed the objects I could see that the difference are minimal, besides a slight difference in weight and mechanical resistence to flexion, at this scale the differences are practically imperceptible.

For Mechanical Design Project I designed/modified and printed a couple of parts:

Motor coupling

To make the union between the motor and the rod I had to modify this motor coupling that we found on thingiverse and then printed it with PLA.

To modify the STL file we used Autodesk Fusion 360:

Open Fusion 360

Go to Insert > Insert Mesh and select the file you want to modify

On Model Tab go to Create > Create base feature

Go to Modify > Mesh > Mesh to BRep

Select the mesh and click Ok

Go to Patch Workspace

Go to Modify > Merge

On merge window, active Select Chain box

Select faces to merge and click Ok and Finish base feature

Now you can make the modification that you need

Modify

Save it on STL format and print it

via GIPHY

Download Coupling STL on Thingiverse

End effector support

During the project we decided that the end effector it was going to be a marker, so I designed a marker holder, where the marker fits by pressure. And the only three parameters that we need to consider are the marker diameter, diameter and height of bolts.

via GIPHY

Download Support STL on Thingiverse

Parameter	MakerBot	uPrint SE Plus
Color	Yes	Yes
Resolution	Good	Very high
Support Material	Same model material	Soluble support material
Enclousure	Open	Close
Manipulating Print Parameters	Highly manipulable	A few predefined parameters
Cost	Medium	High
Finish details	Acceptable	High Quality
Post Process	Cut supports	Submerge in solvent to remove the support material