This page presents the assignments for week 5 of Fab Academy 2020: “3D Scanning and Printing”.
To do list:
Group
- test the design rules for your 3D printer(s)
- design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively,
- 3D scan an object,
- and optionally print it
Week 5 CAD files:
3D_printed_parts.scad (own work)
Carbon_Tube_Square.scad (own work)
Parameters_CDM.scad (own work)
cyl_head_bolt.scad (Johannes Kneer work, details inside)
sg90.scad (Tim Gremalm and devilholk github users work, github link)
fastener_2.scad (Tim Gremalm and devilholk github users work, github link)
Week 5 "hero shot":
Figure 0: 3D printed junction between carbon tube
Table of Contents
1 Group assignment
I worked with Serena, Benoit, Ambroise and Jonah (Fab Manager) to test the design rules of the 3D printers in the Lab.
1.1 Overview
We used the Cura software for Ultimaker 3 printers and the PreForm software for the Formlab printers.
1.2 Step by step 3D print design process
1.2.1 Ultimaker 3
Step 1
Import the .stl file describing the object in Cura as shown in figure 1.
Figure 1: Cura interface
Step 2
Set the parameters in the the right column menu in in figure 1
Once all the
parameters are set, Cura automatically slice the model and give a good
estimation of the 3D printing time, with the set up.
Step 3
Cura will automatically detect the USB and propose to “Save to Removable Drive” and then to “Eject” the USB as shown in figure 2.
Figure 2: Cura interface save to USB
Step 4
Plug the USB in the
Ultimaker 3. With the rotating selector choose the appropriate gcode to
print. And click on the center of the rotating selector to launch the
impression
Step 5
Figure 3 shows an example of a printing process successfully started.
Figure 3: 3D printing successful start
Step 6
Step 7
Cut the plate adhesive with a utility knife as shown in figure 4.
Figure 4: Cut plate adhesive
2 Individual assignment
2.1 3D printing a small object
2.1.1 Junction for carbon tube
3D CAD model
Figure 5 shows the CAD model design for the junction between two orthogonal carbon tubes.
Figure 5: CAD Model “junction for the carbon tube
Cura settings
Figure 6 shows the settings in Cura before printing
Figure 6: Cura settings “junction for the carbon tube
3D printing the model
Figure 7 shows the 3D model printed
Figure 7: 3D printed object “junction for the carbon tube
2.1.2 Nose front bayonet pin module
3D CAD model
Figure 8 shows the CAD model design for front bayonet pin module
Figure 8: CAD Model “Nose front bayonet pin module
Cura settings
Figure 9 shows the settings in Cura before printing.
Figure 9: Cura settings “Nose front bayonet pin module
3D printing the model
Figure 10: 3D printed object “Nose front bayonet pin module” top view
Figure 11: 3D printed object “Nose front bayonet pin module” bellow view
Making it substractively
For both objets, it is possible to make them substractively but it is way harder.For the junction between carbon tube, starting from a cylinder, one using a CNC machine must find a way to hold the cylinder in place. Then one need to remove the material in the cylinder to make the first cylinder. Then one must precisely rotate the cylinder by 90 degrees to remove the material for the second hole.
For the bayonet pin module it is even harder as one need to remove material from a half sphere but still let some material for the spheric locks (Cf figure 8). It is possible to easily make half of the spherical lock but then the other half is much harder to create by removing material.
2.2 Scanning with FabScan
2.2.1 What is FabScan?
As stated on the FabScan home page:
“FabScan is an open source 3D laser scanner. The project started in
2010 at Germany’s first FabLab in Aachen. The FabScan PI is the next
generation of the FabScan 3D Scanner.”
The next subsections follow the FabScan documentation page steps.
The Mechanics
Figure 12 shows the Fab Scan case that I have assembled at home.
Figure 12: Fab Scan assembled case
The electronics
Figure 13 shows the FabScanPi HAT parts.
Figure 13: FabScanPi HAT parts
Figure 14 shows the FabScanPi HAT with soldered parts.
Figure 14: FabScanPi HAT with soldered parts
2.2.5 First Scan
Figure 15 shows the first software test I did at home.
Figure 15: FabScanPi software test
Figure 16 shows a screenshot of the .stl obtained after first scan of modeling clay snowball.
Figure 16: Screenshot of the FabScanPi resulting stl