______ _ ___ _ _____ _____ __ ______ | ___| | | / _ \ | | / __ \| _ |/ | |___ / | |_ __ _| |__ / /_\ \ ___ __ _ __| | ___ _ __ ___ _ _ `' / /'| |/' |`| | / / | _/ _` | '_ \| _ |/ __/ _` |/ _` |/ _ \ '_ ` _ \| | | | / / | /| | | | / / | || (_| | |_) | | | | (_| (_| | (_| | __/ | | | | | |_| | ./ /___\ |_/ /_| |_./ / \_| \__,_|_.__/\_| |_/\___\__,_|\__,_|\___|_| |_| |_|\__, | \_____/ \___/ \___/\_/ |_|

Student Archive || Student no - 183 || FabLab CEPT, Ahmedabad |

3D printing and 3D scanning


Assignment goals

3D printing - Group assignment

We printed several test print templates to check the following variables of our 3D printer -

We documented it in our lab page here - Group page of 3D printing design rule test

Designing the file

This was my first time using Fusion-360, so I followed along this tutorial which used similar commands to model a lampshade - 3D print Lampshade - Fusion 360

First step is to create a sketch on any vertical plane, I'm assuming the sketch mode in fusion 360 is analogous to 'FreeCAD's' sketch workbench, applying constraints to geometry seems to be similar to FreeCAD, but the auto-constraints of FreeCAD seemed mre robust and useful, I had a rough idea of the overall dimensions of the object and that aided in quickly finishing the sketch
The next step was to revolve the sketch with the 'revolve' tool, it involved selecting the axis of revolution and the geometry to be revolved
The next step was to use offset construction planes, which will be used to split the object into three parts to create the bottom and top plates of the HourGlass-like object
The object is now split into three different bodies, notice in the lefthand 'browser' that there are now 3 different bodies, now all these can be 'shell'ed
Next step was to go to a new sketch and use the revolved and split geometry to project onto the sketch plane and draw an inclined rectangle, the purpose of this rectangle will be clear in the next step
The rectangle extruded and intersected with the revolved and shelled spline to create a rib which will be polar arrayed around the centre
The polar array command is called 'polar pattern' in Fusion 360, and variables include the axis, the number of items to be repeated, and type of geometry
I placed spheres on the bottom plate with the surfaces in contact, hoping to knock it off after the print finshes and let it loose
Fusion360 has a utility to export models for 3D printing apart from all the CAM abilities, Fusion360's capabilities of defining machine paths might translate to the ability to create customized gCode, which unfortunately I could not explore in this week
The .stl file exported from Fusion360, I opened in Cura- Ultimaker's native application to export gCode , Cura afaik is designed to be more user-friendly and hence many of the 3D printing parmeters are absent when compared to other slicing software.
Alot of the 3D printing mechanisms and parameters can be understood by just playing with the parameters seen above and seeing how that affects printing time
The sphere i put inside the enclosure seems to have printed alright albiet the stringing seen in it and the enclosure
As the print continued I was pretty sure that the top half would break off without any supports but was quite pleased to see that it did not happen
I increased the retraction speed to see if tat yields in a cleaner print; and it did.

Printing - time-lapse videos

3D Scanning

Assignment goals

Photogrammetry - Autodesk 123D catch

123D catch is a freemium multiplatform photogrammatery app by autodesk, as of March 2017 123D catch is being phased out for Autodesk ReMake which has integrated mesh cleaning tools and '.stl' exporting options as well.

The opening screen is a live gallery of 3d scans from other users, start by clicking the '+' icon on the top right
And then 'Start a New Capture'
This will initiate the camera mode which also conviniently tracks your movement relative to the object by using the phone's gyroscope and compass
Keep the object in focus, do not let it get cropped and more the number of photos - the merrier
Once, you submit the photos, the status of the processing and uploading will be displayed in the sidebar as well

Photogrammetry - Autodesk ReMake

Cleaning the mesh in ReMake

Autodesk remake has a similar workflow as 123D catch till the photos get uploaded and the mesh gets created
The mesh can be inspected in several display modes, this is wirefram+texture mode which is the most definitive of the four
This is shaded mode where surface smoothness and depth is easily comprehended
The 'wireframe' model is most helpful in guaging the detail level and the 'heaviness' of the mesh
Mesh cleaning is easiest with the lasso tool,parts of the mesh can be lassoed and deleted with the 'Del' key
Another key cleaning tool is the slice and fill tool, this slices the model at a given plane and fills the hole, I used it to create an even base
Notice the mouth is absent? I used the push/pull brush tool to correct that and create a void for the mouth
Remake also has an auto-issue fixer for 3d printing, it detected a few minute overlaps and fixed it automatically
Hero shot 1

Hero shot 2

Printing 'FaceMan'

File Downloads