5. 3D printing and Scanning

Goals

Group assignment:

[x] test the design rules for your 3D printer(s)

Individual assignment:

[x] design and 3D print an object (small, few cm3, limited by printer time)
[x] that could not be made subtractively
[x] 3D scan an object (and optionally print it)

Tools Used

Formlabs Form 3L - Large format SLA 3D printer
Preform - Formlabs slicing software
Artec Leo - High performance general purpose 3D scanner
Artec Studio - The software that is bundled with the Leo to process scans
Pureref - An amazing program for gathering images into a big moodboard
Concepts - My go to sketching app on the ipad
Fusion 360 - 3D CAD/CAM software from autodesk
Blender - Free and opensource 3D software that can be used for anything from sculpting to animation and much more.
Bambu Lab P1S - The printer I use in my farm, I don’t do much multi colour printing but I have one with an AMS that I used for this project.
Orca Slicer - My main slicer for Bambu Lab 3D printers, open source and has the ability to store “k-values” along with your material
Bambu Studio - Bambu Labs own slicer, needed for doing multi colour prints.

TLDR; Nice images

Group Project

This week for our group we each tool a different printing process to and printed the same models to compare our findings. My prints were testing SLA printing on a Formlabs Form 3L

My write up can be found on our nodes site along with the rest of our groups exploration.

Summary

Overall the resin prints fared very well in the test though there were some key considerations.

While the resolution of each layer is overall higher you still have the same considerations with overhangs than you do with FDM prints and if they are not accounted for you will have similar low quality results
New issues like Cups must be taken into account, this can mean reorienting your part and relying on support material in ways that you would typically avoid in FDM
Mind to keep you cleaning solution fresh! I think mine was too saturated with resin and did not fully clear the parts, this caused the clearance test to bind up at a value of 0.6mm. A very poor result, not representative of what the process is capable.

Individual Project

1. Design and print a thing

This is the week I am committing on my final project. I will be making my Cad peripheral for my final project but the twist I have landed on is splitting out all 6 of the axis of motion into individual knobs, dials, sliders etc.

1.0 Sketching

On my aesthetic considerations for the project I have been pulling a lot from music equipment. In particular I have been referencing features from Teenage Engineering this week.

So for this week I wanted to take one of my concepts and print it out as a non functional prototype to get a sense of the scale and to incorporate some print in place elements.

1.2 Fusion 360

In fusion my first goal was to establish my proportions. so I created a block based of my sketch and added some construction geometry to lay out the space

My dials needed to be print in place elements so I first drew them simple cylinders and as a new body’s.

I used a rotated cut to remove material on the dial to create the print in place feature. The opposing 45 deg wedges were designed to lock the piece in place in the housing

I then subtracted the dial away from the main body.

And used press pull to add a 0.2mm tolerance to that the print in place feature

I continued to build out the design using patterns and aesthetic cuts on the top surface. I wanted to create a spinning disc feature as the focal feature of the design. To do this I decided to use skateboard bearing I had to hand. To fit this as a press fit I added some oversized nubs on my slot to that the bearing could be retained in the part.

1.1 Testing my tolerances

Before I print the full design I cut out the ideas of the design that have critical tolerances using an extrude with the operation set to intersect.

Brought my stl files into Orca Slicer and sent to my Bambulab p1s

My first print would bound up and would not function

So after a few more iterations, pushing offsets back and forth a few I had the test parts fitting together and I felt comfortable moving on to printing the full part

1.2 Printing the full part.

I added some colour to my design in Bambu Studio, (Note one trick hear was to cut of all the top elements in my design in fusion before I output the stl, this means that I can use the object selection view in bambu studio to add colour without using painting) and sent to my p1s

In the end my print failed very close to the end due to a tangle in the AMS but it was close enough that I didn’t want to reprint and waste material.

These are all my components laid out.

Printed body
Printed disc
Skateboard bearing
Some rubber bump stops to act as feet

Complete!

And a shot of the print in place features on the back along with the feet and an hole where I can remove the bearing.

1.3 Nice Shots

Happy with the final result, key thing to bring forward is needing longer sliders.

And its now a nice fidget toy for my daughter 😙

2. 3D Scanning with the Artec Leo

2.1 Scanning

This week I scanned an arm to use in a render of my project proposal. Instead of printing the scan I wanted to explore using the scan as part of an animation.

The reason for this is that one of the under utilised aspects of scanning is that you get a fully textured model for free along with the geometric data. This can help add a lot of production value to animation as texturing is often on of the most challenging parts of the process.

For the scanning technique I find the most important things are to;

Pretend your spray painting the model so as to get even coverage
Set up your workspace so that you can get all the way around your subject, as you can see in the image I pulled the table into the middle of the room.
If scanning a person or part there of, they are going to move and twitch, so if you can give them something to rest on it can be a big help. In this case I used a dial indicator stand.

The scans in my experience are rarely perfect straight out of the scanner. The first step is to run the global registration.

In this case as I was scanning a person that can not sit perfectly still so I needed to use the align tools to snap parts of the scan back together.

I then used the eraser tool with the lasso to select only the arm and remove all the information I do not want in my scan.

Now I can use my cleaned up point cloud to create a mesh of the file. I then filled any holes in the mesh using the built in tool in Artec Studio.

And lastly applied a texture to the model and exported my result as a .obj file.

2.2 Scanning

Instead of printing the model from the scan I thought it would be more interesting to use it as part of a mock advertisement animation in blender.

Setting the scene

Import .obj file of arm into blender
Import .stl file of product from previous section
Use Grab and Rotate tools to position the part in the hand
Add product to its own collection

Select part and go into edit mode
Press a to select all and then p to separate by loose parts
Now we can apply different materials to different areas of the model. I mostly use the basic BSDF shader and just change the base colour and the roughness

Add a basic plane to act as a background.
Use the add images as planes with a shrink wrap modifier to add decals to the design.

Lights, Camera, Action!

Set the world light colour to a sky texture. This is important as we will be animating the position of the sun to me our shadows move later in the image. The nice thing is that with this setup we don’t need any other lights

Set the camera to a position and focal length you like
Now the fun stuff, animation!
Make sure that the frame 0 is selected in the timeline
keyframe the following values using the i key.
- The location and rotation transform values of the camera
- The focal length of the camera
- The sun rotation, ozone and strength of the sky texture
Now move your slider further down the timeline, I chose frame 240 as this gives us 10 seconds for movement at 24 frames per second
adjust the values of all the items that we keyframed until you are happy with the final angle of the shot
add new keyframes for all items above there new location and value using i

Exporting

set your render passes to something your computer can handle in a reasonable time, for me on a mac laptop this is about 50 samples per frame with de-noising turned on (de-noising is an absolute life saver and makes working with blender on lower powered machines so much easier)

Render engine is cycles and device is GPU
I like to set colour management to filmic and contrast to medium
Set your output type to your preferred image format, in this case I used .png
- Note that this will export 240 images to whatever folder you point it at so it is a good idea to point it towards an empty folder in your directory.

Render animation with cmd-f12
Let computer chug for a bit, go get a coffee ☕️

Bringing frames back together

Open a new blender document but this time select video editing
In the timeline select Add and then Image/Sequence and select all our frames

In my case I wanted to hold on the last shot to add text so I used Add to bring in the last image into the editor and dragged it out over a few seconds at the end of the video
Use the Add menu to add text and set how long you want it be on screen
Images can also be added this way
Under the Add menu you can chose to fade in these details
In the Output section set the file format to FFmpeg, it defaults for H.264 compression which is fine for this.
As we did in the modeling environment render animation with cmd-f12

The result

In Summary

This week I really narrowed down exactly what I will be doing for my final project, being a week where I could print something was good timing as making a physical object helps me get an understanding of scale and layout that does not come across in a sketch

I used the scanning assignment as an excuse to do a bit of animation and frankly this was just because starting to get a sense of direction about where I am going got me jazzed about the project and making a nice render was a great way to dive in.

This is my typical workflow, modeling in fusion and rendering in blender so I wanted to push a bit as last week I felt I mostly just ticked boxes.

Things I would do differently next time

Using hardware for the print was good for feel but I feel given the spirit of this weeks assignment it would have been nice to make the center dial print in place as well

See below link to to files created this week:

Week 5 Files