5. 3D Scanning and Printing
Assignments
Here you can find a recording of the lecture from the 19th of february.
This week's assignments and learning outcomes, see here:
Group assignment:
- Test the design rules for your 3D printer(s)
- Document your work on the group work page and reflect on your individual page what you learned about characteristics of your printer(s)
You can find the documentation for our group assignments here.
Individual assignment:
- Design and 3D print an object (small, few cm3, limited by printer time) that could not be easily made subtractively
- 3D scan an object (and optionally print it)
Questions to be answered/from Nueval:
Have you answered these questions?
- Linked to the group assignment page
- Explained what you learned from testing the 3D printers
- Documented how you designed and 3D printed your object and explained why it could not be easily made subtractively
- Documented how you scanned an object
- Included your original design files for 3D printing
- Included your hero shots
Hero shot
Hero shots from individual assignments
3D model scanned with Kiri Engine
3D model scanned with Polycam
Trying to scan with Revopoint
3D model designed in Tinkercad
Hero shots from group assignments
All in 1 test with Bambu Lab X1 Carbon
Bigger print test with Bambu lab X1 Carbon
Joints test form Bambu Lab X1 Carbon
Summary
This week, as a group, we tested the design rules for our 3D printers. We documented the results on our group page and you can find it here. I was responsible for the Bambu Lab X1 Carbon. Then I documented here what I learned about the characteristics of my 3D printer.
In the the individual assignments I made a model out of clay and scanned it with three different techniques to create 3D models.
Subtractive processes
Here is an explanation on what a subtractive process is. According to it, when you manufacture something with a subtractive process it means that you remove material from a workpiece like a solid block. This applies to different types of techniques like laser cutting, machining and grinding. Laser cutting is when a high-powered laser beam melts away, burns or vaporizes material away. Machining can include tools like lathes or drills chipping away material. Grinding is when an abrasive wheel grinds away or smoothens the surface of material.
Additive processes
Here you can find an explanation on additive manufacturing. According to it, additive manufacturing is when an object is created by adding layers one at a time. Additive process is therefore the opposite of subtractive process. Usually this process refers to 3D printing but it can refer to other techniques, such as molding.
CAD Design Tips for 3D Printing
CAD design tips for 3D printing
Andri Sæmundsson pointed out this poster by @BillieRubenMake with CAD design tips for 3D printing. I found it very helpful when trying to understand what works well and what to avoid when creating models for 3D printing.
Work process detail
3D scanning an object
In the Computer-Aided Design week I took my first steps in creating a model in Blender. I tried to make a model of a whale but it was terrible. I wanted to see if it would work better to create a model of a whale out of clay and then 3D scan it. I live in a small town and the only clay I found in the shop was Play Doh, a soft clay for children. I used it for this experiment and scanned it in two different ways.
Revopoint POP 2 3D scanner
Revopoint POP 2 3D scanner
We have a Revopoint scanner in our Fab Lab Austurland and I was testing it for the first time. I had been told that it there were some problems with it and I wanted to see if it worked. According to the Revopoint website the Revopoint POP 2 3D scanner is an older version of Revopoint 3 3D scanner and it should have a perfect scanning fluency. The screenshot from the website here below shows how you set up your model and scanner when scanning.
Model placed on a revolving base
I placed the round plate on top of the base. This base revolves slowly when turned on. Then I used two steel pins between the model and a lump of clay. I pressed the lump down onto the lid of the clay box. I did this so that I could scan the lower part of the whale.
Unstable connection with the Revopoint
As you can see in the image below, the Revopoint managed to create a part of the model in the preview. The problem seemed to be to keep the scanner working long enough for it to finish the scan. The scanner always turned off and the connection was lost. The Revopoint was powered by the computer it was connected to and I made sure that it was fully loaded, so the power was not the problem. I tried again and again, but could not find the reason. I gave up and decided to use another method for scanning.
Polycam app
Polycam app
I searched for a scanner that I could use with my Iphone. The Polycam app seemed fine and I downloaded it. You can use the app for free, but some additional features require payment. Below you can see the interface of the app in the phone.
Interface in Polycam/Photogrammetry
In the screenshot of the Polycam interface here on the left, you can see for different scans that I made. Only one of them turned out ok. The app said that one of them failed, and I don't know why. The other two failed because they didn't capture the whale model I was using, but created a model of other things in the surrounding.
Scanning the model
In the photo below you can see behind the scenes. I used a black sweater for background and placed it on a chair. Then I used the revolving base from the Revopoint set.
Workflow in Polycam/Photogrammetry
I used the Photogrammetry creator and viewer. By taking photos showing different angles all around the model, the app combines those photos to create the 3D model. You need a minimum of 20 photos and a maximum of 2000 photos. When you think you have taken enough photos you click on Done, choose if you want to use Photogrammetry or Gaussian splat, choose how detailed the model should be and finally, if you want to use Object masking. Then you click on Upload & process and the app creates the 3D model.
A screenshot of the 3D model scanned with Polycam
In the image below you can see a screenshot of the 3D model that was scanned with Polycam.
Design files for Polycam
Possible to use online link to model
I like the option in Polycam to use a link to the model. This way, people can view and download the model. The model shows details very well. You can see that it was starting to form cracks and loosing some details because of all the experiments over the day, where it fell on the side sometimes. But the model is very good. I will only continue with the free version but not the paid subscription so I don´t know if the model will be accessible with the free version. Let´s see how it turns out.
A link to 3D scanned model
Link to 3D model on Polycam website
This is a link to the model on the Polycam website. I want to see if the link will work with the free version or not. Sorry if it doesn't.
Link to .stl for whale model on Sketchfab
This is a link to the .stl model on Sketchfab.
A link to a failed 3D scanned model
Link to failed model on Polycam
This is a link to a model that failed on the Polycam website. It only shows the sweater and the base, but not the whale.
Link to .stl for failed model on Sketcfab
This is a link to the .stl model on Sketchfab.
Kiri Engine scanning app
Kiri Engine Scanning App
I was not happy with all scans when using Polycam so I decided to try out another app called Kiri Engine. I found it on App store. It can be used for free but as with the Polycam app, it has more features when paid for. I wanted to use the Featurless object scan, which was only available if you buy a perscription, so I decided to pay for a Pro plan.
Kiri Engine Interface
This is what the interface of Kiri Engine looks like. You can see my scan at the top and if you want to scan another object, you click on the plus.
Beginning to scan in Kiri Engine
These photos show how you begin by choosing which type of scan you want to do and then you choose between taking photos/video or uploading photos.
I like the Kiri Engine app
I liked using the Kiri engine scanning app. The model seems to be scanned with good detail.
A screenshot of the 3D model scanned with Kiri engine
Links to design files for KIRI Engine
Link to .stl for whale model on Sketchfab
This is a link to the .stl model on Sketchfab.
Model from Kiri 3D printed
Prepairing the model for 3D printing
I opened the model that I scanned with the Kiri Engine scanning app. Then I got a message about the model being very large. I also got an error message telling me that the model reached outside the plate.
Scaling the model
After opening the model I scaled it down to a 3cm model.
Painting the model
After opening the model I used the paint tool to change the colours of the model.
Model fully painted
Here you can see the fully painted model. When a model is printed in more than one colours the 3D printer, the nozzle needs to be cleaned between colours. That is the reason for the three coloured brick on the side.
File very large
I downloaded the .3mf file from Bambu Studio after painting it and it was very large, or 10.2MB. I could neither upload the file to SketchFab nor my Repository. For that reason I uploaded it to my personal drive and here is a link to it. It is a read only file:
Slicing the model
After scaling the model down and painting it, I sliced the model. Then I decided to use the "Tree" support. After that it was ready to be 3D printed. Here you can see how the model turned out. You can see the tree and also the brick that was made when the nozzle was cleaning itself between colours.
Surface of model rather rough
The model was rather rough and if I wanted to print it again this small, I would probably use a smaller nozzle than the 0.4 nozzle. I would also check if I could tune the roughness down with some settings in the Bambu Studio. The photo here is a screenshot from the star I designed in Tinkercad (see later on this website) and it shows the nozzle size. I used the same nozzle for the mini whale model here.
Video of mini whale model that was 3D printed
Video of the mini whale model that was 3D printed
Here you can see the 3D model that I printed in Bambu Lab X1 Carbon. With the model I was trying to visualize what the final model should look like. If the whale is supposed to hover in the air with the help of magnetic force, the levitation module will be placed in a base and the float has to be placed inside the 3D model. The float is round and flat, so the bottom part of the ocean in the 3D model, should contain the float. I think I made the sea too tall because if the model is too tall it might be hard to balance it. In the final model I need to create space outside and around the float so that I can add steel balls or something alike in the right places to balance it. P.s. In the background you can see the fjord where I live; Norðfjörður. We often see whales appear, not the Humpback whale but other species.
Mini whale model that I 3D printed
Designin in Tinkercad
About Tinkercad
Tinkercad is a free app with an online editor. As you can see here, Tinkercad can be used for designing electronics, coding and 3D design. It has a learning center with lots of tutorials. Here you can find the signup or login site for Tinkercad. I had already created an account but only tried simple designs like a house.
The design I made
Interesting project in Tinkercad
I saw that Thinley Wozer Dorji created a star in many layers in Tinkercad, a fidget toy. I saw that I could learn a lot from this project and decided to follow his directions on how to create this fidget toy. The reason is that I would like to be able to teach my students, which are both elementary and secondary students, to do similar things in Tinkercad. Below you can see the interface of Tinkercad.
Choosing a form to work with
I chose a star to work with. I decided to use the same sizes as Thinley Wozer Dorji did, but I used 5 vertices. As you can see, each time you choose a form you decide if it is a hole or a solid form.
Stars and holes
I duplicaded the star and made the other one as a hole. Then I duplicaded the stars until I had five of them. Then I did the same with the holes. The picture here shows how I set the sizes.
Alligning
To allign objects you choose the objects you want to allign and then click on the dot at the end of the line you want them to be alligned to. Here I alligned two and two stars together at a time and then I alligned all of them. On the lower image all the stars and all the holes are alligned as one.
Just one star with one hole
After alligning all stars and holes as one, I clicked on Group. Then I noticed that instead of many layers of stars, I could only see one star and one hole. I realized that this happened because when I grouped all elements the biggest hole swollowed all smaller elements. I had to use the Undo button until I could group just one star and one smaller hole together, one star and one hole at a time. Then I had five stars that were hollow. After that it was possible to allign and group the five hollow stars.
Removing a part of the star
To cut of the upper part of the star, I added a cube as a hole. Then I elevated the cube/hole and clicked on Group.
Elevating the star
Then I elevated the star for 5mm.
Duplicating and alligning
The next step was to duplicate the star and rotate the copy for 180 degrees. When I tried to allign the two parts, they just wouldn't allign.
Trying to rotate both halfs
I tried to rotate the upper and lower half so that they would fit, but the rotation was always too many degrees.
Deleting the lower half and rotating the upper one
I decided to delete the lower half and rotate the upper half before I duplicated it again.
Star in many layers ready
This worked and I could easily allign the upper and lower half. Then I chose both halfs and clicked on group. Then the design was ready! This object would not be easily made subtractively, because you would have to drill or cut through the upper parts to be able to work on the lower parts.
Star 3D printed
Star prepaired for printing
The star was prepaired for 3D printing in the Bambu Studio slicer. Here you can see the interface. I enabled support because of the steep angle under the star. After slicing the app shows among other things how much filament will be used and how long it will take to print the model.
Star printed and failed
When I saw the printed star I realized that it had failed. I knew that the angle could cause spaghetti to appear but I thought that by enabling support in the Bambu Studio slicer, it would be ok. As you can see here below, the results were bad. I have to find out what went wrong.
Backside
When I looked at the backside, I couldn't see any support. When I sliced the model I added the support and sliced again, but maybe it didn't generate and I didn't look closely. So later on I have to be more aware of this.
Design file - Tinkercad
Learning outcome
Learnings from the group assignments
I found it very useful to compare the printing texts to this poster with CAD design tips form 3D printing. The design tips help a lot and by using them as a guidance it is more likely that a model you design will turn out fine. We have only had our Bambu Lab X1 Carbon printer for a few months and it was good to see how well the 3D tests came out. It was also interesting to do the joint test that Jóhannes Andrésson designed because I am quite new to 3D printing and I did not understand what clearance is. Now I understand better how important it is for the clearance to be adequate and I saw that with the joints test in the Bambu lab printer when joints with little clearance broke.
Learnings from the individual assignments
It was interesting to try different techniques to scan an object. I was surprised to see that it wasn't always working but I was just as surprised to see how cool the 3D models could be.
I learned a lot from following the directions that Thinley Wozer Dorji made in the Tinkercad project. I understand the difference between additive and subtractive processes. I still need to learn more about 3D scanning, creating 3D models and 3D printing, as can be seen in the star that I printed and failed.