6. 3D Scanning and printing¶
For this week’s assignment, we looked at 3D Scanning and printing. The group assignment was to test the design rules of the Labs 3D printer(s), document the work done, and explain the limits of the printer(s). While the individual assignment was to identify the advantages and limitations of 3D printing, apply design methods and production processes to show knowledge of 3D printing and demonstrate how scanning technology can be used.
- Group Project Link
3D Printing¶
3D printing uses computer-aided design (CAD) to create three-dimensional objects through a layering method. Sometimes referred to as additive manufacturing, 3D printing involves layering materials, like plastics, composites or bio-materials to create objects that range in shape, size, rigidity and color.
Advantages of 3D Printing.¶
1.Flexible Design: -allows for the design and printing of more complex designs than traditional manufacturing processes.
2.Rapid Prototyping: - can manufacture parts within hours, which speeds up the prototyping process. This allows for each stage to complete faster.
3.Saves Space: - it doesn’t need a lot of space to stock inventory, unlike traditional manufacturing processes. This saves space and costs as there is no need to print in bulk unless required. Design files can also be stored virtually, also reducing space.
4.Strong and Lightweight Parts: the material used in 3D printing is plastic, although some metals can also be used for 3D printing. However, plastics offer advantages as they are lighter than their metal equivalents. This is particularly important in industries such as automotive and aerospace where the weight of parts. Also, parts can be created from tailored materials to provide specific properties such as heat resistance, higher strength or water repellency.
5.Reduced Waste: - the production of parts only requires the materials needed for the part itself, with little or no wastage as compared to alternative methods which are cut from large chunks of non-recyclable materials. Not only does the process save on resources but it also reduces the cost of the materials being used.
6.Cost-Effective: - As a single step manufacturing process, 3D printing saves time and therefore costs associated with using different machines for manufacture. 3D printers can also be set up and left to get on with the job, meaning that there is no need for operators to be present the entire time. As mentioned above, this manufacturing process can also reduce costs on materials as it only uses the amount of material required for the part itself, with little or no wastage. While 3D printing equipment can be expensive to buy, you can even avoid this cost by outsourcing your project to a 3D printing service company.
7.Ease of Access: - 3D printers are becoming more and more accessible with more local service providers offering outsourcing services for manufacturing work. This saves time and doesn’t require expensive transport costs compared to more traditional manufacturing processes produced abroad in countries such as China.
Disadvantages of 3D Printing.¶
1.Limited Materials: - While 3D Printing can create items in a selection of plastics and metals the available selection of raw materials is not exhaustive. This is because not all metals or plastics can be temperature-controlled enough to allow 3D printing. In addition, many of these printable materials cannot be recycled and very few are food safe.
2.Restricted Build Size: - 3D printers currently have small print chambers which restrict the size of parts that can be printed. Anything bigger will need to be printed in separate parts and joined together after production. This can increase costs and time for larger parts due to the printer needing to print more parts before manual labor is used to join the parts together.
3.Post Processing: - Although large parts require post-processing, as mentioned above, most 3D printed parts need some form of cleaning up to remove support material from the build and to smooth the surface to achieve the required finish. Post-processing methods used include water jetting, sanding, a chemical soak and rinse, air or heat drying, assembly, and others. The amount of post-processing required depends on factors including the size of the part being produced, the intended application, and the type of 3D printing technology used for production. So, while 3D printing allows for the fast production of parts, the speed of manufacture can be slowed by post-processing.
4.Large Volumes: - 3D printing is a static cost unlike more conventional techniques like injection moulding, where large volumes may be more cost effective to produce. While the initial investment for 3D printing may be lower than other manufacturing methods, once scaled up to produce large volumes for mass production, the cost per unit does not reduce as it would with injection moulding.
5.Part Structure: - With 3D printing (also known as Additive Manufacturing) parts are produced layer-by-layer. Although these layers adhere together it also means that they can delaminate under certain stresses or orientations. This problem is more significant when producing items using fused deposition modelling (FDM), while polyjet and multijet parts also tend to be more brittle. In certain cases it may be better to use injection moulding as it creates homogenous parts that will not separate and break.
6.Design Inaccuracies: - Another potential problem with 3D printing is directly related to the type of machine or process used, with some printers having lower tolerances, meaning that final parts may differ from the original design. This can be fixed in post processing, but it must be considered that this will further increase the time and cost of production.
7.Copyright Issues: - As 3D printing is becoming more popular and accessible there is a greater possibility for people to create fake and counterfeit products and it will almost be impossible to tell the difference. This has evident issues around copyright as well as for quality control.
3D Printer/Group Project¶
This weeks grooup assignment was completed by the following Fab Academy students:
- Ravi Baldeo
- Nerene Bhagwandass
- Terrence Carew
- Marvin Holloway
- James Khan
In the Lab we currently have the Flash Forge Creator Pro based on open-source technology. It allows owners to upgrade various parts of the printer, making it very flexible. This 3D printer has the following features:
1.Software
The Flash Forge Creator Pro is not restricted by proprietary software meaning that users have many options to use when working with this printer such as:
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Simplifiy 3d
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Skeinforge
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Cura
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3D Builder
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Slic3r
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ReplicatorG
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FlashPrint
Note. ReplicatorG is currently software used with the printer.
2.Heated Build Plate
The build plate is approximately 6.5mm thick and made from aluminum. It also has the additional ability to be heated to various temperatures meaning that it can work with different materials.
Note. Be cautious not to burn your hand when removing parts from the bed.
3.Build Volume
The build volume of this machine is approximately 227mm (L) X 148mm (W) X 150mm (H) or 8.94inches (L) X 5.83inches (W) X 5.91inches (H).
Note. If parts or models are larger than the build volume, consider breaking up the model into smaller parts that can be printed by the machine and then assembling after.
4.Nozzle/Extruder
This printer is a dual extruder (left & right) and allows for smooth filament loading. The extruders also contain fans to improve modeling and both extruders can also print at the same time. Also, by the nozzle diameter for both extruders are .4mm and can reach temperatures of 240 C (463 F)
Note. Dual extruders allow for the printing of two materials at the same time increasing model variety.
5.Materials
Apart from its ability to use two materials at the same time the printer also allows this use of different types of materials such as PLA, ABS, woodfill, copperfill, brassfill and flexible filament
Note. Each filament may require a different temperature to be used effectively.
Limitations of the 3D Printer¶
In order to test the limitations of the printer we used the various test builds provided on the Fab Academy Schedule for the 3D Scanning and Printing week click here
1.Angle
This test looked at what angle could be successfully printed without requiring any support. The angles used were 0,10,20,30,40,50,60,70,80 &90. Following the test, it was observed that angles between 0-40 all had some defects whereas 50-90 appeared to be ok
2.Overhang
This test looked at the distance that material can be placed without having support. The distances used were 1mm to 10 mm. Following the test, it was observed that most of the pieces had errors.
3.Bridging
This test looked at the distance material can be placed without having supports. The distances used were2mm,4mm,6mm,8mm,10mm,12mm,14mm,16mm,18mm and 20mm.Following the test it was observed that distances between 6mm-20mm resulted in errors in the build while distances between 2mm-4mm showed no errors.
4.Wall Thickness
This test looked at the minimum thickness a wall could be using the 3Dprinter. The thicknesses used were 2mm,4mm,6mm,8mm,10mm,12mm,14mm,16mm,18mm and 20mm.Following the test it was observed that thicknesses between 6mm-20mm was not suitable for walls.
5.Dimensions
This test compared the dimensions of the design vs the dimensions of the 3D print. Following the test it was observed that the dimensions of the 3D print varied by .06 mm from the design
6.Surface Finish
This test looked at the at the finish of the final part created.
ReplicatorG¶
1.This software can run a variety of 3D printers from MakerBot Replicator, Thing-O-Matic, CupCake CNC, RepRap machine, or generic CNC machines. It accepts either GCode or STL files. It’s a cross platform, easily installed, and is based on the familiar Arduino / Processing environments. ReplicatorG is growing the number of printers it can operate.
2.When you open the application, you will find a blank page and it will identify the connected printer.
3.When an stl file or gcode is added a model will appear in the black area with options for manipulating the model.
4.To print the model select generate code and options will appear that control various settings of the 3D printer such as extruder temperature, build plate temperature, infill, extruder to be used, supports, and rafts. After the preferred options have been selected and generate the gcode to create the object. When this is completed select the build option an the printing process will begin.
Note. While the machine tab provides a list of printers that can be used with the software. The Thingiverse tab links to a database where many models can be found to use with the machine.
3D Print¶
Based on the limitation for the 3D printer identified from creating the test print I created my design using Fusion 360.
1.Firstly I opened Fusion 360, ensured my units were set to mm and created my sketch.
2.Then created my overall shape and dimensioned it to ensure that it had the correct measurements. Also note that the angles value was chosen from the angle test printed that showed no errors.
Note. When using fusion 360 you may run the risk of over-dimensioning your design making it more difficult to make changes later.
3.Then I offset the design based on a wall thickness identified from the wall thickness test print. I also closed the shape by drawing two lines to the top to ensure it could be turned into a 3D object.
4.Then I performed a revolve using my design as the shape.
5.Then I used the fillet command to curve the shape edges by 5mm. This would make the final model smoother.
6.Then I performed the align command until the model was placed in the desired location.
Note. A reference point may need to be created to align the object to. Also, another option would have been to draw the initial sketch in the position you would want to place the final model and revolve it from there eliminating the need for aligning.
7.Then I exported the model as a stl to be 3D printed.
8.Then I opened the file in replicator, placed the model in the preferred location, generated the gcode and sent the model to be printed.
Note. Be mindful that in a dual extruder machine if you are using a single extruder, the extruderthat is not being used may hit the model when it is building your design which can affect the quality of the final model.
3D Scanning¶
1.Firstly I imported the pictures of my model into meshroom, selected my save location and then selected start.
Note. Not all images are the same, so some images may not be reconstructed using meshroom.
2.Then I removed 3 nodes from the operation as they resulted in issues when I ran the process previously. After which I connected the remaining nodes together
Note. Ensure that the sensor database is updated this will provide better results.
3.Then I selected start and it took me through the options of saving the render that will be created in a preferred location.
4.Then I removed the images that could not be reconstructed.
Note. Ensure the you take a lot of quality photos as some may have to be removed affecting the end result
5.Then I selected start and ran waited until the process was completed the images that could not be reconstructed.
Note.Unfortunately, the scan did not come out well but I will try another location and make some changes and see if I can achieve better results.
3D Scanning Take 2¶
1.This time I decided to use a mobile app.After some review watching I chose
2.After installing the app and setting up a free profile, I started the process to create a new scan by selecting the “+” icon to the bottom of the screen.
3.When the options appeared I selected the first option photo scan as my account was freeand id did not have access to the pro options.
4.Then the app indicated that free version had a limit of 70 photos.
5.After taking my 70 photos I was given some options to name the scan and make a few customization.
NB. I only added the name and did not change the default settings.
6.After uploading the photos by selecting upload the app gives a message when the images have been uploaded successfully.
7.After waiting a few minutes to have the images processed I was presented with a successful 3D scanned object.
NB. Due to the fact that processing of images is performed online the time taken to render the final scan may vary depending on your internet connection.
8.Unfortunately,the free version does not allow exporting of the 3D image.However you are provided with 3 options to acquire the download if you desire.
