Cal Poly Pomona Additive Manufacturing 3D printing ME Laboratory the lab is easy and does not require any calculations but you need to answer all questions

Cal Poly Pomona Additive Manufacturing 3D printing ME Laboratory the lab is easy and does not require any calculations but you need to answer all questions and do some research about it . please read carefully MECHANICAL ENGINEERING
LABORATORY
4600:484
3D Printing Lab
(Design and Print 3D Structures)
Room: 15B (near the wind tunnel)
Faculty Supervisor: Jae-Won Choi (jchoi1@uakron.edu)
Teaching Assistant: Daryl Philip (dgp17@zips.uakron.edu)
ME LAB: 3D PRINTING
OBJECTIVE
This lab is designed to introduce 3D printing (also officially called Additive Manufacturing)
technologies and their applications using extrusion-based and/or jetting-based 3D printers. 3D
printing technologies are emerging and there are many benefits over traditional manufacturing
processes such as lathe, mill, etc. 3D Printing is a layer-by-layer joining process to
fabricate/manufacture a 3D structure. The objective of this lab is to have students understand 3D
printing processes and technologies through hands-on practice from designing to manufacturing
using commercial 3D printers as an alternative manufacturing process as well as production
process.
BRIEF INTRODUCTION OF 3D PRINTING
A 3D model is designed in CAD/CAM software such as Creo, SolidWorks, CATIA, Siemens NX,
etc. This model needs to be converted to the standard file, which is .stl or .amf. The converted
file includes approximated surface information. And this is sliced into thin layers, which is
accomplished in 3D printing software. Finally, tool paths in each layer are generated and 3D
printing starts. Below is the step-by-step 3D printing process.
The different categories of 3D printing / additive manufacturing.
Vat Photopolymerization
o Uses a vat of liquid photopolymer resin
o Ultraviolet (UV) light cures / solidifies layer of liquid resin, the process called
Photo polymerization
o Does not use support material, unlike powder based methods, however supports are
required
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o Stereolithography Apparatus (SLA), Projection, etc.
Powder Bed Fusion
o Uses either a laser or electron beam to melt and fuse a thin layer of powder together.
o Polymer/metal/ ceramic
o Selective Laser Sintering (SLS), Electron Beam Melting (EBM), Selective Laser
Melting (SLM) etc.
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Material Extrusion
o Extrudes a material through a heated nozzle and then deposited layer by layer
o Polymer/low-temperature alloy
o Fused Deposition Modeling (FDM)
Material/Binder Jetting
o Material jetting creates objects in a similar method to a two dimensional ink jet
printer, using either a continuous or Drop on Demand (DOD) approach.
o Material is jetted onto the build surface or platform, where it solidifies and the
model is built layer by layer.
o Polymer/ceramic/metal
o 3D Printing (3DP), Multi-Jetting, etc.
FDM and/or Multi-Jetting printers will be shown in the ME Lab.
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LAB INSTRUCTIONS
PART A: 1st model Design
Design a mug using SolidWorks. Follow the specifications given below:
Draw the sketch below on the front plane
Use ‘Revolve’ feature to revolve the sketch with respect to the vertical line through origin.
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Use the ‘Shell’ feature with shell thickness 2 mm and the top face of the part.
Draw the following sketch on the front plane
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Create a new plane. Start with having right plane selected.
Right plane would be first reference. Click on the purple point to select second reference.
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Use the newly created plane, ‘Plane1’ to draw the following sketch.
Use the ‘Swept Boss/Base’ feature, choose the sweep profile and path to make the handle
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Check ‘Align with end faces’ from the ‘option’ while working on ‘Swept boss/base’
Save the file as an ‘STL’ file
Click yes to save
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PART B: 3D Printing
Print the mug with two different settings in MakerBot (use one setting for one machine)
High quality printing (Layer thickness of 0.10 mm)
Low quality printing (Layer thickness of 0.30 mm)
Print the mug using uPrint the layer thickness 0.013 inch and ‘low density’ infill
Print the mug using Dimension with layer thickness 0.01 inch and ‘solid’ infill
The 3D printers use specific software to prepare manufacturing information, provided by the
manufacturer.
The example shown below is from a commercial software by Stratasys available to download
online for students, educators and professionals even. The machine uPrint and Dimension provided
by the manufacturer for the pre-processing of the model created.
(1) Opening your .STL file using GrabCAD
Open GrabCAD.
Select New Project – select Add Models – Locate and select the STL file that you have created in
Part A
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GrabCAD Software allows you manipulate your design before sending it to the uPrint for printing.
It simulates the uPrint printing pad so you can orient, scale, re-size and rotate the 3D print to get
the best result when printing. Become familiar with the software and understand the functions
before starting your first print.
(2) Set properties for the model from the different option tabs on the left
(a) Tray Setting – Slice Height (Layer resolution)
There are two options for the layer resolution: 0.01in & 0.013in. Set to 0.013in.
(b) Model interior
This establishes the type of fill used for the interior areas of the part. There are three types of
model interior:
• Solid – Best used for maximum structural integrity.
• Sparse High Density – This is the default model interior style and is highly recommended.
Build times will be shorter, less material will be used and the possibility of part curl
For geometries with large mass will be greatly reduced.
• Sparse Low Density – The interior will be “honeycombed” or “hatched”. This style allows
for the shortest build times and lowest material usage but will decrease the strength
of the part.
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(c) Support fill
Support styles will affect the support strength and build time of the print. There are three
support styles:
• Basic – May be used for most parts. Basic support uses a consistent spacing between
support toolpaths.
• SMART – minimizes the amount of support material used, reduces the build time, and
improves support removal for many parts. It is the default for the software.
• Surround – The entire model is surrounded by support material. Typically used for tall,
thin models.
(d) STL units: Inches or Millimeters
(e) STL scale
(3) Set the orientation for the model in Orientation tab
The Orientation tab has an expanded preview window. It provides options for viewing a part,
measuring a part, orienting a part, processing a part and viewing the layers of a part. How a part is
oriented in the preview window will determine how the part is oriented when it prints. Orientation
impacts build speed, part strength, surface finish and material consumption. Orientation can also
affect the ability of GrabCAD to repair any problems with the STL file. You can choose to auto
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orient your part, which allows GrabCAD to determine the best orientation for the part for the fastest
build time and least material usage, or you can manually change the orientation of your part.
The part has to be reoriented as shown in the picture below by using the orientation options. To
ensure the part is properly oriented and on the build plate,
Select ‘Orient Face to Plane’ – Select the bottom face of the cup – Select ‘Bottom’ – ‘Done’
NOTE: Orientation Considerations
• Build Speed – Closely related to material use. A lesser amount of supports will allow for a
faster build speed.
Another factor affecting build speed is the axis orientation. The printer can build faster across
the X-Y plane than it can along the Z axis. Orienting a part so that it is shorter within the modeling
envelope will produce a quicker build.
• Part Strength – A model is stronger within a layer than it is across layers. Depending upon
what features you want your part to demonstrate, you may need to orient your part to have its
greatest strength across a specific area. For example a tab that needs to be pressed would be
weakest if you are applying pressure across layers.
• Surface Finish – Much like orienting for strength, how the part is oriented will determine
how the surface finish will look and allow the printer to provide the smoothest finish for a specific
area. For example, if building a cylinder, orienting the cylinder upright will have a smoother
surface finish than building it on its side.
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• STL File Repair – It is possible for an STL file to have errors while appearing to be trouble
free. If the STL file contains errors, GrabCAD may have problems processing the file.
GrabCAD has the ability to automatically correct some STL file errors. How the part is
oriented can impact this automated repair function.
(4) Show Slice Preview.
When you click on Show Slice Preview, GrabCAD will show you a preview on how the model
will be printed, including the support structures, in a layer by layer fashion.
(5) Printing your STL file:
Click the Print button on the right-hand side bottom corner.
GrabCAD will now process the part and send it to the printer to print.
You can also view estimates such as the Print Time, the amount of material to be used and the
amount of support material that will be used. Click the ‘View Estimates’ button next to the ‘Print’
button.
1. From uprint workstation, send a part to the printer. The display will show Idle/Ready to
Build and the name of the first file that is in the queue waiting to be built.
2. Insert a modeling base.
3. From the display panel press Start Model to start building the part.
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PART C: 2nd Model Design and Print
Create the second part
Draw the following sketch on front plane. Each straight line has equal length of 5 mm
and angle increases by 15°.
Extrude the line drawn 2 mm. Use thin feature thickness 2 mm.
Save the model as STL file.
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Print the part using MakerBot:
Click on ‘Add Models’ from the ‘Project Panel’to open the STL file in MakerBot
software
Click on the part to do any translation, rotation, or scale change
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Reorient the model like the figure shown below (rotate 90° along x axis)
Make sure the part is just on the platform. Scale the part up to 200%.
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Click on ‘Settings’ to change print mode to ‘Balanced’ – Under ‘Support Type’ select
‘Breakaway (PLA) Support’
Click on ‘Print Preview’ to view the model with the support structure as well as print
time and amount of material being used.
Click ‘Export’ or ‘Print’ to then send the part to the printer to start printing.
PART D: POST PROCESSING
Post processing example is given for uPrint and Makerbot.
(1) Removing a completed part
When the printer has completed building a part, the display will show Completed followed by
the file name. It will also show Remove Part and Replace Modeling Base.
1. Open the chamber door.
2. Turn the modeling base retainers down and remove the modeling base by sliding out.
3. Insert a new modeling base by sliding in and pushing down, turn the retainers up.
4. Close the chamber door.
5. After you have opened and closed the door, the display will show Part Removed? ONLY
after removing the part and replacing the modeling base, from the display panel press Yes.
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After you press Yes, the display will show the status as Idle or Ready to Build for the next
part in the queue.
(2) Remove a part from the modeling base:
1. After removing the modeling base from the printer, firmly flex the modeling base back and
forth with your hands to loosen the part.
2. Pull the part off of the modeling base or use a putty knife to completely remove the part.
(3) Removing support material
uPrint SE uses soluble support material which is designed to dissolve in a soap and water based
solution. Use the water bath (support removal tank) for few hours in high temperature. It needs 6
packs of cleaning agent (Ecoworks A,B) for the whole tank. Your part is left with a smooth and
clean finish with the fine details intact. The soluble support material can be removed by hand
with relative ease, but is designed to be dissolved from your parts for hands free finishing.
PART E: Evaluation
Measure and compare dimensions (at least 5 measurements for each part)
o Thickness of the printed mug (average and standard deviation)
o Handle width and depth (average and standard deviation)
o Compare the measured dimensions and those in the 3D model
Qualitatively compare the quality of the mugs printed in uPrint, and MakerBot (e.g.
surface roughness, appearance, burr, supports, etc.).
At which angle did the part start getting support material for the 2nd model? Relate this to
the part orientation.
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Report/Presentation Guideline (The following should be included)
1. Part E (Evaluation) should be presented on the report/presentations. Lessons learned
during the lab, including the building processes, post-processing, materials, pros and
cons, etc. (20 points)
2. Present the entire process with photos to print the mug. Discuss parameters to be taken
into account. (20 points)
3. Choose the best orientation for each model? Explain why. (20 points)
Cube
Half cylinder
Cube with a through hole
Hemisphere
Half cylinder with a
horizontal through hole
Spring
L shape
Part
4. What 3D Printing processes exist other than the processes that you used during the lab?
Classify the processes by materials and material joining technology. Provide a
representative commercial system for the classified processes. (10 points)
5. What is 4D Printing? (10 points)
6. Suggest your own examples with 3D printed parts. Why is 3D printing needed for these
examples? You can refer examples from websites. (10 points)
Grammar, spelling, clearness, reference citation (5 points)
Arrangement of report/presentation (5 points)
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