N3D Safety Code Introduction 1. Getting Acquainted with

Makerbot Replicator (3D Printer) Tutorial Updated: 1/23/2013

Notre Dame Design Deck 1

N3D Safety Code

All posted safety guidelines must be followed at all times. The current safety code is posted

around N3D an available at http://engineering.nd.edu/groups/n3d/safety.

Introduction

This tutorial walks through the process of creating a keychain of the Notre Dame monogram. It

is meant for the true beginner and steps through the entire process from getting acquainted with

3D modeling (through SketchUp) to the final printing of the keychain.

1. Getting Acquainted with SketchUp

Requirements

Trimble (formerly Google) SketchUp

3-buton mouse. A one-button mouse can also be used, but this tutorial will follow the use

of a 3-button mouse

skp_to_dxf plug-in (Found at http://www.guitar-list.com/download-software/convert-

sketchup-skp-files-dxf-or-stl)

Viewing Your Model When using SketchUp, you are treated as if you were looking at a model through a camera.

There are several tools that are used to view your model in a 3D space. The most commonly used

camera tools are the Orbit tool, Pan tool, Zoom tool, and Zoom extents tool.

Before you can practice viewing a model, there must be something in your drawing area. We’ll

create a simple rectangle for demonstrational purposes. To begin:

Select the Rectangle Tool ( ) from the toolbar, or press R.

SketchUp works with a Click-to-start/click-to-end method. Click anywhere to start your

rectangle, and click somewhere else to finish. We’ll worry about measurements later.

Orbit Tool

1. Click the Orbit Tool ( ) in the toolbar, or press O.

2. Now click and drag anywhere in the drawing area to rotate your view.

3. 3-button mouse shortcut: Click and drag using the middle-mouse button/mouse wheel.

There is no need to click on the Orbit Tool when using the middle-mouse button.

Pan Tool

1. Click the Pan Tool ( ) in the toolbar, or press H.

2. Click and drag to pan.

http://engineering.nd.edu/groups/n3d/safety

http://www.guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl

http://www.guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl



3. 3-button mouse: Hold down Shift. Click and drag the middle-mouse button to pan.

Zoom Tool

1. Click the Zoom Tool ( ) in the toolbar, or press Z.

2. Click and drag up or down to zoom in and out, respectively.

3. 3-button mouse: Roll the scroll wheel to zoom in/out.

Zoom Extents Tool

1. Click on the Zoom Extents Tool ( ) in the toolbar, or press Shift + Z. Your model is

centered in the drawing area.

Creating Geometry with the Push/Pull Tool

1. Pushing and pulling is the essence of model building in SketchUp. We will continue to

use the same rectangle you created before.

2. Click the Push/Pull Tool ( ), or press P.

3. Click on the rectangle you created previously.

4. Move your mouse up or down to increase (decrease) volume.

5. Press the Esc key at any point during the operation to start over.

6. Click again when you reach your desired volume size.

7. Try pushing and pulling different surfaces of your shape.

Creating a Void

1. Draw a rectangle on the front of your first one.

2. Then use the Push/Pull Tool to push the rectangle in until you see a dialog saying “On

Face,” and your cursor turns blue. You may have to change your camera view to achieve

this.

3. Click to create a void.



Drawing and Dimensioning Shapes

SketchUp allows you to make models with accuracy by allowing you to enter the dimensions of

a shape while creating it.

Before creating any shapes, under Window, click Model Info. Click Units on the sidebar. For

Format, select Decimal and Inches.

Now, for example:

1. On a New file (Top menu, File > New), create a rectangle.

2. Type in the following: 2’, 3’, including the comma. The measurements will be shown on

the lower right corner of the windows. Press Enter. This creates a rectangle that is 2 ft.

wide and 3 ft long. Typing in m’s instead of the apostrophes would create a rectangle that

is 2 m x 3 m.

3. Create another rectangle. Now type: 1.5,1.75, without the the apostrophes and then press

Enter. Since the default unit is inches, then a 1.5”x1.75” rectangle is created.

Try the same with a circle. Create a circle with the Circle Tool, enter its radius, and press Enter.

You can also push/pull a shape and then entire its desired height. Note: At any point you can

press the Esc key to redo an operation.

Installing the skp_to_dxf plug-in

1. In SketchUp, under the Window menu, select Ruby Console.

2. Type in the following: Sketchup.find_support_file("plugins").

3. This is the address where the plug-ins may be located.

a. Windows: C:/Program Files/Google/Google SketchUp 8/plugins

b. Mac: /Library/Application Support/Google SketchUp 8/SketchUp/plugins

4. Move the skp_to_dxf.rb to this folder.

5. Restart SketchUp.

For more information on other tools, you should visit

http://support.google.com/sketchup/bin/answer.py?hl=en&answer=36207.

http://support.google.com/sketchup/bin/answer.py?hl=en&answer=36207



2. Creating the ND Monogram Coin

Creating the Coin

1. Open a New file. Make sure your units are set to inches and Decimal format.

2. Create a circle at the origin with a 0.675” radius.

3. Pull the surface of the circle up 1/8” (0.125”).

4. Using the Offset Tool ( shortcut: F), click the edge of the circle and drag your

cursor slightly towards the inside of the circle. Type 0.05 and press Enter.

5. Using the Push/Pull Tool, push the inner circle in 1/16” (0.0625).

6. Zoom into the top edge of the circle. Select the Circle Tool.



7. Hover your cursor over the edge of the circle until it says Midpoint.

8. Move your cursor down, making sure a green dotted line appears on screen. This means

you’re moving along in a straight line along the green axis.

9. Make sure your cursor is a small distance from the edge. Draw a circle with a radius of

0.075”. Push it to create a void. Don’t worry about the location of the circle. We can

always change this later.

10. Triple-click the model. Right-click and select Make Group.



11. Save your model under File > Save. Name your model coin.skp.



Creating the ND Monogram

Creating the “N”

1. Create a rectangle that is 0.73” by 0.81”.

2. Using the Tape Measure Tool ( shortcut: T), create a guideline that is 0.20” offset

inward from the left side of the rectangle.

3. Create three more guidelines: One offset 0.20” from the right side of the rectangle, and

two offset 0.11” from the top and the bottom.

4. Draw a horizontal line on the top guideline that is 0.078” long, off the left edge. Then

draw a line all the way down to the bottom guideline. Lastly, draw a line to the edge of

the rectangle.



5. Similarly draw a 0.78” long line from the right side. Then draw a vertical line all the way

down the bottom edge.

6. Draw two lines that extend the length of the rectangle on the vertical guides.

7. Use the Protractor Tool ( ) to create an angled guideline that is offset 30º from the

vertical. Click on the Endpoint shown. Click upward along the line. Type 30 and press

Enter.

8. Draw a line from the endpoint along the angled guideline until it meets with the left

guideline.



9. Select the line by using the Selection Tool ( shortcut: spacebar). Select the Move

Tool ( shortcut: M). Hold down Alt (Option on Mac) and drag the line by the

endpoint until it meets with the top edge.

10. Draw a 0.078” line from the edge shown (bottom edge). Then draw a line that meets with

the bottom edge.

11. Repeat the same for the top edge.

12. Under the Edit menu, select Delete Guides.

13. Using the Eraser Tool ( shortcut: E) delete the highlighted lines (left edge also).

You must delete them one by one. If you make a mistake, under Edit, select Undo, or

just press Ctrl+Z.



Creating the “D”

1. To the right of the “N”, create a 1” x 0.5” rectangle.

2. Make three guides: one offset 0.185” from the left edge and two 0.11” offset from the top

and bottom edges.

3. On the top guide, draw a 0.06” horizontal line from the left edge. Continue that line

downward until the bottom guide, and then finish it off on the left edge.



4. Draw a rectangle between that intersects the guides and is 0.7” wide.

5. Create guides (2) that are offset 0.033” from the rectangle that was just drawn. Draw a

line as shown below. Make sure it turns pink to ensure that it is being drawn at a 45˚

angle. Do the same for the bottom edge.

6. Draw two more lines as shown below, for the outer edge of the “D”.



7. Delete the guidelines. Erase the highlighted lines shown below. You must also delete

them one by one. Select the inner surface and erase it as well.

Assembling the Monogram

1. Create a guide that is offset 0.168” to the left of the top left corner of the “N”. Create

another guide that is offset 0.15” below the top left corner.

2. Using the Selection Tool, double-click the “D”. Move the “D” from the endpoint shown

to the where the guides intersect.



3. Erase the highlighted edges. Using the Selection Tool, double-click the monogram.

Right-click it and select make group.

4. Save the file as monogram.skp.

Assembling the ND Monogram coin

1. Create a new file. Under File, select Import… Look for coin.skp and import it. Make

sure the Format is set to SketchUp Files.

2. Click the origin. If you can barely see the coin, use the Zoom Extents tool (Shift+Z).



3. Import monogram.skp, place it on the coin. Make sure the cursor says “On Face in

Group.”

4. Double-click the monogram to enter the group. Pull it up to the height of the edge of the

coin. One way to do this is to pull it, and then hover your cursor until it shows “On Face

outside Active”.

5. The final coin should look as shown.

6. Under Tools, select Export to DXF or STL. Click Yes on the pop-up box. For export

unit, select mm. (ReplicatorG uses mm.) For Export to DXF, select stl. Click Save.



3. Printing the Coin

Before beginning, download ReplicatorG from http://www.replicat.org.

1. Connect the Replicator to your computer. Turn it on. The switch is on the back.

2. Open ReplicatorG. Under Machine> Machine Type(Driver), select The Replicator Dual.

Then under the same menu, this time Connection, select COM4 (Note: It might be a

different one. On Mac, select /dev/tty/usbmodem...).

3. Click the Connect button at the top. ReplicatorG should now display a green status bar.

a) Under File>Open, locate your .STL file. Click OK.

b) Click the Generate GCode button. Ensure the following are checked:

Use Right/Left extruder. You can use either one.

Use Raft/Support UNCHECKED.

Use support material > None.

Use default start/end gcode

Use Print-O-Matic

c) Ensure the following settings are entered:

Feedrate (mm/s): 50 (Default is 30)

Travel Feedrate: 50 (Default is 30)

d) Click Generate Gcode. Then click Build. The machine should start operating.

Important Notes on the Settings

Use Raft/Support: This creates a raft underneath the object being printed. Sometimes

having the raft is helpful if the object is not sticking to the platform.

Use support material has three options. In order to use supports, “Use Raft/Support” must

be checked.

o None

o Exterior Support: If the object has overhangs, it is necessary to use supports.

o Full Support: Selecting this option tells the Replicator to put supports inside the

object where needed, as opposed to just around the object.

Object Infill: Dictates the density of the print. 100% will make the object solid, while

0% will make it hollow.

Layer Height: Determines how flat each layer will be, defining how fine the print will

be. You can experiment with layer heights of 0.1mm for finer detail.

Number of shells: Refers to the outer perimeter of the object. Every object starts with

one perimeter layer, so the number typed is actually how many layers are added. For

example, typing 2 is the equivalent of having 3 concentric perimeters.

Feedrate: The speed at which the machine moves while extruding. “Travel feedrate” is

the speed at which the machine moves while the machine is not.

Note: The defaults are always a good place to start, but only experimenting will produce

satisfactory prints.

http://www.replicat.org/



Troubleshooting

The Replicator (printer) will not connect to the computer.

o Open ReplicatorG with the Replicator disconnected. Then connect it, and go to

“Rescan serial ports” in Machine->Connection (Serial Port).

The model is not sticking to the platform.

o Try using a raft. In some cases, this might alleviate the problem.

o Run the leveling script to level the platform, under Utilities -> Level Build Plate.

The Replicator is shaking due to a high speed while printing. This could harm the

machine.

o Turn the acceleration on. This can be done through the onboard menu on the

machine, or through the Onboard Preferences in ReplicatorG.

o If the acceleration is off, or you cannot find how to turn the acceleration on, then

you should not print at speeds higher than 40mm/s.

Deliverable

Design and print an object (no larger than 2”x2”x2”) that requires the use of supports. The object

you print should show some level of proficiency using SketchUp or some other 3D modeling

software. Email a photo of the final print to the TA.



Quiz Questions

1. What file format is used for for 3D printing? a) .stl

b) .skp

c) .prt

d) .dxf

2. In order to create guidelines, you should use the

a) Line tool

b) Offset tool

c) Tape measure tool

d) Scale tool

3. To dimension a rectangle, you

a) Use the dimension tool after creating the shape

b) Use the tape measure tool

c) Use the scale tool by selecting the edges

d) Type the dimensions in after you created the rectangle

4. (True/False) In order to print a sphere, you must use supports.

5. What are the units that ReplicatorG utilizes?

a) in

b) mm

c) ft

d) cm

6. (True/False) If the plastic does not stick to the platform while printing, this is considered a

misprint, and you must restart the print.

7. (True/False) If the Replicator is shaking, the feed rate may be set too high.

Documents

N3D Safety Code Introduction 1. Getting Acquainted with