Laser Cut Cardboard Dalek Eyestalk

What devoted Whovian would not want to own a full size replica of a Dalek Eyestalk? Using some photos of Daleks (like the one in the fifth photo) as a guide, I used Autodesk Inventor to create a 3D model of a Dalek Eyestalk, Autodesk 123D Make to create a sliced model of the eyestalk, a laser cutter to cut the slices out of cardboard, and glue and a steel rod to assemble the parts and produce a model like images in this step.

I made this at TechShop.

Step 1: Parts

You will need the following parts and tools to make the Dalek Eyestalk:

Eyestalk Parts:

• Six sheets of 18" x 18" corrugated cardboard.  You can cut up corrugated cardboard boxes or you can order pre-cut sheets at office supply stores like Staples (only four sheets are shown in the photo).
• White glue.
• One 1/4" #20 threaded rod at least 24" long.  You can get these at hardware stores like Home Depot.
• Heavy nuts and washers to be used as weights while gluing.

Stand Parts:

• One sheet of 1/8" Acrylic at least 9.25" x 10".  Sheets of acrylic are available from plastics retailers like Tap Plastics. 
• Acrylic cement like IPS Weldon-On #16.  Available at plastics retailers.

Tools:

• Vise attached to a workbench.
• Laser Cutter.  I used an Epilog Helix 45 Watt Laser cutter at TechShop.

Computer Software:

• Autodesk Inventor or Autodesk 123D Design.
• Autodesk 123D Make
• CorelDraw

Step 2: Create Sketch of the Dalek Eyestalk

Using photos of Daleks I found on the web, I created an outline of a Dalek Eyestalk with measurements like the ones shown in the first three drawings.  Using AutodeskInventor 2012 (you could do something similar in Autodesk 123D Design if you don't have access to Inventor), I created a sketch of the outline of half of an eyestalk as shown the fourth through seventh screenshots. 

Step 3: Turn the 2D Sketch Into a 3D Model

Using the "revolve" tool in Inventor, I selected the center line of the sketch, did a full revolve (first two screenshots) and created a 3D model of the Dalek Eyestalk as shown in the third, fourth, fifth, and sixth screenshots.

Step 4: Add a Hole to the Model

Next, I put a 0.26" diameter hole in the center of the model using the hole tool in Inventor as shown in the first two screenshots.  The resulting model, with the hole, is shown in the third to sixth screenshots.  This hole is the same diameter as a 1/4" #20 threaded rod.  The rod will be used to align the pieces during construction and to provide stability to the model once complete. 

The resulting Inventor 2012 file is attached to this step.

Step 5: Create the STL File

Using the "Save copy as..." function, I created a STL file of the model.  This STL file will be used with 123D Make in the next step to create the cardboard slices of the model.

A zip file containing the STL file is attached to this step.

Step 6: Use 123D Make to Create the Slices

123D Make is an easy to use tool that will take a STL file as input, make slices of the model and create files that can be used to cut the parts on a laser cutter.  The process is easy and straightforward as follows:

1. I started the Windows version of 123D Make on my computer as shown in the first screenshot.
2. I opened the STL file produced by Inventor using the "Import" button (second screenshot).
3. 123D Make then rendered an image of the Dalek Eyestalk (third screenshot).
4. I selected "Stacked Slices" under "Construction Technique" and 123D Make then displayed what the sliced model will look like as shown the fourth screenshot.
5. 123D Make made the model to be 8" long.  I changed the length to 22.34" to make a full size eyestalk (fifth screenshot).
6. 123D Make, by default, sliced the model in a direction that was not what I wanted, so using the "Slice Direction" function, I changed the slice direction so that the slices would be based on the model's center line (sixth, seventh, and eighth screenshots).
7. Using the "Manufacturing Settings" button, I changed the settings to use 18" x 18" sheets of cardboard as shown in the ninth screenshot.  This resulted in a design that would use 6 sheets of cardboard and 126 slices/parts.  The tenth and eleventh screenshots show a couple of views of the sliced model.
8. Finally, using the "Get Plans" button (twelfth and thirteenth screenshot), I created a zip file containing .eps files for each of the sheets to be used on the laser cutter in the next step. 

The zip file with .eps files is attached to this step.

Step 7: Cut and Assemble the Cardboard Slices

In this step, the parts are cut using a laser cutter and assembled:

1. I imported each of the .eps files into CorelDraw in preparation for laser cutting.  A zip file containing the CorelDraw files are attached.
2. I used the laser cutter to cut each sheet.  I used the color mapping settings in the laser cutter print preferences to cut the blue part outlines and used a low power setting to have the laser cutter mark the red numbers on the parts.  I used an Epilog Helix 45 watt laser cutter with these settings:
   • Blue: Vector cutting: Speed 25, Power 40, Frequency 500 Hertz.
   • Red: Vector cutting: Speed 25, Power 5, Frequency 500 Hertz
   • A zip file containing the control file with the settings I used is attached.
3. After cutting all the parts, I collected them up (second photo) and put them into numerical order (third to fifth photos).
4. I put the rod in a vise and carefully slid each part in order onto the rod with white glue in between.  I found I got the best results doing about six slices at a time and waiting for the glue to hold before doing the next group of slices.  I used heavy nuts and washers to put pressure on the parts while the glue was drying (examples are shown in the sixth to tenth photos).
5. I assembled the parts into six components as shown in the eleventh and twelfth photos.  The thirteenth to fifteenth photos show the Dalek eye from various angles.
6. I then glued each component together one at a time on the threaded rod as shown in the sixteenth photo.

The finished model is shown in the last two photos.

Step 8: Build the Stand

So I could proudly display my Dalek Eyestalk, I made a simple display stand out of laser cut acrylic (the stand could also be made out of wood):

1. I created a simple design for the stand in CorelDraw (file attached).
2. Using a 45 watt laser cutter, I cut out the parts of the stand (first and second photos). For the 1/8" acrylic, I set the vector cutting settings to Speed 10, Power 90, Frequency 2500 Hertz.
3. Then using acrylic cement, I assembled the stand as shown in the third and fourth photos.

Step 9: Behold the Finished Dalek Eyestalk!

Voila! The finished model is shown in the photos for this step.The fully assembled Dalek Eyestalk and stand are shown from various angles.  An eyestalk any Dalek would be proud to have!

'EX-TER-MIN-ATE!

'I-OH-BEY!'