ATEC-FAB UTDallas : Brian Uretsky

Serial Slices Project: USS Enterprise

This is one of my more interesting (and expensive) projects. I wanted to build something related to my ongoing Star Trek theme. I started looking at my past models for some inspiration when I stumbled upon my NCC 1701-D USS Enterprise model. I built this model about six years ago in Google Sketchup.

As is probably evident, I am a huge Star Trek fan and I would love the opportunity to build something like this.

Google Sketchup Screenshot

To use the Contour command in Rhino to build my serial slices, I first need to get this Google Sketchup model into Rhino.

I used Google Sketchup to export my model as an .obj file, then imported it into Rhino.

Unfortunately, with all the extra geometry from the text decals and windows, the model took ages to load and had a giant filesize.

Luckily, the decals and windows were not integrated parts on the model. They were separate models sitting on top of the ship. I needed to select the ship model and reverse-select everything else.

Google Sketchup (Model Selected)

With all the extra models selected, I can now delete them.

Google Sketchup (Details Selected)

Google Sketchup (Clean Model)

Google Sketchup (Color Removed)

What a beautifully clean model!

After exporting to .obj, I can now import into Rhino.

Rhino Import (Wireframe)

The transfer seemed to turn all my polygons into triangles. It will be a lot more work to cut the serial slices, but it's completely doable.

Model Underside (Wireframe)

My only concern are the small details present in the model. A lot of these small shapes and window gaps are too small to be present in the final serial model.

Model Underside (Shaded)

Model Nacelle (Shaded)

I'm going to ignore them now and fix them later.

Now that I have my model imported into Rhino, I will use the Contour command at 0.13 inches (the width of the cardboard) and create my serial slices.

Contour Command

Contour Slices

There are over 90 slices to my model. It started to look like a very daunting task, but I was determiend to make this model.

Once I verified that the contour command would work properly, I began thinking about how to keep my model structurally sound. I needed to find out how to set up my rods.

There are four major sections to my model; the saucer section, the drive section, and each of the two nacelles.

I plan to use round 1/4" rods to I created two slots for each major section and one for each nacell.

Below is a screenshot of how the model should look with the rods.

Rod Fittings

After contouring the model and examining each serial slice, it was apparent that it needed a lot of work. If you look at the screenshot below, you can see how many control points are created after slicing the model. From a laser-cutting standpoint, the laser must go through each control point. With the model as it is now, it would take hours to cut all the slices.

Serial Slice Control Points (Original)

In Rhino, I had to go through each slice and thin out the control points:

Serial Slice Control Points (Reduced)

Here is the model after I determined where to put the rods. The colors represent laser color codes. The magenta shell represents outer cuts, and the blue represents internal cuts.

Rhino Screenshot

Notice how the end tapers down to a point thinner than the width of the rods. To solve this issue, I will have to cut off the rod's intersecting slices and just keep the parts together with glue.

Rhino Screenshot

Below is a screenshot of my two serial slice cut-sheet. I had so many pieces that I needed to split them onto two boards.

Cut Sheets

Notice how each part is marked in red. Red represents a light engraving. These engravings will help me identify which part goes where.

Serial Slices

After just over an hour or laser cutting, I got all my slices cut out.

Laser Cut Parts

One thing I didn't realize was how small some of the parts were. The parts below show some of the end pieces, nacell slices and pylon parts. Some of these parts are smaller than the width of the cardboard. I'm probably not going to be able to fit these pieces together properly, but I've got to try!

Laser Cut Parts

I grabbed the larger pieces and put them together according to the engraved numbers.

Assemlbed Drive Section

It looks pretty remarkable! I didn't realize how well it would turn out. Below is an example of what it should look like.

Google Sketchup Drive Section Cut

Assemlbed Drive Section

It definitely looks accurate. I'm anxious to get started on the saucer section.

Assembled Saucer Section

It's definitely very cool. I've never built something like this before.

The photos below show what the model looks like when both sections are put together.

Assembled Saucer and Drive Section

I'm very impressed by the way it's starting to turn out. It's beginning to look exactly like my design.

Unfortunately, I had a lot of trouble with the pylons and nacelles.

Assembled Pylons and Nacelles

The parts are incredibly thing and very flimsy. The cardboard doesn't offer any structural integrity.

Similarly with the nacelles, the circular rods mean the nacelles can't orientate themselves properly.

Assembled Pylons and Nacelles

If we look at the saucer section, the entire structure warps. The rods didn't keep it secure at all.

I decided to halt my efforts here and go back to the drawing board. Cardboard is not the solution. I needed something stronger.

I decided to go with 1/8" MDF hardboard. I also needed to redesign some of my parts.

Saucer Section

This is the original design for section 63 of the drive section.

Original Serial Slice Design

Here is the updated design. The etched numbers worked very well for keeping my parts organized, but I changed the circular rods to 1/4" square dowels.

Updated Serial Slice Design

The square shape should also keep the structure rigid and stable.

Updated Serial Slice Design

Updated Nacelle Design

After spending a considerably longer time in the laser cutter, the wood eventually completed the cutting process.

Firstly, the material is a lot nicer to work with. Unlike the cardboard, the parts are completely solid.

Cardboard vs Wood

The smaller pieces are now a lot easier to work with.

Wood Slices

Nacelle Designs

Cardboard vs Wood Nacelle Parts

Updated Designs

This is the new drive section. The wood makes it look a lot more premium and sturdy. It looks amazing!

Assembled Wood Drive Section

Below is the assembled fully-assembled mdoel.

Assembled Wood Saucer Section

Below you can see how the square dowels keep the shape solid.

This Loctite Superglue works very well with the model, especially for the parts that have no support structures.

Completed Model

The model turned out to be a lot heavier than I had imagined it to be. It's unique shape means there is no way to keep it upright without it getting potentially damaged.

I adapted spare parts from our last slots model to create a base station to hold the model.