Building a Studio Scale Death Star Laser Tower Model, Part 3

This month, prop maker David Goldberg shares with us his build of a studio-scale replica of the Death Star laser tower from Star Wars. Previously, David covered sourcing his reference, creating a 3D model, and the core structure fabrication. Today is all about the finer details!

The original models built for the Star Wars films were detailed with hundreds of little parts taken from plastic model kits. These parts were often referred to as nernies or greeblies. This was the first time this approach to adding detail for film models had been used to such a great extent and it was one of the defining characteristics of the realistic “used hardware” look of the film. There are photographs of the ILM model shop back in the day showing entire walls stacked high with hundreds of model kit boxes. Models kits of all types and scales were used for “donor parts” but it seems there was a fondness for models of military subjects, especially tanks and other vehicles.

A great deal of time and effort has been spent by members of the Replica Prop Forum (The RPF), Studio Scale Modelers (SSM) and other online sites analyzing photos of the original models and tracking down precisely which parts from which kits were used for the added details. Some of these model kits are still in production and many more are available on EBay, although sometimes at extremely high cost! Other than purchasing the Mig 21 kit to use for the barrels, I decided I didn’t want to spend what could amount to many hundreds of dollars purchasing all of the necessary donor kits, some of which are quite rare. Instead I decided to replicate many of the parts with 3D printing, laser cutting and scratch building. In the end, several ‘authentic’ parts were donated for use on this project by some of the very kind members of the RPF.

Before applying detail parts some additional layers of plating were needed. Styrene sheet, cut by hand, was used for this plating on the original models but I wanted the benefits of precision and speed that could be achieved using a laser cutter, and styrene doesn’t laser cut cleanly, the edges tend to melt a little. Instead I laser cut the plating panels out of a material called Polybak, a cardboard sheeting which has been impregnated with resin to make it water resistant. Polyback is often used to back cabinet panels in moist locations and as a backer for thin wood veneering. It laser cuts beautifully and takes paint well.

I laser cut a series of panels to go on the top of the tower as well as a bunch of randomly sized rectangular panels that I could stick on the casework wherever desired. Before cutting, I applied double-faced adhesive tape to the back of the Polyback sheet so that to attach the parts all I would have to do was peel off the backing paper and stick the parts down. In additional to the plating, several custom parts were laser cut, some with partial surface etching to represent bolt heads and other details.

Creating the several dozen bent metal ladder rungs proved to be a unique challenge. The holes for the rungs were precisely drilled into the MDF tower sides as part of the CNC process. To fit these holes, the ladder rungs would all have to be bent to exactly the same width, a very difficult task to do by hand with a pair of round-nose pliers. The solution was to make a bending jig out of acrylic sheet milled to the correct profile with the CNC router and then use these on a jig plate to bend the pieces of brass rod. The acrylic parts were held in alignment on a steel jig plate using dowel pins. The larger piece was able to slide on the pins and the smaller piece was pinned firmly in place. A bar clamp was used to squeeze the two jig plates together with a piece of 1/16 inch brass rod in between. To make the brass rod easier to bend, it was first annealed with a torch.

To bend each rung, an annealed piece of brass rod was placed in the jig between sliding acrylic jaw and the fixed acrylic plate. The bar clamp was used to force the two plates together conforming the brass rod to the desired shape. The finished rungs were then glued in place on the model,

As I had mentioned before, the detail parts on the original model came from (now) vintage plastic model kits. Some of the model makers on the RPF go to great lengths to make sure they have the exact correct part (and only the exact parts) on their models. A process that can take years. I greatly admire that approach, but on the other hand I’d like to get my model built as quickly as possible. As I like to say “Done is my favorite color!” So as I go about detailing the model I’m not really trying to make an exact replica of the filming miniature. I figure it’s a BIG Death Star! There are a lot of Laser Towers on it and there are bound to be some differences! Every studio scale replica is in some ways an artistic interpretation of the original and this one is mine.

The task of replicating the kit parts used on the original model was done in several different ways depending on the characteristics of the part. Some of the more complex parts were 3D modeled using Rhino software and then 3D printed. Photos of the filming model and in some cases of the individual model parts themselves were used as reference.

A couple of the larger 3D printed parts were glued directly to the model but as multiples would be needed of many of the smaller parts, silicone molds were made from which urethane resin parts could be cast. The patterns for other flat parts were engraved and cut using the laser and a ring shaped key component seen at the base of the laser barrels was machined out of aluminum using a metal lathe and the CNC router. The castings of these parts, as well as parts from a bunch of other plastic kits on hand formed an extensive library from which I could detail the laser tower.

The time had come to start gluing all the various detail parts onto the model. For the most part I used thick super glue to hold the parts in place and a kicker to set the glue instantly.

In addition to the 3D printed, laser cut 3D cast resin parts, some of the details were added the good ol’ fashioned way, built up out of styrene strip and rod along with brass wire of various diameters to represent piping..

Once all the various detail parts were in place the model was ready to paint. It’s fun to see how the original model makers at ILM reused details from other models they were making for the film. The grey detail casting on the top of the turret in between the two barrel slots is known as the “Droid Strip.” It’s the same detail casting used on the X-Wing Fighter models, on the top of the fuselage just behind the cockpit.

Next up, painting and weathering!

Photos and images credit David Goldberg

David Goldberg is a professional modelmaker, propmaker, visual effects supervisor and mechanical designer with more than 30 years experience working in the motion picture, television and theme park industries.

Part 1: Sourcing Reference

Part 2: Building the Casework

Part 3: Fabricating the Details

Part 4: Painting and Weathering

Maker Faire 2016 Recap – Still Untitled: The Adam Savage Project – 5/24/16

It’s been a busy week for Adam and the gang. Last Friday, we were down in LA for the Star Trek fan event, which Adam hosted, and then flew back to the bay area for this year’s Maker Faire. We recap both events and talk about some of our favorite moments from the weekend.

Tested Builds: Foam Propmaking, Part 1

Welcome to a Tested week of builds! We’re joined in the studio by prop and armor maker Bill Doran (Punished Props), who shares with us his techniques for making awesome foam weapons. Throughout the week, we’ll be designing, fabricating, and painting foam props that can be used for cosplay! (This first video is available for everyone–watch the rest of the build by signing up with the Tested Premium member community!)

Adam Savage’s Large Vacuum Forming Machine

Adam wipes the dust off of his old large vacuum forming machine and uses it for an ongoing Apollo spacesuit project! Here’s a primer on vacuum forming and how it’s been used in special effects and prop-making. Adam’s machine has a few quirks, so let’s see how it performs!

Shot and edited by Joey Fameli
Music by Jinglepunks

Episode 351 – Farewell, Tested Office – 5/19/16

Big news this week! Norm, Jeremy, and Kishore record the final episode of This is Only a Test…at the current Tested office. We’re moving! In this listener’s choice episode, we talk about Doom, Nvidia’s GeForce 1080 performance, Origami robots, surprising reactions to VR. Plus, hot takes of news out of Google I/O!

Ask Adam Anything #9: Working Music

This week, Adam answers a question about what music he listens to in the cave while he’s working on projects. Adam digs up his current favorite playlist and runs through some of his favorite songs and artists. If you have a question or something you want to share with Adam, post in the comments below! (Music recommendations as well.) We’ll be back next week!

Building a Studio Scale Death Star Laser Tower Model, Part 2

This month, prop maker David Goldberg shares with us his build of a studio-scale replica of the Death Star laser tower from Star Wars. In Part 1, David explained sourcing reference images and creating a 3D model. Today, he dives into the fabrication of the tower and laser cannons.

While the some of the materials and construction methods used to build the original Death Star Laser Tower filming model are not known, it was most likely made of a core structure of either wood or Plexiglas covered with panels cut from styrene sheet. The original model also had a mechanical armature and motors inside it that would rotate the turret and move the barrels to simulate firing at the Rebel X-Wing fighters. I’m building a static, non-moving display model so an interior mechanism won’t be needed. (At least for now. I’ve designed the casework in such a way that I can put a mechanism into it a later time if desired.)

Laser Tower as seen in Star Wars. Laser Tower as seen in Star Wars.

I’m going to fabricate the model using a more high tech approach than was available to the modelmakers at ILM in the 70’s. Rather than hand cut styrene panels to clad the core structure, I’m going to use a CNC (Computer Numerically Controlled) router to both cut out the structural components as well as cut panels lines into the surface using the .dxf drawing files exported from the 3D computer model.

The material from which I’ll cut the casework is a special premium MDF (Medium Density Fiberboard) ¼ inch thick made by Plum Creek. This material is similar to the fiberboard found at most home center and lumber stores except that it has a smoother surface and a denser, more consistent core. It’s used mostly for making paint grade cabinets and signage and paints beautifully, even the cut edges.

The .dxf files were loaded into the computer that controls the CNC router. I use a software program called V Carve from Vectric. The .dxf files are imported into the program where the various cutting depths, speeds and bit sizes are determined. V Carve calculates and exports the “G-Code” which is a standard machine language used to control CNC machine. The G Code is then imported into a program called Mach 3 that actually sends the control signals to the stepper motors that drive the router.

The parts were cut out of the MDF sheet material with a ¼ inch diameter router bit and the panels lines routed into the surface with a 1/16 inch diameter bit.

After being cut out on the CNC, the outer corners of the sides were mitered to a 45-degree angle on the table saw. In the end I had a stack of parts, my own kit, ready to assemble!

MDF is a wood product and can be glued together easily with carpenters glue. The precision of the computer cut parts ensured that everything went together cleanly and accurately.

In order to be able to get into the turret for assembly I wanted the bottom panel to be removable. This was achieved by 3D printing corner brackets with angled sides that could be glued into the inside corners. The printed brackets had little hexagonal pockets into which hex nuts were glued, which in turn allowed for the bottom panels to be held in place with flat head machine screws.

The assembled casework for the tower is of a really impressive size! Man this sucker is big! And the CNC routed panel lines are really clean and sharp.

The curved tracks alongside the laser barrels were made by first cladding CNC cut pieces of MDF with styrene sheet. On top of the styrene were glued short pieces of Plastruct ABS plastic Tee structural shapes, the same material that was used on the original model. This was then capped with a narrow styrene strip to complete the assembly.

With the structural casework of the Tower finished it was time to turn my attention to the details.

Building the Laser Cannons (Pew Pew!)

The twin laser canons were comprised of three main components – the barrel (the engine from the Mig kit), a slotted sleeve into which the barrel was inserted and rectilinear base assembled out of laser cut acrylic sheet. I was only able to purchase one of the vintage Mig kits on EBay so it was necessary to make a silicone mold of the engine part and cast the two pieces needed for the model.

The slotted tube sleeves were cut from plastic tubing available from Plastruct. To cut the eight slots in each tube I leveraged the power and precision of computer modeling, 3D printing and CNC routing. I design a jig fixture comprised of 3D printed octagonal end buttons which fit into the ends of the cut piece of Plastruct tubing and were held in place by a length of threaded rod and a couple of hex nuts.

This assembly was then clamped into a set of matching 3D printed cradles which in turn fit into rectangular pockets milled into a MDF base plate on the CNC. Once the tube was securely clamped into the cradles the correctly sized slot could be cut using the CNC router.

Then the tube/button assembly was rotated 45 degrees in the cradles, clamped down and the next slot cut. This was repeated until each tube had been cut with eight identical slots. A little bit of clean up with a square needle file to sharpen up the corners and the sleeves were done.

The bases of the laser canons were first 3D modeled in Rhino and then broken down into the component pieces, the same way as was done for the MDF tower casework. In this case the parts were to be laser cut from 1/8″ and 1/16″ thick acrylic sheet. As with the drawing files for the CNC, the files for the laser cut parts were exported as .dxf files which were then used to run the laser cutter.

The cut parts were glues together with solvent cement. Short pieces of 1/8″ square styrene strip we glued into the inside corners of the structures to help re-enforce them.

That completes the casework of the tower and cannons. Next week, we’ll dive into the detailing with greeblies!

Photos and images credit David Goldberg

David Goldberg is a professional modelmaker, propmaker, visual effects supervisor and mechanical designer with more than 30 years experience working in the motion picture, television and theme park industries.

Part 1: Sourcing Reference

Part 2: Building the Casework

Part 3: Fabricating the Details

Part 4: Painting and Weathering

Overcoming Self Doubt – Still Untitled: The Adam Savage Project – 5/17/16

This week, Adam shares how he overcame a recent funk he was in after a bad day at the shop. We discuss the universal feeling of self doubt and impostor syndrome, and how we each move past it. Plus, an appreciation for the movies Pleasantville and The Truman Show!