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“This [issue’s] parts continue the growing internal framework for the body, and also enable you to carry out a key stage of the assembly, as you install the lightsaber ejector tube in the dome, then wire up all of the electronics inside R2-D2’s head.”

The Understanding Robotics section is missing again, which means there is going to be a lot to do in this issue!



Materials: The Left Leg Support and Leg Support Bracket are metal, but everything else is plastic.


  • Building The Galaxy – Studio and Location Work
  • Droid Directory – Infiltrator Demolition Droids
  • Build R2-D2: Model Instructions


Assembling the Leg Support

Step 1

Fit the Leg Support Bracket over the two pins on the Left Leg Support, as shown:

Steps 2-3

Secure the Leg Support Bracket in place with two (2) 2.5×6 mm silver screws:

Steps 4-6

Retrieve the internal framework from Issue 75. Then, align the two pins on the bottom of the Left Leg Support into the framework holes in the location below and press it home:

Step 7

Secure the leg support to the Middle Ring from below with two (2) 2.5×8 mm silver screws:

This is the completed framework so far:

Fitting the Lightsaber Ejector

Step 1

Retrieve the dome assembly from the previous issue. Remove three (3) of the Allen Screws from the sprue. The three that remain on the sprue are spares in case you need them.

I recommend using sprue cutters or a sharp hobby knife here for nice clean cuts:

Steps 2-5

Retrieve your Dome assembly. Screw the Allen Screws into the locations in the dome below.

As I mentioned back in Issue 64, I did not use the supplied plastic Allen screws. Instead, I used stainless steel versions.

Step 6

Retrieve the Lightsaber Ejector mechanism we last handled in Issue 53. We will also need the Cable Ties/Cable Tidy from this issue:

Steps 7-10

Wrap the Cable Tidy around the lightsaber ejector’s upper wiring, as shown:

Step 11

Use a Cable Tie to secure the upper wires to the mechanism, as shown.

These two Cable Ties do not need to be super tight. They are just used to keep the wires close to the tube so they will not get caught in the dome’s motor mechanisms when the dome rotates:

Step 12

Use the remaining Cable Tie to secure the wires inside the Cable Tidy to the tube, as shown:

Step 13

Cut off any excess from the Cable Ties.

I added a spare twist tie to the bottom of the yellow wire to keep it from moving around. Do NOT put anything through the long gap next to the tube. That is where the lightsaber mechanism moves up and down:

Then, I cut off the excess Cable Ties:

Step 14

Take note of the round lightsaber cutout in the top of the dome, behind the flap. Be careful the flap is not damaged while handling the dome.

I kept this ‘flap’ taped closed until I needed it open. Here, it is easier to see the ejector tube mounting points from inside the dome:

Steps 15-17

Feed the Lightsaber Ejector mechanism into the dome with the wrapped wiring opposite the electronic Distribution Board, as shown. Align the two holes in the mounting tabs to the points indicated in the previous step:

Steps 18-19

While holding the ejector tube in place inside the dome, secure it to the mounting points from above with two (2) 2.3×6 mm black screws:

NOTE: From this point on, the Dome assembly must be stored on the Dome Support Stand. This lightsaber ejector tube sticks out from the bottom of the dome and could be damaged by not using the stand.

Wiring Up the Dome

Step 1

The Distribution Board has seven white sockets, labeled as such:

  • G    Y = Green/Yellow LED Processor State Indicator (Rear)
  • LCD1 = LCD Screen (rear)
  • LCD2 = Logic Functions Display (front)
  • R    B = Red/Blue LED Processor State Indicator (Front)
  • Projector = Projector assembly
  • LS = Lightsaber Ejector Switches
  • M = Lightsaber Ejector Motor
Step 2

Remove any twist ties still wrapped around your wiring. Keep them as we will use them later to tidy up as we go.

Steps 3-6

Route the wiring from the rear Processor State Indicator under the three Cable Clips, as shown:

Step 7

Connect the plug of this wiring to the first socket labelled ‘G   Y’ on the Distribution Board, as shown.

These plugs have polarity and are designed to only fit one way. Do not force them in backwards:

Steps 8-10

Next, route the wiring from the rear LCD Screen under these two Cable Clips, as shown:

Step 11

Connect this plug to the second socket labelled ‘LCD1’ on the Distribution Board:

Steps 12-13 

Next, take the plug from the front Logic Function Displays and connect it directly into the third socket labelled ‘LCD2’ on the Distribution Board.

If this wire is too long or missing from the back of the Logic Function Displays, check your R2-D2 electronics testing rig for the wire:

Steps 14-15 

Then, take the plug from the front Processor State Indicator and plug it directly into the fourth socket labelled ‘R   B’ on the Distribution Board:

Steps 16-17

Secure these last two wires into a nice bundle with a twist tie:

Steps 18-19

Reach in and grab the wiring leads from the Projector assembly, and plug them into the fifth socket labelled ‘Projector’ on the Distribution Board:

Steps 20-23

On the Distribution Board, plug the yellow/black leads from the Lightsaber Ejector mechanism into the sixth socket labelled ‘LS’ and the red/black wiring plug into the seventh socket labelled ‘M’:


This issue took quite a bit of time, but it was totally worth it! The dome wiring might look a little crazy in there, but the head has a lot of electronics in it. Keep this dome assembly safely on the support stand until Issue 98 when we will install the video camera next.

Next Up

 Issue 78 – Left Tool Compartment/Door, Gripper Components, Tool Arm Components, Cover Connectors, Hinges

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