Return to the BUILD

“This issue’s parts include the microcontroller unit that acts as R2-D2’s brain. It is equipped with sockets into which all his sensors, motors, displays, other electronics, and power supply will be plugged.




Materials: The non-electrical parts in this issue are plastic.


TypeQuantitySizeColorHead TypeFor
Screw52.3x6 mmBlackPanPlastic
Screw32.5x10 mmSilverFlangedMetal
Screw32x4 mmSilverPanMetal
Screw52.5x6 mmSilverPanMetal
Screw53x12 mmSilverPanMetal
Nut32.5x5 mmSilver
Spring Washer53 mmSilver
Spring Washer72.5 mmSilver


  • Building The Galaxy – Picture-Perfect Planets
  • Droid Directory – R2-D2 Astromech Part 15
  • Understanding Robotics – Robotic Hands
  • Build R2-D2: Model Instructions


Fitting the MCU

Steps 1-2

Fit one of the Cable Clips over these two mounting holes in the MCU with the open end towards the edge of the MCU, as shown. Then, secure the Cable Clip in place with two (2) 2.3×6 mm black screws:

Steps 4-5

Repeat these steps with the other Cable Clip and two (2) more 2.3×6 mm black screws, facing the open end the same way as shown:

Step 6

On the back of the MCU are two slotted lugs which will be used to mount it in the next steps:

Step 7

Those lugs will fit into these keyhole slots of the Circuit Board Bracket we installed in the previous issue:

Steps 8-10

Fit the MCU lugs into the keyhole slots (facing this direction) and slide it down the slots to secure it in place, as shown:


“The chief function of the body is to carry the brain around.” – Thomas A. Edison

Our little R2 unit is no different. It would be nothing without this MCU ‘brain’. Based on the size of it, there is a lot going on inside that box. I am excited to finally see it all hopefully working soon!

Next Up

 Issue 95 – Dome Spindle, Dome Motor Support Plate, Bearing Housing Halves, Dome Drive Shaft, Cable Retainer, Bearings/Retainer

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