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“The main part provided is the drive motor for R2-D2’s left wheel, which is supplied complete with its integral gearbox and circuit board. After you have fitted the motor to R2-D2’s foot, you will be able to complete the wiring and fit the casing to his leg.”




Materials: The only part in this issue, the motor, is made mostly of metal.


TypeQuantitySizeColorHead TypeFor
Screw52.5x10 mmSilverPanMetal
Screw252.3x6 mmBlackPanPlastic


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Fitting the Drive Motor

Steps 1-2

Fit the shaped drive spindle of the Left Wheel Motor/Gearbox into the matching hole of the Axle from the previous issue, and align the motor’s four mounting holes to the plate:

Steps 3-4

Secure the motor into place with four (4) 2.5×10 mm silver screws, as shown:

Step 5

Retrieve the Motor Cable supplied back in Issue 46, unwrap it, and connect the larger plug to the socket on the motor’s circuit board:

Step 6

Thread the other end of the Motor Cable up through the gap between the leg and the Left Ankle Mounting Plate:

Steps 7-8

Retrieve the Sensor Cable from Issue 45 and unwrap it. Thread the larger plug end of this cable up the leg in the same way:

Step 9

Make sure the smaller plug end of the Sensor Cable is 135mm from the retaining loop (circled below) on the leg.

I measured from the small plug end and marked the cable with a pen at 135mm to line this up:

Steps 10-11

Retrieve the Cable Ties from Issue 46. Using one tie, secure it around the wires and retaining loop marked in the previous step.

TIP: Make sure the ‘square’ on the ends of these Cable Ties do not block any of the mounting holes of the leg frame. If these holes are blocked, it will make it more difficult to fit the leg covers on later in the build:

Steps 11-13

Repeat adding Cable Ties to the remaining three retaining loops going up the leg:

Step 14

Cut off the surplus ends of all four Cable Ties:

Fitting the Leg Casings

Step 1

Retrieve the Leg Casing assembly from Issue 48. Take both of the cables we just tied down and feed them through the large hole in the leg casing (along with the black shoulder ultrasonic sensor cable):

Steps 2-3

Align the inner and outer casings of the leg and press them together. The Left Ankle Mounting Plate will need to be slid down to the base of the leg in order to fit these together.

I slide the Left Ankle Mounting Plate up to hold these together for the picture:

Step 4

Slide the Left Ankle Mounting Plate up over the two leg casing halves to lock them together:

Step 5

Retrieve the left leg shoulder assembly and fit it to the outer leg casing:

Step 6

Secure the leg casings together with twelve (12) 2.3×6 mm black screws:

Step 7

Retrieve the left ankle assembly (from Issue 43) and fit the posts through the holes in the leg assembly, as shown:

Step 8

Drive one (1) 2.3×6 mm black screw into the indicated hole from the other side to lock the ankle assembly in place:

Step 9

Take the Left Leg Bottom Cover (from Issue 47) and press the ankle fitting assemblies (from Issue 45) into each side:

Steps 10-11

Fit this cover assembly over the inside of R2-D2’s ankle, ensuring the cables fit into the recess of the cover.

This is the recess the cables need to fit into:

Fit the cover assembly to the ankle, guiding the foot cables into this recess:

Step 12

Screw these parts together with four (4) 2.3×6 mm black screws:


Wow, these leg assembly issues are much longer than others! It also means we are finally able to combine a lot of parts that have been sitting around in storage for a while.

Next Up

 Issue 56 – Dome Panels, Powerbus Cable Mounting Plate, Outer/Inner Foot Casings

4 thoughts on “ISSUE 55”

  1. Hi.

    Following this guide has been really helpful, esp where the magazine instructions are erroneous.

    I think step 12 of this issue needs to be changed to (4) 2.3 × 6mm BLACK screws, as you did in issue 30 for the right leg. Just thought I’d let you know.

    Thanks again for the additional guide, extremely helpful.

  2. Thanks for the great guidance! It is very helpful for building my R2D2.

    In steps 3-4 the four screws for the motor are 2.5×10 mm silver screws instead of 2×10 mm.

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