ISSUE 91

 Return to the BUILD


“This [issue] includes all the parts you need to complete R2-D2’s centre foot and attach all three legs to his body framework. The first step is to install the infrared sensor and switches used to detect obstacles in his path.

OK, this issue is so big that they removed both of the Droid Directory and Understanding Robotics sections. I had to include more than 50 photos here just to cover it all. Prepare yourself!

Contents


Parts

Materials: The Leg Pivot Cover and Castor Wheel frame are metal, but the rest of the parts are all plastic.

Hardware

TypeQuantitySizeColorHead TypeFor
Screw52.5x6 mmSilverCountersunkMetal
Screw92.5x4 mmSilverPanMetal
Screw32x6 mmBlackPanPlastic
Screw22.6x8 mmBlackPanPlastic
Screw242.3x6 mmBlackPan
Plastic
Screw92.5x8 mmSilverPanMetal
Screw72.5x6 mmSilverPanMetal
Nut2LargeSilver
Spring Washer2LargeSilver
Flat Washer2LargeSilver
Spring Washer92.5 mmSilver

Tools

  • Spanner

Magazine

  • Building The Galaxy – Post-Production Factory
  • Build R2-D2: Model Instructions

Build


Fitting the Sensors

Steps 1-3

Unwrap the Microswitches and fit the right microswitch (with the black wires) into this location in the Centre Foot Base.

The two holes in the white part of the switch fit over the matching pegs, as shown:

Steps 4-5

Repeat this process with the left microswitch (with the red wires) on the opposite side, as shown:

Steps 6-7

Unwrap the Infrared Sensor Cable and connect the smaller plug to the socket on the Infrared Sensor:

Steps 8-9

Fit the Infrared Sensor into this location of the Centre Foot Base, and secure it into place with one (1) 2.3×6 mm black screw.

Do not over-tighten this screw as you may damage the circuit board:

Steps 10-11

Place the Right Switch Retainer over the right microswitch as shown, and secure with two (2) 2.3×6 mm black screws.

Make sure this pin of the retainer (arrow below) is not obstructed by the switch wiring. I had to bend the switch pins a bit to make this fit better:

Step 12

Repeat this process with the Left Switch Retainer using two (2) more 2.3×6 mm black screws.

As in the previous step, make sure this pin does not trap the wiring (arrow below):

Fitting the Castor

Steps 1-2

Fit the Castor Wheel up through the hole in the center of the Centre Foot Base aligning the nut with this hexagonal recess:

Step 3

While holding the wheel in place, fit one of the large flat Washers over the exposed end of the Castor Wheel bolt:

Step 4

Then, fit a large Spring Washer over that flat Washer:

Steps 5-6

Finally, add a large Nut and tighten it fully using the supplied Spanner wrench:

Assembling the Foot

Steps 1-2

Retrieve your Centre Foot Mounting Plate (from Issue 89) and feed the two sets of wires from the foot up through this square hole as shown:

Step 3

Retrieve your Centre Foot (Left Side) from Issue 89. Run the wires that are between the Centre Foot Mounting Plate and the foot into this recess, as shown.

The Centre Foot Mounting Plate is to the left of this picture, while the foot is to the right side:

Steps 4-5

This should allow you to fit the Center Foot Mounting Plate over these four mounting posts without pinching any wires, as shown:

Step 6

Secure the Center Foot Mounting Plate into place in these side holes with two (2) 2×6 mm black screws:

Step 7

Slide one of the Foot Details (from Issue 89) down into this recess at the front of the Centre Foot (Left Side).

Make sure the L-shaped tab of these Foot Details sits fully down and flush with the side of the Centre Foot (Left Side), as shown:

Step 8

In the same way, slide the other Foot Detail (from Issue 89) down into this recess at the rear of the Centre Foot (Left Side):

Step 9

Slide the Pivot Rod through the two holes of the Bumper Bar (both from the previous issue), as shown:

Steps 10-11

Slide the end of the Pivot Rod into this short post at the front corner of the Centre Foot (Left Side).

Make sure this Bumper Bar is inserted in the correct orientation. It should hang down past the foot, as shown:

Step 12

Retrieve your Centre Foot (Right Side) from the previous issue. Start to fit the two sides of the foot together.

Make sure the free end of the Pivot Rod fits into this matching short post:

Step 13

This should allow you to close the two foot sides together, lining up all four internal screw posts:

Steps 14-15

Secure the two foot sides together with six (6) 2.3×6 mm black screws as shown:

Steps 16-17

Fit the Centre Foot Base up against this foot side assembly. At the same time, gently pull any slack wire up through the foot assembly.

Make sure the two bulbs of the Infrared Sensor fit through the base correctly and the two microswitches are behind the Bumper Bar:

Step 18

Secure the Centre Foot Base to the foot sides with four (4) 2.3×6 mm black screws:

Step 19

Fit the Angled Plastic Plug into this upper ankle hole, aligning the plug so it is flush with the surface:

Step 20

Fit the Straight Plastic Plug into this lower ankle hole:

Steps 21-23

Remove the other Plastic Plugs from the sprue. Then, match the angle of the heads of each Plastic Plug with the foot surface and insert them into each of these four side holes:

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

The center foot is now complete!

Make sure the Castor Wheel can rotate freely and that the Bumper Bar moves freely and engages the microswitches behind it. If you want to test this Infrared Sensor, you can use the same test procedure as before (back in Issue 53) by plugging this Infrared Sensor Cable into the 3-pin socket on the Test Board, powering it up, and check the green LED only lights when the foot is on a solid surface.

Fitting the Legs

Steps 1-3

Retrieve the Left Leg assembly (from Issue 61) and, starting at the shoulder, wrap all the wires with a Cable Tidy:

Step 4

Repeat this process on the Right Leg assembly (from Issue 38) using another Cable Tidy:

Steps 5-6

Retrieve your body framework assembly last worked on in Issue 85. Feed the wires from the Left Leg assembly through the hole in the left Shoulder Fitting on the framework, as shown:

Step 7-8

Keep feeding the wires through until you can fit the Left Leg assembly over the Shoulder Fitting, aligning the four mounting holes:

On my model, this would not sit flush. It turns out the black Ultrasonic Sensor cable was getting caught between the fittings. I used a set of tweezers to push it out of the way and everything fit perfectly:

Steps 9-10

Secure the leg to the shoulder using four (4) 2.5×8 mm silver screws.

Be sure to put a 2.5 mm Spring Washer onto each screw before installation:

Steps 11-12

Like with the Left Leg, feed the wires from the Right Leg assembly through the hole in the right Shoulder Fitting on the framework, as shown:

Step 13

Keep feeding the wires through until you can fit the Right Leg assembly over the Shoulder Fitting, aligning the four mounting holes.

I had the same problem with the black Ultrasonic Sensor cable on this leg too. Just move it out of the way:

Step 14

Secure the leg to the shoulder using four (4) 2.5×8 mm silver screws.

As before, be sure to put a 2.5 mm Spring Washer onto each screw before installation:

Steps 15-17

Thread the bundled leg cables from each leg down through the square hole in the Leg Support Bracket on that same side:

Here is the left side:

And, here is the right side:

Completing the Shoulders

Steps 1-3

Push the square tip of the Leg Key Handle firmly into the matching hole in the Leg Key Head:

Steps 4-5

Secure the parts together with one (1) 2.6×8 mm black screw:

Step 6

Align the tabs of a Leg Pivot Cover to the slots in either outer shoulder joint and press it into place, as shown.

One Leg Pivot Cover is supplied with this issue and the other one was supplied back in Issue 04:

Steps 7-8

Use the Leg Key to turn the Leg Pivot Cover clockwise until it locks in place:

Step 9

Repeat this process with the other Leg Pivot Cover on the opposite leg:

Fitting the Bottom Panel and Foot

Steps 1-2

Turn your entire R2-D2 framework upside down. Retrieve the Bottom Panel assembly (from Issue 88) and feed the two wiring leads through these two openings, as shown:

Step 3

Fit the Bottom Panel to the framework lining up the holes around the edge. The captive screws of the battery Access Panel may prevent it from sitting flush, but this will be fixed in Step 5:

Step 4

Secure the Bottom Panel into place using six (6) 2.5×6 mm silver screws at these locations:

Step 5

Secure the two captive screws of the Access Panel into place as well:

Steps 6-7

Feed the wires of the Center Foot assembly through the middle hole in the Bottom Panel, aligning the foot like this:

Steps 8-9

Align the four pins on the Center Foot assembly with the four matching holes in the framework and press the foot into place:

Step 10

While holding the Center Foot assembly in place, turn the entire framework over, and make sure the center foot is correctly positioned:

Steps 11-12

Fix the Center Foot assembly into place from above with four (4) 2.5×6 countersunk silver screws:

Thoughts


OK, that was easily the longest issue of the entire build. However, we completed so much along the way, and R2-D2 can now stand on his own three legs! It really is a sight to see as I love this little guy.

Next Up


 Issue 92 – Battery Box/Cover, Battery Tester/Charger, USB Charging Lead

Leave a Reply

Your email address will not be published.