I built R2-D2

R2-D2

Styrene body, legs and feet with and Aluminum dome and resin detail parts
Plans

I'm following the Dave Everett Styrene plans from astromech.net they need to be printed full scale at your local print shop.
Plan transfer

Cut out the different parts from the plans and attach to the styrene using a spray glue. I started with the body. The body rings are cut out on a router.
Gluing parts

Straight piece's are cut out with a ruler and utility knife. Tools for assembly. Needle bottle, 90 degree brackets, to keep everything square) several are needed as you work thru the parts abnd lots of clamps of all sizes
Body Interior

This shows the body after adding all the layers in an eggcrate frame approach. The openings are carefully laid out on the plans so that body components in the skin will line up.
Leg

This shows the typical interior layout of the legs. The central chase provides a raceway for foot motors this gets overlaid with 1/8" material and eventually a 1mm skin of styrene.
Skinning the legs

This view shows the 1mm styrene skin being applied to the completed leg. This opening is for the under shoulder detail.
Body Skins

2 layers of 1mm skins are glued to the frame this creates a strong light weight body. The inner skin and outer skin goe together to simuate body panel openings
Skirt

Lots of cutting. This view shows the skirt that goes on the bottom of the body with the center foot opening. my droid is 3 leg only so there is a flat surface to mount the center foot to. Similar to the legs an internal structure of 1/8" material is glued together then 1mm skins are attached to create the exterior surface.
Using some leverage

The 1/8" material used on this curve needed some extra power to hold down until the glue cured. This shows how you have to get creative in clamping odd parts.
Skirt side

1 mm skirt side is chamfered to fit the opening
Skirt curve

This shows how internal supports are added so that a curved piece can be cut to fit the skirt
Skirt Ribs

I layered 2 pieces of 1/8" styrene and used a disk sander to fit each piece individually into the opening.
Center ankle parts

This shows the center ankle parts that have been cut from the plans and are ready for assembly. The paper is removed and goo gone is used to remove the reside.
Center Ankle

This shows the beefy construction of the center ankle. I had to create a jig to hold the ankle square so I can drill and tap the ankle so it can be bolted to the body
Ankle cylinders

I used 1" PVC to create the ankle cylinders. I set up a stop on the band saw to cut the groves in the part. The tab were created with layered 1/8" styrene and formed on a disk sander.
Ankle cylinders

Finished cylinders painted. I used a blue automotive paint that had some metal flakes that gave a great look. I also settled on using Valspar metallic aluminum paint I was very happy with the results.
Main Feet

This shows how the internal structures are built up. I had to make two so I did them both at the same time. her you can see having lots of clamps and 90 degree angle brackets help in moving the build forward. each piece is held in place with brackets and clamps then the glue is applied with the needle bottle after the glue is cured you can remove the clamp s but over night will allow parts to fully cure.
Main feet

The out side of the feet require lots of chamfering to get the angles to butt up together and get a good glue. I made a lot of used of the bench sander to shape the correct angles.
Main Feet

Take note of the center foot channel the sides are beefed up to allow for a strong connection with the ankle
Main foot

The side is made with two layers of to give the appearance of a panel. the bottom piece is 1mm with no openings. the outer skin (1mm) is cut to look like a panel and glued on.
Main foot motor detail

A 6" wheel from dfrobots along with a small 12 Volt electric motor (jaycar YG2738) drive the feet. A standard drive for light weight droids but for every droid builder there are as many ways to power the droid.

astromech.net/droidwiki/index.php?title=Suppliers_Index#Motors

main feet and battery boxes

Battery boxes show how they are cut out to feed wire from the legs to the feet and have space for the motor. Larger motors take up a lot of this space. my small motors have plenty of room.
Battery box

At this point of the build its an exercise in patience as its the repeated dogma the internal structures are made of 1/8" material and skinned with 1mm material that is easy to curve. The seam is hidden on the side that bolts to the foot so it's concealed and doesn't need to be filled.
Foot assembaly

Lots of test fitting of parts and reference to the plans are required to make sure things line up.
Foot assembaly

A nice tight fit between the battery box and foot as they mate together took a lot of preparation and planning.
On three legs

With the feet built, bolts are used to attach the ankles and feet together. bushings in the ankles ensure the bolts don't wear out the plastic thru use.
Profile

Trivia time R2's legs are at a 33 deg angle. The corner of the shoulder should line up in the middle of the body.
Front foot

Front foot

A 3" castor is used in the center foot. To access the bolt a panel is made I used magnets so he hardware would be concealed.
Detail parts

Test fitting detail parts, every part has a name to eas in construction as you build and buy parts. These are a pocket vent and coin return, a full list can bee seen here.
astromech.net/droidwiki/Terminology
scratch building vents

1 mm material is used to create my parts. then silver paint or silver Rub n Buff is used to create the look. These parts are laid out by hand and cut out.
Octogon ports

lots of parts can be made by hand helping you to reduce the cost of your droid. These were made using scrap material from previous parts.

lots of tutorials are provided by the website to help in construction.
astromech.net/droidwiki/Category:Tutorials

Painting

This shows silver Rub-n-Buff and the blue paint I chose Sonic Blue Peral
Test fitting detail parts

Time is taken to trim and fit each component into its opening and support material created to hold them in place. Little kids and bumpy ground will be your main culprit in knocking these pieces out.
Center vent details

1mm styrene is cut to fit in a resin detail piece.
center vents

I used a Dremel with ta barrel sanding bit to slowly cut out the blue panel for a tight fit.
Horseshoes

boxes are created in the Horseshoe to create openings for details to be added latter on.
Ankle constrcution

This shows the use of a drill press and step bit to cut access holes in the ankle. I would recommend a drill press and bench sander if you want to tackle this project.
disassembled for paint

After all parts have been built and assembled they are taken apart and prepped for paint. I used tamyia White Putty to fill gaps fix any opsies with the knife. Everything was then wet sanded to 1000 grit. A good quality automotive plastic prier was used. Then the white paint was applied. I used Rustolium satin white. (a little birdie tells me this is the paint used on the Episode 7 droids)
Booster cover

This is an example of a club part made from aluminum. Runs of parts in aluminum or resin are found some happening frequently others not so much. So building many parts from scratch helps keep your build moving along. Unless you want an all Al droid then you may be waitng a while.
coin return detail

I created this detail from aluminum flashing usinfg a epoxy to hold it together. It is secured in place with a silicone adhesive like E6000.
internal wiring

fuses, motor controllers I kept mine simple with RC motor controllers from Dimension Engineering sized for your motors mine are a Sabertooth 2×12 to provide tank style drive to astandar airplane controller and Syren 10 for the dome motor.
Details weathered

Weathering is built up using brown and tan acrylic paint. Using both wet washes and dry brushing. I'd recommend Adam Savages weathering tutorial on Tested.
Weathering detail – with acrylic paints

Building up that Tatooine grime – going heaver lower to the ground painting on the acrylics heaver and spraying with a water bottle and wiping of with a damp cloth in several layers gives a great result.
Weathering detail – with acrylic paints

Splotches here are created with a tan acrylic with a dry brush teqnuique
Right profile

Left profile

3/4 view

Front view

Back view

Final product

More detailed build logs, plans and links to part runs can be found at Astromech.net
Source : smokey_sunrise from Reddit