After the 2-3-2 mechanism was basically functional, I moved on to completing the many details of the body including one of my Droid's more innovative features: the aluminum skins. Nearly all styrene builds use styrene skins for the simple reason that the skin, when glued to the frame, provides substantial structural strength to the body. I wanted to do something different. I purchased a set of skins from Guy Vardaman, another great builder who has supplied lots of parts to the club. Mocking up the front inner skin was all I needed to convince me I was on the right path.
The inner skins were attached to the frame using tiny screws and the outer skins were then glued to the inners.
The modifications to the frame were extensive, and included cutting down the outside diameter. Gluing the outer skins on was a big day...uh...week. I could only glue small sections at a time.
Having the outer skins was a pivotal moment in my build. He looks like R2!! Sadly, the Utility Arms are just placed there for fun. Mounting them was a major headache that I completed much later.
I couldn't use Frank's design for the Utility Arm carrier because it couldn't handle the weight of the aluminum arms I wanted to use. After a bunch of practice cutting aluminum for the 2-3-2 gears, I felt confident enough to cut a redesigned carrier from metal.
I designed the belt drives for the arms myself using pulleys designed for 3D printers.
I secured the carrier to the Large Data Port which was used to secure it to the frame as well.
I also used my new aluminum cutting skills to make inner panels for all the body doors. The inner panels give the hinges something to bolt to and also look cool. I also integrated magnets into the corners of the doors to keep them closed.
Perhaps the most challenging parts I made were the Pocket Vents. The complexity of these parts really speaks to the creativity of the original movie prop designers. I built several styrene prototypes of these before the aluminum versions were cut. I've since offered the styrene versions to other club members. The inner portions of the vent were cut from 1/8" aluminum.
All of those small parts needed to be cut, drilled, tapped, and screwed together with tiny 0-80 screws.
The outer skins of the vents were cut in 0.040" aluminum sheet. These parts needed to be bent to follow the curve of the body and then glued onto the inner structure.
The finished vents came out great.
They're held in place by built in magnets.
In that same photo are the so called "coin returns" which i also cut on my CNC. The interior was cut with grooves to make the folding of the metal easier.
Folded and glued to the surround.
Frank's leg kit was terrific. I modified them extensively to house the ankle motors for the 2-3-2 system. For more information on that check out the 2-3-2 page.
The leg detail parts are a combination of purchased and home built pieces.
The final version of the center ankle has linear bearings built in. The angled bar connects to the lift mechanism.
Here's the center ankle installed as seen from the bottom of the Droid.
I designed the center foot with inspiration from Frank's, modifying it to have two omni wheels instead of a caster.
The omni wheels provide stability for the 2-3-2 transition, but also allow R2 to drag is center foot sideways when turning. This was a pretty innovative feature when I first built it, but omnis are now the standard for center feet.
The center foot was finished with a styrene skin of my own design that better matched the more recent standard the club is using.
The outer feet are also styrene, but they're basically just a shell that slips over the drives. The picture below is an incomplete foot with the waste parts still in place in the door area.
Once again the original designers imaginations are on display on the foot doors. Such fun, complex shapes!
The completed door. They are also held on with magnets.
The skirt at the bottom of the frame was directly from Frank. It's a great piece.
Once the major construction was done, I assembled R2 and even went to a few events with him in his unpainted state. I considered these shakedown runs to determine if he had any obvious problems. I loved the aluminum skin, and was really sad to finally paint him. But I was determined that he'd be R2D2 and not some other Droid.
Before leaving for his first event, I took a little video of what R2 could do.