So you are a fan of the Star Wars Universe and you want to build your own representation of a working Astomech Driod. If you're not concerned with accuracy but just want something that looks good and works then this Instructable is for you. By searching through some household items you can build one that will satisfy your needs.
Step 1: Disclaimer
Just a quick disclaimer to state that we take NO responsibility for anything that happens as a result of following this instructable. It's always best to follow the manufacturers instructions and safety sheets when building anything so please consult those documents for any of the parts and tools you use to build your own droid. We are simply just providing information on the steps we used to create our own hobby droid. We are not professionals. As a matter of fact, 2 out of 3 of the individuals who participated in this build are children.
Step 2: Acquire the Parts.
1. Scrap wood
2. 1 Large round plastic container with lid (we used a pretzel container)
3. 1 Small round container (we used a cool whip container)
4. 2 LEDs
5. 2 1k ohm resistors
6. 1 hobby servo motor
7. 2 hobby continuously rotating servo motors
8. 1 HC-06 Bluetooth module
9. 1 piezoelectric speaker
10. 1 Arduino Uno
11. 2 4 AA battery packs
12. 1 push button switch
13. 1 breadboard
14. 2 servo wheels
15. Many wires
16. 1 small caster
17. Assorted screws, nuts, bolts, and washers.
Step 3: Tools
1. Wire Strippers
2. Needle Nose Pliers
3. Phillips Screw Driver
4. Drill and Drill Bits
5. Band Saw
6. Hot Glue Gun
Step 4: Prepare the Large Plastic Container
Since the goal is to make our robot resemble an Astromech Droid the bottom of the body needs to taper slightly. We discovered a large pretzel container upside down would look good. So we cut off about a 1/2" of the top of the container and turned it upside down. The we cut out a circle from a 1/4" sheet of plywood that would fit in what was the top of the contain but is now the bottom of the body. This plywood will be used to mount the front leg and wheel assembly and conceal the electronics. Once the plywood fits properly within the hole in the container sand all edges smoothly for painting later on.
Step 5: Fashion the Legs
Build 2 back legs using your scrap wood in the general shape of an Astromech Driod back leg. We used some scrap pine and added 1/4" plywood to the lower section for added stability and visual effects. Before attaching the 1/4" plywood sections, on the inside of the back legs, we drilled a 1/2" hole half way through the center of the curved area. We also drilled a 1/4" hole from the bottom of the back leg intercepting the 1/2" hole at the top. This provided a means of hiding the 3 wires that would power and control the servos later. If you do not have a long enough drill bit then you could just cut a grove on the inside as it will not be very noticeable in the finished product. Once the holes are completed attached the 1/4" plywood to the inside and outside of each leg. Cut out a recess in the bottom of each leg that will accept the servos you selected for the project. Finally, with another scrap piece of pine create the shoulder that will be attached to the inside of each back leg. Our plastic container was tapered where we wanted to mount these back legs so our shoulder is in the form of a wedge that matches the taper of the container. Your maybe different.
For the front leg we again cut it out of a scrap piece of pine. This piece was roughly 4" x 2" to start and then we cut the top at an angle that appeared visually pleasing. We then cut a second piece of scrap pine to about 4" x 4" with all 4 sides being beveled to about 17 degree angle. We attached the 4" x 4" piece was attached to the square section of the 4" x 2" piece and then the castor was mounted to the underside of the 4" x 4" piece.
Mount the front leg to the round plywood that you cut in earlier.
Step 6: Mount Legs and Bottom
First you'll need to build an internal structural piece that provides both a mounting point for the electronics as well as an attachment for the bottom. Using some 3/4" x 3/4" pine scrapes build an inverted U shape. Make the horizontal member of the inverted U the exact length of the inside diameter of your large plastic container. Since our large plastic container had a significant taper above the horizontal member's mounting area the vertical members of the inverted U are attached 1" from other end of the horizontal member. The vertical members are 1/4" shorter than the distance from the top of the horizontal member to the top of the container. This 1/4" is to allow for what will become the bottom to recess inside of the container. Glue and screw the pieces together. Finally, drill holes through the sides of the plastic container to attach the horizontal member of the inverted U to the container.
Next, drill 2 holes on each side of the plastic body to attach the side legs. Also, drill 1/2" holes in the center of the attachment area directly adjacent to where the 1/2" holes in the legs will be. This allows you to run the power and control wires from the Arduino to the servos.
Place the 1/4" bottom made in the previous steps on top of the inverted U and attach it with screws. Ensure that the front leg is properly centered in what will become the front of your Astromech Driod.
Finally, remove everything, finish sand and paint. We choose to paint ours similar to Q5 from the Star Wars Universe but you can choose an color combination you would like.
Step 7: Building the Head
Drill a small hole in the center of the head (small plastic container). Attach another section of 3/4" x 3/4" pine scrap inside the plastic container using the hole you just drilled with a small wood screw. This will become the supporting structure used to rotate the head. Center and attach a servo horn to the 3/4" x 3/4" pine. Press the servo into the horn.
With the painted and dried body, drill a 1/2" hole in the top of the body (remember we inverted the large container so this hole is actually in what was the bottom of the original container). Make sure the hole is not in the center. Anywhere towards the outer edge of the container is fine for this hole. This hole will later be used to run the power and control wires for the servo that spins the head.
Next, using a hot melt glue gun, place a substantial amount of glue on the bottom of the servo mentioned above and quickly place and center the head assembly on top of the main body. Make sure you hold it firmly in place for a few minutes to ensure the hot melt glue adheres properly.
Remove the screw holding the small plastic container in place and gently remove it from the assembly. Now add more hot melt glue to area surrounding the servo to ensure it is mounted substantially enough.
To conceal the screw attaching the head to the supporting pine structure add 2 small pieces of pine scrape on either side of the top of the head. Place the lid that you saved from the large plastic container over top of these small pieces of pine and secure with small unobtrusive screws.
Finally, paint and decorate the head assembly in keeping with the theme you selected.
Step 8: Adding the Controller and Other Electronics.
Remove the inverted U assembly from the inside of the body. Attach the breadboard to one side of the assembly and the Arduino Uno to the other side. Ensure that the locations of both the breadboard and the Arduino Uno will not interfere with the inside of the body when reattaching the assemble. Now is probably the best time to load the provided Arduino sketch. If you need help in loading an arduino sketch the internet has many tutorials on this subject.
Drill mounting holes in the body to attach the LEDs and the power switch. We placed a red LED in the back top of the body to indicate when the droid was backing up or at a stop and a green LED in the front top of the body to indicate when the droid was moving forward. We mounted the power switch low on the back of the body. However, these mounting holes can be placed where ever you prefer. Now begin wiring the components as shown in the electronics diagram above. You may need to deviate from the diagram if you substitute other parts. Also, please follow the instructions that were provided with your Bluetooth module instead of relying on this diagram as most are different.
Once everything is wired you'll want to test out the circuity before reassembling everything. Attach your batteries and turn on the power. Send the F, R, L, S, C, P, 1, 2, 3 commands to the Arduino via a Bluetooth connection like the Android app ArduinoRC to ensure that each servo operates properly. Once satisfied, turn of the power and reassemble the droid.