Introduction: RobBox 3.0 the Self-made, Walking, Humanoid Robot (completion in Progress)
This instruction is not ready yet. I am currently working on the completion, I published it because one of my friends is already building this robot and he needs the instruction.
When I first saw the film “Real Steel” I wanted to build a robot which should be able to detect others and fight against them. While searching the web for the parts I could need to build my first robot, I discovered a robot competition named “RobotChallenge”. Visiting the “RobotChallenge” raised my interest in robots and I soon wanted to build one myself. Two months later I had finished the upper part of my first robot. It was able to do shadow boxing and was relative flexible.
Till now I have built 3 complete robots, the first version was made of wood, the second one of aluminum parts and the latest generation (“RobBox 3.0”) contains many 3D-printed parts. All of them are able to walk, scan their environment for objects and fight against them. They are also able to stand up immediately after they have fallen down.
My robots competed at the “RobotChallenge” in Vienna twice. There, they walked as fast as possible or pushed other robots out of the arena. “RobBox 2.0” came in fourth in 2015 and “RobBox 3.0”, which was named “XOXObot” for this competition, even finished third in “Humanoid Sumo” in 2016. “RobBox 3.0” also won the first place at the “FabContest 2015” which was organized by the “HappyLab” in Vienna. In three years of building robots I had to face some problems and always tried to solve them as well as possible. Every year, after the “RobotChallenge” I started a new robot project, which included lots of improvements.
I also discovered other construction kits, which are currently available online, but my robot only costs about €450 which is a lot cheaper than others. This price is calculated without the cost for 3D-printing and CNC-milling!
"RobBox 3.0" uses 21 servo motors, 4 per arm, 6 per leg and one to turn the head. 3 sonic sensors are used to measure distances to other objects and one gyroscope is used to detect if the robot has fallen down. The robot can display data like the measurement of its 8 line sensors, which are build into the foot plates, or the current voltage measurement on its inbuilt LC-display. All the parts are listed on the next page.
Step 1: Necessary Equipment
To build such a robot you need to be able to use some machines."RobBox 3.0" requires 3D printing and CNC-milling. Currently I am working on a possibility to use a laser-cutter instead of the CNC-mill. As it is relatively expensive to buy all of these I would recommend to search for a "FabLab" like the "HappyLab" in your area.
The upper body, some connections in the legs, the head and the sonic-sensor mountings are 3D-printed. The files are available on the next page.
CNC-milling is used to produce some brackets for joints and the foot plates.
Moreover you will need:
- wire cutter
- M3 nut
- soldering iron
- other basic tools
Step 2: The Parts You Have to Buy
An excel-sheet with all the necessary parts is available here.
Furthermore you will need one nano servo to turn the head, but you will have to search it by yourself. Its dimension should be not bigger than 20x8.8x25mm. Also some electrical components like the voltage regulator are not shown here, because you can buy them at your local technical store, but I will mention all these parts during my instruction.
Step 3: 3D-printing
You have to print all of the files at least once. The first object has to be printed in a mirrored version as well. It may be necessary to split the upper body into a few parts and glue it together afterwards, because the part is relatively complicated. Furthermore you will have to cut a M3 threat into all 2.5 mm holes.
If you want to change or improve something on the parts just download the ZIP folder. It contains all of the parts and the whole model in PRT format. This format is used because the whole robot was modeled in Creo 2.0. If you make any changes, please let me know in the comments!
- 2x + 2x mirrored : 3_servo_joint.stl
- 2x : battery_mount.stl
- 1x : cover_back_upper_body.stl
- 1x : cover_front_upper_body.stl
- 1x : head.stl
- 1x : head_cover.stl
- 2x : sonic_sensor_hand.stl
- 2x : sonic_sensor_hand_cover.stl
- 1x : upper_body.stl
Step 4: CNC-milling
The parts have to be CNC-milled according to the file "CNC-milling.dxf". A 2 mm Aluminum sheet works best for milling as well as for bending afterwards. I am currently trying to use other materials than Aluminum, which can be cut with a laser cutter, but that needs a lot more testing. After the main milling process you will have to cut a M3 threat into all 2.5 mm holes. Cutting the threats works best if you are using appropriate cutting oil. Some of the holes only have a diameter of 2 mm, those are used to connect the "sonic sensor attachment" with the hand by using little screws.
The measurements where to bend the parts are shown in the pictures "bending_...".
Tipp: Using a bending machine really helps to produce clean edges.
Step 5: Upper Body: Front 1
At first you are going to place the Arduino and the gyroscope inside the upper body and fix them with screws. The Bluetooth-module is held in place by a short piece of double-faced adhesive tape but you can glue it in as well. The voltage regulator must have an output voltage of 5V. I used this one in the design TO-220. The voltage regulator is secured with an M3 screw as well. Afterwards it should look like "Picture 1".
Now you are going to solder the voltage supply, therefore I am using breadboard and some female connectors. Those are soldered in a row until every side is connected through ("Picture 2"). This piece gets glued into the little recess, using a hot-melt gun.
The sonic sensor has to be pushed inside the 2 holes and the LC-display is secured by M3 screws. Closing the upper body works by tightening the 4 screws on the side of the robot.
Step 6: Upper Body: Back 1
Start by fixing the "arm servos" ("Picture 1"). The "leg servos" have to be modified to fit. Therefore you have to use utility knife to cut a opening into the side of the servo motor (you have to open the servo motor before doing this). The opening should be exactly as big as the original.
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