Video of Robot Arm: https://youtu.be/2zVjGslPVg8
- The power system consists of 6 servo motors
- All bracket fittings are made of 2mm thick aluminum plate
- Imported cup bearings are used at the steering joints
- Model: MG996R analog steering gear
- Working voltage: 4.8V-7.2V
- No-load current: 100mA
- Machine torsion: 10kg.cm
- Limit angle: 180°
- Gear material: Metal gear
- The Servos require a separate 5 V power supply rated at 2 amps
The kit comes without instructions. A very good video to support assemble can be found at https://www.youtube.com/watch?v=hTZ2z_C9dSU The servos must be supplied with a separate 5VDC power supply rated at 2 amps.
An important feature of the code is a method to reduce the speed that the arm transitions from original destination to final destination. The method involves creating a function that moves the arm from the initial position to the final position in 1 degree increments or decrements. This eliminates the large interia that would result in the arm moving between positions at maximum speed resulting in stress on the metal gears.
- Red Power Button – sets arm to Home position
- ST/RPT Resets all stop execute functions
- Func/Stop Enables fine setting of Joint angles using trim potentiomenters
- EQ Enables Lissajous Like Arm Motion
- Pause Enables Horizontal and Vertical Scanning
- 0 starts a complete tower build sequence
- 1 starts a Home to Position 1 to Home sequence
- 2 starts a Home to Position 2 to Home sequence
- 3 starts a Home to Position 3 to Home sequence
- 4 starts a Home to Position 4 to Home sequence
- 5 starts a Home to Position 5 to Home sequence
- 6 starts a Home to Position 5 level 2 to Home sequence
- 7 starts a Home to Position 5 level 3 to Home sequence
- 8 starts a Home to Position 5 level 4 to Home sequence
The IR control allows selecting different Robot Arm operations.
Selecting "0" start 1 complete 4 block tower building pick and place operation. Selecting "1" starts a single Arm movement from Home position to Position 1, and then back to Home. Similarly selecting "1" through "8" will start a single Arm movement to posiitons 2 through 5-level-4 Positions.
The EQ button enables Lissajous motion of the robot arm. The arm can execute circular, elliptical, figure 8, and slant line Lissajous like motion
The Pause button enables a sweeping motion left/right and right/left incrementing vertically after each lateral sweep
To start another another sequence requires resetting the stop execute function. This is done by depressing the ST/RPT button.
Shown on the photo are:
- Arduino Nano mounted on KeeYees Nano I/O Expansion Board Extension Shield
- Trim Pot board
- i2CLCD1602 - 2x16 character display using i2C communication to Nano
- Sevo routing board
- Not shown is the IR Receiver
The Joint angles are identified 1 through 6. Angles for Joints 1 through 5 are in degrees (0 to 180) while the end effector Joint 6 is either O for open or C for Closed. Joint 5 and Joint 1 angles are both located at row/column 0/0 and will override each other. Thses angles are updated at the beginning of the joint travel and the end of joint travel.
The angles for each of the joints can be set using the 6 trim pots. The wiper voltages of the trim pots are fed to 6 A/D converter inputs. To enable pot setting joint angles, press the EQ button on the IR remote. To disable this operation press ST/RPT on the IR remote.
The arm Joints 1 and 4 have sine waves generating the arm motion to display Lissajous like motion. The default setting has sine waves of equal amplitide and frequency with Joint 4 phase shifted 90 degress.
