Build a Ball-Counting Robot Using Makeblock and Lego

The lever is very easy. Since all the Makeblock parts are compatible with Lego, you don’t need to worry about the connection. The distance between the holes is same. And there is a thread groove on the beam, very flexible.

The most important thing is, you need to find the right weight on the right side to balance the force while the ball is falling, as you can see in the video. There are two methods:

1st: Modify the distance between the basket and the weight. This is coarse tuning.

2nd: Fortunately, there are lots of holes on the Lego beam. You can put some screws in the holes to find the most appropriate weight.

Finally, install the limit switch on the right side of the lever. It should look like the 3rd picture.

In this case, I used a plastic cup which holds the balls at first. Cut a hole at the bottom of the cup so that the balls can pass through.

The hole should be the right size to allow just one ball to pass. The black points in the picture are two screws, which used to install the cup on the beam.

This the frame of the structure. It consists 3 parts: the groove, the bearing structure, and the electronic modules and motor.

As for the groove, you can build it with Lego parts. Fix one side on the frame, and place a motor on the other side. The motor is used to control the balls so the fall down to the lever one at a time. I used some hot-melt glue to fix two beams on the shaft of the motor. There is also a side-effect: the weight of the motor causes the groove to be slightly inclined. : )

Watch the video to see how it works.

After that, install the electronic modules and the cup on the beams. There are holes on the PCB so that you can just screw them on the beam.

In order to control the flow rate of the balls, I need an on-off mechanism at the bottom of the cup. In this case, I install a little servo.

Fix the servo on the beam with hot-melt glue.

Screw the servo and beam on the frame. You can use a 3×3 bracket to adjust the angle.

In order to prevent the balls from locking up in the cup, I need a rabbling mechanism to move the balls.

Extend the shaft of the motor with a coupling. Fix the beam on the side of the shaft.

Install the rabbling mechanism on the back of the structure.

Tips, in this case, I chose the motor whose rotation speed is 14 RPM, which has enough torque to move the balls when they lock up.

We have finished all the steps to build the structure. Next, let’s connect the cables and upload the program to make it move.

Me Baseboard is the controller in this case. And as for the connections, you might notice that there is a color tag on each modules of Makeblock. Please connect the them to the Baseboard’s PORT of whose color is same with the module’s.

MeServo servoDriver(PORT_3,DEV1);

MeDCMotor motor1(M1);

MeDCMotor motor2(M2);

MeLimitSwitch limitSwitch(PORT_6);

MeNumericDisplay disp(PORT_5);

After you finish the connection, please install Arduino IDE and install the library of Makeblock, you can follow the instruction here： http://wiki.makeblock.cc/index.php?title=Library_Download

Before uploading, click Tools->Board, choose Arduino Leonardo. And click Serial Port, choose COM XX(Not COM1 and COM2). Then, upload the program to Baseboard.

You can find the program here: http://forum.makeblock.cc/t/build-a-ball-counting-robot-by-makeblock-and-lego-complete-instruction-on-may-25/518

After that, plug in the power cable and open the switch to start the contraption. Adjust the structure and the program, especially the lever, to find the best balance for it.

If you have any questions, you will find me on Facebook, https://www.facebook.com/qy.xuma target=”blank”