How to create a robotic arm with your students

1 Introduction
- Some ideas before taking this course
- Quiz 1. Arm Unit. Introduction
  4 questions05 min
2 Theoretical concepts
3 The printing process
4 Arm assembly and electronics

How to create a robotic arm with your students

Arm assembly

Lesson objective: Assembling the arm. Use CAD programs to visualize complex 3D objects. Know how to interpret 3D designs and assemble the arm based on them.

One of the reasons why we have chosen this arm is because the author has taken great care of the material that he distributes including several STP files which can be opened by a CAD program and you can clearly see how the arm has to be assembled.

For this, an investigation has been made of which will be the simplest and most suitable program for the group. Finally we have chosen Freecad and gcad3d for Ubuntu. Two free open-source tools that will meet the needs we have.

Freecad and gcad3d

For the assembly of the arm, the project has an STP file which allows it to be opened with a 3D modeling program. Given that in class we use the Ubuntu Linux system, we have chosen Freecad and gcad3d which are a more than adequate tools to visualize 3D projects through different perspectives and to be able to get an idea of the assembly sequence and the relative position of each of the pieces.

Viewing the robotic arm design in FreeCAD

View of the same STP file with gcad3d

Viewing the robotic arm design in gcad3d

The advantage of gcad3d is the ability to display all the pieces together and highlight an individual piece as well as its name.

After analyzing how to assemble the robotic arm with the different programs, it is time to proceed to assemble it.

It is important to have the right tools, enough light, the right screws, nuts and washers, etc.

Assembly must be done safely and with enough time to finish properly.

One of the most delicate parts of the assembly is the base. It is important that the base is correctly assembled because it will receive most of the weight and because they will be the parts that will have the most friction and tension.
Below is an image from the creator of the Florin Tobler arm showing the correct way to assemble the base.