For quite some time, my fascination with robotic motion systems has been a driving force behind my journey into the world of DIY manufacturing. Starting with humble projects like CNC machines and 3D printers, I gradually delved deeper into robotics and mechanical design. It wasn't long before my curiosity led me to explore more complex systems, particularly robotic arms.

My introduction to the AR4 Robot platform came through Chris Annin's YouTube video showcasing the AR4MK2. The comprehensive documentation and open-source control software provided with the robot were game-changers, addressing the major hurdles I had encountered in previous attempts to build a robot arm.

In embarking on my own AR4MK2 build, I set out with three primary objectives:

1. Kinematic Replication: I aimed to replicate the kinematics of the AR4MK2 using the provided technical drawings to ensure compatibility with the software and motion system.

2. Cost Minimization: Keeping costs low was crucial for this project.

3. Metric Bearings Integration: Residing in Germany, I faced difficulty sourcing imperial bearings, so I focused on using metric bearings for all joints.

Challenges and Solutions:

Complex Assembly: The original design comprised numerous parts and screw connections, making assembly laborious. To streamline this, I consolidated multiple parts, such as merging the J1 turret platform and J2 turret housing.

Before

Optimized

Mechanical Demands: Certain components, like the J2 spindle, demanded precise dimensional accuracy which demanded it to be printed along the Z axis of my printer, which creates a weak point because the layer lines don’t follow the force flow. I reinforced this mechanical weak point by drilling thru holes in the design for internal steel reinforcement.

Before

Optimized

Metal Parts Fabrication: Fabricating metal parts like the J4 main shaft posed challenges, especially since I lacked access to a lathe. I opted for readily available materials like ground welded stainless steel tubing as a replacement, simplifying the process significantly.

Redesigning J5 and J6 Components: The original design of the J5 and J6 components presented printing and structural challenges. I redesigned these components to improve printability and durability.

Through these solutions, I overcame various hurdles in the build process, ultimately achieving a more streamlined and cost-effective AR4MK2 robot arm. This project not only deepened my understanding of robotics and mechanical design but also empowered me to contribute to the DIY robotics community.

Stay tuned for more updates on my robotics endeavors, and feel free to reach out with any questions or insights you may have!

Further Contend:

I am working an a YouTube Video that goes in further detail of the Design.

I am working on an option to make the STP Data available for others.