Index

Part 1: Shoulder

Part 2: Mending the shoulder

We’ll be working on the left arm and making sure that everything fits together fine before moving on to the right one (the right arm shares most of its parts with the left arm)

First, let’s lay out the parts:

Shoulder (half-complete)

Arm attachment bracket (needs some cleanup work)

Arm rotation component with servo pre-installed

Arm rotation component (lower side)

Elbow joint

Hand

You might be wondering how we managed to secure the rail to the shoulder part here using screws. Fun fact: we messed up and forgot to add screw holes so it’s glued :P The CAD files have been updated with screw holes already though, so you won’t have to face the same issue.

Ultraviolet-cured glue is your friend :D

Shoulder bracket, cleaned up.

Next we’ll be screwing in a servo horn, so we’ll turn to our box of knick knacks.

Inserting M2*5 screws

All four screws are done (you can do eight, but four is sufficient)

View from the bottom

This is the servo horn we’ll be attaching

Servo horn attached. Now we’ll connect the servo horn to the servo installed in the arm rotation component.

The two parts are now attached.

Next we’ll secure the two together using an M3 screw.

Done.

For the shoulder, we’ll first slide in the servo horn for the side that is geared

And screw in the servo horn on the opposite side, which is free to turn

The servo horns have to be attached before we try to connect the arm to the shoulder.

The arm snaps into the shoulder with some effort.

But the screw holes don’t line up :(

Looks like it’s back to the drawing board.

In the next part we’ll be correcting the hole alignment in Fusion 360, and then reprinting the arm attachment bracket (hopefully we’ll have better luck next time). Please clap on this article if you like what you see, and see you around!

Index

Part 1: Shoulder

Part 2: Mending the shoulder

Project OpaNoid is developing a robotics platform for education, research and more. It is a SolverHub Project.