Stronger bolts, threadless arms. and double threaded arms.

Because I wanted to be about to chain the arm segments together via 2 arms > 1 arm > 2 arms > etc. I created a threadless arm to let the bolts pass through and let me chain these infinitely without ending up with some joints having two threaded ends (This makes tightening a mess). 

Also, glue the bolts together. Dry fit them first to make sure you are not accidentally glue two of the same side of a bolt (when printing multiple).

Why did I do this? What purpose? Pfft, what good is robot-like arm if not biggest robot-like arm?

Split the bolts and reduces the size the the head by 50%. The split bolts come in 4 sizes to fit single, double, triple, and quadruple arm pieces per bolts. The bolt split and orientation increases the strength of the bolts a metric frick-ton.