Awesome job ! thx for sharing with us :)
dude, I love the design, awesome job! My only issue is the arms or whatever you want to call them don't seem tight enough and can't stand up even not holding anything. I was thinking of re-printing the balls a little larger.
hmm... in what layer heigths you print out the joints.? If you print them in lower quality they have a much ruffer surface and so they sit tighter. Another way to get them stronger iss to lower the pieces of joints. All of them increase the stabilty.
But anyway printing the joints a bit bigger can also be a solution for mor stability.
Let me know if it works.