The T-pipe section looks like a hip joint to me, and above that (albeit inverted in the pics) is the torso of a robot. It's probably not what you're building, it's just what it looks like to me, at this point.
That's a lot of cutting in 2 mm styrene so I switched to the scroll saw :
Roughed-out with the scroll saw , then finished with sanding sticks using a jig to ensure exact duplication :
So , at the beginning of all this I checked the O.D. of the aluminum with this drafting template conveniently hanging next to the bench ,
Imagine my delight when the tube , which I guess we're calling 3/8 pipe now , wouldn't fit into the hole .
The first drill bit I had in the press had way too much run-out ( probably why it was in the Bad-Bits-Bin ) so I switched it out with a different brad point .
I figured I grabbed a 31/64 bit or something .... . Nope.
It's actually .516 inches ( 13.13 mm ) O.D.
Terribly inconvenient .
I used that little jig to slice that 2 hundredth's of an inch out of the way using a sharp #11 blade .
Time Consuming .