Pneumatic cylinder

First go at a pneumatic cylinder. Bore will need some sanding as well as the piston. Work in progress so will update as improved.

Update: New cylinder rod does not need sanding (bore should still be sanded for smoothness). Piston will need bridging material removed after print, exposing o-ring gaps. O-rings can be made with 2-part silicone molding material. Bottle manifold threads to a standard soda/pop bottle. I have found petroleum jelly (Vaseline) makes a fantastic lubricant for the piston.