Simple Robust Water Pistol / Piston

This water pistol is assembled with 25mm (1") and 20mm (3/4") conduit. This PVC electrical conduit is made against an Australian standard so you may need to play with tolerances and gaskets to get this to work with other international standards for PVC conduit.

The outer diameter (OD) and inner diameter (ID) for the conduit I was working with are as follows:
25mm (1")
OD: 25.05mm +/- 0.10mm 
ID: 20.90 mm +/- 0.10mm 

20mm (3/4")
OD: 20.05mm +/- 0.10mm 
ID: 15.50 mm +/- 0.10mm 

The plunger will require at least one o-ring (ID) 16mm with 2.65mm wall thickness. I am yet to test the model with other o-ring sizes but is should work with 2.50mm wall thickness.  But you will like need to use double o-rings. The design uses double o-rings to ensure food grade plumbing lubricant is retained in the gap between the o-rings. It will work with on but the seal will loose lubricant if a single o-ring is used.

Print the parts and glue in place with superglue. I used PLA for prototyping but this will deteriorate over time as this polymer is not UV stable and will degrade quickly. But for some quick fun it's hiworth a shot.

This is my first post for a make as a new to printing users. Happy to receive pointers as to how I can improve or enhance understanding of the design.

Note this is the third iteration of this build during prototype work. The layout is intended to be printed without supports and without a brim. If you change the handgrip orientation and supports are inserted into the conduit mounting holes, it still works but it is an interference fit, which on the plus side means you could omit the glue from the handles, but you will still need glue for the piston and nozzle