3Dprinting Quick Exhaust Valve

Ok, guys .. I inaugurate the post section with this last project ...  
This project is one step on the way to build a toy gun that fire salt bullets :D .. I don't know if I will succeed.

The final idea is create a printable QEV with regulator for time to shot, below the shema.

and two image of the first test prototype .. 
Obviously I thought a print with 100% of infill could have this problem of air leakage. The valve works but ... the video is more exaustive ;)

The outlet hole is 6,8 mm, it is right to be threaded to M8.
The other hole are 5mm, it is right to be threaded for M6.

I share this on Thingiverse after I have removed the 4 holes on front of base because it not needed. 

I need a time to thinking to that ;)