HGDT is a great program to determine this, as it is no longer available online I have attached a zip file. Thank you! Nice solidworks drawings by the way, I assume you have access to machining facilities if you intend to build this? Never really got in to Solidworks, this was modelled using CATIA. ...

I like the design. Thank you I'd like to see the barrel side diameter be closer to the pilot side diameter, similar to how you had it in your first drawing, but not quite that close. I see a small edge of engagement where the piston seats against the T-housing. I'd like to see a larger step there. ...

The piston won't open. The area of the barrel side need to be smaller than the area of the pilot side. Thank you for replying. It was obvious really! I'm made some changes to the design, incorporating a weld-in bush to reduce the diameter of the piston at the barrel side. Again, any thoughts and co...

Hi all, Attached are some images of the designs of my first hybrid cannon. I've been working on piston valve and wanted people thoughts on the design that I'm at currently. I plan to use o-rings to seal the chamber from the barrel - anyone had any luck with a design like this? All comments welcome N...

Hello all, 1st post here. I've been telling myself I would build a hybrid cannon since I first built a spudgun over 10 years ago. I've started working on the design on CAD and should have something to work with in the next few weeks (when time allows) There seems to be quite a lot of contradicting i...