10XGB - My First Venture into Hybrids
Posted: Tue Nov 01, 2011 10:54 pm
Ever since joining this forum, well before this forum was even around and Spudtech was the "it" place for spud gun talk - Hybrids have fascinated me. Seeing a 2X made of Sch80 PVC was somehow more intriguing than any of the large bore air cannons at the time.
I took a good while to get here, but I've jumped ahead a bit in the journey. Learning from others accomplishments and formulating a few ideas of my own I started designing this gun over 2 years ago. Without further ado, I give you the time line of progression for this gun:
The gun evolved quite a lot along the way, but a few things stayed the same. The chamber, all metal fittings and barrel consist of a mix of 316 and 304 stainless parts. All welding was done with tig process. Using the standard Barlow’s formula for this material, the chamber has a theoretical bursting pressure of 5Ksi internal pressure, This gun will probably never see half of that, but it was nice for a little overhead.
One of my biggest issues with hybrids was the implementation of a multigap spark ignition, with precise intervals. This could be accomplished by placing multiple ports in the chamber with spark plugs in them, but this will weaken a chamber designed for high pressure. My gun is my no means a super high pressure gun, but I wanted to prototype a multigap spark plug design with only 1 point of chamber entry, and that's when I came up with this design:
With this being my first functional prototype
This prototype was hydro-tested up to near 3000psi and held without developing any leaks. My final design I don't have photos of, but it is a more evolved version and will eventually lead into the concept for a much higher mix gun where this integrity is necessary.
Another focus of this gun was developing a fueling system that had the capability for automation. This involved precise monitoring of the fuel and oxidizer pressure, as well as electronic control of both. I came up with a make-shift box utilizing this concept with a programmable pressure switch, which can be seen here:
This box is an "all-in-one" design where all I need to do is hook up an air source and the remote trigger. It's not revolutionary or anything but I was really pleased to have everything integrated into one box with automated fueling capabilities. The obvious flaw in the fueling system is the manual chamber ball valve, but again this has been addressed in future designs, I kept it on this gun because it was cheap and met the requirements for up to 20X shots.
Here's a short photo build log for those who didn't follow on my other post:
Initial chamber weld up (this would later change)
Construction begins on the final iteration stand:
The Gun Cradle portion:
The lower stand portion:
Elevation control added:
All painted up!
And finally done!
Now, the part most people are waiting for... does it work? Well why yes! I waited until this video was finalized to post it though lol.
(Due to a freak Halloween snowstorm in my area, almost everyone lost their power, and this preliminary test had to be run with the aid of a generator, so powering my large high pressure compressor was out of the question. Unfortunately all shots are only 7X in this video, but as you'll find out - they accomplished what I was trying to do... vaporize food)
[youtube][/youtube]
::UPDATE:: Video's will now be posted below as well as deeper in the thread
Second Day of Shooting:
[youtube][/youtube]
Third Day of Shooting:
[youtube][/youtube]
Fourth Day of Shooting:
[youtube][/youtube]
I took a good while to get here, but I've jumped ahead a bit in the journey. Learning from others accomplishments and formulating a few ideas of my own I started designing this gun over 2 years ago. Without further ado, I give you the time line of progression for this gun:
The gun evolved quite a lot along the way, but a few things stayed the same. The chamber, all metal fittings and barrel consist of a mix of 316 and 304 stainless parts. All welding was done with tig process. Using the standard Barlow’s formula for this material, the chamber has a theoretical bursting pressure of 5Ksi internal pressure, This gun will probably never see half of that, but it was nice for a little overhead.
One of my biggest issues with hybrids was the implementation of a multigap spark ignition, with precise intervals. This could be accomplished by placing multiple ports in the chamber with spark plugs in them, but this will weaken a chamber designed for high pressure. My gun is my no means a super high pressure gun, but I wanted to prototype a multigap spark plug design with only 1 point of chamber entry, and that's when I came up with this design:
With this being my first functional prototype
This prototype was hydro-tested up to near 3000psi and held without developing any leaks. My final design I don't have photos of, but it is a more evolved version and will eventually lead into the concept for a much higher mix gun where this integrity is necessary.
Another focus of this gun was developing a fueling system that had the capability for automation. This involved precise monitoring of the fuel and oxidizer pressure, as well as electronic control of both. I came up with a make-shift box utilizing this concept with a programmable pressure switch, which can be seen here:
This box is an "all-in-one" design where all I need to do is hook up an air source and the remote trigger. It's not revolutionary or anything but I was really pleased to have everything integrated into one box with automated fueling capabilities. The obvious flaw in the fueling system is the manual chamber ball valve, but again this has been addressed in future designs, I kept it on this gun because it was cheap and met the requirements for up to 20X shots.
Here's a short photo build log for those who didn't follow on my other post:
Initial chamber weld up (this would later change)
Construction begins on the final iteration stand:
The Gun Cradle portion:
The lower stand portion:
Elevation control added:
All painted up!
And finally done!
Now, the part most people are waiting for... does it work? Well why yes! I waited until this video was finalized to post it though lol.
(Due to a freak Halloween snowstorm in my area, almost everyone lost their power, and this preliminary test had to be run with the aid of a generator, so powering my large high pressure compressor was out of the question. Unfortunately all shots are only 7X in this video, but as you'll find out - they accomplished what I was trying to do... vaporize food)
[youtube][/youtube]
::UPDATE:: Video's will now be posted below as well as deeper in the thread
Second Day of Shooting:
[youtube][/youtube]
Third Day of Shooting:
[youtube][/youtube]
Fourth Day of Shooting:
[youtube][/youtube]
) a few years ago to do something similar (see first cannon in my sig) but I'd think 2x would be the limit for that trick.