SpudFiles

I recently started working on a full sized metal golfball hybrid, and so far I have the meter, chamber, burst disk, and sparkplug all setup. At the moment I'm lacking a 60" aluminum golfball barrel with appropriate adapters and a shooting chronograph to properly test this thing. I hope to have it bare-bones functional by the end of the month and hopefully fully finished by spring.

All concerns and questions are welcome, I really don't want to screw such a large project up.

Whole gun as of January 4:


Back view of meter showing empty fuel and air input ports:

Maybe I'm crazy - but I would prefer to remote mount a nice digital pressure sensor like that vs. hard mount it. It's not my gauge though!

What's the chamber cc? and what ignition design are you using? Surely 60" is on the short side of what that thing deserves for a barrel!

Haven't measured the true chamber volume, but it's an 2" x 8" nipple, so I'd estimate the volume is close to that of a 2" x 12-14" chamber.

This ignition system is a simple electric BBQ hooked up to that sparkplug I tapped into the coupling (1/8" NPT plug) I might get a second one, but I'm seeing how this works first

1.68" x 60" seemed overkill to me since my chamber's only about 2" x 12" , but you'd have more experience than me. Do you think a 72" barrel would be better?

Very nice setup. Love the digital gauge....

HGDT could shed some light on the barrel question.

So are you using the cam-locks as the burst disk holder? Has anyone actually tried that before with such a large diameter? I was even worried about using them just to attach the barrel to my hybrid. Is that the spark plug up by the cam-lock as well?

Spudblaster used a similar setup for a 10x hybrid with aluminum cam-locks, so I'm pretty confident with this at 5x.

And yes, the spark plug is tapped into the coupling. It protrudes about an inch into the chamber so I shouldn't have your sparkplug problem (hopefully)

Re: the sparkplug, was just thinking whether it'd be better to have it at the back of the chamber as the burning gases have to ignite towards the rear and then move back to the front again. Though I don't really know what I'm talking about so best wait for a second opinion

I may add a second plug on tapped into the back coupling, but I need to make it work before I work on performance.

I would highly recommend not to mount that digital manometer on your gun permanently, you wouldn't be the first one to experience balll valves aren't all that durable when it comes to hybrid pressures

Other than that, looks great

Wish I still had the picture of the gauge I ruined...

Oh wait.

I understand the concern with the digital gauge, and even though its currently protected by 2 ball valves, I'll air on the safer side and mount it on a QD coupling so that I can remove it when I'm firing. Thanks for the advice, I'd hate to have to find another one