High pressure co-axial build log- updated 11/14/08

[pizlo]

Sick is good? 8) It will look similar to a bullpup assault rifle when done.

Not only could I take it to 6000psi, I did...for proving (see the pic with the gage). Designed operating pressure is 3000psi. All parts exposed to pressure have a minimum rating of 9000psi. (calculated using yield strength of the material)

"Where do you work?? "

Only the shadow knows!

yes, sick is quite good. And in the last sentence are you referencing the 1920s radio show about "the shadow"?

[jackssmirkingrevenge]

Accuracy will be the issue not power. A mold for foster slugs will have to be made.

Hence the "50 yard" specification

Shame you couldn't have made it closer to 0.72" calibre, that would have made all ammunition made for smoothbore shotguns avaialbe as a ready-made option for ammo - though I suppose a few layers of duct tape wrapped around the said projectiles would still make them good enough for you.

[Gippeto]

Pizlo, Yes. It seemed funny at the time.

JSR, I know Lyman makes a 12ga slug mold for sabot slugs, I'll check to see if they make a foster slug mold. (I cannot see why they would not)

I did some quick searching and turned up that 10 gauge shotguns have a nominal bore size of .770". 10ga foster slug mold? I'll have to look.

[RDX,]

how are you going to trigger the hammer ?
if you have any plans for trigger system, I would like to get some plans from you for my hammer valve rifle

[Gippeto]

The hammer will be triggered with a fairly conventional sear arrangement. There will be a linkage running past the pilot vent and check valve to the trigger. I have not yet decided whether the linkage will be double or single sided, but I am leaning toward double sided. (like a ladder)

I don't have printed plans, but it's just a trigger and sear, there are many ways to set it up.

It really depends on where your trigger and sear are in relation to each other, and the types of adjustment you wish to incorporate.

[jackssmirkingrevenge]

I did some quick searching and turned up that 10 gauge shotguns have a nominal bore size of .770". 10ga foster slug mold? I'll have to look.

They certainly exist, that's over 750 grains worth of lead, and more weight equals lower velocity but better efficiency so the foot pounds would go up.

Beware the recoil though

[Gippeto]

Several brands load a 10 gauge slug, but can I find a simple mould?

Not yet. (although Corbin does offer some ideas)

http://www.corbins.com/slugs.htm

[FordGtMan]

If this is kicking a topic, sorry, but have you made any progress on the check valve that your redoing? This is going to be my favorite cannon ever when finished . Just love that coax look

[Gippeto]

You bet. The check valve and probe style fill are done. (pic is at the top of the thread)

I have finished mocking up the sear, and have the carbon steel piece layed out and ready to cut. Should have the sear ready for heat treat by the weekend.

By mock up, I mean I welded small pieces together to develope the shape, then I transferred this shape to a piece of carbon steel. This will give me a part which is all one piece.

The mount for the sear is at the approximate same stage.

[Gippeto]

I'm going to bump my own thread, sorry if I offend anyone.

I finished the sear to a point where it is workable this morning.

Being curious, I assembled the co-ax "fully" for the first time, with a schrader in place of the check valve (easier right now) for a function check.

Charged to 120psi, it "spoke" to me for the first time.

Works beautifully! This is going to be a beast!

Will try and get a vid today.

Edit: Vid is up on first post.

[SpudFarm]

i hope you get a high pressure vid also:P

[Velocity]

I tried searching a bit, but I couldn't find anything that would help me out. Could you explain exactly how a hammer valve functions? Thanks.

Nice cannon by the way!

[Gippeto]

Thanks.

If you're interested in hammer valves, Ant has some simple but very effective designs in the bbmg/strafer showcase area.

http://www.spudfiles.com/forums/bbmg-st ... e-f10.html

These would be a good place to start. He has animations/drawings of them, which will make it easier to understand.

If after studying Ant's stuff, you still have questions, I'll be happy to help however I can.

[Mitchza89]

God god mate. You're turning out to be one of the more skilled spudders on this site. I love everything you've put out so far. Keep them coming and I'll be sure to keep my eyes peeled on this post .

[trae08]

just curious how do you get to 6000 psi?

and that is one of the most amazing coaxials i have seen.