hybrid cartridge protoype without burst disk

[Heimo]

JSR how about something like this



tightening the screw cap compresses the rubber tube, this will make the burst pressure adjustable...

[Zeus]

I see what you're saying Crna, but sealing it would be a problem, good thought though. I presume you mean having it similar to a drill chuck inside the cartridge?

Also JSR, what CAD program are you going for? I've got a free package downloading now, and I'll be trying to get a copy of Solidworks.

[jackssmirkingrevenge]

tightening the screw cap compresses the rubber tube, this will make the burst pressure adjustable...

The o-ring setup I already have allows similar adjustment, moar compression = more pressure retention (for example one of the o-rings I tried starts out at 6mm ID, but compressing it enabled it to hold a 5.5mm projectile).

It's too difficult get right though - a fraction of a turn is enough to make the difference between not being able to contain 100psi of pre ignition pressure, and not releasing over 2000 psi of combustion pressure.

Maybe I need to find a shallower thread, hmmm...

Also JSR, what CAD program are you going for? I've got a free package downloading now, and I'll be trying to get a copy of Solidworks.

I'm currently inclining towards a (legal 0_o) copy Solidworks, in conjunction with a joint venture that's on the horizon, more on that (much) later.

[Crna Legija]

ill draw it up real quick didn't have time before

edit: something like this

[jackssmirkingrevenge]

You're still left with the problem of sealing though, unless your collet is a length of silicone tubing...

[myinisjap]

jsr instead of trying to guess at the proper tightness. Why not use a feeler guage to measure between the detent cap and cartridge? It might take a while but if you change the amount the cap is screwed in by a small amount then test. You should be able to maintain a pretty good firing probability if the cap and cartridge gap is always set the same.

[the unit]

jsr instead of trying to guess at the proper tightness. Why not use a feeler guage to measure between the detent cap and cartridge? It might take a while but if you change the amount the cap is screwed in by a small amount then test. You should be able to maintain a pretty good firing probability if the cap and cartridge gap is always set the same.

do that then make a spacer so all you have to do is torque the detent cap

[jackssmirkingrevenge]

In an effort to make a quick and easy cartridge, trying out a simple diaphragm valve built as per the diagram below, prototype curing as we speak.

[wyz2285]

I don´t think the diaphragm will hold a lot of mix

[warhead052]

You may need to add a spring. But all the same, who knows until you try right?

[al-xg]

I'm currently inclining towards a (legal 0_o) copy Solidworks, in conjunction with a joint venture that's on the horizon, more on that (much) later.

Still not working out eh ?


How does the air get behind the diaphragm in the first place ?

[jackssmirkingrevenge]

Still not working out eh ?

Haven't tried yet

How does the air get behind the diaphragm in the first place ?

see attached, in practice it will be filled through the "barrel" but should still work.

[Gun Freak]

I don't get the diagram.

[al-xg]

Well filling from behind makes sense, but surely filling through the barrel will just flex the diaphragm back and it will prevent any air from getting behind it to equalize?


A bit of a .gif fail there

[jackssmirkingrevenge]

Well filling from behind makes sense, but surely filling through the barrel will just flex the diaphragm back and it will prevent any air from getting behind it to equalize?

Sounds like it in theory but I gave it a quick test at 50 psi and it held pressure

A bit of a .gif fail there

The spudfiles uploader has a problem with animated gifs, if you click in it to open in another window it shows up correctly.