Increase shot chamber volume to shoot 2" foam rockets

[Hooptie]

Greetings,

I'd like to ask the experts if increasing the shot chamber volume on a spool design (let's use the gamma core) can provide enough air to shoot a 2" foam rocket.

The thought I have is the Metadyne Havoc has a ~7/8" dia. opening to 2" dia. barrel. A EMEK has a ~11/16" dia opening which is of course less than the Metadyne Havoc, yet can be sufficient to launch a foam rocket (as the Metadyne Havoc can go the distance and not necessarily needed at maximum range).

So to get the air needed to push out a foam rocket for a EMEK barrel port, the shot chamber volume needs to be increased dramatically (Metadyne Havoc shot chamber is about 4.5"L x 2" I.D.). Does this sound right?

[markdem]

Yes, if you were to make an emek with a large enough air chamber, it would work. You might sacrifice some performance with a small-ish valve opening but it i have a feeling youre not going for absolute performance

[latches109]

if your foam rocket is 3g and you get one of the machinist to make you an autococker threaded barrel with a power tube you slip the rocket onto, then it should shoot just fine. this sounds like fun!

[Ecapnation]

I actually modified an A5, yes and inline blow back, to shoot Nerf rockets at one point.

All I did was cut off the front half and only exposed the power tube, made amount for a proper diameter barrel, put a very weak spring in the valve just barely enough to keep the poppet sealed then I put a heavy mainspring into it and change the center core that is normally plastic on the Tippmann hammers to a brass core.

Worked like a charm

[Pyrate Jim]

There are two basic ways to regulate air flow.
A fixed volume with adjustable air pressure.
or,
A fixed pressure with adjustable volume.

The second one is easier, since volume can be adjusted by dwell. It's not the size of the chamber as much as the amount of air going through it.

[Trbo323]

I'm not sure the emek is the right choice for this. 2 problems I see,

1) dwell is not really adjustable. It may stay open longer if you increase the dump chamber size but you really don't have a great way of tuning it if it doesn't work for you

2) I suspect you'll need an uncomfortably long barrel in order to flow that much air

Look at the mkx launcher. That thing operates on around 200 psi and has a massive dump chamber as well as a spool opening that's around a full inch and still has about a 2 foot barrel after that

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[Hooptie]

Hello, I saw this on IG. Looks like an GOG Enmey updated to shoot tennis balls. The vertical metal bottle looks like the additional chamber space. Felt this approach is like increasing the shot volume of a gamma core design to shoot those 2” foam rockets.

[William the Third]

It's a modified "Vetgun", which is basically a supersized GoG eNMEy (1.00 cal vs 0.68cal).

[Trbo323]

Hello, I saw this on IG. Looks like an GOG Enmey updated to shoot tennis balls. The vertical metal bottle looks like the additional chamber space. Felt this approach is like increasing the shot volume of a gamma core design to shoot those 2” foam rockets.

You're still stuck with the dwell problem on a gamma core. If someone wants to try it be my guest, maybe the additional volume will force the dwell up but the dwell on that valve is more or less mechanically controlled and you have no way to manually adjust it. That alone would push me to do this on a different marker

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[RPP]

You're still stuck with the dwell problem on a gamma core. If someone wants to try it be my guest, maybe the additional volume will force the dwell up but the dwell on that valve is more or less mechanically controlled and you have no way to manually adjust it. That alone would push me to do this on a different marker

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Added volume would force a longer dwell on a gamma core. The shot chamber volume needs to vent in order for the switch to reset/move forward. You are correct though that it is mechanically fixed dwell in its current setup.

You would just have to worry about adding so much volume that you unbalance the system and force the stem/switch backwards which would force a shot, but I don't know if its possible to force the solenoid spool to vent that way... who knows... sounds like a fun project.

[Hooptie]

https://www.paypal.com/instantcommer...Hk7T82O7HqRi7w

Available for a week only. The tennis ball launcher reminds me of American Gladiators (show from the 80s)