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Some thoughts on automatics

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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Unread postAuthor: POLAND_SPUD » Thu May 01, 2008 7:06 am

@judge no I didn't misunderstand you... acctually you misunderstood my post...

I meant that blowback wouldn't need a delay mechanism, but JSR already pointed that out.... I said that the mass of the bolt would be enough to slow it down so that it opens only after the projectile leaves the barrel...

ok enough talking I have to test it myslef
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Unread postAuthor: judgment_arms » Thu May 01, 2008 12:59 pm

POLAND_SPUD wrote:…obviously the bolt needs to be heavier than the projectile it fires but the only question is how heavy…

If you're going to have a solid bolt, rather than an air-through bolt, you can fill it with different amounts of steel BBs or lead split-shot to adjust weight; packing it in with paper or cloth to keep it from redistributing the weight or sloshing around.

If your gut says it’ll work, then by all means go for it.




Currently I’m experimenting with recoil operation.
My preliminary test of a cal .84 barrel were promising, but a 43 3/4 grain projectile doesn’t offer much recoil energy; three, on the other hand, showed quit a bit of promise
More information to come, I got a few more things to try in this caliber.
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Unread postAuthor: iknowmy3tables » Thu May 01, 2008 8:48 pm

shorter stroke lengths and larger dia. breaches will only worsen performance because it will cause the bolt to open sooner.

sooo what is the problem? not opening, or too soon, I though normally it is difficult to get the bolt to open with standard diameters
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Unread postAuthor: judgment_arms » Thu May 01, 2008 9:06 pm

iknowmy3tables wrote:sooo what is the problem? not opening, or too soon, I though normally it is difficult to get the bolt to open with standard diameters


The problem is they open too soon, preventing the projectile from generating any appreciable performance.
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Unread postAuthor: iknowmy3tables » Thu May 01, 2008 9:19 pm

that is strange compared to JSR's testing, I recall the solenoid operated breech that he couldn't quite get to work on blow-back alone.
I have to agree mass is the most simple, reliable, and adjustable change, it doesn't mean that it can't have the holes for gas in it, more mass will require more energy to get it moving, and when its moving it will have more momentum
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Unread postAuthor: judgment_arms » Thu May 01, 2008 9:38 pm

Perhaps a revisit to the Wookie gun is in order, I’ve got 90% of the parts still…
What do y’all think?
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Unread postAuthor: iknowmy3tables » Thu May 01, 2008 10:38 pm

as long as none of it is too messed up, I meant how hard will it be to remove the A1 changes cleanly?, and fix the valve?
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Unread postAuthor: THUNDERLORD » Thu May 01, 2008 10:52 pm

judgment_arms wrote:THUNDERLORD, you’re going to run into a problem, when the valve opens the gas will hit the projectile, with no way to lock the bolt to the barrel the minute any pressure hits the cartridge it’ll pop the bolt right off, if not then, once the projectile enters the barrel, then it’ll commence cycling, producing very little to no performance.

This is what Jack meant be using a longer traveling bolt, the pressure circuit will stay closed longer.


POLAND_SPUD, you seem to misunderstand me, I’m not saying it won’t work, I’ve proven that it will indeed work, what I’m saying is that you will get no power from pure blowback in a LP cannon.

Iknowmy3tables, shorter stroke lengths and larger dia. breaches will only worsen performance because it will cause the bolt to open sooner.

Whatever you're on your own now. Bye
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Unread postAuthor: THUNDERLORD » Sat Feb 07, 2009 7:57 pm

Double, But I've had a bunch of new thoughts on this old thread that was recently linked to.

Where the heck is "the Judge"? :roll:

Anyway, I was thinking of a gatling or mini-gun design where the magazine feed wells face inward into a central magazine.

But the Paintball guns would simply be fitted with a solenoid attached in the trigger gaurd.

As the PB pistols revolve they would simply touch a contact (copper plate) which works as a switch to activate the solenoid (hitting the trigger).

I actually dreamed up the idea thinking of four or five 9mm handguns with the handles removed...(but that would be against the rules...)

Also, I've been dreaming up a piston valve with a spring plunger that would press they pilot valve once proper pressure is reached (full-auto)

Similar to a pop-off pilot, only I like this design more. :) 8)

EDIT: BTW, Srry I'd gotten frustrated on my last reply. :(
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Unread postAuthor: judgment_arms » Mon Feb 09, 2009 7:00 pm

THUNDERLORD wrote:Double, But I've had a bunch of new thoughts on this old thread that was recently linked to.

Where the heck is "the Judge"? :roll:


Sorry, been busy lately with .68 caliber stuff and Brass tubing...

Anyway, I was thinking of a gatling or mini-gun design where the magazine feed wells face inward into a central magazine.

But the Paintball guns would simply be fitted with a solenoid attached in the trigger gaurd.

As the PB pistols revolve they would simply touch a contact (copper plate) which works as a switch to activate the solenoid (hitting the trigger).

I actually dreamed up the idea thinking of four or five 9mm handguns with the handles removed...(but that would be against the rules...)

Interesting...
Basically, five Tib8's that spin to shoot, right? :D
If not, you threw me with the 9mm reference...

In the first line, about the feed, you're talking centrifugal feed, no?
Centrifugal feed only works if the RPMs are high, not a problem for a Minigun, but a Gatling gun would have feed issues until you brought it up to speed. ;)


What you could do is get a handful of Mavericks/Traccers or some other cheap Nelson based pump gun, and use a cam mechanism to "pump" them and let the Auto-Trigger drop the hammer.

Cheap Nelsons can be had for ~$40 or less, usually less.

Also, I've been dreaming up a piston valve with a spring plunger that would press they pilot valve once proper pressure is reached (full-auto)

Similar to a pop-off pilot, only I like this design more. :) 8)

Sorry, it differs how? :?
Perhaps by allowing for a higher flow/larger bore pilot?


EDIT: BTW, Srry I'd gotten frustrated on my last reply. :(

Bah, don't worry about it, we all lose our cool once in a while. :D




EDIT:
Just for an update, and to anyone curious:
The Wookie is long dead, piston seized and most of the rest scraped...
I've got four .68 caliber projects that are drawing all my funds, but once completed I will go back to the drawing board on Auto-Cannon.
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Unread postAuthor: THUNDERLORD » Sat Feb 14, 2009 9:31 pm

judgment_arms wrote:... been busy lately with .68 caliber stuff and Brass tubing...


Two words on that...Great Scott!! :D
Did I miss that in showcase or are you "getting too good" for SF's? :P

Anyway, I was thinking of a gatling or mini-gun design where the magazine feed wells face inward into a central magazine.

But the Paintball guns would simply be fitted with a solenoid attached in the trigger gaurd.

As the PB pistols revolve they would simply touch a contact (copper plate) which works as a switch to activate the solenoid (hitting the trigger).

I actually dreamed up the idea thinking of four or five 9mm handguns with the handles removed...(but that would be against the rules...)


Interesting...
Basically, five Tib8's that spin to shoot, right? :D
If not, you threw me with the 9mm reference...


Just a sort of "Poor man's" Mini-gun. My mistake to say "Gatling" ...respect Gatling...:)
not the most advanced mechanical way, but a simple solenoid with one lead running back to contact a copper plate connected to the battery.
(at a certain point on the wheel.. top or recoil(?) bottom)
Each trigger gaurd would be fitted with one and it would involve very little modification...Simple.

I'm not very familiar with PB models but whatever auto-loader should work... At high RPM's maybe 3-4-5- or 600 rpm's (common Drill speeds)

As for the 9mm reference, just explaining how I thought of it.
Guess the front of the handle wouldn't be removed (to counter-sink and bolt on the aluminum front of the pentagram shaped magazine) and a piece of magazine inserted/adapted.
Some sort of slot would be needed to keep [conical] shot in position.
Course with a large enough bearing and revolving around the outside, shots could be added through the middle from a larger box mag if desired.

5 guns @ 500 RPM's (revolutions PM)= 2500 RPM's (rounds PM)
2500/60 (seconds)= 41.666RPS
And 250 capacity/41.666= About 6 sec.s :shock:
Sure it would sound like a jet engine and certain rounds would look like a big ray or laser. And it would spit casings.
It should spin clockwise from the business end... :twisted:
I changed my mind... I think four AMD-65's instead...I must stop before I break the rules though... :roll: ...PaintBall...

Also, I've been dreaming up a piston valve with a spring plunger that would press they pilot valve once proper pressure is reached (full-auto)

Similar to a pop-off pilot, only I like this design more. :) 8)

Sorry, it differs how? :?
Perhaps by allowing for a higher flow/larger bore pilot?


Well the spring plunger is larger and easier to adjust the pressure.
But the main thing is that on it could travel rearward to press the pilot,
it could maybe pull a shot, dropping into the barrel and move further closing the opening (a pull back bolt?) Before pressing the pilot.
Only problem I forsee is once fired the spring plunger will move forward.
Maybe a lever could be in there (somewhere(?)...and it would work.

Thanks for replying Judge. Glad to know you're still Spudding!
BTW, I am Deputizing you to reply
HERE :D 8)

EDIT: ...Otherwise it would need to be fitted with a Blow-Forward bolt.
I like the spring plunger better because I was thinking of a long muzzle-loader barrel.
A section would be cut off and used for the air reservoir.
(over-under...w/ welding, tapping involved). A CO2 tank or 3000+ PSI tank would fill that.
The spring plunger would move rearward (out the back of reservoir) pressing the piston valve's pilot valve (think co2 bike filler or modded pressure washer...compact yet safely within specifications).
Power adjustable and possibly working a simple pull back bolt.
Hmmm... I was fortunate to discuss something similar with JSR back when I was less knowledgeable. It would be awesome to see it's completion :wink: 8)

EDIT2: Dang I don't like editing more than once, and I hope this isn't the last reply here. But just look at the shape of StickyTape's copper gun for example, And imagine the spring plunger coming out the back of the reservoir to press the blow-gun nozzle. And another gas chamber in front filling the reservoir.
While fitted with a pull back bolt connected to the plunger OR a Blow-Forward Bolt fitted to the barrel. There you go! 8)
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Unread postAuthor: judgment_arms » Sun Feb 15, 2009 7:28 pm

THUNDERLORD wrote:
judgment_arms wrote:... been busy lately with .68 caliber stuff and Brass tubing...


Two words on that...Great Scott!! :D
Did I miss that in showcase or are you "getting too good" for SF's? :P


Not finished yet, that and, as strict as the Mod's are 'round here about "this is a SpudGun forum", not sure how welcome it would be...


Just a sort of "Poor man's" Mini-gun. My mistake to say "Gatling" ...respect Gatling...:)
not the most advanced mechanical way, but a simple solenoid with one lead running back to contact a copper plate connected to the battery.
(at a certain point on the wheel.. top or recoil(?) bottom)
Each trigger gaurd would be fitted with one and it would involve very little modification...Simple.

I'm not very familiar with PB models but whatever auto-loader should work... At high RPM's maybe 3-4-5- or 600 rpm's (common Drill speeds)


In this case, go with Spyders, cheap as dirt and not to hard to maintain. :wink:

5 guns @ 500 RPM's (revolutions PM)= 2500 RPM's (rounds PM)
2500/60 (seconds)= 41.666RPS
And 250 capacity/41.666= About 6 sec.s :shock:
Sure it would sound like a jet engine and certain rounds would look like a big ray or laser. And it would spit casings.
It should spin clockwise from the business end... :twisted:
I changed my mind... I think four AMD-65's instead...I must stop before I break the rules though... :roll: ...PaintBall...

:lol: :roll:



Well the spring plunger is larger and easier to adjust the pressure.
But the main thing is that on it could travel rearward to press the pilot,
it could maybe pull a shot, dropping into the barrel and move further closing the opening (a pull back bolt?) Before pressing the pilot.
Only problem I forsee is once fired the spring plunger will move forward.
Maybe a lever could be in there (somewhere(?)...and it would work.

I think JSR was working on something similar...

Thanks for replying Judge. Glad to know you're still Spudding!

Thanks for remembering that I'm "Judge" :D
...you know, I've never use a Spud as a projectile...
BTW, I am Deputizing you to reply
HERE :D 8)

...Dang...


EDIT: ...Otherwise it would need to be fitted with a Blow-Forward bolt.
I like the spring plunger better because I was thinking of a long muzzle-loader barrel.
A section would be cut off and used for the air reservoir.
(over-under...w/ welding, tapping involved). A CO2 tank or 3000+ PSI tank would fill that.
The spring plunger would move rearward (out the back of reservoir) pressing the piston valve's pilot valve (think co2 bike filler or modded pressure washer...compact yet safely within specifications).
Power adjustable and possibly working a simple pull back bolt.
Hmmm... I was fortunate to discuss something similar with JSR back when I was less knowledgeable. It would be awesome to see it's completion :wink: 8)

...Good luck with that...
Sorry, I was supposed to play paintball today at the field I work at, I got there and there was four ref's and not a one of them knew how to fill tanks and handle rentals...
I got drafted into working on my day off... :(
Now I have a headache and I feel like counting coup...:evil:

EDIT2: Dang I don't like editing more than once, and I hope this isn't the last reply here. But just look at the shape of StickyTape's copper gun for example, And imagine the spring plunger coming out the back of the reservoir to press the blow-gun nozzle. And another gas chamber in front filling the reservoir.
While fitted with a pull back bolt connected to the plunger OR a Blow-Forward Bolt fitted to the barrel. There you go! 8)

Ah, I think I get it...
It's an interesting concept...
Either that, or I'm so far out of it that the illogical seems logical. :shock:
...I need a Dew...
But we're out!!! :cry:
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Unread postAuthor: THUNDERLORD » Wed Feb 18, 2009 12:52 pm

judgment_arms wrote:I think JSR was working on something similar...


That wouldn't surprise me... or if it's a more complex design that what I'm thinking.
Thing I'm worried about with it is leaking in the spring plunger rod or friction if it doesn't leak.
I suppose if the plunger rod had as small diameter as possible, a tiny leak wouldn't matter but testing is still in order for me.

Thanks for replying Judge. Glad to know you're still Spudding!

Thanks for remembering that I'm "Judge" :D

How could someone forget? :roll: 8)

BTW, I am Deputizing you to reply
HERE :D 8)

...Dang...


You're telling me my good man!
Where to even start with those kretins???
Thanks for checking that one out.
I actually have enjoyed that pain in the neck post! :) :x :D :? :( :wink: 8)

Ah, I think I get it...


Cool, Now I'm thinking of using the handle, trigger and most of a co2 bb, pellet or PB gun for the pilot valve, and if it has a nice semi-auto trigger-pull, the spring plunger could press against the trigger, OR lock the plunger in place for normal semi-auto trigger pulls.

But if the plunger leaks I may adapt the solenoid-in-the-trigger gaurd idea
And connect the solenoid to the pressure gauge (Jerry-rigged pressure switch I refer to as a "Thunderswitch" sometimes) :lol:

Course maybe a popoff pilot could be used and triggered somehow differently for full auto and the air-gun pilot for semi-auto.
Thanks Judge! 8)

EDIT: Forgot to mention, I'm thinking of a magazine design with an air bladder connected to a regulator to give constantly the same pressure on the rounds. (It wouldn't take a Whole lot of pressure to work either)..
Got to go, my lady thinks I'm out looking for new work..But I know I'm just a worthless dreamer sometimes... :lol: :P 8)
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Unread postAuthor: judgment_arms » Fri Feb 20, 2009 2:59 pm

THUNDERLORD wrote:Thing I'm worried about with it is leaking in the spring plunger rod or friction if it doesn't leak.
I suppose if the plunger rod had as small diameter as possible, a tiny leak wouldn't matter but testing is still in order for me.

Do like Smart Parts, if you can't get a good seal, use grease...



BTW, I am Deputizing you to reply
HERE :D 8)

...Dang...


You're telling me my good man!
Where to even start with those kretins???
Thanks for checking that one out.
I actually have enjoyed that pain in the neck post! :) :x :D :? :( :wink: 8)

It's hard to talk to those with deaf ears...
All I can say is: may God have mercy on their souls and open there eye's before it's too late...


Cool, Now I'm thinking of using the handle, trigger and most of a co2 bb, pellet or PB gun for the pilot valve, and if it has a nice semi-auto trigger-pull, the spring plunger could press against the trigger, OR lock the plunger in place for normal semi-auto trigger pulls.

...Ah, okay took me a second...
Gas ram hits the trigger when the pressure chamber is full...
I see either crap performance from running a HP system off of LP, or a ridiculous ROF since the recharge rate of most semi-auto paintball guns is upwards of 40-60 CPS.

Or is the gun used as a pilot?


But if the plunger leaks I may adapt the solenoid-in-the-trigger gaurd idea
And connect the solenoid to the pressure gauge (Jerry-rigged pressure switch I refer to as a "Thunderswitch" sometimes) :lol:

Sounds like my "timer circuit" that used a wind-up analog clock... :roll: :lol:

Course maybe a popoff pilot could be used and triggered somehow differently for full auto and the air-gun pilot for semi-auto.

Have your selector switch bump OP up to blow-off pressure?

Thanks Judge! 8)

No problem, gives me an excuse not to work. :D

EDIT: Forgot to mention, I'm thinking of a magazine design with an air bladder connected to a regulator to give constantly the same pressure on the rounds. (It wouldn't take a Whole lot of pressure to work either)..

I've thought up similar designs, all of mine used a gas ram and were to lone because of it, a bladder on the other hand would work so much better... until the bladder starts cracking...

But I know I'm just a worthless dreamer sometimes... :lol: :P 8)

I know the feeling...
At least you got a lady... :wink:
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Unread postAuthor: THUNDERLORD » Fri Feb 27, 2009 3:12 pm

judgment_arms wrote:Do like Smart Parts, if you can't get a good seal, use grease...


That's what I was thinking too!!


...Or is the gun used as a pilot?


The co2 pistol or PB gun would be used as a pilot for a much larger volume (unregged co2) piston valve.
Just think replace the blow nozzle with one.
The co2 would be piped in or fed into a dummy co2 in the handle where a 12 gram normally is. (I made a seperate post about it recently BTW) :wink:


....(Jerry-rigged pressure switch I refer to as a "Thunderswitch" sometimes) :lol:

Sounds like my "timer circuit" that used a wind-up analog clock... :roll: :lol:

:lol:

Well thanks Judge!
I had some more ideas I forgot at the moment. I'll get back.
Been getting over the flu or similar lately... :( :) 8)

EDIT: Just remembered one, I was thinking with the solenoid triggered mini I mentioned, a Photocell could be used and an LED on the revolving gun, With all other light blocked and perhaps there would be no need for actual contact (copper plate with brush)... :roll: 8)
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