Jack's semi pellet gun?

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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Solo
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Mon Apr 09, 2007 9:35 am

Hey Jack, whatever became of your design for a .22 pellet gun that used a hammer to knock the bolt forward, simultaneously loading a pellet and allowing air in through holes in the side of the bolt? You said it broke but then you changed somehting and it worked, and you had ordered a solenoid to run it, and that was it. (This was all on the spudtech archive, btw.)

Also, how would the power of that gun stack up against a single-shot piston? Seems like the restriction of the holes would cause lower power.
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jackssmirkingrevenge
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Mon Apr 09, 2007 12:05 pm

I had got the solenoids, here, I even made a little "animation" to show how it would work:

Image

Unfortunately, the solenoid didn't have the stamina to operate it against the friction caused by the seals. Basically, the theory is sound, but in order to operate effectively the "bolt" portion needs to have grooves machined into it for the fitment of o-rings that would provide an effective and relativley friction-free seal.

Honestly, I really need to stop half-finishing my prototypes :roll:

Of course the power would be reduced when compared to a single-shot piston launcher, due to the reduced flow and slower opening valve - but then again, you'd have a lot more lead at your disposal so the effect on target would be more impressive.

For those of you who have no clue what we're talking about:
Attachments
breech cutaway with bolt open and vents closed (loading)
breech cutaway with bolt open and vents closed (loading)
HAMMER2.JPG (27.21 KiB) Viewed 7573 times
breech cutaway with bolt closed and vents open (firing)
breech cutaway with bolt closed and vents open (firing)
hammer.JPG (32.78 KiB) Viewed 7573 times
Last edited by jackssmirkingrevenge on Mon Apr 09, 2007 12:18 pm, edited 2 times in total.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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FeLeX
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Mon Apr 09, 2007 12:18 pm

Hey ya think I could use one of the nerf gun valves and attach maybe a 2 litter bottle to it as a bigger reservoir?
Edit: About your design, I have a furnace that can melt aluminum and you think I could make a cast for that bolt? Your desing is just freaking awesome. When ever you tested it out was it any powerful? How many shots did you get and from what size of a reservoir.
Last edited by FeLeX on Mon Apr 09, 2007 12:38 pm, edited 1 time in total.
iknowmy3tables
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Mon Apr 09, 2007 12:33 pm

first I'd like to say that is a sweet design
second I have a solution instead of a solenoid use the back and forth motion from an AEG piston if it has enough power to create all the pontenial energy in a piston system then it should have enough energy to power this
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Mon Apr 09, 2007 12:53 pm

iknowmy3tables wrote:first I'd like to say that is a sweet design
second I have a solution instead of a solenoid use the back and forth motion from an AEG piston if it has enough power to create all the pontenial energy in a piston system then it should have enough energy to power this
That's no way to reason. If you have a heavy car and want to make it go faster, make it lighter, not fit a bigger engine.

*chuckle*

The eternal difference between the American and European mindset shines through again heheh
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Apr 09, 2007 1:09 pm

I’m hoping you’re being sarcastic Jack…
It looks nice; the thing is it’s by no means revolutionary. If it was me I’d use a triggering method along the lines of a Colt SAA, but that would make it single action (which is what I prefer). You could also try for double action, but ether way, all you need is a bigger hammer.
How much machining did it take?

Back to my first statement, and your post, if that’s true, why is it that any American muscle car will out perform an import racer any day? There is no such thing as to much power.
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Mon Apr 09, 2007 1:47 pm

judgment_arms wrote:I’m hoping you’re being sarcastic Jack…
Not at all. I believe in efficiency (have you noticed how much I hate cloud strafers :roll: ), but everyone subscribes to a different religion :wink:
How much machining did it take?
None at all, I don't have a lathe so it's all epoxy castings. i attached a breakdown of the materials I used.
Back to my first statement, and your post, if that’s true, why is it that any American muscle car will out perform an import racer any day? There is no such thing as to much power.
Will it, really? and with how much more power? There is no such thing as too much power, but power is a terrible thing to waste. I'm all for adding more power, as long as it's all used up.
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FMJ1.JPG
FMJ1.JPG (32.87 KiB) Viewed 7532 times
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Apr 09, 2007 2:22 pm

Actually no I haven’t noticed how much you hate them, you’re rather new, and I don’t click on many topics about BBMGs. But I don’t blame you for not liking them, I don’t even like the vortex BBMGs.

If it’s all epoxy how much pressure can it handle?

And finally,
Don’t look at me for all the details, all I know is when they hit the nitrous (I believe that’s how it’s spelled) on those import racers they get about the same horse power as a muscle cars has, maybe not even that much, except the muscle cars have that horse power all the time.

As for efficiency, when a car burns nitrous it’s using about twice the fuel as a car that has a super charger. Sorry if those numbers aren’t accurate, I specialize in projectile weaponry, not automobiles. All though I do know that a gasoline engine is about 22% efficient a diesel about 35% and a steam engine about 72%, but that was slightly random.

But, let’s not change the subject to cars.
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Mon Apr 09, 2007 3:49 pm

if you want to talk effiency a gear system is way more efficent for this cause. it's gotta use alot less energy to operate look at the size of a small light AEG motor and its small electo magnets verse that entire solinod which will need a rely circut to operate on fully automatic
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Mon Apr 09, 2007 5:39 pm

jackssmirkingrevenge wrote:
Honestly, I really need to stop half-finishing my prototypes :roll:
Hey, friend, I think that goes for a lot of us. But at least it give us dweebs (ok, maybe just me) something to build! :lol:

How much trouble would it be to cast the epoxy with an ID o-ring groove? Seems like you could lube up your bolt with grease, slide a wax ring on it, and cast the epoxy around it. When it's all done, squirt some boiling water in there to get the wax out, and stuff a little o-ring up in there.
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Mon Apr 09, 2007 5:50 pm

You should have a spring-loaded hammer to slam that piston foward....... that would work quite well. also, if the solenoid doesnt have enough kick, use a photo-flash mechanism and just wire the soleinoids wires DIRECTLY do the capacitor (with a switch inbetween, of course). this actually works quite well for actuating non-modified sprinkler valves................ but here it wouild give you the kick you wanted.
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Mon Apr 09, 2007 6:58 pm

You might as well grease it up well, add the o rings and cast right over them don't you think?
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Tue Apr 10, 2007 8:34 am

Sure, why not? It sounds like it would work. Duh. :oops:
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Tue Apr 10, 2007 11:16 am

well springs if you have some mechanizm that flings it forward it will open faster but then it will normally be in the open position and waste air, if you make it so the spring flys back then that solves the problem but it just will open slower
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Tue Apr 10, 2007 12:00 pm

judgment_arms wrote:Actually no I haven’t noticed how much you hate them, you’re rather new, and I don’t click on many topics about BBMGs. But I don’t blame you for not liking them, I don’t even like the vortex BBMGs.
I'm not a fan of BBMGs purely because they're so wasteful of air, which is why after making my own vortex and cloud designs, I came up with another version free of dead space that was much more efficient, and gave me over double the muzzle energy for the same pressure.
If it’s all epoxy how much pressure can it handle?
In my mini-coaxial, I've taken the pressure up to 400 psi without ever having a failure, basically the PVC will fail long before the epoxy does. It's all a question of using string adhesive and applying it properly.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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