Semi-Auto Pneumatic Bolt

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How's my design?

Good
2
40%
All right
1
20%
Bad
2
40%
 
Total votes: 5
iknowmy3tables
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this is the difference in surface area
yep its pretty crappy
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yep its a crappy diagram
yep its a crappy diagram
area.JPG (27.5 KiB) Viewed 3019 times
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Flash
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Can you explain why? And does that mean the bolt will work?

Anyways if it does work, I'm going to build a prototype to see just how fast the bolt moves. I designed it so I can build all of it using cheap, durable, light weight, and available materials from Mcmaster. I put together the order list and everything will be under $50.00. Its a prototype because it will only have the firing chamber and the 3 way valve. Instead of building a separate airtank to hold all of the air at a high pressure and using a regulator to bring down the pressure to something safe, I'm just using a
pump to fill the chamber. I also made the firing chamber larger to compensate for the lower pressure that will be used.

Here's some picture of the design, pretty close to scale.

Image

Image

Image

Image
iknowmy3tables
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the area I painted yellow is the area where the chamber's pressure is not countered by the pilot's pressure, that means when the system is pressurized the force will be greater on the chamber side and it will not close, just try a non telescoping system
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Flash
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The purple section is not part of the bolt, its the bolt rod. The bolt rod acts as a stopper and covers the back part of the bolt when the chamber is being filled. The actual bolt and the o-ring are the only parts that move. So wouldn't the front and back of the o-ring determine if the bolt stays?

Here's a diagram of the o-rings front and back:

Image

The bolt rod covers the back part of the bolt and since it can't move, it would make it so only the o-ring is the only exposed part that matters.
iknowmy3tables
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in those areas pressure is applying to the o-ring, and you forget the entire inner ring/layer that I highlighted
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Antonio
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This design is exactly the same as the ION paintball marker. Exept that this one doesnt cut of the air supple when the bolt is forward. I think those sliding parts are ganna be hard to get perfectly sealed without too much friction occuring. If you dont have the machinery this is near to impossible. But good luck. Would be amazing if you could make these parts in real life:)
The ions internals:
Image
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Flash
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I don't understand how the inner layer tubing would affect it. The bolt stopper completely covers it.

ant wrote:This design is exactly the same as the ION paintball marker. Exept that this one doesnt cut of the air supple when the bolt is forward. I think those sliding parts are ganna be hard to get perfectly sealed without too much friction occuring. If you dont have the machinery this is near to impossible. But good luck. Would be amazing if you could make these parts in real life:)
Hehe, its funny that you mentioned that. I must have looked at the Warpig.com's Ion diargam like a million times throughout the design process. My goal was to simplify the Ion so it would only need one source of air to the firing chamber and the bolt. I wasn't able to, but al-xg did for me :P.

And the a combination of special tubing from Mcmaster and the right size o-rings should make putting things together pretty simple.

EDIT: what CAD program do you use and how long did it take you to make the Ion diagram?
iknowmy3tables
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you'll have to keep the length of the ion, the wider part near the back in necessary to balance to force, the makers of the ion wouldn't have made that part longer and increase the dead space if it was so possible to make the forces equal, but your design currently is physically impossible to make balanced because the plug seal is inside of the pilot seal, and the difference of that plug's OD and the smaller diameter of the pilot is the difference in the pilot's surface area and the chamber's
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Flash
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iknowmy3tables wrote:you'll have to keep the length of the ion, the wider part near the back in necessary to balance to force, the makers of the ion wouldn't have made that part longer and increase the dead space if it was so possible to make the forces equal, but your design currently is physically impossible to make balanced because the plug seal is inside of the pilot seal, and the difference of that plug's OD and the smaller diameter of the pilot is the difference in the pilot's surface area and the chamber's
I didn't want to be too picky about ant's design, but here's a more accurate one, from a pretty big pb site. Link

The plug seal isn't only inside, it covers the entire backside too. That's why there is more SA when the chamber is being filled. The bolt rod is stationary. The forces acting on the plug don't move the bolt because the bolt moves seperate from the bolt rod.
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Antonio
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Flash wrote:
iknowmy3tables wrote:you'll have to keep the length of the ion, the wider part near the back in necessary to balance to force, the makers of the ion wouldn't have made that part longer and increase the dead space if it was so possible to make the forces equal, but your design currently is physically impossible to make balanced because the plug seal is inside of the pilot seal, and the difference of that plug's OD and the smaller diameter of the pilot is the difference in the pilot's surface area and the chamber's
I didn't want to be too picky about ant's design, but here's a more accurate one, from a pretty big pb site. Link

The plug seal isn't only inside, it covers the entire backside too. That's why there is more SA when the chamber is being filled. The bolt rod is stationary. The forces acting on the plug don't move the bolt because the bolt moves seperate from the bolt rod.
I didnt make that picture> I just found a pic of an ion on the net. I use this site as well. Its really handy to c how things work etc. The ion is the most efficient paintball marker> that impresses me allot. Would be great if we could make this as well. But yeah u really need a mill for this one. Good luck
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Flash
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ant wrote: I didnt make that picture> I just found a pic of an ion on the net. I use this site as well. Its really handy to c how things work etc. The ion is the most efficient paintball marker> that impresses me allot. Would be great if we could make this as well. But yeah u really need a mill for this one. Good luck
Oh, I never saw that picture of an Ion before so I thought you made it yourself.

Thanks
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