Circular Stroke Piston System


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zollen
May 22, 2011, 04:48 PM
http://img703.imageshack.us/img703/1829/pistondesignv2.png

There are two key features I would like to point out.

1. Thumb Screw Pressure Adjustor for different barrel length or suppressor setup. The thumb screw simply increase or decrease the internal blow back gas pressure for the appropriate operation.

2. Composite Piston Dish pushes the bolt carrier group for shell extraction and feeds magazine bullet to the chamber. It completes one operation cycle without the need of buffer tube. This feature helps reduce weight and allows the attachment of folding stock.

3. All key Piston + push arms components are made with heat resistance light weight composite materials.

4. Hopefully the reduction of recoil would be able to achieved by the absent of buffer spring

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Sam Cade
May 22, 2011, 05:02 PM
ummmm... OK.

Basic nomenclature and typographical errors aside, there are some serious flaws here.

zollen
May 22, 2011, 05:03 PM
ummmm... OK.

Basic nomenclature and typographical errors aside, there are some serious flaws here.
Please Please Please tell me. I would like to improve the design.

Sam Cade
May 22, 2011, 05:18 PM
Its completely unworkable.

This is like a beta type Stirling steam engine but without constant pressure on the system...

No real "design" here, I think you are vastly underestimating the complexity of what would have to happen in order to make something like this work.

Êtes-vous un francophone québécois?

zollen
May 22, 2011, 06:18 PM
Its completely unworkable.

This is like a beta type Stirling steam engine but without constant pressure on the system...

No real "design" here, I think you are vastly underestimating the complexity of what would have to happen in order to make something like this work.

Êtes-vous un francophone québécois?
Would you be specific other which part of the system that failed? I really want to learn.

I am a Canadian, but I am not from Quebec. This is only a draft conceptual diagram, not design.

Are you suggesting I should have used a dual pistons system where each piston regulates one end of the operation?

Sam Cade
May 22, 2011, 07:42 PM
Are you suggesting I should have used a dual pistons system where each piston regulate one end of the operation?

No.

I am suggesting that the entire concept is flawed.

Reciprocation,to rotary motion,to reciprocation with nary a spring in sight.


1. Thumb Screw Pressure Adjustor for different barrel length or suppressor setup. The thumb screw simply increase or decrease the internal blow back gas pressure for the appropriate operation.
This is just a mess. I think you are trying to say that there is an adjustable gas block.

3. All key Piston + push arms components are made with heat resistance light weight composite materials. Ok. Do you know how much heat the parts have to endure? Do you know how the structural properties of various "composite" materials change when subjected to the kinds of temperatures that the gas system will generate?

2. Composite Piston Dish pushes the bolt carrier group for shell extraction and feeds magazine bullet to the chamber. It completes one operation cycle without the need of buffer tube. This feature helps reduce weight and allows the attachment of folding stock.

Here is where the fundamental problem lies. Without any sort of spring in the action everything would have to be wildly overgassed in order to get the thing to cycle, also, Its entirely possible to have a folding stock AND the mainspring in the butt stock. The Para-Fal does it just fine.

4. Hopefully the reduction of recoil would be able to achieved by the absent of buffer spring

Explain that. Keep in mind that recoil is linear along the bore axis.



So assuming that we are talking about AR type rifles:

The reciprocation of the buffer inside of the receiver extension actually serves to slow down the recoil impulse getting to the shooter.

An in-line DGI system like Stoner designed is about as simple as you can make a self loading firearm short of blow back, open bolt, full auto, advance primer ignition buzz-gun.

W.E.G.
May 22, 2011, 07:45 PM
http://i227.photobucket.com/albums/dd7/rkba2da/smileys/facepalm.gif

Unistat
May 22, 2011, 08:34 PM
I don't want to be negative, and I'm not an engineer anyway, but I do admire your innovative mindset and I think you should keep trying. One of these days someone is going to come up with a true revolution in gun design, why not you?

4thPointOfContact
May 22, 2011, 09:29 PM
I see the flaws thus....
1) You need a half rotation to extract the fired cartridge
2) You need a half rotation to chamber the next cartridge
... as illustrated, while the fired cartridge is being extracted the rotary piston is rotating the piston dish and feeding arm past the point where they will be usable for to lad the next cartridge.
3) Once the piston dish has rotated..... what do you do with it now that the feed arm is out of position?

Springs have already been mentioned, but that's a minor point if the mechanical linkages are good.
Reciprocal to rotary and back works fine.. steam locomotives use it all the time. (Of course, they have both steam and vacuum to do the work of springs so it's hardly a fair comparison.)



Lastly, I must add that the return spring for a paratrooper model FN FAL is not located in the folding buttstock, instead the mainspring is retained in a recess of a different bolt carrier, one without the usual 'rat tail'.
http://cnr-ffl.us/FAL/para_bbc_btm_sm.jpg

4thPointOfContact
May 22, 2011, 09:47 PM
Now... if you really want to come up with something both useful and inventive...
Come up with a way to make an easily loaded magazine for a rifle that uses Dardick 'trounds'
The revolving cylinder loads faster than inline and allows cooling as it cycles, but I can't think of any way to easily load trounds in a magazine that doesn't use feedlips.
Tround, note equal-sided elliptical cartridges.
http://www.thegunwiki.org/wiki/images/thumb/Dardick_tround_pat_2865126_fig4.png/180px-Dardick_tround_pat_2865126_fig4.png

Dardick feeding concept, note- no feedlips as the trounds slip sideways into the next chamber of the revolving cylinder.
http://www.cornellpubs.com/Images4/dardick_1958.jpg

Actually... I can imagine a way, but it would feed like a P90 PDW and require a rotating piece.... hmmm....

zollen
May 22, 2011, 10:05 PM
Thanks for the inputs. Yes, my concept was inspired by piston internal combustion engine and stream powered locomotion. Let me think about everyone inputs and hopefully I will come up a better concept. I still think the circular concept is possible If I could work out the details. The main problem is durability, too many moving parts and everyone know there are plenty of simpler designs out there.

Kliegl
May 22, 2011, 10:44 PM
It's not a good idea. I mean, I'm all for you being creative and all, but this idea is not mechanically efficient. You are trying to apply a mechanical device to the wrong application, and are putting little things on it to make it work. The IC engine is the way it is because it takes expanding gases (like a gun) and turns them into shaft power (NOT like a gun.) The only reason the crank is there is to make shaft power. If you don't need any, don't make any.

Sam Cade
May 22, 2011, 10:51 PM
The main problem is durability

The main problem is that cartridge firearms are a simple, mature technology in which pretty much every reasonable way to stuff a cartridge into and yank it out of a chamber has been tried.

There hasn't been any significant technological advancement in what constitutes state of the art in say, self-loading pistols in 100 years.

Is a Glock (designed ca.1980 or so) significantly better than a 1911 whose design roots go back to 1900?

A Glock is "better" in the sense that it is cheaper to make,tougher and has a longer service life but either tool in good repair will perform the same tasks.

Sam Cade
May 22, 2011, 11:24 PM
if you really want to come up with something both useful and inventive...
Come up with a way to make an easily loaded magazine for a rifle that uses Dardick 'trounds'

H&R apparently gave this a go.

zollen
May 22, 2011, 11:30 PM
Now... if you really want to come up with something both useful and inventive...
Come up with a way to make an easily loaded magazine for a rifle that uses Dardick 'trounds'
The revolving cylinder loads faster than inline and allows cooling as it cycles, but I can't think of any way to easily load trounds in a magazine that doesn't use feedlips.
Tround, note equal-sided elliptical cartridges.
http://www.thegunwiki.org/wiki/images/thumb/Dardick_tround_pat_2865126_fig4.png/180px-Dardick_tround_pat_2865126_fig4.png

Dardick feeding concept, note- no feedlips as the trounds slip sideways into the next chamber of the revolving cylinder.
http://www.cornellpubs.com/Images4/dardick_1958.jpg

Actually... I can imagine a way, but it would feed like a P90 PDW and require a rotating piece.... hmmm....
So.. you think it is possible to utilize Dardick trounds for replacing the standard AR Reciprocating shell extraction and shell feeding. Thereby eliminating the need of gas tube, gas block, buffer tube, BCG and springs all together.

I am not sure I understand what is the difficulty of loading trounds rounds into a magazine.

Here is what I think it could be done...

Imagine a standard AR magazine that could be loaded elliptical cartridges from the bottom (instead of from the top). A user would hold such a magazine upside down, then open the bottom cover, and just 'pour' elliptical cartridges into a magazine until the magazine is full. Then finally a user would manually rotate the cylinder (which is part of the magazine) to properly load the cartridges in the cylinder's empty chambers.

Sam Cade
May 23, 2011, 12:01 AM
-- Dardick trounds --Thereby eliminating the need of gas tube, gas block, buffer tube, BCG and springs all together.

In short, NO. You still have to power the cylinder turning.


...anyway, the Dardick failed for a reason:
It was inferior to other already extant designs.

zollen
May 23, 2011, 12:08 AM
In short, NO. You still have to power the cylinder turning.


...anyway, the Dardick failed for a reason:
It was inferior to other already extant designs.
True. It does not change the fact that the conventional design of BCG and buffer tube would be no longer needed. It would still need gas block, gas tube and a new design of a firing pin and springs.

Jim Watson
May 23, 2011, 12:11 AM
There was an open chamber machine gun running Trounds, the HiVAP. But it was a rotary with external motor, not self actuating.

Sam Cade
May 23, 2011, 12:23 AM
It would still need gas block, gas tube and a new design of a firing pin and springs.

...and a way to time the thing to keep it locked/unlocked at the right times.

So.... you a mechanical engineer or a machinist? :uhoh:

deadin
May 23, 2011, 12:33 AM
Here's another concept called a "split breech" that has been worked on several times since a Fokker design during WW1. The idea is to do away with linear motion all together. (The Dardick falls into this category.)

http://www.quarry.nildram.co.uk/Split%20Breech.htm

Sam Cade
May 23, 2011, 12:40 AM
Here's another concept called a "split breech"....

From the link:
Finally, it should be noted that the split-breech approach was the subject of a US Patent in 1861
150 years :-)

http://patimg1.uspto.gov/.piw?Docid=00032316&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D0032,316.PN.%2526OS%3DPN%2F0032,316%2526RS%3DPN%2F0032,316&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page

zollen
May 23, 2011, 12:52 AM
This concept would also simplify the parts inter-changeability for different calibers. All we would need are barrel and magazine (which house the cylinder) for the desired caliber. A quick change barrel system like Remington ACR and RGP, would greatly improve this concept modularity.

I don't like the idea of using specialized rounds like trounds rounds, it would be better to utilize the standard 5.56mm cartridge. Another problem is that the magazine would be much heavier and bigger than any conventional AR magazines. It is because this type of magazines would housed the metal cylinder and the ejection port.

Let me think about this....

LJ-MosinFreak-Buck
May 23, 2011, 07:36 AM
Here's my attempt on building onto your rotating piston design. The only way I could see something like that working is on a reciprocating platform with a secondary gas piston to actuate lock up. Here's my picture, it might be easier to figure out.

zollen
May 23, 2011, 09:25 AM
Here's my attempt on building onto your rotating piston design. The only way I could see something like that working is on a reciprocating platform with a secondary gas piston to actuate lock up. Here's my picture, it might be easier to figure out.
I have already considered a dual pistons design where each piston regulates one end of the movement. But it would increase the complexity of the system while I am trying to simplify the concept.

LJ-MosinFreak-Buck
May 25, 2011, 02:54 AM
I couldn't really see any way of it working other than that, so. If ou get it to work out better, let me know, I'd like to see that.

bigalexe
May 25, 2011, 02:23 PM
This concept is bad.

Guns work because of springs. They rely on linear motion.

Your concept is based on an engine. The only reason an engine takes a linear motion and converts it to rotary is because the output MUST be rotary. Ideally the motion would remain circular all the way through but it is ridiculously hard to come up with a good rotary propulsion system outside the water wheel (excepting Mazda). There is just too much loss of energy and also too much complexity in the design when you convert from one energy direction to another.

Apocalypse-Now
May 26, 2011, 06:37 AM
interesting concept, but i can't get it to work in my mind (i majored in design too lol).


modify, and talk to a mechanical engineer if you can.

you'll get no sound advice that'll get that functioning off of an internet gun forum.


keep thinkin on it outside the box, that's how advancements are made :)

moonpie
May 26, 2011, 12:11 PM
http://img703.imageshack.us/img703/1829/pistondesignv2.png

There are two key features I would like to point out.

1. Thumb Screw Pressure Adjustor for different barrel length or suppressor setup. The thumb screw simply increase or decrease the internal blow back gas pressure for the appropriate operation.

2. Composite Piston Dish pushes the bolt carrier group for shell extraction and feeds magazine bullet to the chamber. It completes one operation cycle without the need of buffer tube. This feature helps reduce weight and allows the attachment of folding stock.

3. All key Piston + push arms components are made with heat resistance light weight composite materials.

4. Hopefully the reduction of recoil would be able to achieved by the absent of buffer spring
interesting idea. try building a lightweight model and see where that leads. don't worry about what the experts say ; they'll always know everything and let you know how ignorant you are. pm me if you like .

Vern Humphrey
May 26, 2011, 12:19 PM
Would you be specific other which part of the system that failed? I really want to learn.
There are two basic problems.

First, how do you extract and eject the fired case? Your design feeds another cartridge, but doesn't clear the chamber of the previous case.

Second, how do you lock the breech?

Bloodysneeze
May 26, 2011, 01:21 PM
Lots of poor feedback in this thread. Nobody makes a successful, fully detailed design on their first try. John Browning didn't do it, Eugene Stoner didn't do it, Gaston Glock didn't do it. They likely had people telling them that their design was just wrong also. You'd also likely be surprised at where some good designs started. Nobody is going to keep trying if they just get told thier designs are "wrong" and "bad" and criticism like this would likely get you booted out of a design meeting.

That being said, this is an interesting idea but needs some refinement. You'll likely need a spring of some sort to reverse the mechanism. This could be a torsional spring in the dish, a linear spring in the piston cylinder, or something else. Also, try to reduce the number of joints. Moving the dish so the point where the rod links to the dish is in line with the piston rod would remove the need for an extra joint. You'd likely have to slot the dish also. Don't really have a lot of time to look at this any further.

I'd suggest getting a hold of some simple CAD software for practice. It will help you immensely in design and motion studies. If you're really interested in mechanical design it's also an invaluable skill for any design.

And FYI and am a practicing mechanical engineer. If you'd like some help or some modeling done I might be able to help you out.

Unistat
May 26, 2011, 01:42 PM
You know, the Army is soliciting for an assault rifle design that is capable of a "hyper-burst," that is, one(1) trigger pull that fires two(2) or more rounds with one(1) perceptible recoil impulse. That requirement is going to have to be a radical design. The only current firearm that does it is a Russian rifle that has a reciprocating barrel.

Keep thinking outside the box Zollen!

Br
May 26, 2011, 05:38 PM
Fig. 4 that 4thPointOfContact posted reminds me of the Wankel engine, a proven design at least in combustion engines. Circular stroke piston systems are certainly nothing new, but as others have pointed out, you have the extraction & feeding that needs to be just right.

http://en.wikipedia.org/wiki/Wankel_engine

At any rate, an interesting post.

Zak Smith
May 27, 2011, 02:04 AM
If the rotating mass is designed to capture energy and use that energy to chamber the next round, how does it stop when the next round is chambered? If you apply that much energy to a "lightweight composite" disc, it's going to be rotating very fast and the bolt is going to flop forward and back until the system runs out of energy.

The idea of capturing the energy during firing to use it later to reset and reload the mechanism is good - but not novel, since that's what springs do; however, this particular setup has some serious flaws.

Apocalypse-Now
May 27, 2011, 05:01 AM
well, for one thing, the reliability of a counterweight would be dependent on the angle of the rifle during firing.

zollen
May 27, 2011, 07:04 AM
well, for one thing, the reliability of a counterweight would be dependent on the angle of the rifle during firing.
You are correct. The counter weight is totally unnecessary.

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