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End of Barrel Hop-up Prototype Device

4523 Views 17 Replies 5 Participants Last post by  becklr1
I found out machining plastics is kind of hard. Here is how it came about.

I went to the bowling alley the other day with the kids. Have you ever seen the ball return where the ball returns on rails that are at like 4 and 8 o-clock. They do that to stabilize the ball since rolling it alone would make it hard to roll in a straight line. It also keeps the ball spinning. That made me think about a hop up.

The premise is what if you spun the bb and the had a relief in the bottom for the bb to settle in like the bowling ball. It would remove friction from the bottom of the bb and reduce the bottom friction which tries to undo the back spin. Then what is you made a few additional relief slots at 10 and 2 o-clock.

In the end straight slots like the falcon barrel and then a channel in the bottom.

The what if you had a hop up which was an o-ring making it easy to support. If you did to want to use a hop up you could plug the whole hop up portion.

The what if you made it so it fits inside a silencer. Silencers have a cylinder and 2 ends that screw together. What you do is get a slightly longer barrel that sticks out into the silencer.

Then you tighten the silencer down. But then you back off the rear cap a 1/4 turn. Then you stick an o-ring o the back of the device and slide the device into the silencer until it hits the barrel and you wedge it on. Then you pin the silencer to the outer silencer cylinder wall with a small machine screw. Then you tighten the outer silencer wall back the 1/4 turn you previously loosened. If you size the barrel correctly the o-ring o the back of the device will now compress into the back side of the silencer wall ad make an air tight seal.

Well I did not want to spend too much time on it so I made something quick and the channels and slots re not sized right and the hop up intercept is suspect. I used Oilon which is a self lubricating nylon used where you need low friction but do not want to use lubricant. Aluminum for those that do not know is very grabby. Not the slickest stuff. Something like this in aluminum may or may not work but I do know brass would be better by far. It is slicker. Aluminum is so dam grabby. Hence a specialty plastic which is ever slicker. Of course machining plastic is tricky since it tends to want to melt and what not.

Anyhow, here it is. The hole for an o-ring to slide though to intercept the bb. A tapped hole in the top to put a set screw to apply pressure to the o ring. Some wide rings to support the device inside the silencer front to back to keep it stable. A deep channel in the bottom to act like a bowling ball return A few small channels to relieve friction a bit higher. Perhaps make the bb spin more consistently and an o-right relive in the back to seal the back of this device against the back of the silencer.

I do not know if it works. It is more of a concept piece. Many posts people talk or show pictures but I prefer to actually show something made, I find it easier for people to visualize. Perhaps making something will inspire people to make something. You can always find someone or a local machine shop to make something for you. Not having equipment is not reason to not make something if you have an idea. All you need is a Visio diagram with measurements.

I have the measurements fro a silence I bought a year back and when I went to get the silencer to put this in I can not find it. I believe I sod them with my vsr parts on ebay a few moths ago. Heck someone out here may even have bought the stuff.

This this part will go untested it is relegated to a concept part. Feel free to use it or ideas from it.

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I feel compelled to add this was the result of an afternoons worth of thinking. It is not vetted out, I actually see 1/2 a dozen issues all of which can be refined driving this towards a possible viable solution. I am in no way claiming this solves anything or even that it will work. It is just a physical manifestation on an idea on an idea.

Ideas have to start somewhere so consider this a start for someone else to possibly develop. Or not.

None the less, it is yet another part developed out of this great site.
I thought there would be more comments on this. Bad idea, good idea... something. Not so sure I'll branch out like this anymore if it is not helping anyone to see ideas come to life.
I'm not sure I understand your Idea completely but props for even trying it out. The one thing I'm confused about is if your idea is based around the the BB stays on the bottom of the barrel? If you could draw up some simple paint schematics that'd be a great help for me to understand it.
Part of the problem is that no one knows how good or bad an idea it may be or what to make of it altogether, because nobody has ever seen anything like it. On the other hand, your other thread, which is full of similarly innovative constructions of yours, is one of the most active threads on the entire site. But I would say the majority who have dealt with the VSR's stock 45 degree sear system or the small, sears and thin trigger boxes of other guns have at nothing else questioned the long term reliability of that. Or their piston end. Or worried about breaking their bolt handle. Or blasting off their cylinder head. And of course everyone is concerned with accuracy stuff like hop-up chambers in the gun like everyone is familiar with. Innovations that make things stronger, or more effective in an easy to see or understand way. But this is an abstract concept to everyone.

This is the first time I'm seeing this. It is also a new concept to me. I will try to help, but obviously this will all be mere speculation.

Well, I take that back, this first thing isn't speculation. The conventional hop-up bucking does more than make the bb spin. It allows for the nozzle on the cylinder to seal properly with the barrel. You will need to find some way to produce a seal between the bucking and barrel, for instance by using a bucking with no internal mound and a barrel with no window in the rear, and an anti-blow-by ring to ensure that the bucking doesn't simply expand from the pressure. Nothing to provide hop obviously.

But from here on it's speculation. In a conventional barrel system, the bb hits the bucking (on in this case, o-ring), it is pushed down, and then subsequently shot upward. The bb bounces a little and is eventually stabilizes... somehow (the exact means being debated in that other thread). But regardless of how it occurs, the bb has no chance of becoming stabilized within a barrel before its final exit vector is determined. The exit vector will only be determined by the hop-up chamber. The barrel will only serve to give the bb space to accelerate. The way I see it, it is little different than the bb coming straight off a hop-up chamber in a conventional setup. The only difference is, the bb's velocity, since it has already accelerated, will be as high as it should be from whatever barrel length you use when it hits the chamber. That means that the bb will still travel far, assuming it picks up a good spin from the chamber. But as in an incredibly short barrel, the bb will not get a chance to stabilize at all after leaving the hop-up. To that end I suspect accuracy will suffer. Again, this is all speculation.

The other thing about this setup is the use of an o-ring for the contact surface for the bb. I have not seen this done before either, so it is also speculation. But I do know that most o-rings are considerably harder than most buckings. And hard buckings tend to in my experience be less effective in producing a stable, consistent spin, particularly with heavy ammo. The other thing is that hop-up units with greater contact surface such as the G-hop have shown themselves to be more effective in producing a stable consistent spin than those with smaller contact surfaces. I have not tested this myself, but it is on my to-do list, and I have seen plenty of documented testing on AirsoftMechanics to show it. I don't really understand why it works. I will thus speculate, that due to the harder material, and small contact surface, that an o-ring would not be especially effective in producing the stable, consistent hop. However this is just a guess. I also have no idea how it would behave in this case, because the bb is hitting the hop-up at it's full velocity if it's at the end of the barrel rather than it's relatively small velocity at the very beginning, which may completely change what is most effective for all I know.

So there's my "speculation", not sure if it was much help, but that's all I've got at the moment.
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Added illustration to the first post, perhaps this will help. Thanks for letting me know about a graphic helping! In my mind it all makes sense. Sorry about that. ::)
Now that I look at it, you have some testing ahead of you. If the O-ring really does apply as much hop up as mentioned, you may have the rounds jumping into the silencer and not exiting because the BB's will only be influenced for a small bit before leaving the unit.
Good point, I was not planning on testing it though. Do not have a gun with a longer inner barrel anymore. If someone else wants to test it that is fine.
Hey Beck if you want to make something for the PWD so I can attach her to the end, I can do some testing for you ;)

PM me and I can send you some details.
Yeah, if you need testers, many of us will be willing to test this thing out.

I'm just not sure what the goal of this is though... are you trying to make a second, fine tuned hop at the end? Or replace the hop at the start of the barrel preventing the air leaks and other problems? A little confused on where this is going...
Are you trying to make a second fine tuned hop at the end? - Yes
Or replace the hop at the start of the barrel preventing the air leaks and other problems? - Yes

awagg, the goal is any or all of the items mentioned. Such is the problem with coming up with a solution before defining a problem.

That said, his exercise was designed to show how an idea can be physically created quite quickly. I am not trying to solve a problem per say, rather it was an idea about an idea. There are several concepts here that may or may not be viable. How well it works or what it evolves to is for someone else to determine.

I am all about R&D. This component was the result of rapid R and rapid D. If it spawns ideas that someone can use to start a company, great! If not oh well not all ideas are winners. :)
Hmm... I think this idea could definitely work... First, just test and see if the oring will apply too much hop, because the bb is going full speed. Then we can go from there.
Well if someone has a gun with a longer inner barrel and silencer I'll send it to you. Feel free to but the outer silencer sleeve bits down to fit in yours. Woogie?
Let me get to a computer and I will vet you some info. Still not sure what kind of adapter is needed for suppressor, but will find out and go from there. If not, can use the 500mm barrel in my L96.
Pretty much turn down the plastic to fit in a suppressor. I bought a few from WGC. It drops right in there but I don't have them anymore just the dimensions.

ACTION-SL-SI05 Action Silencer 40 mm X 220 mm
KA-AD-VSR1004 King Arms Silencer Adapter for Marui VSR-10 G-Spec ( 14mm- )

It drops right inside a silencer, just trim to fit and put a button head set screw to hold it in place. the screw head gives you a visual to find TDC. Of course a barrel will need to be sized just the right length.

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Could it fit just on the barrel as a temporary set up w/o the silencer? Seems like it would be easier to test for the time being. I'd just try it on the end on the barrel to see how it works. What may end up happening is the oring provides way to much hop, and needs to be rethought... or something along those lines.
I should be able to come up with something that will work with the L96. Have suppressor and all needed parts at home now. And can do some small modding to the rifle if needed. So if you want to make a few or what not, let me know and I can test them out for you.

Like what was said earlier .... This may work due to the bb already being at speed when hitting the o-ring. I am thinking it may act like the choke on a rifle barrel.
Yeah I think it will but I also think it may speed it up. Temporary pause and then pressure builds up and then pops it out. accuracy, that is another story, who knows. It may work horrible but moving the o-ring .1mm up may make it the best device in the world.

Got to build got to test. Other boards talk talk talk but do nothing. Out here we build and test. Not all devices are winners.

Shoot me your address. :)
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