thanks for being a king of random without clickbait

@sevret313

7 жыл бұрын

The problem isn't the click bait, but the weak content.

@kitchenmaiden81

7 жыл бұрын

With the caps and emojis and no DIY, just "experiments."

@swf4iubrh4s

7 жыл бұрын

YES. A.H.W.

@koolcrazycow3307

7 жыл бұрын

rocknexus king of random is click bait his channel went to shit

@superalvin7208

7 жыл бұрын

That what happens to KZreadrs when they care more about the money than the content

I wonder if the mass of your flapper valve is part of the problem? The heavier it is the slower it will be to be pushed out of the way by the air pulse in front of the projectile.

@Nighthawkinlight

7 жыл бұрын

It's quite light, I don't think it could be made any lighter while remaining strong enough to work. I used a lighter hinge and smaller attachment bolt for the valve in this video than my last one.

@fryncyaryorvjink2140

7 жыл бұрын

NightHawkInLight you should make a bypass pipe that lets some air around the projectile to open the door

@Gyropilot42

7 жыл бұрын

The best thing I can think of to make this work without the drawbacks of the burst disc or the valve would be some kind of curtain made out of rubber. If it was fixed on the botton of the end of the pipe and had some loose attachment on the top and sides and enough material on the sides to seal the vacuum chamber... Something like this could work, I guess

@Nighthawkinlight

7 жыл бұрын

That's actually not a bad idea at all. A cork would work well, though the projectile would almost certainly hit it from time to time

@Gamerdu45

7 жыл бұрын

I guess that the one way to fix it is by making another smaller pipe that would be opened faster than bigger one, and helped the bigger opens little bit faster.

Try using something like a paper cup for the valve. Just insert it into the pipe bottom side in so that it wedges itself in and holds the pressure when it's being pulled back. You can cut most of the cup off since you just need the wedge shape, and since it's light enough it'll just become part of the projectile like the aluminum did. Alternatively, if you can bring a small vacuum along and have a minor vacuum between the plug and piston going all the time, than you can use anything flat and light as the plug since the vacuum will hold it in place and you won't need the wedge shape. So you'd load the projectile, cover the face with a paper plate or a small piece of cardboard (for stiffness), and it'll be held there by the minor vacuum until you fire. If you're going to use a vacuum pump however, make sure you have a check valve in line so that the pressure doesn't shoot back into the pump. Third option is to get a female-female adapter pipe and just slide that over the aluminum sheets (instead of taping it around the edges each time).

@Nighthawkinlight

7 жыл бұрын

A cup is a really good idea! I think maybe a smooth plastic cup would work well. I'll try it

@eugenes9751

7 жыл бұрын

My concern with the plastic cup was that it's going to be much thinner than a paper cup (since you can make thinner plastic), and it might be more likely to crumple under the vacuum. Also, if you're going to try the route of breaking through the plug, maybe consider making the projectile more pointed so that it cuts through the plug easier.

@Nighthawkinlight

7 жыл бұрын

The way to do it would be to put the plastic cup bottom first into the pipe like a cork. The plastic cups I'm thinking of I don't think will have any trouble standing the pressure in that configuration. Whether they move out of the way or not they will be easier than making burst discs. I will try it.

@ivanhazelton

7 жыл бұрын

+NightHawkInLight , The bottom of an aluminum can is almost as light, but much stronger, due to the radial corrugation. You just need to find an aluminum can larger than the diameter or your PVC tube to cork it up.

@keks9662

4 жыл бұрын

NightHawkInLight you need to make a barrel that will reduce its diameter during charging and increase during a shot

Need a Joerg Sprave patented rubber-powered valve release.

@Kalanchoe1

7 жыл бұрын

that is both true and hilarious!

@God8-O

7 жыл бұрын

Daniel Forsman BUT... *"We must double up the rubber!!!"* *"HA HA HA!!!"*

@harbingerofwarx995

7 жыл бұрын

That's what I was gonna say. Might be difficult though.

@revimfadli4666

5 жыл бұрын

Need a collab

@V-C137

4 жыл бұрын

Joerg doesn't patent any of his inventions

You can add a rubber band to the valve, and adjust the pivot point, so the closed position is very unstable. A small opening of the valve will cause it to slam fully open.

@user-kz8ts7dn9z

Жыл бұрын

I actually thought the same. I think the problem is that the liitle amount of air inside the chamber Knocks the valve then the air escapes and the only thing pushing down the valve is gravity which is not ideal because the valve makes something like a circular motion and it takes even more time to fully open. So a rubber band in a position that when the inside air kicks the valve a little bit then the rubber band takes action and clears the bore. Maybe it wont work as well but i think its worth it

You're an inspiration as always! I have three suggestions for easing the opening of the valve: 1. Make the actual flap part (or rather all that is moving) lighter so that less energy is required to move it. Just grinding of excess bolt and "skeletonize" the metal hinge should make a considerable difference. 2. Hold the valve assembly on with elastic bands to make any potential impact less destructive. 3. When the projectile hits the flap it soon engages with the bottom of it, giving it very little leverage, a pin either at the top of the flap or in the middle of the projectile that engages instead of the actual flap part should yield better leverage.

That is pretty awesome! When I was a kid, I built a pressure cannon using a plastic tube, bicycle pump, and a projectile. When the pressure built up enough in the tube, it shot the projectile pretty high. Thank you for sharing.

I love that you really spend the time to explain the forces and other factors involved in your projects. Keep up the good work!

You may be able to use a spring or several rubber bands to accelerate the flapper open faster than gravity can. I have made a simple diagram that I hope is understandable in how you might be capable of achieving a faster opening of the flapper. i.imgur.com/Or6Rrlu.png

@1Superfry

7 жыл бұрын

I agree - this was the same thought I had while watching the vid. It's usually called an 'over-center' spring mechanism. The spring stretches just barely over center of the pivot, then will accelerate faster that gravity can pull it down once the air pressure gets it started. It's a great mechanism also used on a lot of latches. It may take a little bit of tuning to get the geometry just right. I had two other thoughts - one was to reduce the mass of the valve, but it still needs to be strong enough to resist ambient pressure. The other idea was to split the valve in half so it swings open from either side. The down side is you need two hinges, and a more complicated seal in the middle.

@gabewrsewell

7 жыл бұрын

This is a fantastic idea

@arcsmith4115

7 жыл бұрын

ejler thomsen You could have a cone shaped valve that opens up like a flower into several triangles, that way if it does get hit it will slide and open.

@MrRolnicek

7 жыл бұрын

Thats pretty much exactly what I suggested in the last vdeo, but your diagram is far superior to my clumsy explanation.

@carlosserna_boi921

7 жыл бұрын

ejler thomsen yeah that would honestly work! wow

I believe many people think of this but just don't say it because it seems obvious and like videos are supposed to be like that so there's nothing to go crazy about. I wanted to say that you make amazing videos, amazing projects and we see that you do put a lot of effort in your videos and projects and I wanted you to thank you for that and I hope you continue making these videos. you never disappointed me and I watched your videos from the beginning.

This is the best DIY channel on KZread. No clickbait, just honest and detailed tutorials with great quality. Keep it up!!

i made one large enough to fit myself into and smashing the burst membrane from inside, controlling the vacuum pump on the outside via my mobile. Using high explosives I normally suffer burns and lost toes but thanks to this man i arrived at my destination abroad completely and intact apart from a little brain damage, and burn-free.

Please angle the valve! Then it will need to move out of the way less! You would need to alter the pipe, but I am very confident it will change your results!

@nogmeerjan

7 жыл бұрын

Sounds like a good idea. This does mean there will be a need to keep it closed while creating the vacuum.

@kennethgrieger1327

7 жыл бұрын

Create more of a cap! Have a lip around the edge for some friction

@kennethgrieger1327

7 жыл бұрын

It will need to be a balance between friction and easy release, but I think it can be done

@kennethgrieger1327

7 жыл бұрын

Brett Coryell true it would add more mass to get moving, but I am hoping after seeing the slow motion footage that have the valve angles at 35 or 45 degrees will be enough to overcome both the added mass and problem of getting out of the projectiles path

@kennethgrieger1327

7 жыл бұрын

Brett Coryell I think it could work, but the only issue is a little bit of back and forth. He had said that he could hold the cap closed with a piece of string, but that just adds another element to time correctly. I am sure if he can create a trigger system like you explained that it would be easier to fire, but how complex do you want something like this to get? It would probably work, but it is a little complex

Original. High Quality. Wonderful content. Love this channel

@BadBoiFX

7 жыл бұрын

I'll become a patreon soon :)

3 years later... Still one of the best videos, of one of the best educational conntent creators.

Rewatching your entire channel again and I just love these videos man, you're so good at it

An awesome video as usual. By chance can you make the burst flap lighter, maybe using styrofoam. That way the air would require less force to move it faster.

Have you thought about making a smaller handheld version with the same technique?

@NoCokeOnlyIce

7 жыл бұрын

Julius P vacuum would be too weak

@Nighthawkinlight

7 жыл бұрын

I have but I haven't tested it yet. The shorter the barrel gets the weaker it will be, but I think it should still work down to 3' long or so.

@lauchsalat2998

7 жыл бұрын

I guess most people here would prefer a version that needs a car to pull back the piston. :P

@Pape1080

7 жыл бұрын

NightHawkInLight that was my thoughts too, but what if the ammunition was .177 pellets in a 3 feet pipe?

@bernardolozano7429

7 жыл бұрын

Maybe you could have a longer barrel or a manual vacum pump

my favourite videos are the cigar box guitar videos, the long build process is super satisfying to watch

Excellent! I have used your previous video in my science class to ask the kids to guess what would happen. This one would be very clear for them to see exactly what's going on. Thank you.

@Nighthawkinlight

7 жыл бұрын

I love hearing about my videos being used for such things, thank you!

Sometimes the simplest things work the best

Very cool concept

One suggestion: it seems you would need additional mechanical spring type support to open the flapper. The key would probably be to engage it only at the end of the procedure when the pressure already built up. So maybe a string cut at length to coincide with the moment you are pulling the piston to engage the additional flapper spring right before you shoot.

@krisk7

7 жыл бұрын

I thought about this a bit more and it's a big challenge. Theoretically without an air cushion (some air remaining in the pipe) the flapper stays against a vacuum till the last moment - when it's hit by the projectile. Another wild addition to the spring idea above would be to add additional little pipe over the main pipe and near the flapper. The purpose of the additional pipe would be to equalize the pressure just before the flapper (one inch from the end - first entry) when the projectile moves close the flapper (let's say 10 inches from end - second entry).

First of all, let me say that i love the videos and i think you're at least a borderline genius. With that said, here is what i think is happening. The hinge is a great idea, but it has an inherent flaw. In order for it to work, the flap has to move forward with the inrush of air, but it can't because the hinge actually inhibits the forward motion that it must have to get out of the way. The pressure exerted on the flap is equal all the way around the circumference of the pipe and it's trying to move it forward, but it can't move forward because of the hinge and the way it restricts movement at the bottom of the pipe. if the hinge were able to slide horizontally it would help it get out of the way, but this action would take time that probably isn't available. i say that only for those of you that haven't tinkered with these. Instantaneous is not a good word for it. When the vacuum releases, it happens so fast it's mind boggling. The videos are great, but they really don't do justice to how incredibly fast the action is. My only suggestions would be to try something that doesn't seal quite as well inside the barrel, so a little air can go around it and help push the flap out of the way before it gets to the end of the pipe, try something a little heavier, or a combination of both with a slightly longer barrel. Keep up the good work Sir. There is at least one old fogy out here that enjoys them immensely.

I have an idea about how to open the valve. It's adding a secondary tiny cannon that opens the valve some miliseconds before the real proyectile came to the end of the barrel.

Looking at the slow motion frame by frame, it looks like the flap maintains a constant (too slow) angular velocity after it loses its seal. Perhaps you could design a valve that is slightly recessed into the barrel and sealed with an o-ring like your piston. This might give the air pressure more time to accelerate the flap to the necessary speed to push it out of the way, instead of only pushing in the instant before it loses its seal.

@Nighthawkinlight

7 жыл бұрын

I agree, an inset valve might be what's needed

@sandervanduren2779

7 жыл бұрын

NightHawkInLight what if you had a small piece of maybe cardboard plugging the end, the vacuum could keep the cardboard stuck to the tube, but when the pressure increases between the projectile and valve, the cardboard loses all adhesion to the pipe, letting it fall away. Plus, if the projectile hit it, it probably wouldn't affect its trajectory/velocity, since the cardboard would have very low mass, and as such, very low inertia to overcome.

@sasjadevries

7 жыл бұрын

Not too sure, a valve that's inside the pipe sits tighter, and will probably be heavier. However omitting the hinge will help to some degree; and if there is some (light) piece glued to the valve that's inside the pipe to hold it you won't need a hinge. And if that piece inside the barrel is making a pour seal it won't have much friction with the walls, but it will give the piece a chance to accelerate more. _(you that you would still use that same disk for holding the actual vacuum seal)_ --- @all the engineers: because of the hinge the valve needs to *get both Angular velocity and horizontal velocity,* so it needs to *overcome both* angular inertia and linear inertia. (MV² + *Iω²)* That's one reason why the hinge is slowing it down. Then consider the fact the hinge is made out of metal, adding mass, and adding inertia. And then the hinge is not designed for fast opening with minimal friction, I mean nobody opens their funiture doors with the speed of sound. Another (minor) reason is that once the valve has opened by a little bit, it's at an angle, somewhat working as a ramp redirecting the air in stead of being pushed away by it.

@GordieGii

6 жыл бұрын

I'm thinking a lower mass convex seal (think half a ping pong ball) with an over center spring (or rubber band) in the same direction as gravity. Only a little force to push it past the pivot, but then it should snap down really fast.

To make a lighter valve, get a sheet of silicone and a thin plastic disk. Much lighter than a furniture slider. You could easily keep the whole construction at a few grams

I have a pretty simple idea about your valve problem. Instead of making a mechanism that relies on that hinge you could use a magnet mounted to the tube just to hold the disk on with the least amount of force so when the air rushes back in it just pops the valve off as it travels along the tube.

So the issue seems to be you need to get the flap to open before the projectile gets too near it. The only suggestions I can think of might be too mechanically complex. You could borrow a technique from semi-automatic rifles that use the gas pressure from the barrel to operate the bolt., except in reverse. A separate gas tube that will use a piston (instead of a bullet) to open the valve as the air comes rushing in. A spring would also help, using the same "over-center" sort of arrangement you're using with gravity and the hinge, it wouldn't take much force to open the valve enough for considerable spring pressure (A rubber band mounted perpendicularly to the barrel) to yank the valve open quickly. Timing becomes a problem because since you're depending on the vacuum in the barrel to launch the projectile, you want that opening to come as late as possible. You'd need to use your high speed to figure out how long it takes for the valve to clear the barrel and how far from the end of the barrel the projectile has to be to give that time. The moment that valve opens, you lose any thrust because the vacuum is relieved. Frankly, you might just be better off with a faster way to make foil caps, say, making a bunch of collars that you can prepare in advance that fit over the end of the barrel.

@THEOGGUNSHOW

7 жыл бұрын

Dr. Mauser I thought about this, too. Good one!

@Dr_Mauser

7 жыл бұрын

The trick would be to tap the barrel in two places. Say, for starters, one place near the front of the barrel, and one about halfway, each connected to the ends of a tube. The tube would have a piston in it that emerged from the front and could hit an extension on the flap hinge. The timing would be controlled by where in the barrel the rear tap was. In operation, when you pull back the plunger, the piston sees vacuum at both ends. When the projectile is released, it passes the rear tap, opening it to air pressure, while the front of the piston still sees vacuum, which pulls the piston forward, popping the flap. Then the over-center spring/rubber band takes over pulling it out of the way. However, thinking it through, there are issues. The volume of the upper tube contributes to the amount of air in front of the projectile, So the piston needs to fill it, so there's little volume. but it also needs to be strong enough to pop the flap open against the vacuum in the barrel, which suggests a large diameter. Also, if the piston doesn't seal the tube, Air would leak through into the vacuum side as the plunger was withdrawn. Also, while withdrawing the piston you'd have the same situation of vacuum up front and atmosphere in the back, which would pop the flap as you were trying to draw. So making it work properly would be complex. Way beyond the scope of this kind of fun project.

@GordieGii

6 жыл бұрын

Ooh! You just gave me an idea. An over center spring/rubber band holds the valve closed (just like gravity) once there is a vacuum a small cylinder tips the bottom of the spring past the pivot (limited by an adjustable stop) so that when the projectile is hurtling towards it, and the vacuum is dropping, the spring will open it just before the small puff of air hits it. The stop adjusts the timing so the spring has just enough time to yank it out of the way. It's only a little more complicated than the current version and it won't leak the vacuum. What do you think?

This will probably also not work, but instead of one big valve at the end you could use... two half valves. Maybe if one half opens to the top and one to the bottom they need less time to tree the way for the projectile. Last but not least suggestion: Put some corn starch in the end of the tube, so it gets shot out by the projectile.

@Naomi_Boyd

7 жыл бұрын

I had a similar idea, but the half flaps would need to open from the sides instead of top and bottom. Otherwise gravity would help the bottom flap and hinder the top. If the projectile hits the flaps, it needs to hit both at once to prevent deflection and reduce damage.

@Discesaveloce

7 жыл бұрын

It's a very good idea because the moment of inerzia decrease, the only doubt is about the sealing...

@cmuller1441

7 жыл бұрын

Thadox maybe a half sphere cut in halves could do the job.

@Discesaveloce

7 жыл бұрын

c muller no, because if you use a half of a sphere, the center of mass is over the end of the cannon further than it is in the video, moreover the moment of inertia increase, so it's difficult to make it rotate around its axis, as a result it takes more time to open.

@Joemama555

7 жыл бұрын

in front of a candle!

I'm sure we would all love more x-carve videos! Love your content! Keep up the great projects.

Never stop being amazing. Never stop making us say "wow!! How did he think of that?!" Never stop making us excitedly show our other science nerd friends your videos. Never stop delivering smiles to all you reach.

awesome vids keep them up

maybe you could get a faster valve with a mice trap like mechanism (spring loaded valve)

@cybercat1531

7 жыл бұрын

Something I've suggested before. The problem with that is just that it gets complicated to trigger since those mechanisms usually require direct contact to actuate. Likely the only way to get that to work requires electronics with an optical interupt sensor placed near the end of the pipe to detect the projectile passing by and then release the spring within a *very* short time.

@DesignedbyWill2084

7 жыл бұрын

I had the same idea while watching. I was thinking about how rocket hold down clamps are quickly released right before liftoff. Something like the bimetallic jumping disks, a snap spring that would hold in the vacuum, then the pressure of the projectile would make it snap back against the lid to kick it off.

@darronjknight

7 жыл бұрын

CatSay how about a piece of string that is a bit longer than the piston, so that it pulls the valve down just as the piston is pulled out of the barrel? extend the hinge part that valve is attached to, tie the string on the end of that and tie the string on to the piston handle.

@HenryLoenwind

7 жыл бұрын

You don't actually need a trigger. The "moving of the pivot" trick works with springs, too.

@littleman8674469

6 жыл бұрын

I was thinking the same thing!

Fantastically simple, yet so refined.

the slow mo cornstarch/smoke shots are interesting because they show a resonance of the air going in and out

thats a shame that you have 1.2mil subs but a little views

@mylesbishop1240

7 жыл бұрын

Arvīds Gills dudes a freakin weirdo that's why

I didn't know Ted Cruz had such a smart brother

@cylosgarage

7 жыл бұрын

actually tho

@aidenbatista5986

7 жыл бұрын

Shplingo damn i will never unsee that...

@doublebubleguy12

7 жыл бұрын

+Shplingo Well considering Ted Cruz graduated from both Princeton and Harvard it's not that big of a surprise.

@-----REDACTED-----

3 жыл бұрын

SpydreX Official Oooof, that’s kinda damning for both Princeton and Havard if true...

You could try adding a spring to the valve hinge so it opens quicker. Of course you'd also need a latch to hold the valve up until you prime the cannon. You could also add a simple ratcheting mechanism to the piston so you can leave it primed without having to keep pressure on the handle. It wouldn't be too complicated to set up, and it would make the firing process a little easier. Another advantage is you can hold the spring valve on with whatever latch you want and then remove the latch once the cannon is primed.

Thanks for doing those experiments and sharing them with us! Idea: Wouldn't a spring-loaded flap do the job? I mean a powerful spring. But you would need some sort of latching mechanism. Thanks for reading this!

Why even use a hinged valve? Soft rubber or silicone on a piece of aluminium should hold it to a well sanded pvc edge by itself and pulling the tube into vacuum will secure it in place, add a couple of feet of fishing line on the valve and to the barrel (or ground) to recover it. Hinge just adds extra weight & friction.

@GordieGii

6 жыл бұрын

Connected near the ground so it will swing out of the way, like an inverted pendulum.

ich mag Züge...

This was the first Vacuum Cannon video I saw, and I immediately went to watch all the others, this is so cool. I'm gonna try to make one

I love the sound it makes when it fires.

I like trains...

@super95bleifrei13

7 жыл бұрын

bird on a rock because i can 😉 and everybody has to know that I like trains 😂😂😂😂

@Naomi_Boyd

7 жыл бұрын

Мне тоже нравятся поезда.

I really like the idea of a reusable vacuum cannon and would suggest using a weak magnet for attaching the projectile to the pump. Also another suggestion would be to use very weak magnets for attaching the valve to the end of the vacuum cannon. I really hope my suggestions help you with this project and keep on making great videos. -Beau

I recently started watching your channel and love it!!! Two problems with the cannon:A-Use same bent/set forward valve with a Vertical Spring/or L shape coming back under. B:-Use a Magnet or Electro-Magnet to hold the projectile... I guess winning the science fair in grade school paid off... Lol... Simple, yet effective. Hope it works for you. I think I'll build my own now too! Awesome videos you are great at this. If you use an Electro-Magnet, just use a small wire that disconnects just before the end of the pull or not depending on how powerfull it has to be... L8R. -Chad.

Fantastic work!

You can also make a small device based on your coaxial piston design. Put a cap onto the outer pipe and drill a hold to accommodate a smaller pipe, maybe a half inch wide, to use as a barrel. Using the same centering technique from the coaxial cannon video, make sure it doesnt extend all the way past the length of the outer pipe. Then, modify the piston by drilling a hole at the top to create an airtight seal with the inner barrel and the outer casing. This way, when you pull it back, it will extend past the inner barrel and air will rush in creating a VIOLENT SUCKING MACHINE

I'll never forget the awesome cheese ball machine gun. Nice job. -Douglas

you should try to put a set of magnets in the piston/projectile to hold the projectile back when loading :)

I've been here for a while. i stumbled upon your channel for aprox 6-7 years ago searching for fireworks on KZread. i watched alot of your content back then but i were only about 10 or 11 so i didnt think of subscribing. You popped up in my suggested feed not to long ago and im glad i found my way back. Your content is top notch, and i wish you all well with your youtube career

Its awesome that you still read all of your comments!! Keep the awesome videos coming!!

one thing i'd love to see with this design is a miniturized "hand cannon" type version that can be shot while held with one hand. would be neat to see!

You should try to spring load the flap valve. The problem is that it obiously won't stay closed in the beginning. You can ask a friend to hold the valve closed until there's enough vacuum in the pipe, for example when the piston is in the middle of the barrel, then hopefully when the piston fires the valve will open just in time.

@Lele422

7 жыл бұрын

If this sistem works you can upgrade it so that you can operate the vacuum cannon alone. I suggest you to create a system identical to the one you have used in the video, with the pivot of the hinge positioned outward, but this time you will put rubber bands with one end connected in the central bolt of the disc of the valve and one end in the bottom part of the support of the valve, just before the hinge. The bands will apply a force with the same direction that gravity applies on the valve but the force is way more intense. The principle is the same you have used in the video but the valve will open faster. Maybe the valve would struggle to pass the point where the rubber bands force it against the pipe, try different rubbers and different configurations and see if this system could work.

You could try adding a spring or a rubber band to pull the valve down before the projectile hits it. You would need a latch to keep it close though. Also to make the barrel smoother you could try taping sandpaper to the projectile. It would likely make the inside cloudy but it would be hilarious to watch

@Nighthawkinlight

7 жыл бұрын

Ha, yeah not so sure about that sandpaper idea

@britishcadet

7 жыл бұрын

I was thinking of spring loading it, small piece of tape to keep it closed and once ready to fire, pull a small piece of string to remove the tape then fire

@Dansharpjr

7 жыл бұрын

NightHawkInLight You can use a magnet in the end of the piston and a external magnet on one side attached by string to the valve. This way when the piston is at the end of the barrel, you can push the spring loaded valve in place and use the magnet to keep it there temporarily. Once the valve is pulled back there should be enough pressure to hold the valve in place and at the same time the magnets will separate and the external one will fall to the side, out of the way of the impending destruction coming out of the barrel lol

Nice work--you could try using a very light material (like a carbon fiber disc) to seal the end, and you could also have a hinge that could move out as well as down--attach the hinge to a light rod that slides out of a tube connected to the cannon, for example.

If you link the valve with a spring to the piston, such that the valve is being pulled open by the spring when the piston is pulled back, but isn't having any force applied when the piston is all the way forward, the spring will help open the valve faster, and you'll still retain the property of the valve staying closed on it's own. You could even tie some string between the valve and the piston handle, and loop it through a weight. If you set it up so the weight is resting on the ground when you're all the way forward, but is lifted when you pull it back, the weight will assist in opening the valve

Add a magnet to the front of the projectile and a magnet to the flap so that they repel. By experimenting with the size and strength of the magnets you could adjust the buffer between when the flap opens. If that doesn't work try adding a reed switch to the top of the cannon and putting a small magnet in your projectile. Make a spring loaded flap from a mouse trap and then connect a servo to your switch which will trigger the mouse trap when the projectile passes your switch.

I was a subscriber years ago. about 6 years I think. WOW thing have gotten a lot better. old subscriber coming back.

You could use a dremel to make notches in the projectile to help the vinyl tube grip the projectile slightly tighter, and you could put some kind of metal plastic or rubber spring on the front which would cushion the impact with the valve somewhat so that the valve was not impacted directly by the projectile its self which might then allow the valve to be reused, although depending on the length, shape and potential whipping action it might cause the projectile to tumble. Also perhaps a tiny balloon on the front which would deliver some push and cushion but would explode in such a way that it did not contribute any rotational force to the projectile.

In subwoofer cabinet design, port flaring is done to allow for a smoother transition point from a high pressure area into a low pressure area. I wonder if a flared inlet could improve performance at all.

A couple of suggestions. Put bumpers on the flaps made of rubber and where the flap hits the bottom of the cannon. Then install a push rod at the front of the projectile that pushes the door open this would then allow the door to be open and continue on. You could also make a second smaller gas tube that is tuned to push the flap open when you desire with a smaller projectile. Much like a gas tube on a semi-automatic runs the action of the pistol. Though this second one would be difficult.

Hmm, what about a flap valve made from leather, reinforced on the back with a metal disc? The projectile will still hit it, but it should be much more durable. Another idea is to cut the muzzle end of the barrel at an angle, and have an elliptical flap valve- the projectile won't be smacking into it so hard since the shallower contact angle makes more a softer impact... in theory...

An amazingly calming video (I guess it's thanks to your voice and the music :D ) Always hyped when I see an upload! I definitely consider becoming a patreon, 'cause it's in my head for some while already! I think it's about time now :)

Add a little rubberband assist to the valve that gets tensioned about halfway into the draw by a wire attached to the grip section. If enough negative pressure is built up before the valve opener is tensioned it should stay closed until release.

Suggestion for the valve: Use a weight or a spring pulling vertically downward on the valve so that when the valve is closed the force is holding it closed, but when the valve moves beyond the tipping point the force is now pulling down on the valve. This might also keep the valve from bouncing back.

Glad to see you still active with quality vids :) Thanks for sharing as always and keep up the great work!

I have a suggestion!!! It will be difficult but I think it may work if done right. I think this valve idea will work if you drill two holes in the pipe and attach them to each other with another pipe used to carry the air. (This is like an Ak47 where the pressure created by the bullet is used to draw the bolt back for the next shot.) My thought behind this is that if you have a hole directly in the middle of the cannon and another hole maybe one inch behind the valve, when the "bullet" passed the whole the pressure will rush through the smaller connecter pipe giving the front valve a burst of air to open before the bullet reaches it. Of course this will create less power but I believe it will work with the correct placement of the holes. I would think that the best place to put the holes would be in the back and as close to the valve as possible. My second idea would use the same idea with the secondary smaller pipe connecting close to the valve but this idea would be a second piston attached to the one you pull back on. The second piston will go inside the smaller tube and when you pull out the one,the other one will release at the same time (theoretically). With this design you can adjust the length of the smaller tube to optimize the time between when the air shoots to open the valve and the bullet is released. (Shortening the small pipe will let air in before the shot. And that will be what happens the valve. But if it is to short the pressure difference will slow the bullet and lose power. The ideal timing will be when the valve opens at the last possible second before the bullet hits it.) Thank you for putting up with my lengthy comment but I think this will work. I'm a 16 year old aspiring engineer so I love these thought puzzles. Thank you for your time

I suggest having some rubber bands aiding the release of the valve. Have the rubber be in front of the hinge fro the most of it's position, but just pass the hinge when you close it, that way it will hold the valve against the tube, but a light nudge will send it flying. Essentialy same as gravity, just faster and stronger.

One of the things I've become interested in lately is water rockets. There's a lot you can do with them, including 2 stage rockets. I'm not really into rocketry but there is something different with using water as propulsion for me. Might be a cool idea to check out

In my opinion, you should take advantage of the principle of energy conservation! Build a bullet that hermetically seals the top of the tube and has the same mass, or a slightly lower mass, than the bullet that collides behind! It should have a one-way valve inside to get out the compressed air just before the impact !! Do this test !!! ;)

@Nighthawkinlight

7 жыл бұрын

Interesting idea, you're the first to suggest it. I'll have to think about that one.

@cri-tech1476

7 жыл бұрын

If the bullet at the top of the tube splits, use the one-way valve as a pneumatic shock absorber !! Make sure that the flow of air out of the valve can be varied!

Have you experimented with using the end cap AS the projectile? For instance place a wider cup around the muzzle so that the original barrel forms a lip inside and then fix a rubber O ring to rest on the lip or the rim of the original barrel. By placing a projectile over the mouth of the barrel within the cup extension the projectile should act as a plug against the O ring when the shaft is pulled back. I am unsure how this would preform in actuality and I have a sneaking suspicion that the trajectory may be less than impressive but it could be worth the experimentation.

what if you drilled a small hole on the proyectile so a little air rushes in through there in front of the proyectile therefore pushing the valve open?

Suggestion for the flapper valve: You need to make a spring loaded valve with a good deal of spring force to pull it open. You could make a simple latching device that would lock it into place before pulling the vacuum. The latch could be released by a small vacuum piston that is connected to a hose and tapped into the barrel a few inches from the muzzle. That way, you can load the barrel and click the valve closed and it will stay closed even though a large spring is trying to snap it open. As you draw the plunger back, the plunger creates a vacuum in the barrel and when you pass the point where the hose is tapped in, the vacuum is transferred to the small hose and it pulls the release on the valve so that it is no longer latched. Now the vacuum is all that is holding the valve shut. When you fire the gun the valve should move very rapidly open when the vacuum is removed.

@Nighthawkinlight

7 жыл бұрын

Springs and bands can also be made so they would hold the valve closed until it opens slightly, then they would pull it downward. But even so I'm not sure it will open fast enough. I have a new idea I'll be testing this next week

@USWaterRockets

7 жыл бұрын

Also consider a "barn door" or double door valve for the end. The doors would have less mass and would move faster, plus they are shorter in length and would clear the projectile faster.

I think these are gonna be my science project next year.

Run a small spring along the outside of the latch, over the hinge. Keep the latch extended so when it is in the closed position so it acts like the cam on a compound bow. Yeah, just a simple spring elliptical cam. The little bit of air would flip it enough to push it past the crux of the ellipse and the spring would pull it down and out of the way.

By upscaling this design, the present air will be able to reach the front faster, leaving more time for the valve to open. You would need to calculate the time it takes for the flap to open, and lengthen the pipe accordingly. You may need to allow more air initially. We obviously need a 50' vacuum cannon anyway.

Been watching for years, love this guy’s content 👍🏼

Cut the front end of the tube at a 30-40degree angle. Make an ovular valve to cover the opening. This way, the valve would have to travel a shorter distance to get out of the way of the projectile. Gravity would also assist the valve better this way. Use a string to hold the valve in place until the vacuum build up is enough to hold the valve, then let go off the string, then pull the piston further until release.

You could try mounting a strong magnetic beneath the hinge, and also mount a second strong magnet to the top of the valve face. When it bursts open, the magnets should connect and prevent the valve from bouncing back.

Maybe you could use some sort of stiff balloon material for the valve. If you choose something that flexes inward a little, the release of the vacuum will also allow the valve to gain momentum as it stretches back, just make a support ring for it that fits around the end of the tube and keeps whatever rubbery material you choose from being pulled inward. It might be possible to use multiple layers of party balloons attached to, or wrapped around, some sort of ring and the ring could be attached with a rope or wire.

1. A smaller pipe alongside, maybe with its own piston, with the end sealed against an extension of the flap. The air will travel faster as it doesn't need to push a projectile. Might be a little too fast, though. 2. An off-center spring that will accelerate the flap once it passes the equilibrium point. 3. An inset valve, so that it accelerates to greater speeds before losing the seal.

If you have a large projectile behind a smaller one will the momentum of the larger one make the smaller one move faster?

@GordieGii

6 жыл бұрын

Ooh! OOH! Sabot!

I just love your voice. So soothing.

I'm so glad i found this channel, its amazing!

You could add a secondary, small chamber that pulls a vacuum at the same time, but have this secondary chamber slightly shorter in length than the firing tube, so that the air rushes in right before the projectile barrel. This secondary tube could be a much smaller diameter, and would be used to open the valve of the larger firing tube. Another idea; use cutouts of plastic that you can just place onto the end of the barrel, possibly with some sugru applied at the end of the barrel to make a better seal (look at TKOR's video on homemade sugru). This plastic piece would have no hinge, you could either just leave it be and have it shoot off with the projectile, or attach it to the end of the firing barrel with a piece of string so it doesn't fly away every time. An alternative of the above idea would be to dangle the plastic seal via a string (or 2 for stability) above the cannon, in such a way that it can easily be pushed away by the projectile, flinging it upward and around, constricted by the length of the string A final idea, unrelated. Try to put a thick piece of rubber, like multiple balloons on the end of the barrel. try to find a rubber, maybe spandex, that you could just stretch around the barrel, and possibly aid in holding it with a pvc sleeve that slides over it. I would like to see how much the rubber is pushed in to the vacuum by the normal atmosphere, which leads to the final idea. Get a thick, maybe 6 inch inner diameter piece of acrylic tube, and place a seal on one end for pressurizing. Mount the vacuum cannon tube inside it, maybe with multiple filed out bushings to center it inside the acrylic (or use acrylic for both tubes). The end cap on the outside tube would have two valves on it. The inside tube would be connected to one of these two valves. Use a screw on end cap if possible for ease. Pull a vacuum in the inside tube, and pressurize the outside tube. You end up with a vacuum cannon inside a pressurized tube, in such a way that the projectile makes it out of both tubes. I will send this to your email, along with a diagram I drew in order to visualize it.

if you make a spring/rubberband loaded valve and attatch a string to it to close the valve while pulling the piston back, it should work fine.

What about if you installed two strong opposing magnets on your cannon? One on the frontside of the projectile and one on the inside face of the flapper valve? Yes they would have to be quite strong magnets and if you try this I think it will also be worth trying to reduce the mass of the flapper valve as this would make a huge difference in its effectiveness. I'd imagine there would be a sweet point between weight of the flapper valve and strength of the magnet used on it if that makes sense, as the heavier it is the more force that it required to move it, hence the more compressed the air will need to become. Great work though, this is the first vacuum cannon video of yours I have watched and it is awesome! :)

I've loved your videos for the last couple of years, and I'll always enjoy them. :)

so do you get better results if you fire out a smaller barrel sow that the psi has a larger compression chamber resulting in reduced overall size vacuum canes that have a heavier draw force lick gearing a gearbox dawn

I would try going back to the upward hinge but put a slightly tight spring on it to pull the flap up. But then youve got the plastic cup idea thats already functioning. Great build either way

You could try replacing the front cable tie with a spring and optional weak magnet. The valve cap may need a tiny lip at its base that sits inside the pipe to act as a catch that stops the spring from releasing/expanding, when it releases forward, the spring pushes the arm down assisting gravity. Replace the rear cable tie with a hinge to allow the whole arm to fall which overall means you may not need to reduce the mass of the valve cap.

I believe one of the things that is happening is that the whole barrel is in tension,so it is actually moving forward as it's firing thus holding the plug on. You need something more Ridgid than cable.

I like the comment below that suggests cutting an angle on the muzzle of the barrel so that the valve is already in the attitude of falling and only being held in position by the vacuum within the chamber. It would require holding the valve closed temporarily while vacuum is created in the chamber, and then having a lock or spring that prevents the flap from springing back and colliding with the projectile. Also I wonder if a toilet flapper would be a good end valve?? about the right size and may have less mass than the current one.

When using a burst disc, add a check valve near the end to see if it will allow the gas to escape before the projectile hits the foil.

You might try a valve design that I used for one of my blowguns....you will need to cut your barrel's muzzle at a bias off the bottom ( at least 45 degrees) and make a valve cover to fit the new elliptical shape. What this accomplishes is it reduces the number of degrees movement to "fully open" by half, so the valve is out of the way twice as fast. It's kind of like being half open already when it is fully closed. Some sort of spring-assist for the valve wouldn't hurt, either. Place the vector for the spring's movement such that it barely holds the valve closed, but after only a few degrees of movement it wants to jerk it open! Well, that's MY two cents....love your V-Cannon, man!

Could'nt the valve be spring loaded to assist a speedy opening once it starts to open just a little? also though sealing may be a little difficult, cutting the valve into two semicircles would halve the distance needed for the valve to get out of the way.

It may have been already mentioned below, but you could probably make the flap valve work by making it lighter and adding some form of tensioning system that increases the force that pulls it out of the way. You could decrease its mass by putting the gasket material mounted to the tube so it can remain stationary. Also, the flat shape requires more mass than a domed one. Maybe you could use the bottom of a soda can, they are extremely strong and light. Just not sure if the diameter is large enough though. The other thing is the hinge itself. A pinned hinge such as you used is very strong and fairly heavy too. If you replaced it with a strip of spring steel you could even pre-tension it when in the closed position so that it springs open under the added force of the spring once the vacuum force isn't enough to keep it closed.

1. reduce the mass of the valve (foil, reinforced with a plastic "spider web"?) 2. Add rubber bands to assist the fall of the valve. A force vector acting in the direction of gravity would help