This Nerf gun defies physics

[@krooms4733]

No subscription for clickbating losers!!!

[@linodiogolol]

Agreed

[@I.PAddress]

lol why was this pinned xD

[@mikeb3d727]

@@I.PAddress pin of shame

[@benjii_boi]

imagine having such a smooth brain that you think it's possible to actually defy physics and then getting upset enough to comment when it doesn't happen

[@johnathanrichardson]

@@benjii_boi myself personally im just tired of clickbait. i clicked on this video because i like this channel and i think he makes stuff i want to watch. you dont need a clickbait title to attract viewers, just show the actual cool thing your doing and people will come.

[@lady_draguliana784]

It's called a "Bernoulli Pump" and we used them in the Navy to multiply the volume of water that our pumps could move, for about the same power. A stream of moving fluid (air being a fluid here) tends to draw surrounding fluid along with it. the air is compressed and pressurized by the plunger, pushing it against the primed dart, and the release is the air rebounding like a spring let free: equal and opposite reaction means the launcher and the dart air pushed away from each-other. upon release; the air is high pressure at the face of the plunger and the rear face of the forward dart, but it's motion in the middle is suddenly flipped to low pressure. (until equilibrium is reach based on the mass of the air, if your barrel were long enough and the system were sealed, you could stop the dart dead in the tube as the air is "stretched", until it's density (and thus, pressure) is too low: making a vacuum force where atmospheric pressure is pushing the dart into the blaster, rather than out.) (this flip commences from about the middle of the mass of the compressed air, and radiates outward rapidly) the low pressure of the moving air "sucks" (rather, the higher pressure of ambient air is pushing) the dart forward. If you ran constant air through it with a compressor air tank, you could continuously feed darts into it without having to feed them all the way in front of the moving air: the Bernoulli Effect would draw them forward into the moving stream of air. EDIT: spelling

[@raedev]

"If you ran constant air through it with a compressor air tank, you could continuously feed darts into it without having to feed them all the way in front of the moving air" Sounds to me like Matt needs to look into a fully automatic nerf air-tank-powered blaster now!

[@kilotheneko2064]

So are you saying the plunger system is not necessary, and it can be replaced with a compressor or that the plunger system can have the air compressor feed darts as it recocks without pulling air ?

[@perchperkins6720]

That's probably what's going on here. It somewhat reminded me of barrel evacuators on tanks and how they pull the smoke out of the barrel.

[@Billybibjoe-f6o]

@@kilotheneko2064yes, you know some odd vacuums are made this way.

[@nidhu595]

sounds to me like a mouth powered atomiser ( www.google.com/search?q=mouth+atomiser )

[@rymanjones3]

im loving all of these stupid simple solutions to things, like putting water on the dowels to make them expand. The blaster's design is also pretty awesome

[@matt_yuan]

e x p a n d

[@stevenramsay5887]

Bigmode​@@matt_yuan

[@tomarmadiyer2698]

That's so brilliant.

[@eashw]

that pen holder from the beginning is very clever!

[@matt_yuan]

ty!

[@kartikgkalita]

His entire way of machining is genius

[@ALuLdz]

To be fair I wouldn't be surprised if Matt could find a way to defy physics

[@some_random_toaster]

Because he can.

[@Gamer3427]

Honestly, probably the best "build explanation" section I've seen out of any of the building channels I watch, because you went step by step on everything and explained how you did pretty much every little section, while most building channels tend to just cover the key points.

[@pedrohenriqueboscofi]

Genius, not because of the blaster design but how smart you were manufacturing it

[@indoraptor-k6f]

That drill press balance is such a good idea

[@Tamakhanz]

Matt, your production quality has actually gotten that of a professional.

[@matt_yuan]

tyty

[@TastySlowCooker]

Your English has actually gotten that of an amateur

[@badsamaritan8223]

The dart is so excited for it's turn to get launched, that it wiggles forward into the barrel.

[@darth_dan8886]

I think the key moment for the back dart is when the front dart exits the barrel. The higher pressure air is then connected to the outside atmosphere, which sucks it forward, which in turn propels the back dart as a temporary low pressure region is created behind the air wave escaping the barrel.

[@AlexLanyu]

o7 rip sacraficial dowels

[@matt_yuan]

they will not be forgotten

[@Okamika44]

@@matt_yuan type F in the chat

[@xrad1us]

F

[@wertacus]

F

[@galning2768]

F

[@TheOnlySoycicle]

I love how this channel grew from simply modding a long shot and now defying physics itself

[@thebfiaid957]

Gotta admit, the dart head as a dampener is pretty smart. Love your ideas, may not be good for quick firing, but they work and its goofy yet useable and reliable.

[@VaIentineUK]

Very clever ideas in this project, but the production value of the video is what really impressed me. You've put a lot into this video and it shows!

[@SteakToad]

Your resourcefulness and clever tricks are a treat to watch and make you more defined from other channels

[@blockshift758]

0:40 my guess is how vaccums work

[@blockshift758]

Welp it was simpler than expected.

[@DavidTorpid]

yeah just started the video and I'm going to guess the pressure on the front of the dart pulls it.

[@DavidTorpid]

it's less simple and more dude was being disingenuous

[@SamCaracha]

10:04 Bernulli principle: fast air moving over a hole (the tip of the dart, plugging the entrance from behind) creates a negative pressure, or a drag from the hole.

[@BlademanZX]

Yup I didn't know the right terms but I figured it was creating pull

[@Gryndir]

He's gonna be amazed when he finds out about the venturi effect and that he doesn't need any moving parts at all

[@gadgetdeez7069]

The dart moves forward because the air mass in the barrel has a ton of energy. When the main piston stops moving and the air mass in the tube wants to keep going, it creates a massive vacuum that sucks the dart into the barrel. This is legitimately how engine performance exhaust headers work to clear the combustion chamber of all spent gasses and allows the chamber to be under vacuum for the next intake cycle.

[@simontillson482]

Yep. Great explanation, man. It’s all down to momentum.

[@Qikx]

Holy cow, this channel's production quality has skyrocketed since I first subbed. Great to see the work you continue to put into making these projects!

[@Cheezeball99999]

I was expecting the venturi effect, and we observed the venturi effect here... just not exactly how I imagined. Firing creates a low pressure zone in the chamber, which pulls the rear dart forward. Pressure differential isn't nearly enough to fire the dart all the way through, of course, as we see. Brilliant build, I love it.

[@BC-wj8fx]

It is not the venturi effect though. Venturi effect exists in a steady state flow, and the reduction in pressure from the venturi effect is only a reduction of pressure relative to the flow itself. When you have hundreds of psi pressure in an airgun you're not going to get a drop below atmospheric pressure (14.7 psi). Rather what we see is a pressure drop after the firing sequence because the air in the barrel had momentum and continued to travel out. Only a momentary pressure drop, a single pulse of low pressure, not a steady state process like venturi.

[@nirodha7028]

Everything about this build is clever and shows your skill as a designer ‘and’ craftsman. Well done!

[@beretnarf]

Have you ever brought your builds to a game? Would be cool to see it used in action as well. But the build process is awesome keep up the great work.

[@matt_yuan]

nope

[@beretnarf]

@@matt_yuan 😥

[@azurepattycake]

@@matt_yuan You really should, all of your stuff is very cool and reminds me of old Nerf homemades

[@solarsoldier2456]

Dude, I gotta say your fabrication techniques are really smart. By the 5 minute mark I had learned 3 new things for fabrication. Heve you ever thought of doing a series on fabrication?

[@SlavicEgg]

I have a suggestion for the next blaster. Try and design, a ww1 era, open-bolt rifle, fed by clips ofc, really wanna see your take on that

[@terence79chan]

Nice work as always! Thanks for the useful techniques to accomplish that precise slot on the cylinder.

[@StupidGuy1125]

I’ve been here since your first video. You’ve come a long way.

[@_Greyboi_]

Dude you are such an awesome channel! It’s fascinating watching you build these and all the unique techniques you use, like just adding water to expand the wood, I’d have never thought of that.

[@excell211]

The reason why the dart is pulled by the action is probably the same reason behind a "vacuum ejector", the movement of a higher pressure air passing through a channel can create a vacuum.

[@infinidragon]

Cool video as always! I wonder if you've ever considered making a "shell" or "cover" for one of these completed projects to go around the components to give it that finished Nerf blaster look, just for fun.

[@matt_yuan]

i like the unfinished look

[@infinidragon]

@@matt_yuan If that's your preference no worries, was just curious if it had ever crossed your mind. Appreciate the reply!

[@Rheumatoidarthritis]

hey, your editing is getting pretty good. I'm really looking forward to seeing you improve even further.

[@SpottedHares]

When I was young and I needed to cut pvc pipe long ways I would lay it flat like you did on the drill press then stack wooden blocks and a flat plank to make a long flat line so I could run a sharp knife in a strait line to get the deep scoring. Probably did take more effort then what you did but doesn’t require more then some cheap wood and a box cutter.

[@The_Lord_overdrive]

I had this really cool science teacher in 6th grade and he help made me fall in love with science and you remind me of him

[@prxrb]

Love all the creative solutions to make do with what you got!

[@chikokishi7030]

2:00 im pretty sure a normal ruler would have worked too.

[@SwapPartLLC]

Something may defy your understanding of physics, but nothing defies physics.

[@skylerric3]

Love this kind of content. I'm trying to remake my nerf collection after mom sold it (without my consent). I might just start building my own blasters!

[@insu_na]

I love not just how much planning you put into this, but also how you did everything properly. No "let's eyeball some markings for the drill and then yolo it" as I see so many other creators on youtube doing. I appreciate how much thought and diligence you put into this

[@ocha9520]

mate bloody good job, amazing work

[@omurize2007]

I wonder if this will work with an XBZ as the air source?

[@daltooinewestwood6380]

Gotta love when ppl describe shit with phrases like “this defies physics” followed by demonstrating and/or directly explaining the physics and why it’s functioning exactly as it should.

[@ok198474464]

I automatically knew it uses vacuum pressure basically

[@audendavis9422]

If what you said about the internal pressure being less than the external pressure (10:02), then you need to decrease the barrel length or increase the pressure to increase the bullet velocity. That suction force that pulls the rear dart forward is also slowing down the forward dart.

[@Gtagpaintervr]

Wake up there’s a new Matt yuan video

[@unknowntraceur264]

This is perfect for me to learn Some videos just don’t explain in a way where I understand enough to build my own functional version. And I looked EVERYWHERE and this was just randomly recommended to me. I am so happy! Nice video!

[@doctordingi]

these are some excellent blaster videos, keep it up :3

[@lychiadventures8231]

this is cool. Seems like another variation of the "inline clip". Been using inline clips in most of my projects and this opens up many more awesome potential for this kinda ammo reloading.Thanks

[@westincello]

There are so many smart build tips for working with tubes! Great video!

[@Maxb0tbeep]

I met you and open sauce and shot the blaster you had there. it was super cool! thanks for letting me try :)

[@Bomber-Trebor]

9:55 the awnser to your confusion is suction and yes there is suction created while blowing in a 3 way tube even if it only goes one direction it will create suction on the 3rd hole that was an old old way to create a vacuum

[@Mrjcowman]

Making the drill normal to the pipe by sandwiching a plate between them is a simple but genius solution

[@matthewnardin7304]

I think it's really important to tell people "why" you're doing a thing and you do that well.

[@dragonlordd7894]

Your conception of mechanics is very intuitive and brilliant. I'm impressed. I'm an engineer/machinist and I would of done things slightly differently but that doesn't make your way wrong in any way. Well done. Very smart.

[@matt_yuan]

thanks!

[@adamiozsa2967]

The inertia of the air flowing out, after the first piece left the barrel, creates a bit of lower pressure at the end of a firing sequence which drags the second one in a bit.

[@BC-wj8fx]

Almost right but air can't drag anything, it can only push.

[@indoraptor-k6f]

I'd say the reason why the next dart is brought forward is due to the Venturi effect

[@hondoonaka1823]

Not the Venturi effect, it’s actually another application of Bernoullis principle, so pretty close.

[@pauljs75]

The charge of air leaving the barrel has inertia, so it will draw a vacuum as it exits.

[@Gravedigger933]

It does not defies physics. It defies your understanding of physics.

[@Chaos_God_of_Fate]

Nice clickbait title- you cannot defy physics. *Rings a bell* SHAME! *repeats forever*

[@zephiask1758]

More like "defies your intuition of physics"; would be clickbaity enough while not being a false statement in lots of cases

[@mrfawkes9110]

Oh you can defy physics, it just never works out.

[@GoGoGoRunRunRun]

It's not really clickbait, because everyone understands that...

[@MrSoso1050]

More like...... eh.....idk

[@SpencerPaire]

Actually, you can defy physics, physics being the systems of math we use to predict how reality interacts with itself. Defying these predictions leads to new and better physics! But good luck doing that with a nerf blasters; usually it takes a Large Haldron Collider!

[@aliveandwellinisrael2507]

The way it works is great, but those practical tricks you used when actually making it earned my subscription.

[@Reduncanny]

I want to fully get into modding. I plan to be an engineer when I’m out of high school. I have already modded several nerf blasters with some working and some not working anymore. You got any tips for some one who is starting to get into nerf modding

[@bacaraproductions6931]

Purchase a chronograph and buy a O ring kit so you always have the correct size as well as silicone based oil for plunger tubes

[@FriendlyCynic]

10:18 Its probably the exact same mechanism that is firing the other dart, IE the lower pressure maintained in the system after firing the other dart. It seems to pull it up to seal the hole and then stop. Originally, I thought you just sealed the chamber to the piston except for a tube the same size as, and routed to the hole in the back of the dart. The restricted diameter would create a system where you have a slightly lagged but high pressure nozzle. An additional pressure release that prevents the lag from prematurely firing.

[@mrburns366]

It's interesting to note that nothing can "defy physics." Anything that appears to is only illustrating something we may not have known already.

[@simontillson482]

You’re a very naughty youtuber, but the sheer quality of the video more than makes up for that. Seems pretty obvious why the 2nd dart gets pulled into the breech - the momentum of the air leaving the barrel causes a momentary vacuum which sucks it forward.

[@perchperkins6720]

im probably making this overly complicated but fitting a aloff’s device to the blaster and linking it to the pump handle would be awesome

[@burstingolem8023]

That "let's go 🎉" at the end was the cutest thing

[@lordicarus8807]

What I like most about this kind of videos are the solutions that are given to problems in ways I'd never imagine!

[@xavifores4599]

Man the engineering genius that went into designing this thing is insane and it deserves some respect and recognition 😊

[@kieran.grant_]

Dude, I'm so impressed by your techniques for making this blaster. The pen thing, centering the pipe, trigger mechanism, etc. I'm certainly no expert myself, so maybe I'm being impressed by some pretty basic stuff. But I feel like my mind has expanded from watching you work

[@JonathanTrevatt]

Its a venturi effect. Air moving quickly from a constricted inlet through a larger oriface pulls additional air with it. In this case, it pulls air through from behind the 2nd dart which pushes it forwards. If this is the cause, then it should stop of you seal the breach

[@noahlowrie6742]

I have recently begun building my own homemades (following nerfhaven guides) and I am inspired by your precision and ingenuity. They make me want to bring another level of polish to my blasters :) keep up the great work!

[@prjndigo]

I think its sucking the second dart forward, thats why it stops 'on a dime' over the air port. There's a small rebound of the plunger and a wave of air returning in the front of the barrel.

[@dtplayers]

I'm with you on this. I'd be curious to see what happens when a shot is taken with the back retaining piece held out of the way.

[@jellogiant]

You’re the hero we don’t deserve my friend. Seeing you continue to develop traditional nerf modding give me the warm fuzzies

[@CopperPipe938]

physics been real quiet since this dropped

[@phaedrus12134]

I'm in love with your builds. You should build nerf blasters for NASA.

[@AudioFanMan]

Reducing the length of the barrel would let you know when friction is more powerful than the reduction of air pressure and you would notice this by the rear seal dart not moving forward. Or a stiffer spring moving faster might allow an even longer barrel, tunable again by not allowing the rear dart to nudge forward. Very awesome mechanical engineering and very awesome build ! Impressive!!!

[@jadgpanzerkid]

MAKE A MAGAZINE FOR THIS 🗣️🗣️🗣️🗣️🗣️🔥🔥🔥🔥🔥🔥🔥

[@tommyblair6008]

The rear dart is moving forward because you are not dumping the same volume of air in to the barrel as the there is in the barrel when each darts are on opposite sides. This is creating a small vacuum right before the front dart leaves the barrel. Two options to fix this. One shorten the barrel or two make the compressed air chamber bigger.

[@Valin9275]

Modern day RSCB

[@siosilvar]

Exactly what I was thinking... late 2000s design, but with much better production value than the old homemades.

[@sraven-71]

simplest explanation i can think of: fast air has lower pressure so once that pressurized air expands and accelerates it actually drops below outside pressure and the second dart moves forward from the pressure difference

[@taffy4801]

You are doing homemade designers proud! Build on!

[@matt_yuan]

skewers r cool

[@SirToadNews]

One of my favorite channels!

[@thecompl33tnoob]

The pen-holding technique garnered my subscription. I can't wait to share it (and your channel) with our maker co-op folks!

[@theaureliasys6362]

Venturi. At least that is my first thought.

[@syborg64]

I think that effect is the same principle as fluid hammer ('water hammer') Though the net pressure never drops below atmosphere, gas movement has an inertia that creates a vacuum when the plunger suddenly stops. This similar in principle to the Venturi effect, though the configuration likely means it is not truly Venturi

[@dserrao7188]

It’s over pressure. As the other dart is being blown through, there is still an air gap behind it, which is likely drawing the other dart through, until the first dart exits.

[@recklessroges]

Bernoulli's principle is probably drawing the second dart forward. You can check by loading just one dart and providing a constant stream of air through the barrel.

[@jeffreyyoung4104]

Nice work! The first dart doesn't have enough volume of air pushing it, so the first dart creates a tiny vacuum and pulls dart 2 forward.

[@SlendisFi_Universe]

Pressure difference. The plunger creates high pressure that escapes through the barrel and propels the first dart out. This action causes short but sgnificant enough moment of low pressure like in vacume cleaner that sucks the second projectile inside the barrel. Powerful enough to suck it in but weak enough to not double fire.

[@SrBuhler]

To test if it’s a drop in air pressure in the barrel is what moves the dart forward, you could test using shorter barrels so that there is still pressurized air when the dart leaves the barrel.

[@chumooskie5527]

Who are you, who are so wise in the ways of science?

[@Jamboxxx]

Some of these tips are gold!, centering the drill on a curved surface, watering the dowels, this is all genuis stuff!

[@ArduinoKing]

Thoughly impressed at the build quality. Some very clever build methods. And great attention to detail. You are very skilled

[@Sicsempertyranus313]

I think it’s drag of the air passing the second darts tip and the barrel pressure behind the first dart prevents it from fully entering the barrel

[@CRaZzSHarP]

I'd love to build some of your designs to add to my homemade collection. Awesome work!!!

[@nickmurphy8542]

Would love to see how you made the template at 1:48 Love the build, man! Keep up the good work! 👍

[@matt_yuan]

the template is 3d printed

[@beanhavok2287]

ATF gazing over wood fences INSENSIFIES

[@AarontheFishCat]

Using dowels to support the drill bit was genius and I wish I knew that sooner

[@Blorkus]

Oh, that is so cool! My initial thoughts on how this might work led me to a different idea... -plunger pulls from front to back -Muzzle is capped with a moving cover -Pull a vacuum in front of the dart and put the pressure behind it -when the plunger bottoms out (or some threshold is hit) open the muzzle cover basically a combination pressure and vacuum cannon. Hmmmmmmm

[@justingould2020]

That's some incredibly clean work there. Love it!

[@SpencerPaire]

Slick build! And I love how you're bringing so much innovation to pump action PVC blasters. This is some truly DaVinci stuff; breathing new life into the old arts. My theory for why the dart is pulled forward is a slightly off-tune barrel. I'm sure you calculated the plunger and barrel volumes, but I bet there's a bit of leakage when the blaster is fired, meaning there's not quite enough air to fill the barrel. So the momentum of the shot dart can pull the barrel pressure a bit low, sucking the second dart forward. I'll leave it up to you to see if this is a feature or a bug 😂

[@CrimsonSlug]

My hypothesis is that the rear dart is pulled forward by the high speed air entering the barrel in front of it. As fluids speed up then decrease in pressure and this low pressure will pull the rear dart forward until it blocks the air hole. Hence the short distance moved.