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Just how powerful can we make an air-powered gun using Lego pneumatics? I've made several Lego technic guns that use the power of pneumatics to shoot a projectile at speed. However, unlike other Lego pneumatic shooters out there, mine use a novel technique to provide that air in a more explosive manner.
Using a pipe-crimping technique (I spired by the brilliant technic builder, Nico71), we can release a strong but small burst of air to propel various projectiles. I suspect that this gun might be the strongest pneumatic gun that can be made with standard Lego (and a drinking straw).
In this video, I'll shoot various different projectiles out of a couple different barrels, and measure their top speeds... While destroying bits of my apartment 😁
#lego #gun #pneumatic #shooting
Barrel lenght should be optimal when the internal volume of the air tank is 2-3 times as large as the barrel volume, depending on projetile weight. This is the cylinder to barrel ratio, it is used in airsoft guns for ex. This is why you got better results with a shorter barrel, as the volume of the air in the tanks was not enough to fill the longer barrel at sufficient pressure.
Cristiana Kansas
I believe the math/physics is that as soon as you reach that equilibrium point where the pressure in the tanks+barrel equals atmospheric, the positive before and then the net 0 force at that instance then becomes a negative force to the direction of travel where the "bullet" is now trying to be sucked into the barrel, thus reducing the exit velocity.
@@aidankeys8534 Exactly. When the pressure in the barrel becomes too small to propell the projectile it will just become a negative effect that is slowing it down.
Not shoeving the projectile all the way down tve barrel explains it easilier
and you can utilise the airpressure even more if you put a little bit of foam behind the propelled objekt to seal it
What you need to try is a metal barrel with internal Rifling. This will cause your smaller projectiles (specifically the bullet-shaped wooden ones) to spin and maintain a tighter accuracy to the estimated trajectory of said projectile when fired. It's the same practice used with firearms of the modern era.
Unless you use a tank gun but those things don't rely on. On spin stabilization they use fins or they just have the projectiles be so aerodynamic that it doesn't care about whether or not it's stabilized it just kind of goes in that general direction fast enough
I think the air stored in the tanks is not enough to propell the ammunition out the long barrel as fast as the short barrel. The long barrel needs more air. That's my guess anyway.
Definitely part of the reason. There is an optimum barrel length for every projectile/cartridge size on earth; Too long a long a barrel with too long of a cartridge means that you're wasting potential energy by forcing gas to push against other gas to push the projectile, too long a barrel with too short a cartridge and you're not producing enough force to push the projectile out of the barrel. There are so many combinations to consider when producing a projectile launcher or any sort really. I'm not smart enough to provide any math on the calculations required for optimum length but I feel like the video does a pretty good job of demonstrating it and I'm happy to see that he went through the trouble of finding a few different options and measuring their outputs before deciding on a final type. In terms of projectile length, the knitting needles seem extreme but their length allows for stability during flight akin to an arrow, whereas the small bullet shaped piece of wood tumbles because it has no rifling. You can see the same thing happen with the technic axle as well, although it would benefit from rifling too, it has other aerodynamic flaws that greatly inhibit its performance.
You're spot in there I reckon. The smaller ones tumble quite badly, and the slow mo footage highlights just how badly the tumbling causes the rounds to veer off course. Using darts largely solves that problem, but they tend to be quite light, and there's quite a bit of drag after a few metres. I gotta say, I'm enjoying the knitting needles a lot 😁 The first commenter is also right though - this needs more air, and a larger bore to release it. I reckon a 500ml coke bottle at 60-80 PSI would do wonders ....though Lego compressors wouldn't manage those pressures unfortunately. Thanks for your comments and suggestions!
I think it’s due to the projectile travelling a further distance before it reaches the end of the barrel, so it slows down more
@@JamiesBrickJams In the video we can see you are not putting the proectal fully in the barrel, so in the long barrel the pressure at the end is lower than the shorty, if you'd put it fully in, the long barrel would be better. If you were already putting it fully inside than idk what is appening.
@@JamiesBrickJams ideally you'd want a projectile that's nose heavy at the speeds you're going at. The bullet shaped piece of wood needs to be going in excess of 900FPS before it'd be aerodynamically stable, even if you managed to impart spin on it. The centre of mass is behind the centre of pressure in that shape. You want the centre of mass to be in front of the centre of pressure. Like a badminton shuttle. Maybe see if you have some small screws with a head that fits the barrel tube, and then super glue some cotton wool to the threads. The cotton wool should drag stabilise the screw, no spin needed, and it should make for a bit of a wad in the barrel to help seal it. As for barrel length, a good rule of thumb is that you need 3x the volume of the barrel in pressurised air. I don't know what kind of volume those lego tanks hold, or what the dimensions of the barrel are, but just looking at the relative sizes, I don't think the problem is that you don't have enough air. You have a lack of flow, the "transfer port" (ie. the T-joints) are too small to flow any amount of air. For comparison a 4.5mm air rifle with a 530mm long barrel needs to flow around 12ml of air per shot. Roughly about 1 cubic inch. The easiest way to improve the gun would be to double the "hammer" so the mechanism kinks two hoses, one for each tank. And then fabricobble some sort of Y-joint into the barrel rather than a T-joint. Maybe just cut the ends of the hoses at an angle and just jam them in together. That would double the flow rate from the tank to the barrel. Also try to make the distance from the kink points to the barrel as short as possible, the less dead air you need to accelerate, the better.
The long barrel gives a slower velocity because the impulse into the projectile stops being produced before the projectile reaches the end of the barrel. The last couple cm of the barrel just create drag with no pressure behind the projectile. You’d get more velocity if you made the release of pressure slightly slower so the whole length of the barrel could be used to generate velocity Edit: to give the highest possible velocity to your projectile, try to match the time that the projectile takes to leave the barrel with the time it takes for the impulse on the projectile to finish. If the impulse is too short, you lose velocity to drag. If the impulse is too long, you lose velocity to not using all of your propellant on the projectile, and having some of it still escape the barrel after the projectile has left the barrel.
In a rifle, the longer barrel helps because you get a complete burn of the powder- I.e. all the chemical potential energy is converted to Kinetic Energy. Because your pneumatic gun does not rely on burning powder, I would wager that the longer barrel was only adding more friction, as well as getting none of the benefits of a “complete burn” Nice video and very cool concept!
That was very awesome... Great vid!
Hi
Woah thanks - big fan of yours!
yes this is a good channel
I wonder if you could attempt something like this...
dang i'm a big fan
I think pushing this to its limits would be a really cool series! Looking forward to more videos :)
Thanks 😄 And totally, there are a great many improvements to make! Already got another design to shoot significantly harder. However I'm gonna have to start cheating a little and using a non-lego compressor, and probably some modified pieces. But it's all in the name of science 😜
@@JamiesBrickJams Thanks for the reply!! I'm so stoked to see it, I just turned on post notifications haha, best of luck!
@@JamiesBrickJams using a non lego compressor completely defeats 50% of the purpose.. what's next, a steel barrel and actual bullets?
This is the bullet that killed him they were courteous enough to give us the whole bullet 66% more deadly. What kind of weapon could do such thing, to kill someone with the whole bullet. 66% more bullet.@@GeomancerHT
Theres a lot of disturbing content in this video including the wasting and destruction of pringles and bannanas, but worst of all, empty cans of caffine free coke. I can only hope that it was poured down the sink and noone drank it.
You're right, I should have slapped a no under 18 on this video. I won't comment on the coke other than to reassure you that a great many coke zeros were harmed in the making of this video
I love the exposed pistons they give it so much more character. I could absolutely see this rubbing shoulders with the Tihar air guns from the metro series
Aw thanks ☺️ Yeah the Metro games were definitely inspiration for the general look. Fantastic games
Firearms and air rifles are different when it comes to barrel length due to the different ways they propel the projectile. Firearms create more pressure the longer the gunpowder burns (until it all burns away anyhow), so a longer barrel lets the expanding gas push the bullet for more time, building more speed. When it all burns away or the bullet travelling down the barrel creates enough space, then you get a drop off in pressure, and friction starts to slow the bullet, so the bullet should leave just before that can happen. With air rifles, it starts as a set amount of stored pressure that only decreases as time goes on and the bullet moves forward, allowing the air pressure to drop, so it very quickly reaches a point where the expanding gas is overcome by the friction of the projectile in the barrel. Longer barrels are more accurate, but require higher pressure to propel a projectile, so it's a very fine balancing act.
That makes so much sense, thanks for the explanation! I wonder if it might be worth experimenting with even shorter barrels then for these smaller guns. I do have some ideas for larger guns that use larger tanks (like a small coke bottle). Looks like there's still a lot of experimenting needed to figure out a good combo. Thanks for writing that up!
@@JamiesBrickJams no problem! something else to consider is to decrease the friction of projectile in the barrel while retaining a seal. If you take a look at air rifle pellets, they're shaped to have minimal contact with the barrel on the sides while having a large concave tail end to catch more of the air being thrown its way. Good luck with your future designs, I hope they're even better.
Thanks a lot! There's definitely some experimenting to do with darts I think, which should act similar to air rifle pellets. Will see where this evolution goes 😀
Barrel length has a sweet spot that will vary based on several factors. How much PSI, the weight of the projectile, friction between the barrel and the projectile, and how tight the fit of the projectile is. Ideally you want a barrel exactly as long as it takes for the projectile to finish accelerating. Because any extra length of barrel it needs to travel past the point it finishes accelerating, is only going to slow the projectile down with friction.
I think the seal at the back of the barrels may have been more loosely fitting, which could be why the short barrel outperformed the long barrel. The air may have escaped out of the back of the long barrel before the projectile left the gun, leading to lesser performance. Edit: this is probably also why the thinner metal barrel performed so well; there was a greater seal around the projectile and the back of the barrel. Maybe a longer and thin metal barrel would work?
i'd sugest making rifling on the metal barrel to spin the small wood bullet and increase acuracy
same, but he could also use the normal technic axle, i dont think bullets in rifled guns use anything special compared to smoothbore.
The issue with the accuracy, even with a pointed ammo, is that there isn't a spin that would help with centering the shot. If a shot is spinning on the access of the direction it is fired, then the air resistance would be spread out more evenly, resulting in it not twisting in the air as much when fired. But you can't really add riffling to the inside of your barrels that would induce the correct spin of the projectiles.
Rifling the barrel would give a better accuracy. Also when testing, the speed machine needs to be at a set distance as any small variations will change the result. Shorter barrel gives better speed as it will lose velocity moving up the barrel due to fiction if barrel is tight, or air pressure leaking around the projectile if too loose. You know whats next, a selector switch to have a safety, a single shot and a fully automatic one. Have you considered making a gatling gun?
Barrel length is definetly important, but if its too long then pressure is way too low at the end and you waste energy since the pressure is less than the resistence of the bullet. Also try get a way tighter seal with the technic axels, it looks like you still have a leak since its cross-shape. And if you can those low volume blue pumps should be replaced for longer or thicker ones.
Barrel length is probably a matter of optimizing the friction to pressure ratio. Shorter barrel maintains a higher ratio of pressure to friction. Longer barrel = more friction and lower pressure.
Imagine if someone made a Phalanx CIWS out of lego
Looking at the test piece - you just had air leaking around it, and in longer barrel it did so for longer + the friction. also using slowmo of the gauge it looks like the air supply diameter is too small, it keeps dropping pressure even after the projectile is out
Imagine pulling up to an airsoft match with this
Done. What now?
This video was so cool! Build another version with a magazine that can shoot multiple bullets in a row
Awesome build! Crazy what people like you can do with lego :D
Appreciate it, thanks a lot 😊🙏
you can build in an automatic crimp reset, which re crimps the hose to prevent unnecessary air loss
I think part of the problem with longer barrels is that it normally works better because the rifling spins the projectile more. When you use an air-pressured gun, however, it takes a lot more power to fire out of a longer barrel, and since (I'm assuming) you have no rifling, it doesn't add that extra spin to the projectile.
The shorter barrel is better for compressed air because, as the air expands and pushes the projectile out it becomes less powerful and friction slows it down again.
If you making a casing on top of the barrel and attach a good sight it might help accuracy.
You should try a smaller design where you crank the pump system manually next.
My previous air gun video was pretty much that 😉
Longer barrels are better if the barrel is rifled because it helps spin the bullet but if the barrel is untifled it will just be more friction against the inside of the barrel with less spin
Your storage tanks run out of breath before the projectile makes it out of the long barrel. The resulting vacuum drawn behind the projectile actually decelerates it. Make the barrel even longer and it won't come out. I suspect even the short barrel is running out of air before the projectile leaves the barrel.
I'm sure you're right here, that makes a lot of sense. Looks like the first step is to store more air, and find a way to release more of it. And then experiment with different barrel lengths to match that output. Thanks for commenting, these suggestions are always helpful!
brilliant video really enjoyed it especially graphing the results
Aw appreciate it, cheers! I hoped the basic graphing wasn't too dry for some folks, but I find it interesting for optimising and refining the mechanisms
great video!, but i have a suggestion, as this could be improved as maybe this can achieve higher speeds but needs more air to push with enough force for heftier loads and sometimes can help having a longer barrel but you need some decent amount more of pressure and air to utilize that properly, and i'm sure there is a website with custom pumps with more volume metal shafts and better in general made for lego air piston engines which i think would easily buff this gun with more pressure and reload speed but man that there is definitely cooler than that last one, keep it going!
Thanks a lot! And will look into that. One of the main power limiters right now is simply the bottleneck of how small the Lego pneumatic connectors are. But might look into storing more air in a small coke bottle or something. Would love a better compressor too. Cheers for the recommendation 🙏
Longer Barrel more accuracy, but slower speed, short barrel = more speed, but more spread. That's how I learned it
Thank you for the inspiration! I think you could improve the pressure if you don't use these tiny LEGO air tanks and replace them with a bigger tank made of a empty plastic bottle or something like this. Might be a littele more difficult to mount or glue the connections but should be possible to accomplish. A bottle can store more air and pressure.
You're definitely right, larger bottles will hold muuuuuch more air. Been experimenting with that for a while now 😉
I'm just glad to see I wasn't the only one raised that it's OK to play with your food.
wow, love it! it looks so cool!!
Thanks a lot 😊
i think that you should add a shock absorber to the crimping mechanism to make it automatically crimp it after it releases a burst of air.
My guess for why shorter is better is that both the projectile(s) and air lose speed due to friction. Less barrel, less stuff to rub against.
I know it would be really difficult, but how about on your next gun, you try to have some barrel rifling to perhaps make the projectiles more on target..?
The reasons I believe why the shorter barrel preformed better than the longer is because of 2 things. First of all friction, the ammunition no matter how well it fits the barrel will most likely glide on the sides of the inside of the barrel. Second thing is, that the pressure generated within the barrel isn't strong enough to propel it all the way through. Meaning that as an example the pressure might get too weak by the middle point of the barrel and from then on forwards there is only friction which play a role in force which in turn slows the projectile down. In gun boom boom physics, people tend to talk about "optimal length" of a barrel. Which is when the barrel length is just at the right length to where the pressure of the weapon accelerates it all the way to the end without friction overpowering the process. Meaning nothing goes to waste in form of the pressure and the maximum velocity of the projectile in that circumstance is achieved.
YOU HEARD IT HERE, FOLK!!! SIZE MATTERS, BUT BIGGER ISN'T ALWAYS BETTER!!!
The criping part to quickly release the air was ingenious!
Credit where it's due - I got the general idea of crimping pneumatic hosing from Nico71 who has some incredible technic pneumatic engines that run off crimped hosing instead of valves!
should try coating the amunition in vaseline reduces drag and makes airtight barrels
that's powerful. you suprised me!
I would expand on "For what ever reason" that shorter is barrel. In airsoft, big factor is cylinder to barrel volume. If you have a too long barrel and not enough air volume in cylinder, the BB will be pushed by the pressure behing it coming from the cylinder, but if a barrel is too long, it will lose the pressure because the air behind it will be filled since the barrel is too long. What happens then is, due to friction mostly and other factor, BB slows down by the end of the barrel. Same if the barrel is too short, the cylinder will release the air but the BB will already leave the barrel before the cylinder release it all and made a full pressure behind the bb, thus not being utilized fully and BB will lose power. Thats why the barrel to cylinder air volume ratio is important. The weight of the BB is also an important factor here, where heavier BB requires bigger air pressure behind it, thus requiring shorter barrel.
riffling would help with accuracy for sure!
do this one again, but modify the barrel to have spiral ridges inside. I think your bullets are lacking spin to travel further and faster and accurate. Hence the wobble we see when they fly.
by gearing the compressors differently you could have some which pump faster at the beginning, and then some which pump slower but are able to bring it up to higher pressure - should improve both speed and pressure. ideally you'd have all the compressors driven by a transmission but that feels like overkill
Damn that's such a great idea, thanks for sharing that! Some geared down ones might actually allow it to get up higher. Maybe some kind of automatic transmission could work there. Thanks for the suggestion!
First watch on this channel, INSTANTLY subbed and liked i love this stuff.
Appreciate that, thanks for joining 😁
yo I have a projectile idea: 3d print some fins and a holder to go on the back end of the wooden skewer and put a spring in it so the fins extend when it leaves the barrel (it might not work because it might not be at a high enough speed in order for them to work)
I think camshaft timing could Chance pump volume, the alternating of the pumps meight be inefficient because u end up pumpin it left and reight,
Suggestion for next time, something that i noticed was similar to some real life issues. The Small, wooden projectile functioned similar to APDS, being powerful, but unstable. The solution? APFSDS, which is very similar to what you did with knitting needles, but uses fins to stabilise itself. Try something like that next time you get the chance.
Here's a good suggestion: Add a second tank. Firstly the main tank is pumped to full capacity and once that's done the second/backup tank starts to get pumped automatically. With this you can fire much faster without the need of manually reloading.
That's a most excellent idea, and one I've been playing with recently - it actually works really well! I'll likely design another pneumatic shooter around that in the near future 😉 Cheers for the suggestion 👌
Your long projectiles are tumbling. You either need something like a crossbow bolt (fletched) or else something spherical, which (at subsonic speeds) will be fairly optimal in terms of aerodynamics. Interestingly a LEGO Zamor sphere, will fit pretty snugly into a 4x4 tube structure that could be made with 2x4 macaronis, or equivalent (don't use 4x4 round plates with 2x2 round open centres. The barrel interior won't be smooth). The main issue would be the large calibre and the subsequent, large volume of the barrel. Perhaps you could use a coke bottle as your tank, and beef up the compressor module.
That's why rifling was invented. To impart a spin.
Honestly I think the biggest limiting factor of this is the hose diameter. It's too constricting for the amount of pressure you have. Quite a few times you can hear air still being released well after the projectile has already left the barrel. This denotes a restriction, and thus a loss in power. To get more power, you'd need to dump the air as close as you can to all at once, as fast as you can. As it is though, you are always going to be limited by the small diameter tubing should you continue it.
You're 100% right on this. It's been frustrating hearing that hiss even after the bullet has landed. Of course there will always be some hiss as pressure drops after release and the remaining low pressure air escapes the tubes. But this really needs thicker tubing. I've got some that is a little thicker and still works with Lego pieces, but the Lego pieces are still a limiting factor. I've a couple other ideas though using a coke bottle and thicker tubing. Cheers for your thoughts!
@@JamiesBrickJamsdoesn't a thicker tube exist? From that set where you have a spaceship you can launch with a hand pump attached to an orange tube
The pointed tip is also gonna need rifling in the barrel to shoot straight
Longer barrels work due to actual guns using a gas explosion and gas pressure to: -make the bullet accelerate due to steadily increasing pressure as it travels through the barrel -use the excess gas pressure to push back the charging handle, rechambering another round If you are trying to use a longer barrel effectively, you would need to attain the required gas pressure to accelerate the projectile while it is still inside the barrel, so... Very VERY fast. Also try rifling the barrel, assuming you want more accuracy.
Shorter barrel is better because the volume of air you have is low, if you had a bigger air tank the longer barrel would perform better imo
I need one of these
Longer barrels in firearms have rifling that is the reason longer for them is better, But your weapon is smooth bore and that is why the shorter barrel is faster but less accurate, if you want you can rifle it or make your projectiles fin stabilized (I'm not an expert in ballistics, I'm just saying that might a solution)
Such an underrated channel :)
Thanks a bunch 😁
Amazing video! I spent many years making air guns and work with projectiles for my living. Try using a blow-dart-style round. They are quite easy to make with a very small nail, post-it note, hot glue, and finish off with duct tape. You want the hot glue to fill ~30% the volume of the cone. I find that this makes a phenomenal seal and durable ammunition made for precision. This also scales quite well! I would use a .5” diameter bore, a bolt ~30% the bore diameter, and lots of hot glue and duct tape. At 80% Mach 1 (220 psi with large tank and 4 foot barrel), the rounds would survive 30 ish shots into a very tough archery bag. I’d love to see you give this a shot! Pun intended 😁
Side note, “air-tight” is not possible for solid ammunition. That’s why blow-dart styles are perfect, as the seal is dynamic. As the pressure builds behind the round, the seal expands and conforms better to the barrel. Every barrel and solid round with have imperfections. This is why real guns and air rifles use lead ammunition. The pressure behind the round expands the lead and forms it to the barrel, leading to very marginal losses. Using a solid round (even the one you wrapped in tape) will always have significant losses because it is not designed to expand. Even if the seal felt strong, that “seal” is more cause for friction than it is for velocity because it isn’t expandable and adaptive to the barrel. This is most likely why you saw worse results with the long barrel. As velocity increased, so did friction. Friction will win at length without a huge air tank or massive pressures. I could run the numbers if I had them, but it looks to me that you have enough air volume to make the long barrel better than the short. Because the long barrel was worse, then you know the seal is the issue. Because the seal isn’t proper, the shorter the barrel, the better the velocity. Pretty counter-intuitive! But it makes sense when you think about how friction and pressure leak past the round effect velocity. Expansion is everything when it comes to efficient projectile acceleration!
This is fascinating stuff, thanks so much for sharing your wisdom! I really appreciate comments like this, so cheers for taking the time 😁 This makes so much sense. And the idea of using paper sounds very clever, allowing it to expand wit the pressure without introducing much friction or drag. I'll absolutely be testing that out! I doubt I'll get anywhere near 220 psi, but I'm sure I could get a small coke bottle up to about half that using my handheld compressor. Now you've got me itching to try a few things 😁 Thanks again, and looking forward to putting some of this into practice
@@JamiesBrickJams So glad I could provide some inspiration! Look at an 8 year old vid from “the king of random” about making a homemade blowgun. That’s your ticket to great ammunition! I go a step further with duct tape covering the paper, then trimming the end one more time for that perfect seal. Paper isn’t meant for sealing… but duct tape is 😍. Your designs are seriously incredible. I cannot wait for more vids to come. Thank you for your kind words and inspiration to young engineers 😁
Just checked out what I think is that vid - it actually looks pretty straightforward. Cheers for suggesting that one. I'll give some duct tape a try too, I'm sure there's some lying around. And glad some of these odd contraptions go down well. Take care!
The reason the longer barrel doesn't work as well is because it's a constant, set pressure pushing the object through. The reason longer barrels are better in firearms is because the powder gets more time to burn and create more pressure before the bullet leaves. You don't get that with an airgun.
That makes sense. Sounds like it just needs more air to keep providing that 'push' until the projectile leaves the barrel
theres not enough propelant gasses to keep a positive pressure behind the projectile all the way down the longer barrel which causes a vacuum to form and slow the projectile down, same thing happens with handguns that have overly long barrels
That definitely seems to be the issue here, thanks for the comment! Seems we need more air and thicker tubing
i think you should try making a gun with mechanism that used in nerf and airsoft guns: piston with spring connected to it (when you load the gun you compress the spring and when you pull the trigger it releases the spring which causes piston to quickly pump air from the piston in the barrel)
That is a damn fine idea! I've been experimenting with a large syringe... But a spring loaded burst is a great idea. Thanks for suggesting - I'll see what I can do 😉
Cool video, Now, I feel like if you made the other end of the pipe the projectile is being shot from more airtight, you might be able to yield some slightly better results. Just a thought though
Yeah totally. The metal barrel is actually completely airtight, but the plastic one could do with a bit better seal
@@JamiesBrickJams The metal one is sealed at the other end? I was talking about where the tube touches it. Under a wave of pressure it might break the seal and therefore lose some velocity of the projectile.
Yes 🎉, nice to see you utilized the compressor idea I posted in your 1.0 version 👍
If that was you, then thanks for suggesting! 😜
pneumatic air gun with ball bearings? this guy really just made the Tihar from Metro 2033 out of technic parts.
This man has done the impossible, created a thing that if it is shorter, it is better!
😂
love ur content
Thanks a lot, appreciate you 😁🙏
There's gonna be a magic length that is just perfect. Where if you go past that, then it's too long and you're losing efficiency. Basically, however long it takes for the projectile to accelerate to its maximum. Speed is how long you want it to be in the barrel. I'm sure using a bit of math, you can figure out exactly how long the barrel should be to reach maximum speed.
Best experiments I have ever seen
Thanks a lot for your comment 😊
A side mounted pressure gauge would have been cooler. When lying down somewhere, you can watch the pressure rise with just keeping the gun on yer hands.
Perhaps you could also create a magazine or ammo feed, to prevent manual loading?
Have you tried ramming the axle down the barrel? that might help with speed and make the long barrel faster.
Yup! All those rounds were pushed to the back of the barrel against the crimper output. Probably just didn't film that all that well 😅
One little corection, on most as fields in europe the limit is 2,7 joules for springloaded snipers. most rifles are at around 1,6 joules. But i know in Ireland the limit is 1 joule
Coming from airsoft experience, the volume of the tanks should match the volume of the barrel. Would also love this to fire a projectile with 1.2 joules.
Ah now that makes a lot of sense! Thanks for the heads up - I can try to work with that principle in mind 👌 Agree on the power front too - I certainly want to exceed a joule, and I'm almost there using a new mechanism 😉
if you could somehow rifle the barrel, you could get a lot more accuracy with this.
You need a qrv a quick release valve there.
This is epic
Dam, its like a lego fallout gauze rifle that is powered by air.
I mean, it should be easy to figure out that if that needle shot was tummbling so bad, yet all of today's bullets have that sort of shape, that we have already fixed it. The name of the game is barrel rifling.
if you are able to add rifling to the barrel it will be more accurate
Longer gives you range. Shorter gives you power
A .45 ACP shot from a pistol is about 830fps for reference.
Looks like there's a long way to go still 😉
the reason your small projectiles werent flying straight is bc the tip is lighter than the rear, your longer ones work better due to inertia
A few folks have mentioned that, and that definitely seems to be the case - thanks for sharing! I guess going back to darts is likely a good move to prevent tumbling
also id say a faster release valve would help a lot
awesome!
Cheers 😄
the bottleneck is the literal bottleneck.. but great work! definitely subscribed :) I hope v3 is using a real spring that is torqued using air pressure and worm drive on linear gear.. :D
Aw well thanks for joining 😁 And yeah, Lego has some very real limitations with their standard pneumatic components. But the next version will likely use some 'cheating' to increase airflow 😉
Perhaps if you made some wads from cork you could get them going pretty fast.
Hey that's not a bad idea, thanks for the suggestion!
the longer barrel is a bit wider than the shorter one, atleast I'm pretty sure
It’s really a shame Lego hasn’t made those air tanks for like 25 years
It's a real pity, they're so useful. The ridiculous price for an original I think fully justifies buying knockoffs instead
I guess 2010 was the last year one was in a set according to brinklink. It looks like they go for around $30 a pop. I’ll have to look into the fake ones, though it would hurt my soul since I am very much a purist
So the knitting needle could probably stick a hole in a potassium intruder at point blank. Interesting.
You should probably modify your pistons to make them smoother
Bigger barrel and make a little apfsds round like what’s on modern tanks
I think the shorter barrel is better, because there's less space = more pressure can build up faster, which means, that there will be more pressure at the end of the barrel pushing the bullet out, however in a longer barrel, there's more space = less pressure, which means, the bullet won't accelerate as much. Btw I don't really know anything about air and air pressure and stuff like that😂 It's just what I think could cause it
I suspect you're probably right ... That, and more friction in the longer pipe. I'm just doing this all by trial and error, so I don't really know for sure either!
When the quiet kid plays with Lego.
try to make a lego gun for 60psi and yes it doesn’t have to fully be lego to store the air i just wanne see how insane it gets for v3
The speed thing is called a chronograph it measures in feet per second
“No snacks were wasted in the making of this video.”
I actually did eat the Pringles and banana 😁
Crossbow - Air pamped edition