[It’s on my MIND] designed a clever BB blaster featuring a four-bar linkage that prints in a single piece and requires no additional hardware. The interesting part is how it turns a trigger pull into launching a 6 mm plastic BB. There is a spring, but it only acts as a trigger return and plays no part in launching the projectile. So how does it work?
The usual way something like this functions is with the trigger pulling back a striker of some kind, and putting it under tension in the process (usually with the help of a spring) then releasing it. As the striker flies forward, it smacks into a BB and launches it. We’ve seen print-in-place shooters that work this way, but that is not what is happening here.
With [It’s on my MIND]’s BB launcher, the trigger is a four-bar linkage that transforms a rearward pull of the trigger into a forward push of the striker against a BB that is gravity fed from a hopper. The tension comes from the BB’s forward motion being arrested by a physical detent as the striker pushes from behind. Once that tension passes a threshold, the BB pops past the detent and goes flying. Thanks to the mechanical advantage of the four-bar linkage, the trigger finger doesn’t need to do much work. The spring? It’s just there to reset the trigger by pushing it forward again after firing.
It’s a clever design that doesn’t require any additional hardware, and even prints in a single piece. Watch it in action in the video, embedded just below.
The four-bar linkage mechanism offers a range of advantages in the design of contemporary firearms, making it a valuable choice for engineers and designers in the industry. One of the most significant benefits is its ability to enhance mechanical efficiency. By allowing for smooth and controlled movement of the firearm’s components, the four-bar linkage reduces friction and wear, which not only improves reliability but also extends the lifespan of the weapon. This efficiency is crucial in high-performance firearms, where precision and durability are paramount.
Moreover, the four-bar linkage contributes to improved ergonomics. Its design enables better alignment of the firearm’s parts, resulting in a more comfortable grip and easier handling. This is particularly important for users who may need to operate the firearm for extended periods or in high-stress situations. The adaptability of the four-bar linkage allows designers to create firearms that cater to a diverse range of users, enhancing accessibility and usability.
Another notable advantage is the potential for a more compact design. The four-bar linkage mechanism can facilitate the folding or collapsing of certain components, making firearms easier to transport and store. This compactness is especially beneficial for tactical applications, where space and weight are critical considerations.
In addition to these practical benefits, the four-bar linkage also allows for innovative design possibilities. It can enable unique firing mechanisms and operational features that enhance the overall functionality of the firearm. This flexibility in design can lead to the development of firearms that are not only more effective but also more appealing to users.
In summary, the four-bar linkage mechanism plays a crucial role in contemporary firearms design by improving mechanical efficiency, enhancing ergonomics, allowing for compactness, and fostering innovative design solutions. These advantages contribute to the creation of firearms that are reliable, user-friendly, and effective in various applications.
Thanks, ChatGPT.
When wikipedia came out, there were people who just took wikipedia at face value, even against warnings that the contents can and will be manipulated or just wrong. Over time, it got better, but still you can be completely mislead by wikipedia, so you still shouldn’t take it at face value, and yet people still do.
It’s the same thing.
No, it’s not the same thing. With Wikipedia, one would have to search through articles for relevant content to post this type of response. With generative AI, arbitrary garbage can be generated ad-hoc in response to any question.
No. With Wikipedia people don’t copy paste things verbatim without doing any work. If I want Wikipedia’s thoughts on the matter I go to Wikipedia. If I want chatgpt’s I would do the same. In a comment section, I want the poster’s thoughts on the matter.
What this poster is doing is spam.
This is not a firearm.
Firearms will continue to get along fine without the four-bar linkage. Track record is pretty good and apparently transporting, storing, and trigger pulling all day long have been and will continue to be super easy.
Nobody asked for this crap.
Microplastics! Yum!
Sorry couldn’t help it, very cool project
with 6mm it´s not so micro. There are pressed wood alternatives.
That’s not how you do it.
‘Oh Knows! They builted a 3d printed tigger group! Ban 3d. I demand they unpost the plans. For the childrens.’
c/detente/detent/
Whoops, thanks for catching that.
Can you walk us through your thought process of why you used AI to make a comment? Please don’t use AI for that also.
would kind of like to see how far those things go. Like, across the room? seems like it would be fun in the office.
Probably as far as HR and then out the door….with a greeting by a SWAT team.
Yeah I’m sure a swat team will be all over an orange 3d printed bb gun lmfao
Cube farm intestinal gas wars will never end!
HR knows better then getting involved…
Maybe I just like extra spicy kimchi, hardboiled eggs and cheap beer…
Can’t prove anything…
Not my fault the PHB thought there was a natural gas leak and cleared the building.
They only had to hire one (female coder/unicorn) to put a stop to it all…ratio was worse than engineering school.
It’s racist to call men in cubicals homosexual fart fetishists, but you do you.
“Thanks to the mechanical advantage of the four-bar linkage, the trigger finger doesn’t need to do much work.”
I’m not a physicist or mechanical engineer but please explain to me why this isn’t exactly the same amount of work as the trigger compressing a spring if you use the same sort of linkage in the other direction on a spring?
Also, presumably overcoming the detente robs the bb of some of the compression energy (potential energy?) so it’s even less efficient than spring compression.
Again, not a physicist or mechanical engineer but this “easier” “less work” assertion seems suspect.
It should say that the trigger finger exerts less force. It does so over a greater distance. Work is force times distance.
That’s compression, not tension.
That’s just a bit of imprecise/non-literal terminology. This sentence is just a quick, surface-level description and not meant to be read like a physics paper ;)
It needs less force (because of the leverage), which means it feels easier to push and thus feels like less work for a human operator. You obviously still need to provide the same amount of energy for the same result as with another mechanism.
The real problem is I don’t think this linkage is doing more work than a simple lever. Although there may be room for moving the “middle” link and thus increasing the mechanical advantage.
As it is the pin is right behind where you put your finger on the trigger, so no mechanical advantage from the “front” lever.
This leaves the rear lever as the only one creating increased leverage. Moving the middle link down would make the front lever actually do something, and could increase the effectiveness of the rear lever, as it is now longer and affords more choices of ratio.
As it is now it is an excellent starting point, with no mechanical advantage over having a sliding trigger acting directly on the rear lever.
Also the hopper needs some help, it isn’t really feeding right now (could be the slope of the feed trough, or some trimming needed to the 3D print.)
If the detents are a problem over time you can replace that with an appropriate size o-ring, make a slot for it and drop it in; replace over time as they stretch.
If I remember correctly this is how scale warship air cannons work. Pretty smart to have the wear item be not just replaceable but replicable. Also- scale model warship battles are definitely a thing and definitely super awesome.