17 replies to this topic

[Montymarks]

Right, so this is an idea i've had brewing for a while now.
What somebody made a normal RBPistol and left out the spring, replacing it with:
On back of plunger head, a magnet with a hole fixed to it.
On the catch, a magnet faced so it repels the plunger magnet.
On the front bushing, another magnet attracting the plunger head magnet.
Sound good? Maybe some other angled magnets to keep it going?
Think of it like a really short, possible hyperloop.
Feedback would be good, actually thinking of making this a reality.

-Montymarks

Edited by Montymarks, 07 May 2017 - 06:51 AM.

[CaptainSlug]

And you would get all of 1/8 of an inch of plunger stroke. You're forgetting that the force a magnet can apply drops off immensely with distance. The force is inversely proportional to the distance squared.

You have to be able to move the magnetic field, and do so over a short time frame. That's how gauss rifles and mag-lev trains both work. The power requirements for doing that are way more than simply propelling the darts directly with flywheels.

[mykeypowell]

thats sounds pretty cool

[Montymarks]

And you would get all of 1/8 of an inch of plunger stroke. You're forgetting that the force a magnet can apply drops off immensely with distance. The force is inversely proportional to the distance squared.

You have to be able to move the magnetic field, and do so over a short time frame. That's how gauss rifles and mag-lev trains both work. The power requirements for doing that are way more than simply propelling the darts directly with flywheels.

Point of the follower magnets, like the hyperloop, but it would work. The first one would be to get the starting push, and hopefully the other magnets would keep it going. I have other ideas in mind as well, but I think having a working version of this would be a cool proof of concept.

-Montymarks

[Lasagna]

Does seem cool, but maybe a bit impractical. I know you can get insanely strong magnets online, but from my limited knowledge the kind of magnet that can jump at another one from ~4 inches away depending on draw would be way too big and heavy for this to get any sort of good performance.

[CaptainSlug]

Point of the follower magnets, like the hyperloop, but it would work.

That uses passive magnetic levitation, not propulsion. You don't need or want magnetic levitation because your plunger is being guided by its seal against the inside wall of the plunger tube.

If you want linear motion you need a linear drive, and you can't get that with just magnets. Linear electric motors require a moving electromagnetic field along a sequence of coils.

[Montymarks]

That uses passive magnetic levitation, not propulsion. You don't need or want magnetic levitation because your plunger is being guided by its seal against the inside wall of the plunger tube.
If you want linear motion you need a linear drive, and you can't get that with just magnets. Linear electric motors require a moving electromagnetic field along a sequence of coils.

Unnamed Cell gave me some advice on this. Coils would be around the outside.

Another question is how would I then secure the catch, and other stuff using bolts/screws, to the blaster?

-Montymarks

Someone works in engineering

Edited by Montymarks, 09 May 2017 - 08:00 PM.

[CaptainSlug]

Another question is how would I then secure the catch, and other stuff using bolts/screws, to the blaster?

If you can't figure that out, then you're not capable of designing a homemade.

[Meaker VI]

If you can't figure that out, then you're not capable of designing a homemade.

 

Especially one that uses electromagnetic fields as the power source. The power needed for that isn't safe for the uninitiated.

[Draconis]

I always find it amazing that the younglings think we haven't discussed magnetics before.

[Lasagna]

Now that I think of it, a Coilgun style setup could work, with the coils propelling a plunger forward instead of a metal projectile, but I would be worried about a return mech for the head. However, this could have the potential for an automatic "Springer" gun. Still, you shouldn't mess around with coilgun stuff until you can safely handle super dangerous voltages and currents. Essentially if you don't have the knowledge of a liscensed electrician, treat with caution. Seriously.
Edit: Or just do away with a plunger and use the coils to accelerate a metal weighted dart, like a regular slug. Could make for a simple semiauto clipfed, but still remember that at this kind of current and voltage will most likely kill you super dead if you mess up, like uber dead. Do I really need to restate this?

Edited by Lasagna, 11 May 2017 - 07:34 PM.

[Meaker VI]

Now that I think of it, a Coilgun style setup could work, with the coils propelling a plunger forward instead of a metal projectile, but I would be worried about a return mech for the head.

An extension spring. But I'd be worried about accidentally firing the plunger out of something like that.

[Lasagna]

True. Those coilgun things can put projectiles through a lot of things, and if the front bushing + plunger rod didn't rip out of the gun, the whole PT might come out, a spinning, eye killing, sharp edged piece of plastic tubing.

[TKDonuts]

While I personally do not have a degree in electrical engineering (since I am only a student right now), I would have to say that a coilgun style of plunger acceleration would be highly inefficient, and very impractical. My knowledge of this stems from my personal experience building my own coilgun.

 

First of all, the weight of the projectile that a coilgun fires is minuscule in comparison to what your plunger rod would have to be. Additionally, the deceleration forces that the plunger would be experiencing (i.e. air resistance, friction, etc.) would likely be to great in comparison the the forces that would be exerted by the electromagnet. It is important to remember that the air resistance and friction on a coilgun projectile is relatively small, while an actual plunger has to push a lot of air to be effective, and have will have a lot of friction with a relatively large plunger diameter. 

 

Second of all, again from my experiences building a coilgun, the amount of voltage and current required to power a coil to accelerate a 1" long nail (the projectile I used) to the speed where it could start to break things is incredibly dangerous. Luckily for me, my dad is an electrical engineer, and he helped to prevent me from killing myself, however to the inexperienced, this could be incredibly dangerous. To power the coils, you would need to us a large capacitor which is (a) very dangerous and ( would require time to charge between each shot. Like I mentioned before, this will still not have enough power to accelerate a plunger rod. 

[ca14]

how could you be sure that the stefan wouldn't come apart and essentially just shoot the split shot?

[aydensnake]

While your Idea could work for something that has a very small plunger tube I think a system similar to a railgun. The only issue with a railgun-like setup would be that it could only use darts that have some metal in it such as slugs, the railgun could also break the head off of the slug depending on the adhesive used due to slugs having a metal washer extremely close to the tip. Another issue with the railgun setup is that it would heavily limit the darts you can use unless you somehow get FBR with iron particles in it

[Silly]

Overall: This idea was doomed to fail from the start, it is worse then all current designs, and it would be very VERY dangerous. It was just a bad idea that no one asked for. And even if it is made, it will underperform without a doubt.

[Maniacal Coyote]

Topic ended, could a moderator lock it?