A DIY Net Gun To Catch Whatever You Want

Suspicious drones hovering about your property? Burglars or other ne’er-do-well test subjects giving you trouble? Need to catch a dog that keeps meandering through your workshop? [William Osman] suggests you build yourself a pneumatic net gun that can shoot 20-30 feet to catch them all.

The net gun is built largely out of PVC pipe; the air tank — filled via a tire valve — uses adapter fittings to shrink it down to a 1″ sprinkler valve, with an air gun to act as a trigger. The net launcher is made of four lengths of pipe bent with the use of a heat gun — an Occam’s Razor solution compared to his first attempt — and is coupled to the end, while the net loads in using wooden dowels with washers as weights. It won’t trap any large game, but it will certainly net you some fun.

[William Osman] notes that you have to be sure not to mix up the corners of the net when loading or it’ll tangle itself up to the point of ineffectiveness, and to properly seal all the components to prevent lost off air pressure.

If a net gun won’t stop whatever is bothering you, a DIY railgun might do the trick.

[via /r/DIY]

21 thoughts on “A DIY Net Gun To Catch Whatever You Want

    1. Your comment suggests you think there’s an issue with using PVC as a pressure vessel. However, the video you linked to suggests it’s rather robust. (They need to freeze it then smash it with a sledge hammer before it fails.) It’s not clear, at least to me, what point you’re trying to make.

      1. The sudden failure mode of a PVC pressure vessel makes it unsuitable and unsafe for use as a pressure vessel for air. Particularly around cold temperatures, possible impacts, instances where it could be dropped or in vessels that have aged or have damage to them, among other concerns. The failure mode is extremely quick and very dangerous.

        If the issue is cost, use a proper rated but still extremely cheap steel vessel and move on. PVC pipe is not a suitable container for compressible gasses yet this site continues to highlight builds that use it and at times even actively taunt the commenters who bring up this very well known issue. That’s the specific issue I have here.

        1. The other element worth considering is the performance of joining elements in the system. I’d put my money on a properly taped and tightened brass fitting substantially out-performing the average PVC “weld” connections, not only in reliability and seal, but in failure mode.

      2. I have seen the left overs when PVC has shattered when it failed. below freezing or not that portion of the video illustrates that well. The whole video is problematic as it can’t negate the evidence that PVC can shatter when it fails. Until I find PVC that is labeled for gas at x PSI I wouldn’t use it for compress air. I don’t care what others decide to do unless they do known hazardous things around me.

      1. If you rewind all the way to the beginning they say its 140psi. And they dropped the weight from 12 feet high. I’ve used PVC for a lower pressure container (<30 psi) but I'd never dream of using it for that amount of pressure for anything that will be near people. "Internet" gives good advice here.

      2. Apparently it was 140PSI (I’m guessing that is fairly common for potato guns? I have no idea) and they dropped a sledgehammer on it from ~10ft and couldn’t get it to fail. So they had to freeze it to additionally compromise it’s integrity.

        Tho I will say that when it did fail it failed spectacularly.

    2. Let it go!

      We don’t need you clutching your pearls every time a pneumatic PVC project comes out. Everyone and their brother knows PVC isn’t air rated, and no one cares.

      Caveat aedifex

    1. Just be careful from what source you get the equipment. Never buy it from Acme. Time and time again I’ve been disappointed by their parts. Especially the anvil attached to a balloon, and the rocket shoes. Just bad quality control on their part I guess.

  1. I have been toying around with the idea of making one of these to potentially catch escaped parrots, I’d have to go with a very lightweight net and probably CO2 cartridges, It would have to have a MUCH higher range than this guy’s gun though.

    1. This looks like an excellent “version 1.0”, and I hope the author continues his development.

      Here are some suggested improvements:

      1) That expanded foam he’s using will cut very nicely on the laser cutter, I use it to make stuff for my projects. He can cut circles that will make gaskets for his wooden rods, which will give him a more air-tight interface between rod and pipe. Not tight enough to make a lot of friction, but tight enough to prevent air from escaping along the sides of the posts.

      2) Try using nerf darts instead of dowels. These aren’t very sturdy, but if you wrap them in electrical tape they become *very* sturdy. (I can peg a target at 15 yards using a modified nerf dart and my modified pump-action pellet gun. It’s good against LARP monsters.)

      3) Bigger and longer output pipes will get you more range. Assuming the rod volume is negligible in comparison to the tank volume, the pressure is approximately constant on the back of the dowel as it slides out the tube. The force on the dowel is then pressure (PSI) x area of dowel (Inches). Bigger tube (and dowel) gets you bigger force, and longer tube gets you force for longer time.

  2. Wasn’t it mentioned just recently in another Hackaday article that PVC pipe used in pressure vessels contributes to the decimation of humanity and the general decline of civilization as we know it, along with just being a bad idea?
    Am I remembering wrong? Did anyone else catch this? (ha ha …….)

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