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  • An interesting weapon

    https://www.youtube.com/watch?v=eAHKS0nVlL4

    Perhaps not quite ready for prime time, but very interesting still.

    There is almost zero traditional "gunsmith" stuff involved, but it does put projectiles downrange at a potentially usable velocity.
    CNC machines only go through the motions.

    Ideas expressed may be mine, or from anyone else in the universe.
    Not responsible for clerical errors. Or those made by lay people either.
    Number formats and units may be chosen at random depending on what day it is.
    I reserve the right to use a number system with any integer base without prior notice.
    Generalizations are understood to be "often" true, but not true in every case.

  • #2
    Did he ever fire it? I watched several minutes and finally drifted off to sleep. He definitely majors in the minors.

    Sarge41

    Comment


    • #3
      Cmon sarge, dont insult Gun Jesus like that. Forgotten Weapons as a channel is for the history of a given firearm, not just range videos. Fantastic place to go if you wanna learn more about rare guns, or even just the developmental history of common weapons

      Plus, hes got a few different range videos of that coilgun. The one linked has him firing it in the second half of the video, and he has a second video of him taking the rifle to a BUG match

      Comment


      • #4
        That particular coilgun seems to be an "attractive" variety. Meaning that as the magnetic slug approaches the coil, the coil is "fired", the current is sent through it, creating a field that drags the slug forward . At least that is how it appears. There was mention of a photoelectric detector of the approaching slug, which would go along with that.

        There are other types that are more similar to an induction motor, and ones that repel instead of attracting, the slug. Evidently they went for the most straightforward variety, which is a reasonable decision. It is also probably pretty much self-timing, since each coil fires when the slug is at a given distance from it, rather than in a timed sequence that might do a particular acceleration curve. So different weight slugs might all work pretty well.
        CNC machines only go through the motions.

        Ideas expressed may be mine, or from anyone else in the universe.
        Not responsible for clerical errors. Or those made by lay people either.
        Number formats and units may be chosen at random depending on what day it is.
        I reserve the right to use a number system with any integer base without prior notice.
        Generalizations are understood to be "often" true, but not true in every case.

        Comment


        • #5
          Everyone seems think of this Ian of Forgotten Weapons as “gun Jesus”, but there are those of us who remember, from the pre- internet era, the real “Gun Jesus” named Ian van Hogg. He wrote many books, rich with photos and illustrations, of the firearms of the world. It is from his books that i drew much inspiration for my experiments in artillery.

          Comment


          • #6
            The F-W guy is nothing that special, but he does provide interesting info. He apparently does his research, and certainly has access to a lot of interesting weapons. Since he takes many of them to the range, it is doubly interesting.

            CNC machines only go through the motions.

            Ideas expressed may be mine, or from anyone else in the universe.
            Not responsible for clerical errors. Or those made by lay people either.
            Number formats and units may be chosen at random depending on what day it is.
            I reserve the right to use a number system with any integer base without prior notice.
            Generalizations are understood to be "often" true, but not true in every case.

            Comment


            • #7
              Originally posted by Ironbearmarine View Post
              Everyone seems think of this Ian of Forgotten Weapons as “gun Jesus”, but there are those of us who remember, from the pre- internet era, the real “Gun Jesus” named Ian van Hogg. He wrote many books, rich with photos and illustrations, of the firearms of the world. It is from his books that i drew much inspiration for my experiments in artillery.
              I have a number of Ian Hogg books, my (not then, but eventually to become) mother-in-law who was a serious book lover knew I was interested in guns used to get them for me as birthday and Christmas gifts. I spent hours and hours looking through them, they are great reading.

              I don't know for certain of course, but I always took the references to Ian McCollum of FW as "gun Jesus" as largely a reference to his appearance, ie, the long hair and beard, etc.
              In any event I do find his videos interesting and informative. I appreciate that the style of his presentations is devoid of all the sensational over the top stuff that seems all too common in youtube productions these days and he does have access to some really obscure, rare, and interesting guns.

              Comment


              • #8
                I watched his videos on this magnetic (projectile launcher) when they first came out. Its fun and interesting from a technical point of view, but its little more than a toy.

                These types of magnetic guns have been around for a while with a variety of prototype videos being published on YouTube going back several years.

                I might note that Hacksmith Industries built one some time back. They are a channel devoted to making fantasy tech real (sort of). I think the first videos I recall when the founder was starting out in his garage and testing in his back yard was a mechanical strength enhancing exoskeleton. It was perhaps not quite as grand as that sounds, but technically it did work. I recall one of the comments from Hacksmith in their magnetic gun build was that they deliberately limited the speed of the projectile due to Canadian gun laws which cover not just firearms, but almost all projectile launchers.

                Based on the comments from Hacksmith Ind. I would have assumed that a US builder would by now have made something capable of a little more than punching paper or cardboard.

                Now, I am aware of the capabilities of real rail guns, but those were very large and intended as emplacements or ship mounted guns. Not something that could be carried around if somewhat awkwardly. If you are curious we had some decent discussions on rec.crafts.metalworking some years back about real rail guns, although there are probably better more organized resources than a bunch of machinists and wannabee machinist arguing about nomenclature.

                To be frank, from what I have seen a pneumatic air rifle has more capability at this point, although to be fair lethal capable air rifles have been around for at least a couple hundred years. There were even some interesting experimental setups made that far exceeded what most people consider to be practical velocity limits for pneumatic guns. They proved mid range velocities were possible. Significantly supersonic. Not just a lie on a cardboard box. There was even a fellow developing pneumatic repeating cannon near me (I never met him) with the hopes to sell it to the military.
                Last edited by Bob La Londe; 10-04-2022, 04:22 PM.
                *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

                Comment


                • #9
                  The velocity has a number of limits, depending on how you make the "gun". They seem to have chosen a reasonable method, but it will probably limit velocity.

                  As I understand it, they have an optical sensor that detects the projectile, located a certain distance ahead of (toward the breech) each coil. That detector fires the coil, which attracts the projectile into the coil.

                  That system should handle a range of projectile weights. It is less sensitive to the absolute velocity of the projectile.

                  Limits that occur to me right away include the following

                  1) the distance in advance of the coil that the sensor is, would be related to the delay in getting the coil fired after the detection. You need the sensor far enough away to deal with the inherent delay (at the expected projectile velocity), but not so far that the force from the coil is weakened. That depends on velocity. While the circuit is triggering the IGBT, and current is building in the coil, the projectile is moving toward the coil. There is an optimum distance for attraction, and ideally the projectile is there when the trigger happens. But the location of the sensor then depends on projectile velocity, so that it is in the best range when the coil is starting it's serious pull on the projectile.

                  2) You want the projectile pulled forward. But the magnetic field does not care.... it can pull back as well as forward. The "balanced" position of the projectile is halfway through the coil, that is where it would end up if the current were DC. So you need the current pulse to definitely be over before the projectile gets far enough through the coil for the coil to produce a net backward pull. Ideally, you have pulled it and have stopped pulling before very much of the pull is backward, so that all of your pull is effective at moving the projectile forward. .

                  3) You need a fast pulse of high current. But the pulse should be slow enough to exert a real pull and move the projectile, which has inertia and takes time to accelerate. However, a slower pulse which is good for accelerating a slower projectile can violate the condition of item 2, it may pull back on a faster projectile (which has gone further into the coil in a given time), wasting energy that could increase muzzle velocity.

                  4) You need low inductance coils, in order to have a fast rising current pulse that also falls fast per item 2. But a low inductance coil will not produce the magnetic field strength of a higher inductance coil, so you have a hard time efficiently transferring energy into the projectile, and you do not get as much velocity for a given amount of stored energy.
                  Last edited by J Tiers; 10-05-2022, 02:23 AM.
                  CNC machines only go through the motions.

                  Ideas expressed may be mine, or from anyone else in the universe.
                  Not responsible for clerical errors. Or those made by lay people either.
                  Number formats and units may be chosen at random depending on what day it is.
                  I reserve the right to use a number system with any integer base without prior notice.
                  Generalizations are understood to be "often" true, but not true in every case.

                  Comment


                  • #10
                    Originally posted by Ironbearmarine View Post
                    Everyone seems think of this Ian of Forgotten Weapons as “gun Jesus”, but there are those of us who remember, from the pre- internet era, the real “Gun Jesus” named Ian van Hogg. He wrote many books, rich with photos and illustrations, of the firearms of the world. It is from his books that i drew much inspiration for my experiments in artillery.
                    I have a copy of Hogg's The Guns 1939-45, (part of Ballantine's Illustrated History of WWII). Superb book. Ballentine published something like 156 paperbacks about 20th century warfare in 5 1/4 by 8 1/4 format.

                    Comment

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