Finished Coilgun
Tipp, Sun Mar 26 2006, 11:16PMGot it all hooked up last week and she was good to go!
Cap is 250v 7500 uF. SCR is triggered by 9v battery like suggested [Works perfectly BTW
] Projectiles are custom machined pieces of 1/4" steel rod. The tips were put on with a drill press [stick the rod in the chuck and used sandpaper, grinding stones and files to shape it]. The projectile shown in the pic beside the coil is 2" long. This coming week I'm going to experiment with different attributes to the projectiles [Ex: Having slots run down the middle, having rings cut into the sides, cutting rifling grooves into the front half etc] to see what works best. Right now I can shoot through 3 pop cans and have the projectile still get stuck into a high speed archery target [that foam is TOUGH!]This was brought into school and used in a demonstration of electromagnets. Needless to say, it was quite the popular item
Everything seems to work quite well on this gun. Coil was a pain to wind, though. It's MOT primary wire. This was given to me by a friend, all nice and spooled up. Each layer is cemented in place to keep everything steady. I had to actually bolt the coil down due to excessive recoil [first time I've experianced this with a CG] and to keep all avalible energy delivered to projectile.
And thats it! What do you think?
Re: Finished Coilgun
FastMHz, Mon Mar 27 2006, 12:52AM
Nice job! Did you happen to solder those ring terminals onto the wires? I found on mine that if they weren't soldered they'd slowly burn away the wire strands inside the ring and eventually blow completely off.
FastMHz, Mon Mar 27 2006, 12:52AM
Nice job! Did you happen to solder those ring terminals onto the wires? I found on mine that if they weren't soldered they'd slowly burn away the wire strands inside the ring and eventually blow completely off.
Re: Finished Coilgun
williamn, Mon Mar 27 2006, 10:16PM
Very nice work! You did a great job with the super clean setup.
So when you you start your multistage?
See if you can build or purchase a chronograph, this will provide tremendous help in your CG research.
williamn, Mon Mar 27 2006, 10:16PM
Very nice work! You did a great job with the super clean setup.
So when you you start your multistage?
See if you can build or purchase a chronograph, this will provide tremendous help in your CG research.
Re: Finished Coilgun
Quantum Singularity, Tue Mar 28 2006, 12:47AM
Looks like a great first gun (this is your first, right?). Just a couple of questions, did you tune this setup? Like starting position, number of turns in the coil, etc.? And how high did you charge the cap? Keep up the good work.
Quantum Singularity, Tue Mar 28 2006, 12:47AM
Looks like a great first gun (this is your first, right?). Just a couple of questions, did you tune this setup? Like starting position, number of turns in the coil, etc.? And how high did you charge the cap? Keep up the good work.
Re: Finished Coilgun
Simon, Tue Mar 28 2006, 02:22AM
And of course, the two questions for every new coilgun:
Efficiency?
Velocity?
Simon, Tue Mar 28 2006, 02:22AM
And of course, the two questions for every new coilgun:
Efficiency?
Velocity?
Re: Finished Coilgun
rupidust, Wed Mar 29 2006, 02:20AM
Without a good chrono/means of measurement, efficiency and velocity is guess work. How are you going to measure the velocity?
rupidust, Wed Mar 29 2006, 02:20AM
Without a good chrono/means of measurement, efficiency and velocity is guess work. How are you going to measure the velocity?
Re: Finished Coilgun
Tipp, Fri Mar 31 2006, 12:40AM
Ring terminals were crimped then soldered. Some are just soldered and uncrimped...meh
Tuned? Well...more or less [haha] I wound the coil to the perameters of the cap and it worked out pretty nice.
First coilgun? Not by a longshot! But this is exponentially more powerful then the others [which were all photoflash+ pushbutton etc]
Made a pretty cool discovery this week while working in the shop at school. Some guy had broken a drill bit, so I picked it up and looked at it. Coilgun bullet ideas were floating through my head at the time, and it turned out I was thinking of ways to rifle a projectile. Well, you can see whats coming! Drill bits! You can cut and sharpen any way you like. The flutes will catch the air as it is accellerated and pick up centrifugal spin. Has anyone tried this? Going to fabricate some this weekend. Needless to say I've got quite a few broken 'bits needing some kind of usage
Tipp, Fri Mar 31 2006, 12:40AM
Ring terminals were crimped then soldered. Some are just soldered and uncrimped...meh
Tuned? Well...more or less [haha] I wound the coil to the perameters of the cap and it worked out pretty nice.
First coilgun? Not by a longshot! But this is exponentially more powerful then the others [which were all photoflash+ pushbutton etc]
Made a pretty cool discovery this week while working in the shop at school. Some guy had broken a drill bit, so I picked it up and looked at it. Coilgun bullet ideas were floating through my head at the time, and it turned out I was thinking of ways to rifle a projectile. Well, you can see whats coming! Drill bits! You can cut and sharpen any way you like. The flutes will catch the air as it is accellerated and pick up centrifugal spin. Has anyone tried this? Going to fabricate some this weekend. Needless to say I've got quite a few broken 'bits needing some kind of usage
Re: Finished Coilgun
Remus, Fri Mar 31 2006, 06:49PM
Did you machine the steel yourself, or did you get it ordered from somewhere? Ive looked in Home depot and Lowes, and no-one carries steel bars, do you have an idea of where I can buy a couple of bars from?
Remus, Fri Mar 31 2006, 06:49PM
Tipp wrote ...
Cap is 250v 7500 uF. SCR is triggered by 9v battery like suggested [Works perfectly BTW ] Projectiles are custom machined pieces of 1/4" steel rod. The tips were put on with a drill press [stick the rod in the chuck and used sandpaper, grinding stones and files to shape it]. The projectile shown in the pic beside the coil is 2" long. This coming week I'm going to experiment with different attributes to the projectiles [Ex: Having slots run down the middle, having rings cut into the sides, cutting rifling grooves into the front half etc] to see what works best. Right now I can shoot through 3 pop cans and have the projectile still get stuck into a high speed archery target [that foam is TOUGH!]
Cap is 250v 7500 uF. SCR is triggered by 9v battery like suggested [Works perfectly BTW
] Projectiles are custom machined pieces of 1/4" steel rod. The tips were put on with a drill press [stick the rod in the chuck and used sandpaper, grinding stones and files to shape it]. The projectile shown in the pic beside the coil is 2" long. This coming week I'm going to experiment with different attributes to the projectiles [Ex: Having slots run down the middle, having rings cut into the sides, cutting rifling grooves into the front half etc] to see what works best. Right now I can shoot through 3 pop cans and have the projectile still get stuck into a high speed archery target [that foam is TOUGH!]Did you machine the steel yourself, or did you get it ordered from somewhere? Ive looked in Home depot and Lowes, and no-one carries steel bars, do you have an idea of where I can buy a couple of bars from?
Re: Finished Coilgun
rupidust, Sat Apr 01 2006, 03:17AM
Did you ask or looked? Because of you asked and they said no, then those are some weird Home Depots and Lowes you went to. The rods are next to the sheet metal section. They got tons of rods: round, square, hollowed walls, U-shapes, L-shapes, steel, aluminum, and all from 1/8 to 2 inches. Well thats what the stores in Southern California sport anyway. RC, airplane hobby shops carry a goo supply themselvse, there is called music wire.
rupidust, Sat Apr 01 2006, 03:17AM
Did you ask or looked? Because of you asked and they said no, then those are some weird Home Depots and Lowes you went to. The rods are next to the sheet metal section. They got tons of rods: round, square, hollowed walls, U-shapes, L-shapes, steel, aluminum, and all from 1/8 to 2 inches. Well thats what the stores in Southern California sport anyway. RC, airplane hobby shops carry a goo supply themselvse, there is called music wire.
Re: Finished Coilgun
Remus, Mon Apr 03 2006, 09:00PM
sheet metal? I dont think we have that in our store here, but I go find out again. I went through the whole store...
But yes, i agree, I may have missed it, since I didnt ask.
Remus, Mon Apr 03 2006, 09:00PM
sheet metal? I dont think we have that in our store here, but I go find out again. I went through the whole store...
But yes, i agree, I may have missed it, since I didnt ask.Re: Finished Coilgun
Quantum Singularity, Tue Apr 04 2006, 02:00AM
At Lowes here steel is in the "hardware" section, like were bolts and nails are found. There should be a rack with rods, tubes, flat, and angle steel, along with aluminum too. Its usually called cold or hot rolled steel. There is usually another rack with sheetmetal pieces too nearby. If they dont happen to have this then they have to have bolts atleast. Just find the right diameter bolt that is long enough that when you cut off the threaded part you are left with a smooth steel rod. I believe several bolts are available that the threading only goes part way down the bolt, look at carrage bolts or machine bolts, not sure what other names to look for.
Quantum Singularity, Tue Apr 04 2006, 02:00AM
At Lowes here steel is in the "hardware" section, like were bolts and nails are found. There should be a rack with rods, tubes, flat, and angle steel, along with aluminum too. Its usually called cold or hot rolled steel. There is usually another rack with sheetmetal pieces too nearby. If they dont happen to have this then they have to have bolts atleast. Just find the right diameter bolt that is long enough that when you cut off the threaded part you are left with a smooth steel rod. I believe several bolts are available that the threading only goes part way down the bolt, look at carrage bolts or machine bolts, not sure what other names to look for.
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