Induction AL coin launcher Help
ljfa321, Sun Feb 26 2012, 01:38AMHi,
I'm working on a AL coin or AL disc flipper kind of design I found a while ago.
Here is the video:
Instead of working like a gun, this just simply flip the coin into the air, and that is all I need.
From the video, it looks like only one disposable camera capacitor was used.
However I was not able to reproduce the result with the same setup (base on what I see in the video since the video is lack of some detail).
Assume he just use the camera as what normally do in a simple coil gun, than the only part I'm not sure about my setup will be my coil.
I'm have tried few coil design; flat one layer disc coil, coil with metal center, and even try to wind the coil messy like in the video.
Can anyone give me a hand here on what I might did wrong? And what's the best way to wind the coil to enable it to flip the AL disc (2cm Diameter, 1g, hopefully can lift up to 10g) high? ( I'm using 22, 26, or 30 gauge magnetic wire, will thicker the better? )
Also, will it help if I use washer type AL disc (with hole in the middle)?
Any help will be appreciated.
Thanks,
Jason
Re: Induction AL coin launcher Help
Turkey9, Sun Feb 26 2012, 04:43AM
There's no way he just used one camera battery for that much energy. Most likely it was a bank of five or ten.
Turkey9, Sun Feb 26 2012, 04:43AM
There's no way he just used one camera battery for that much energy. Most likely it was a bank of five or ten.
Re: Induction AL coin launcher Help
Legit_bacon, Sun Feb 26 2012, 05:38AM
from my experience with washer launchers you should use about ~20 turns of the size of your washer with a hole in the middle
Legit_bacon, Sun Feb 26 2012, 05:38AM
from my experience with washer launchers you should use about ~20 turns of the size of your washer with a hole in the middle
Re: Induction AL coin launcher Help
ljfa321, Sun Feb 26 2012, 10:25AM
I'm guessing because Japanese dollar coin is super light, only around 1g.
But more capacitor works for me.
ljfa321, Sun Feb 26 2012, 10:25AM
Turkey9 wrote ...
There's no way he just used one camera battery for that much energy. Most likely it was a bank of five or ten.
There's no way he just used one camera battery for that much energy. Most likely it was a bank of five or ten.
I'm guessing because Japanese dollar coin is super light, only around 1g.
But more capacitor works for me.
Re: Induction AL coin launcher Help
ljfa321, Sun Feb 26 2012, 10:28AM
How about using magnet as projectile?
Is there any setup that can send magnet fly in the air?
Will try to make a simple electromagnet tomorrow and see if I can flip a magnet into the air.
ljfa321, Sun Feb 26 2012, 10:28AM
How about using magnet as projectile?
Is there any setup that can send magnet fly in the air?
Will try to make a simple electromagnet tomorrow and see if I can flip a magnet into the air.
Re: Induction AL coin launcher Help
pauleddy, Mon Feb 27 2012, 12:37AM
i have made somthing similar to this it in this post from a wile back
pauleddy, Mon Feb 27 2012, 12:37AM
i have made somthing similar to this it in this post from a wile back
pauleddy wrote ...
ok here is a short video i made, ther is a big magnet, the veiwing film and disk lanching sorry for the lack of sound i was tired and did'nt feel like narrating.
here is a few pics of the guts of it the large switch is to use the terminals on the side.
here is the coil, it did look better when i had a clear CD over it but that brook off so duct tape will do
ok here is a short video i made, ther is a big magnet, the veiwing film and disk lanching sorry for the lack of sound i was tired and did'nt feel like narrating.
here is a few pics of the guts of it the large switch is to use the terminals on the side.
here is the coil, it did look better when i had a clear CD over it but that brook off so duct tape will do
Re: Induction AL coin launcher Help
ljfa321, Mon Feb 27 2012, 06:23AM
Thanks, thats exactly what I want to make, can you tell me what gauge wire are you using, how many layer in the coil, and how many volt in total?
Thank
ljfa321, Mon Feb 27 2012, 06:23AM
pauleddy wrote ...
i have made somthing similar to this it in this post from a wile back...........
i have made somthing similar to this it in this post from a wile back...........
Thanks, thats exactly what I want to make, can you tell me what gauge wire are you using, how many layer in the coil, and how many volt in total?
Thank
Re: Induction AL coin launcher Help
ben5017, Mon Feb 27 2012, 11:22PM
does the ring have to be AL? what would happen with a ferris matl.
ben5017, Mon Feb 27 2012, 11:22PM
does the ring have to be AL? what would happen with a ferris matl.
Re: Induction AL coin launcher Help
pauleddy, Tue Feb 28 2012, 12:21AM
that little metal ring is AL but it was just a spacer, umm i don't know if a iron metals will help vary much the pulse time is too quick i think. most non-ferris metals will lanch but AL and CU work the best, the gauge is i think is about 12 or 14??? i will have to check, voltage is what ever the disposible camra chager puts out i think 300-400V, the coil is 2 layers 20 each so about 40 turns. this was a demo device i bult for a science project back in high school that i used a bigger varible disk lancher.
pauleddy, Tue Feb 28 2012, 12:21AM
that little metal ring is AL but it was just a spacer, umm i don't know if a iron metals will help vary much the pulse time is too quick i think. most non-ferris metals will lanch but AL and CU work the best, the gauge is i think is about 12 or 14??? i will have to check, voltage is what ever the disposible camra chager puts out i think 300-400V, the coil is 2 layers 20 each so about 40 turns. this was a demo device i bult for a science project back in high school that i used a bigger varible disk lancher.
Re: Induction AL coin launcher Help
ljfa321, Tue Feb 28 2012, 05:42AM
OK, thank a lot!
ljfa321, Tue Feb 28 2012, 05:42AM
OK, thank a lot!
Re: Induction AL coin launcher Help
Forty, Tue Feb 28 2012, 05:16PM
I think gluing any conductive ring in the center of the coil is gonna rob a lot of your energy. You're using eddy currents to repel the projectile but you've essentially got a second projectile "in series" with it but fixed in place. (i understand you were only using it as a spacer)
If you want to try out flux concentrating materials with the coil I'd make sure they were non conductive or at least highly resistive (like powdered iron or ferrite) so that you don't generate a bunch of eddy currents in them as well.
A magnet might work fine as a projectile because the pulse is fast enough that it might not be flipped over. i imagine it might shoot off at an angle though if it begins to flip. neodymium earth magnets tend to shatter when they hit stuff too, so be careful of that.
Another neat thing to try out with the small scale induction launcher would be making a reconnection coilgun
that's something i've been meaning to try out myself.
Forty, Tue Feb 28 2012, 05:16PM
I think gluing any conductive ring in the center of the coil is gonna rob a lot of your energy. You're using eddy currents to repel the projectile but you've essentially got a second projectile "in series" with it but fixed in place. (i understand you were only using it as a spacer)
If you want to try out flux concentrating materials with the coil I'd make sure they were non conductive or at least highly resistive (like powdered iron or ferrite) so that you don't generate a bunch of eddy currents in them as well.
A magnet might work fine as a projectile because the pulse is fast enough that it might not be flipped over. i imagine it might shoot off at an angle though if it begins to flip. neodymium earth magnets tend to shatter when they hit stuff too, so be careful of that.
Another neat thing to try out with the small scale induction launcher would be making a reconnection coilgun
that's something i've been meaning to try out myself.
Re: Induction AL coin launcher Help
pauleddy, Wed Feb 29 2012, 02:28AM
well this thing has quit a kick, it will lanch my little AL disk clear across a room and make dents in my ceiling from the floor so i dont think that it will make that much of a differance. i might try putting a a ferrite in the middle, but the object of the pancake coil is to have the flux spread out over the the disk for uniform force, you can see the how the field looks from the short video i made in the link with the pics.
pauleddy, Wed Feb 29 2012, 02:28AM
well this thing has quit a kick, it will lanch my little AL disk clear across a room and make dents in my ceiling from the floor so i dont think that it will make that much of a differance. i might try putting a a ferrite in the middle, but the object of the pancake coil is to have the flux spread out over the the disk for uniform force, you can see the how the field looks from the short video i made in the link with the pics.
Re: Induction AL coin launcher Help
Forty, Wed Feb 29 2012, 03:14AM
Yea I'm sure it still works just fine with the Al ring in there, I was just clarifying for Ben that Al in the flux path isn't necessary and would probably use up energy. It's impressive how much of a kick you can get out of just a few camera capacitors isn't it? I recently had several small SCRs that I thought I broke so i made up a test circuit for them. To make the testing more fun I discharged a 450uf 350v camera cap into a little coil to launch stuff. Turned out that only 1 out of 7 of them were broken.
Anyways, to be more on topic: for such a small scale induction launcher, you could probably use up to 20awg wire for the coil (to answer ljfa321's question) because the energy levels are pretty small (<100J), the repetition rate is low (limited by charging speed) and your projectile is small so your coil area should be small.
since you've got the camera parts already, you could use the flash tube as a triggered spark gap. just find the connections where the camera flash was originally triggered and use them for your fire switch. when closed the switch will send a signal to a small pulse transformer, which sends hv to the outside of the xenon bulb and ionizes the gas inside, allowing the capacitor to discharge through the bulb. your coil would go in series with the bulb. surround the bulb with something to cover up the flash and shield it in case it pops.
Forty, Wed Feb 29 2012, 03:14AM
Yea I'm sure it still works just fine with the Al ring in there, I was just clarifying for Ben that Al in the flux path isn't necessary and would probably use up energy. It's impressive how much of a kick you can get out of just a few camera capacitors isn't it? I recently had several small SCRs that I thought I broke so i made up a test circuit for them. To make the testing more fun I discharged a 450uf 350v camera cap into a little coil to launch stuff. Turned out that only 1 out of 7 of them were broken.
Anyways, to be more on topic: for such a small scale induction launcher, you could probably use up to 20awg wire for the coil (to answer ljfa321's question) because the energy levels are pretty small (<100J), the repetition rate is low (limited by charging speed) and your projectile is small so your coil area should be small.
since you've got the camera parts already, you could use the flash tube as a triggered spark gap. just find the connections where the camera flash was originally triggered and use them for your fire switch. when closed the switch will send a signal to a small pulse transformer, which sends hv to the outside of the xenon bulb and ionizes the gas inside, allowing the capacitor to discharge through the bulb. your coil would go in series with the bulb. surround the bulb with something to cover up the flash and shield it in case it pops.
Re: Induction AL coin launcher Help
klugesmith, Wed Feb 29 2012, 04:37AM
Forty: how about leaving the flashlamp exposed, where it can illuminate the projectile?
When you fire the launcher in the dark, it will be evident how far the projectile moves while current flows in the coil.
I expect the coil inductance will reduce the peak current and increase the pulse duration, compared to the coil-less flash with extra capacitors. You could substitute a larger flashlamp to safely switch the circuit with extra capacitors.
klugesmith, Wed Feb 29 2012, 04:37AM
Forty: how about leaving the flashlamp exposed, where it can illuminate the projectile?
When you fire the launcher in the dark, it will be evident how far the projectile moves while current flows in the coil.
I expect the coil inductance will reduce the peak current and increase the pulse duration, compared to the coil-less flash with extra capacitors. You could substitute a larger flashlamp to safely switch the circuit with extra capacitors.
Re: Induction AL coin launcher Help
ljfa321, Thu Mar 01 2012, 06:33AM
Thanks, I end up adding 4 more capacitor into the bank :p
I will go find some thicker wire to make my coil, since the thing wire i'm using right now give out some really weird result and terrible performance.
ljfa321, Thu Mar 01 2012, 06:33AM
Thanks, I end up adding 4 more capacitor into the bank :p
I will go find some thicker wire to make my coil, since the thing wire i'm using right now give out some really weird result and terrible performance.
Re: Induction AL coin launcher Help
ljfa321, Thu Mar 01 2012, 06:48AM
This one I made is made out of 22 gauge wire, but terrible performance.
2mm lift :S
ljfa321, Thu Mar 01 2012, 06:48AM
This one I made is made out of 22 gauge wire, but terrible performance.
2mm lift :S
Re: Induction AL coin launcher Help
ljfa321, Thu Mar 01 2012, 06:53AM
This is a coil I found in my junk yard.
Not sure what is this coil's original use.
32~35 gauge wire.
Probably really high on resistance. (Don't make a spark like the coil I made myself when connect to capacitor)
With one capacitor, 15cm lift.
With five capacitor, 15cm lift.
:S
ljfa321, Thu Mar 01 2012, 06:53AM
This is a coil I found in my junk yard.
Not sure what is this coil's original use.
32~35 gauge wire.
Probably really high on resistance. (Don't make a spark like the coil I made myself when connect to capacitor)
With one capacitor, 15cm lift.
With five capacitor, 15cm lift.
:S
Re: Induction AL coin launcher Help
Forty, Thu Mar 01 2012, 06:16PM
So that nice looking coil with many turns works better than the pancake coil with fewer turns? hmm.
I always thought low inductance coils were better for launchers because of the faster rise time.
The projectile is only near the coil for a couple ms so any current flowing in the coil after that is unnecessary (<- wow, spelled that right the first time)
Well keep trying out coil geometries, it'll be interesting to see what you come up with. The two I've been experimenting with are double layer pancake coils (nice because the leads are on the outside and not one protruding from the center) for launching whatever and heatshrink covered copper strip rolled up into a tight spiral (lots of conductor but little surface area) for use with coins.
@klugesmith that's a very clever idea with the flashlamp! I'd be worried about them exploding though. I originally used the flashlamps as a spark gap switch for a coilgun (so even higher inductance in that case) and they'd progressively melt on the inside until the whole bulb just crumbled. They're definitely a temporary switching device when over powered.
A voltage divider and an LED might accomplish the same illumination idea however. I'm not sure if it would help optimizing the coil/capacitor though. You want the current to peak very quickly so that the projectile is still in range to be affected, but no matter what, the projectile is going to leave the surface of the coil while current is still flowing.
Forty, Thu Mar 01 2012, 06:16PM
So that nice looking coil with many turns works better than the pancake coil with fewer turns? hmm.
I always thought low inductance coils were better for launchers because of the faster rise time.
The projectile is only near the coil for a couple ms so any current flowing in the coil after that is unnecessary (<- wow, spelled that right the first time)
Well keep trying out coil geometries, it'll be interesting to see what you come up with. The two I've been experimenting with are double layer pancake coils (nice because the leads are on the outside and not one protruding from the center) for launching whatever and heatshrink covered copper strip rolled up into a tight spiral (lots of conductor but little surface area) for use with coins.
@klugesmith that's a very clever idea with the flashlamp! I'd be worried about them exploding though. I originally used the flashlamps as a spark gap switch for a coilgun (so even higher inductance in that case) and they'd progressively melt on the inside until the whole bulb just crumbled. They're definitely a temporary switching device when over powered.
A voltage divider and an LED might accomplish the same illumination idea however. I'm not sure if it would help optimizing the coil/capacitor though. You want the current to peak very quickly so that the projectile is still in range to be affected, but no matter what, the projectile is going to leave the surface of the coil while current is still flowing.
Re: Induction AL coin launcher Help
pauleddy, Fri Mar 02 2012, 01:25AM
you need a lower gauge wire, lower the R the smaller your time constant. the pulse must be quick enough to put as much energy into the disk before it leaves the field. less the field it self will drag the disk. basicly you want the EMP there and gone before the disk has had a chance to move. keep your wire short as possible as well. lenth of wire also efect the R. when your rise time is in >ms the smallest resistance will greatly effect your energy transfer from EM to kenetic.
try too keep the resistance below 2 ohms the lower the better. I once made a coil out of ribbon cable, for my lange cap bank, i might have an old video on you tube i think it was my first, here it is, just skip to about 2:00
pauleddy, Fri Mar 02 2012, 01:25AM
you need a lower gauge wire, lower the R the smaller your time constant. the pulse must be quick enough to put as much energy into the disk before it leaves the field. less the field it self will drag the disk. basicly you want the EMP there and gone before the disk has had a chance to move. keep your wire short as possible as well. lenth of wire also efect the R. when your rise time is in >ms the smallest resistance will greatly effect your energy transfer from EM to kenetic.
try too keep the resistance below 2 ohms the lower the better. I once made a coil out of ribbon cable, for my lange cap bank, i might have an old video on you tube i think it was my first, here it is, just skip to about 2:00
Re: Induction AL coin launcher Help
ljfa321, Fri Mar 02 2012, 08:15AM
Thanks pauleddy!
ljfa321, Fri Mar 02 2012, 08:15AM
pauleddy wrote ...
you need a lower gauge wire........
you need a lower gauge wire........
Thanks pauleddy!
Re: Induction AL coin launcher Help
BigBad, Fri Mar 09 2012, 06:28PM
Another thing to check is that the washer must be significantly bigger than the skin depth at the frequency you're driving it with; you obviously WANT the eddy currents(!)
BigBad, Fri Mar 09 2012, 06:28PM
Another thing to check is that the washer must be significantly bigger than the skin depth at the frequency you're driving it with; you obviously WANT the eddy currents(!)
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