Lateral Induction Launcher
FastMHz, Tue May 30 2006, 05:45PMAlright guys and gals, I'm up to no good again. This time I'm going to do as was suggested in an earler thread and build a lateral induction launcher. Now I saw this NGC docu on electromagnetic induction launched roller coasters and it inspired me
They have two coils facing each other and aluminum between them...when pulsed, the aluminum moves sideways instead of straight up, thus pushing the coaster forward.My question: how are these wired? Should the coils be wired to push apart? I hope so, cause if they must pull I know the coil would pull right off the wood block and be destroyed. Second, how do I know what direction the thing will fly in??
Re: Lateral Induction Launcher
Grant, Tue May 30 2006, 06:43PM
I'd imagine there is a wealth of information on the subject to be found at the link below.
Grant, Tue May 30 2006, 06:43PM
I'd imagine there is a wealth of information on the subject to be found at the link below.
Re: Lateral Induction Launcher
FastMHz, Tue May 30 2006, 06:57PM
Yes, I saw that thread but need clarification.
Chris says "The gun works by energizing a closely spaced pair (or pairs, in this multistage gun) of pancake coils wired so that their magnetic fields combine without the presense of the projectile. With the disc-like projectile between the coils however, a field of opposite polarity to both coils is induced in it, and the projectile is forced out. So the part of the coils with the projectile between repel the projectile and hence each other, and the field "reconnects" behind the projectile as is passes out, the coils attract here. "
I want to be absolutely sure of how to wire these things so I don't destroy my hard to make coils. So when he says "their magnetic fields combine without the presense of the projectile.", what does he mean, exactly? Should the coils actually attract each other when no projectile is present, or should they be repelling?
FastMHz, Tue May 30 2006, 06:57PM
Yes, I saw that thread but need clarification.
Chris says "The gun works by energizing a closely spaced pair (or pairs, in this multistage gun) of pancake coils wired so that their magnetic fields combine without the presense of the projectile. With the disc-like projectile between the coils however, a field of opposite polarity to both coils is induced in it, and the projectile is forced out. So the part of the coils with the projectile between repel the projectile and hence each other, and the field "reconnects" behind the projectile as is passes out, the coils attract here. "
I want to be absolutely sure of how to wire these things so I don't destroy my hard to make coils. So when he says "their magnetic fields combine without the presense of the projectile.", what does he mean, exactly? Should the coils actually attract each other when no projectile is present, or should they be repelling?
Re: Lateral Induction Launcher
Plasmaniac, Tue May 30 2006, 07:07PM
I think it means they are attracted by each other. The field woldnt combine if they push themself apart.
I think the shoting direction is you tinyest problem. Just try a shoot at let's say 50J and you'll see where it goes :)
Plasmaniac, Tue May 30 2006, 07:07PM
I think it means they are attracted by each other. The field woldnt combine if they push themself apart.
I think the shoting direction is you tinyest problem. Just try a shoot at let's say 50J and you'll see where it goes :)
Re: Lateral Induction Launcher
FastMHz, Tue May 30 2006, 07:11PM
ok, that makes sense...so I should never fire it without a projectile or my coils will suck into each other and be destroyed...well the coils epoxy is curing at this moment and won't be fully cured until tomorrow, so I won't be able to test anything until then. Thanks for the info everyone!
Did Chris ever finish his project?
FastMHz, Tue May 30 2006, 07:11PM
ok, that makes sense...so I should never fire it without a projectile or my coils will suck into each other and be destroyed...well the coils epoxy is curing at this moment and won't be fully cured until tomorrow, so I won't be able to test anything until then. Thanks for the info everyone!
Did Chris ever finish his project?
Re: Lateral Induction Launcher
Plasmaniac, Tue May 30 2006, 07:31PM
The aluminium wont erase the attraction completely. Also it wont do this when it's allready pushed out of the coils. I'd really worry about it, especially if you have a couple of kJ in your capbank.
Try low energys first and dont forget to tape up everything
Plasmaniac, Tue May 30 2006, 07:31PM
The aluminium wont erase the attraction completely. Also it wont do this when it's allready pushed out of the coils. I'd really worry about it, especially if you have a couple of kJ in your capbank.
Try low energys first and dont forget to tape up everything
Re: Lateral Induction Launcher
Electroholic, Tue May 30 2006, 08:16PM
As to which way it shoots, it depends on where you put the projectile relative to the coils.
Just like normal induction launcher, Coils Behind the Projectiles.
Electroholic, Tue May 30 2006, 08:16PM
As to which way it shoots, it depends on where you put the projectile relative to the coils.
Just like normal induction launcher, Coils Behind the Projectiles.
Re: Lateral Induction Launcher
FastMHz, Tue May 30 2006, 08:20PM
I'm beginning to think I might need to engineer something a bit more sophisticated just to keep the contraption in one piece...Chris used fiberglass on both sides of his coils to hold them in place...I don't have access to that, but I do have steel which I could use as the "barrel"...the steel would keep the coils from going at each other, and on the outside I'd use hardboard or something non-ferrous and non-conductive. I know there will be tremendous forces on this thing just from experience with my ring launchers...so yeah I'll have to fire at incrementally higher voltages and keep my fingers crossed.
FastMHz, Tue May 30 2006, 08:20PM
I'm beginning to think I might need to engineer something a bit more sophisticated just to keep the contraption in one piece...Chris used fiberglass on both sides of his coils to hold them in place...I don't have access to that, but I do have steel which I could use as the "barrel"...the steel would keep the coils from going at each other, and on the outside I'd use hardboard or something non-ferrous and non-conductive. I know there will be tremendous forces on this thing just from experience with my ring launchers...so yeah I'll have to fire at incrementally higher voltages and keep my fingers crossed.
Re: Lateral Induction Launcher
Quantum Singularity, Tue May 30 2006, 09:50PM
Looks like your gonna beat me to this one
.... lol.
One of the first things I wanted to try once I get all my parts together is a lateral disk launcher. I got a handheld design on paper that would be roughly equivelent to the Ripper (disk launcher) in Unreal Tournament (computer game). Although judging by that post on the old forum I think mine might be of slightly different design. How many field coils do you plan on using in this launcher? The way I understand it is you have two archimedean sprial coils on top of each other, very much like your parallel arranngment you have, but the coils are spaced slightly and an aluminum (or similar) disk is placed between them, slightly offset from center. The direction of travel would be in the direction the disk is offset from center. I could be wrong as I have not read a lot of info on this, nor done much research here on 4hv. I will have to read that one post above more since I only read the first page and dont have any time right now. In my design I plan on building almost the entire thing out of polycarbonate. Although 1/8" might not be strong enough well se what happens. I dont mind blowing stuff up and I have a lot of it to spare. And I can always rebuild it thicker, but I want to start out with the disk closest to the coil as I can get for efficiency. Good luck on your project.
Quantum Singularity, Tue May 30 2006, 09:50PM
Looks like your gonna beat me to this one
.... lol. One of the first things I wanted to try once I get all my parts together is a lateral disk launcher. I got a handheld design on paper that would be roughly equivelent to the Ripper (disk launcher) in Unreal Tournament (computer game). Although judging by that post on the old forum I think mine might be of slightly different design. How many field coils do you plan on using in this launcher? The way I understand it is you have two archimedean sprial coils on top of each other, very much like your parallel arranngment you have, but the coils are spaced slightly and an aluminum (or similar) disk is placed between them, slightly offset from center. The direction of travel would be in the direction the disk is offset from center. I could be wrong as I have not read a lot of info on this, nor done much research here on 4hv. I will have to read that one post above more since I only read the first page and dont have any time right now. In my design I plan on building almost the entire thing out of polycarbonate. Although 1/8" might not be strong enough well se what happens. I dont mind blowing stuff up and I have a lot of it to spare. And I can always rebuild it thicker, but I want to start out with the disk closest to the coil as I can get for efficiency. Good luck on your project.
Re: Lateral Induction Launcher
FastMHz, Tue May 30 2006, 10:29PM
Thanks Tristan! Yeah this is uncharted territory for me as well. I intend to use just two coils, and I'm going to fire all 3.5kj into the two in one shot. I don't have the components nor spare time to deal with a multistage launcher, so I'm going for simple yet powerful. If this thing has output power or efficiency anywhere near that of my others, I'll be in heaven. The only thing making it different than the one in UT is it's not spinning, though I've thought of ways to make that happen too...frisbee of death or something like that. To spin the disc I would use a little blob of adhesive to hold a center bearing between the coils, and use a friction drive motor to spin the disc via the outside of the ring...so it should be spinning, and upon firing the coils, the glue gives away and the spinning disc of death goes flying
But that's later...first I need to make it work without spinning...
Polycarbonate...that would be nice, but it would need to be thick I think. I wonder what the Gs are on the ring when it takes off? I'd imagine the force on the plastic would be tremendous...I tend to gravitate towards wood since it's cheap and pretty strong, but I've split a few 2x4s just absorbing the recoil already.
FastMHz, Tue May 30 2006, 10:29PM
Thanks Tristan! Yeah this is uncharted territory for me as well. I intend to use just two coils, and I'm going to fire all 3.5kj into the two in one shot. I don't have the components nor spare time to deal with a multistage launcher, so I'm going for simple yet powerful. If this thing has output power or efficiency anywhere near that of my others, I'll be in heaven. The only thing making it different than the one in UT is it's not spinning, though I've thought of ways to make that happen too...frisbee of death or something like that. To spin the disc I would use a little blob of adhesive to hold a center bearing between the coils, and use a friction drive motor to spin the disc via the outside of the ring...so it should be spinning, and upon firing the coils, the glue gives away and the spinning disc of death goes flying
But that's later...first I need to make it work without spinning...Polycarbonate...that would be nice, but it would need to be thick I think. I wonder what the Gs are on the ring when it takes off? I'd imagine the force on the plastic would be tremendous...I tend to gravitate towards wood since it's cheap and pretty strong, but I've split a few 2x4s just absorbing the recoil already.
Re: Lateral Induction Launcher
Chris, Wed May 31 2006, 01:17AM
Sort of. I have fired it several times, but never at full power, and I got bored and started to work on other things before ever firing the second stage. There are plenty of construction pics here if this helps. Also there are some documents out there on a similar device built by Sandia Labs.
You'd better slot that, or you will have constructed little more than a pulsed induction heater. You're probably better off supporting the coils from behind anyway, for example my coils were designed to withstand something like 10 tons of attractive force, the extrapolated peak force when fired at full power. You'll be hard pressed to support that with any reasonably thin material in between. Maybe you could try some sort of ferrous core structure that surrounds a coil of any shape, like some kind of large bobbin.
Chris, Wed May 31 2006, 01:17AM
Did Chris ever finish his project?
Sort of. I have fired it several times, but never at full power, and I got bored and started to work on other things before ever firing the second stage. There are plenty of construction pics here
if this helps. Also there are some documents out there on a similar device built by Sandia Labs. but I do have steel which I could use as the "barrel"
You'd better slot that, or you will have constructed little more than a pulsed induction heater. You're probably better off supporting the coils from behind anyway, for example my coils were designed to withstand something like 10 tons of attractive force, the extrapolated peak force when fired at full power. You'll be hard pressed to support that with any reasonably thin material in between. Maybe you could try some sort of ferrous core structure that surrounds a coil of any shape, like some kind of large bobbin.
Re: Lateral Induction Launcher
FastMHz, Wed May 31 2006, 01:59AM
I love the hi-res pics! You have a well designed unit there...don't know how anyone could get bored with that Looks like your platters were being destroyed...maybe too much energy? Mine is only 3.5kj so nowhere near as powerful...
FastMHz, Wed May 31 2006, 01:59AM
I love the hi-res pics! You have a well designed unit there...don't know how anyone could get bored with that
Looks like your platters were being destroyed...maybe too much energy? Mine is only 3.5kj so nowhere near as powerful...Re: Lateral Induction Launcher
Quantum Singularity, Wed May 31 2006, 02:02AM
Chris... wow it looks like you really put some work into that one. So you didnt ever get the 2nd stage working, thats a bummer. When your trying to switch this much power the multi stage idea becomes a bit harder.
One thing I have learned in this thread that I overlooked originally is the attractive force between the coils. That could doom my large scale version. But a smaller 'lytic powered version should be do-able. I guess my maxwells will have to stick to the vertically launched disk. I am curious though as to when this attractive force peaks. I am wondering if it will try to pinch the disk as it exits or assuming maybe the disk exits before peak power is reached, if most of the pinching action will occur after the projectile is clear? If that is the case then perhaps the launcher could be designed with a certain amount of flex to allow the coils to come together the 1/8" or whatever airgap is left after the disk vacates? If allowed to come together, even using 1/8" lexan under each coil will form a 'solid' piece of lexan between the coils 1/4" thick and I havent run the nbumbers but I would assume that should stand up to a few tons of force over a circular area 3.5"-5" in diameter?
I was thinking simpler like designing the 'barrel' to have a grippy material like rubber along one side (just on the very edge) and a smooth polished surface on the other. But like you said, spinning isnt high on the list.
My original idea was: low powered benchtop prototype using laptop hardrive platter (2.5") and a few hundred joules max (lytic) to perform tests and get some data. Then a higher powered 'fieldable' riffle model using maybe a couple kJ worth of lytics and 3.5" or 5" hardrive platters. Once I determined the forces at play with a couple kJ, then to design one using my larger energy discharge caps and either the 5" platter or a custom 1/4" thick aluminum platter. I guess I'll start from the bottom and work up (in terms of size and energy, that is).
Quantum Singularity, Wed May 31 2006, 02:02AM
Chris... wow it looks like you really put some work into that one. So you didnt ever get the 2nd stage working, thats a bummer. When your trying to switch this much power the multi stage idea becomes a bit harder.
One thing I have learned in this thread that I overlooked originally is the attractive force between the coils. That could doom my large scale version. But a smaller 'lytic powered version should be do-able. I guess my maxwells will have to stick to the vertically launched disk. I am curious though as to when this attractive force peaks. I am wondering if it will try to pinch the disk as it exits or assuming maybe the disk exits before peak power is reached, if most of the pinching action will occur after the projectile is clear? If that is the case then perhaps the launcher could be designed with a certain amount of flex to allow the coils to come together the 1/8" or whatever airgap is left after the disk vacates? If allowed to come together, even using 1/8" lexan under each coil will form a 'solid' piece of lexan between the coils 1/4" thick and I havent run the nbumbers but I would assume that should stand up to a few tons of force over a circular area 3.5"-5" in diameter?
To spin the disc I would use a little blob of adhesive to hold a center bearing between the coils, and use a friction drive motor to spin the disc via the outside of the ring...so it should be spinning, and upon firing the coils, the glue gives away and the spinning disc of death goes flying
I was thinking simpler like designing the 'barrel' to have a grippy material like rubber along one side (just on the very edge) and a smooth polished surface on the other. But like you said, spinning isnt high on the list.
My original idea was: low powered benchtop prototype using laptop hardrive platter (2.5") and a few hundred joules max (lytic) to perform tests and get some data. Then a higher powered 'fieldable' riffle model using maybe a couple kJ worth of lytics and 3.5" or 5" hardrive platters. Once I determined the forces at play with a couple kJ, then to design one using my larger energy discharge caps and either the 5" platter or a custom 1/4" thick aluminum platter. I guess I'll start from the bottom and work up (in terms of size and energy, that is).
Re: Lateral Induction Launcher
Wilson, Wed May 31 2006, 04:37AM
hehe ^^ this is all very interesting indeed.
All the best of luck quantum singularity.
btw, i might join you soon in doing some induction launcher testing ;)
Almost finished an enclosure for my 2.8kJ lytic bank. Just need to wait for the end of exams before i can do some more tests
Wilson, Wed May 31 2006, 04:37AM
hehe ^^ this is all very interesting indeed.
All the best of luck quantum singularity.
btw, i might join you soon in doing some induction launcher testing ;)
Almost finished an enclosure for my 2.8kJ lytic bank. Just need to wait for the end of exams before i can do some more tests
Re: Lateral Induction Launcher
Plasmaniac, Wed May 31 2006, 12:52PM
Do you use aluminium busbars? I had some problems with aluminium on my 2kJ bank.
Plasmaniac, Wed May 31 2006, 12:52PM
Do you use aluminium busbars? I had some problems with aluminium on my 2kJ bank.
Re: Lateral Induction Launcher
Wilson, Wed May 31 2006, 02:18PM
well i use Al. I've tested it to be OK up to 1kJ. Haven't went higher yet.
Copper would probably be preferrably, since its resistance is like 1/2 that of Al, but Al is just so much cheaper...
Wilson, Wed May 31 2006, 02:18PM
well i use Al. I've tested it to be OK up to 1kJ. Haven't went higher yet.
Copper would probably be preferrably, since its resistance is like 1/2 that of Al, but Al is just so much cheaper...
Re: Lateral Induction Launcher
FastMHz, Fri Jun 02 2006, 05:36PM
I just finished my prototype and it works rather well. Starting position of the disc seems to be critical. I'm certainly not getting anywhere near the output power I was with my standard ILs, some of that is due to the disc being 1/4" away from the coil instead of right against it. I'll do some chrono tests in a bit.
FastMHz, Fri Jun 02 2006, 05:36PM
I just finished my prototype and it works rather well. Starting position of the disc seems to be critical. I'm certainly not getting anywhere near the output power I was with my standard ILs, some of that is due to the disc being 1/4" away from the coil instead of right against it. I'll do some chrono tests in a bit.
Re: Lateral Induction Launcher
Maz, Sat Jun 03 2006, 01:52AM
Looks good!, do you think there would be much of a benifit to making the coils closer to the disk?
Maz, Sat Jun 03 2006, 01:52AM
Looks good!, do you think there would be much of a benifit to making the coils closer to the disk?
Re: Lateral Induction Launcher
Wilson, Sat Jun 03 2006, 04:14AM
wow, looking good. Any construction details? It looked like epoxy and wood to me.
Wilson, Sat Jun 03 2006, 04:14AM
wow, looking good. Any construction details? It looked like epoxy and wood to me.
Re: Lateral Induction Launcher
FastMHz, Sat Jun 03 2006, 05:46PM
Bad news - one of the coils got destroyed when I fired it at 3.5kj. The attractive force just sucked the copper right off the epoxy & wood block...
I'm sure it would work much better without the gap, but I don't have a material thin enough that can withstand the force...seem's my 1/4" hardboard flexed too much and allowed the one coil to destroy itself. I will probably abandon this prototype as I see no future for it if I can't fire it at full power. Time for a new design that I have the material to actually make...
I do know that the disc came out with enough force to seriously injure a person standing in the way, but I have no idea what the energy output really was.
This version was made of MDF, hardboard and plywood. The materals weren't damaged, but they flexed too much.
FastMHz, Sat Jun 03 2006, 05:46PM
Bad news - one of the coils got destroyed when I fired it at 3.5kj. The attractive force just sucked the copper right off the epoxy & wood block...
I'm sure it would work much better without the gap, but I don't have a material thin enough that can withstand the force...seem's my 1/4" hardboard flexed too much and allowed the one coil to destroy itself. I will probably abandon this prototype as I see no future for it if I can't fire it at full power. Time for a new design that I have the material to actually make...
I do know that the disc came out with enough force to seriously injure a person standing in the way, but I have no idea what the energy output really was.
This version was made of MDF, hardboard and plywood. The materals weren't damaged, but they flexed too much.
Re: Lateral Induction Launcher
..., Sat Jun 03 2006, 05:57PM
couldn't you use some fiberglass cloth? They sell the woven kind in the autobody department of autoshops and home improvment stores... Seems like a layer or 2 of that on both sides shoud hold up pretty well...
..., Sat Jun 03 2006, 05:57PM
couldn't you use some fiberglass cloth? They sell the woven kind in the autobody department of autoshops and home improvment stores... Seems like a layer or 2 of that on both sides shoud hold up pretty well...
Re: Lateral Induction Launcher
Maz, Sat Jun 03 2006, 07:51PM
I can see fiberglass flexing just as much if not more than mdf. the only thing I can think of for this to work is like 1" thick polycarb with space machined out for the coils. Could you add a steel or iron plate to the outside of the coils, so that it may condense the flux to the interior?
Maz, Sat Jun 03 2006, 07:51PM
I can see fiberglass flexing just as much if not more than mdf. the only thing I can think of for this to work is like 1" thick polycarb with space machined out for the coils. Could you add a steel or iron plate to the outside of the coils, so that it may condense the flux to the interior?
Re: Lateral Induction Launcher
Electroholic, Sun Jun 04 2006, 02:08AM
How about this, make the coils a lil bigger(dia), use steel plates between the coils(might want to slot them), then put a piece of U shape support in it on the edge. as long as the the support dont' concentrate the flux, it should shoot fine.
Might loose eff. due to poor coupling tho...
Electroholic, Sun Jun 04 2006, 02:08AM
How about this, make the coils a lil bigger(dia), use steel plates between the coils(might want to slot them), then put a piece of U shape support in it on the edge. as long as the the support dont' concentrate the flux, it should shoot fine.
Might loose eff. due to poor coupling tho...
Re: Lateral Induction Launcher
FastMHz, Wed Jun 07 2006, 08:18PM
Well here's a pic of the destroyed coil...it deformed or I'd just glue the coils back down to the wood:
FastMHz, Wed Jun 07 2006, 08:18PM
Well here's a pic of the destroyed coil...it deformed or I'd just glue the coils back down to the wood:
Re: Lateral Induction Launcher
Wilson, Thu Jun 08 2006, 06:28AM
What about weaving the coils through some fibreglass cloth and then impregnating the whole thing with lots of CA glue?
Wilson, Thu Jun 08 2006, 06:28AM
What about weaving the coils through some fibreglass cloth and then impregnating the whole thing with lots of CA glue?
Re: Lateral Induction Launcher
Electroholic, Thu Jun 08 2006, 02:54PM
CA glue need OH- to dry/harden....blahblahblah
so a big chunk won't harden like resin/2part epoxy.
Electroholic, Thu Jun 08 2006, 02:54PM
CA glue need OH- to dry/harden....blahblahblah
so a big chunk won't harden like resin/2part epoxy.
Re: Lateral Induction Launcher
FastMHz, Thu Jun 08 2006, 05:39PM
I like the fiberglass idea...since I'm already using epoxy it wouldn't be a big change and would probably add a lot of strength...now where can I get some? Home Depot doesn't have any, though they did at one time.
FastMHz, Thu Jun 08 2006, 05:39PM
I like the fiberglass idea...since I'm already using epoxy it wouldn't be a big change and would probably add a lot of strength...now where can I get some? Home Depot doesn't have any, though they did at one time.
Re: Lateral Induction Launcher
Electroholic, Thu Jun 08 2006, 08:19PM
try body shops, CAR body shops.
there are hobby shops online selling all kinds of fibers,
even kevlar.
Electroholic, Thu Jun 08 2006, 08:19PM
try body shops, CAR body shops.
there are hobby shops online selling all kinds of fibers,
even kevlar.
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