Thanks Mark, That’s a good starting point.

Steve, I recommend doing some careful testing, maybe at lower voltages before you go far with this design.
Holding force in both permanent and electro-magnets drops off very fast at first. When magnets are touching, the distance is near zero. That makes the force very high.
That 550 pounds may be only 50 pounds after the first inch. The square function for distance is easier to calculate
after that first big drop. Maybe try puting the magnet on the ground and hanging one of the electro-magnets well above it.
Keep all body parts well away from the action and slowly lower the electro-magnet until the permanent magnet leaps up to meet it.
Measuring the weight of the permanent magnet and the distance it leaps should give you a good starting point for your calculations.

Thanks Charlie, the support is appreciated. I’m picking up supplies this week and starting construction.

Steve, welcome to EN. This sounds so interesting. Hope it flies soon:)
Were Tesla and other notibles careful? Instead of being careful, just don’t be afraid. Enjoy it… do it! God bless and as Patricia said God speed. It’s time for this one. Get em Brother

Jim, Thank you for your help and the web site. I’m going to check out the site.

Harlan, I’ve planned to cushion the permanent magnet for concern of it shattering on impact. They can be surprisingly brittle and after talking to one of the manufactureres, I’m confident we can work out a way to protect the magnet from both shattering and from the poles being disturbed. Thank you for the input.

Patricia, Thank you for the support. I’ll try to keep you in the loop as I start testing.

Steve, if you are into electromagnets and similar things, check out ‘Pulsed Power Technology’ (Google or Bing). It will get you started in a zany world of railguns, z-pinch machines, can-crushers, coin-shrinking, and my favorite, Lichtenberg Figures. There’s also the Explosive Magnetic Flux Compressor that I think they make Electromagnetic (EM) Pulse Bombs with to fry the electronics in enemy radar (then they send in the real bombs!) Pulsed Power simply involves storing electric energy over a long period of time, usually in a high-voltage, high-energy capacitor, and then discharging it over a matter of microseconds to get almost unimaginable electric current levels (see especially the Z-pinch machine!) People that work in this field are definitely bold, brave, and extremely crazy!

Steve, just a short note to show how nosey I am. I worked on a project sevral years ago involving moving perminent amgnets. I found after several times they began to weaken fast. It finally came out that I needed a “cushion” to sop them at the end of each move. They were stricking a solid stop and this disturbed the polarity. This may not have anything to do with what you need, but I thought I would put in my 1/2 cents worth.

Steve sounds like you have a pretty big project up your sleeve … While I can’t offer any technical advice, the guys have superbly addressed your needs but what I can do is offer support and praise for your extremely fascinating endeavor … Please be safe, wear your goggles and don’t get burndt…. Haha ….. God Speed !!!

Steve, you’re correct in trying to derive the kinetic energy, which is 1/2mv^^2, at the moment of impact. The kinetic energy is the total amount of work done to accelerate the magnetic piston with its given mass to a final velocity at impact. Since work equals force acting through a distance, a solution may possibly be found by integrating over a given distance the two equations of magnetic attraction and repulsion as the piston moves from one end of the cylinder to the other, and where the forces involved are each equal to the magnitude of the magnetic fields multiplied together, divided by the distance (between the magnets) squared. As the repelling force decreases, the attracting force increases. My guess, however, is that frictional losses and air resistance will cause the piston to stop somewhere in the middle of the long cylinder before the attractive force between the end electromagnet and the piston can work to offset those losses. In any case, the kinetic energy determines the amount of work done by the piston if it does strike the end of the cylinder and you apparently want to know if the magnitude of the work done by the piston is great enough to destroy the end of the cylinder. Like Kelce stated, you will most likely have to build and try it to know for certain what will happen, but be careful by all means!

Greg, yes it is non-conductive as well, but thank you for the advice, I’ll make sure to double check conductivity.

Ralph. Never even considered perpetual motion, so no worries. I’m working toward an end goal of transfering the resulting kenetic energy. It’m concerned about the potential of the device to self-destruct on a dry fire, so I will be careful. Thanks.

… 2000 lbs of holding force is pretty darn strong! You might end up with a ‘Rail Gun’ if that velocity is fast enough. Take precautions! I hope this isn’t capacitive discharge perpetual motion tube… Perpetual motion devices are deemed ‘off limits’ … At least by the USPTO they are. : )

Good luck and be safe!

I notice you said non-magnetic on the tube. Hopefully you are going non-conductive, too, or eddy currents may get you some unexpected results.

http://en.wikipedia.org/wiki/Eddy_current

Thanks Kelce, I’ll keep working on it. I may jut build the prototype and see what happens.

You’re likely going to have considerable difficulty with the math.

Velocity is an integral of acceleration: v(T) = integrate(t=0 to t=T | a(t)dt). The standard physics equation v= (1/2)at^2 assumes constant acceleration. Fortunately, the F=ma equation should hold to relate acceleration to the magnetic force and the weight of the magnet. But it will be a small consolation.

Because the forces on your permanent magnet will be an inverse function of distance squared, and the distance will change with time, you will have a situation in which all of the elements are intractably coupled. Velocity is an integral function of acceleration and time. Acceleration is a function of magnetic force and mass of the magnet. Magnetic force is a function of the magnet strength and distance. Distance is a function of acceleration and time.

Good luck!