Magnetic levitation

Well, the one in the video looks like a solenoid with the plunger removed.

They're rather easy to find, and if you're mechanically inclined at all you'll know where hundreds are!

In cars alone:
Pretty much every emissions / vacuum / boost solenoid to control air/vacuum/boost
Power door lock actuators (some may be gear driven, but most are simple push-pull solenoids)
Air conditioning solenoids (in cars)

You can probably buy 20 of them at a junkyard for under $10 bucks, since it doesn't matter if the housing or nipples are broken off of them.

Any equipment that has the ability to turn on and off, let's say.. water or fluid as well.

A solenoid is an electromagnet wrapped in a metal can, with a hollow tube in the middle. The plunger is a steel shaft that sits in the tube, partially spaced out with a small spring.

When electricity is added, the plunger shaft gets sucked into the can, pulling the linkage it's connected to in with it.

Pull the plunger out, and put a bolt with a nut on one side, as the OP did (at least it looks like).

You can epoxy the hall effect sensor on the head of the bolt through the electromagnet.

Hi ea123, can you post the list of components you used?
thanks.

Very cool! Where did you get the electromagnet?

Hello, I bought the electromagnet and magnetic sphere here:

http://zeltom.com/products/magneticlevitation/emlscomponents

they sell a complete magnetic levitation kit (not based on Arduino) or single components.

Hi,
very cool project!
... but... the code is no more available... (503 error) =(

I have been trying to replicate this but am having some difficulty. I have the circuit nominally working, but I can not get it tweaked to levitate the magnet. Either the magnet drops to the base, or slams into the electromagnet ( I am using the same electromagnet, permanent magnet, and code presented in the OP, the hall sensor might be slightly different as I am using the A1321). It is easy to see that the parameters depend critically on the specific permanent magnet being used, the characteristics of the hall sensor, and the electromagnet.

I have tried different magnets, and different settings without success. In trying to be methodical, I run into the complication that the hall sensor itself picks up the signal from the electromagnet. So, trying to turn the electromagnet off and map hall sensor reading to distance from permanent magnet to electromagnet does not help, because that mapping will be distorted depending on the signal to the electromagnet. Another complication is that the permanent magnet is attracted to the metallic parts of the electromagnet so there is an uncontrolled attractive element that increases as the gap decreases.

Can anyone suggest a methodical approach to tweaking the set point, P-gain, D-gain, and I-gain to get this thing floating? Given that there are 4 parameters, and no real equations to guide, I am sort of at a loss at this point.

Thanks!

We are working on a similar project. Kindly let me know about the specifications of the coil used. We want to levitate a small steel ball of weight 0.3 g. I would like to know the voltage and current applied to the coil. Number of turns used. What core did you use for this ?

Is your code available? If it is there i didn't see it.
Thanks
W

The code is in reply #2

It sure is. Thanks

Hi could you please tell us the value of L1..?

Thank you.!

I'm curious, how stable is this? Has anyone ran it for long periods of time?

Si:
At some point, I will update mine to use a Hall sensor - I still have long term dreams of a planetarium ceiling populated with floating, rotating planets!

However, one power outage and it would be raining celestial bodies!

Not if they were tethered with a 'invisible' safety line attached to the ceiling. That would allow them to drop but not all the way to people level.

Lefty

That would allow them to drop but not all the way to people level.

that could be part of the show :wink:

Would this electromagnet work? http://rover.ebay.com/rover/0/e11401.m1842.l3160/7?euid=4da31cf6c6b447e3a49e34bf2a6a599b&loc=http%3A%2F%2Fcgi.ebay.com%2Fws%2FeBayISAPI.dll%3FViewItem%26item%3D170710884727%26ssPageName%3DADME%3AL%3AOU%3AUS%3A3160&exe=10013&ext=100025&sojTags=exe=exe,ext=ext

So I'm having trouble making this work. I don't know if it's because of the electromagnet I used (the one in the link above) or because I used a different hall effect sensor. The sensor I used is the ss495a (a ratiometric type hall sensor commonly used in non-arduino levitators). When I hold the magnet close both of the lights go from being off to flashing rapidly and I can hear the electromagnet and feel a pulse in the magnet I'm holding, but it doesn't levitate.

Any help? I'm so exited to get this working!

That's a great update of this old Popular Electronics project from 1996 —

http://www.coilgun.info/lev_popelex1996/home.htm

You should send it in as a Flashback/Update article...?

Nice work.

Hey how did you make the electromagnet??

I'm about to build an electromagnetic levitation machine myself, but I've got a few questions (being an amateur to Arduino itself...)
-What Hall Effect Sensor should I use? Apparently I'm looking for a non-latching sensor that can vary the strength of the field to counteract gravity (instead of simply tripping ON/OFF whenever a magnet is nearby). Where would I find this?
-Is it possible to use an electromagnet at an angle instead of pointing straight down? If not, is it possible to use a 'bent' electromagnet (i.e. the iron core is bent at an angle, and the wire wraps around it as such)?
-What kind of power supply should I use? Would a stronger power supply (probably more amps? Volts?) equal a stronger magnet (and thus able to 'lift' heavier objects)? If so, how well would a series of NiCd batteries (say maybe 10) fare?
All help is much appreciated, as well as good links.

Nice project! I've always considered creating my own. Where can I find one of the large coils? Would a speaker work once the back paper is pulled off?

I found this (http://www.amazon.com/gp/product/B009M86TFG/ref=gno_cart_title_2?ie=UTF8&psc=1&smid=A3H4GF5KJX48AW) on Amazon. Apparently it modifies the Hall Effect Sensor to better work with the Arduino. Not exactly cheap, though...
Would this work? It has analog output.
Also found this (TSP #22 - Tutorial and Experiments on Magnetic Levitation - YouTube), which helps a lot to explain how to build this kind of circuit.