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The Magic Ref Veteran user Flint, Mi. 302 Posts |
Hi all, I did a quick search and did not find any good answers so here goes...
I would like to build a remote control light heavy box, I have the other normal versions but for routine reasons I need it remote controlled. From what I understand Electromagnets would be the way to go. I understand they require a larger space and are not cheap. The size is no problem my prop can be as large as needed and within reason I'm not worried about the cost, any thoughts as to where I would learn to make something like this? Thanks, Mike
Be Young...Have Fun!
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the Sponge Inner circle Atlanta 2771 Posts |
You're in luck. Such a thing is already marketed. Retails $2500.00 called light and heavy box.
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maurermagic Regular user 110 Posts |
Check with Tom Yurasits Productions.
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AGMagic Special user Cailf. 775 Posts |
An electro magnet is just a length of insulated wire wrapped around a ferrous core. If you can find a round piece of iron, you can buy magnet or bell wire at Radio Shack or the like and just wrap it around the core. Use flat pieces of plastic or non ferrous metal to create flanges on the top and bottom of your round stock to create a channel to hold the wire in place.
You will be using low voltage direct current (battery) to power your magnet so the length and gauge of the wire isn't too critical. Smaller gauge (26 or 28) and more wire length is the way to go. The more wraps of wire you have the stronger the magnet and the less current the set up will use. You can also put a variable resistor in series with the coil to control the power of the magnet. I was thinking of making something like this for myself and have a used coil from a 24VDC magnetic clutch. The coil assembly is about an inch and a quarter high and 5" square. Unfortunately, buying a new clutch for the coil is probably prohibitively expensive.
Tim Silver - http://www.facebook.com/pages/Magic-Woodshop/122578214436546
I know you believe you understand what you think I said, but I am not sure you realize that what you heard is not what I meant. Visualize Whirled Peas! |
gimpy2 Special user 960 Posts |
I would think the easiest way to go would be to find an existing product that could be adapted to work. Maybey a magnetic security lock with remote. If you don't have to spend a whole bunch of time building the magnet/remote part of it you can spend more time on all the other problems that will come up. Noise and movement of the box may prove to be an issue as well as what to set it on.
Good luck
Gimpy
www.gimpysmagic.com |
Ray Pierce Inner circle Los Angeles, CA 2607 Posts |
Quote:
On 2011-08-19 15:37, gimpy2 wrote: I thought the same thing. There are MANY electromagnet products in all sizes ready to go. Unfortunately the REAL way to do this is to work the EM into the stage. The box is mostly an un gaffed piece that is steel lined with a thin veneer on the bottom. The problem of course is practicality!
Ray Pierce
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The Magic Ref Veteran user Flint, Mi. 302 Posts |
Thanks for the info AG Magic. Also a good idea from Gimpy. I can't just buy someone elses L/H box because I need to build it into a specific prop. Ray, good thoughts about how to incorporate it into the show. I think I have that part handled. I think I will look into items already made like Gimpy said and see what might work for me. Thanks again to all!
Be Young...Have Fun!
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Christopher Taylor V.I.P. British Columbia Canada 2314 Posts |
By, "remote controlled" I am assuming you mean battery powered radio control. For the magnet to be strong enough to prevent an adult from picking up the box, you are going to need significant power. Now, your problem is not with making the magnet but in building a radio controlled circuit that will not burn out due to fly back. A relay circuit might work, but then the problem becomes the distinctive "click" as the relay trips. Tricky. Good luck.
Christopher |
jolyonjenkins Inner circle United Kingdom 1181 Posts |
I don't know what kind of current is needed (pretty hefty I imagine) but in principle you can solve the click problem with a solid state relay.
Jolyon Jenkins
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AGMagic Special user Cailf. 775 Posts |
It is not really excessive current, but the flyback voltage created when the magnetic field collapses through the coil of wire when the power is removed. This voltage (peak inverse voltage or PIV) and corresponding current are of the opposite polarity of the applied voltage. The flyback can be many to hundreds of times the voltage originally applied to the circuit (think automobile coil - 12VDC in 12,000 VDC out). This can often be overcome by installing a flyback diode in parallel with the load (coil) to short out the flyback current. In normal operation the diode has no effect as it is blocking the current through it. In flyback mode it shunts or shorts the current created by the collapsing magnetic field. Some, but not all solid state relays have this feature built in. It is a good idea to install flyback diodes accross the coil of a standard electro-magnetic relay.
As stated in my post above, the current depends on the size and length of wire in the coil. More wire (resistance) = less current for the same voltage and the magnetic field is increased by the additional coils around the core. You could also try using a servo driven variable resistor like the speed control in an electric RC car. This would allow the magnetic field to collapse slowly thus eliminating the flyback problem.
Tim Silver - http://www.facebook.com/pages/Magic-Woodshop/122578214436546
I know you believe you understand what you think I said, but I am not sure you realize that what you heard is not what I meant. Visualize Whirled Peas! |
danny123 New user 2 Posts |
Does anyone sell this?
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the Sponge Inner circle Atlanta 2771 Posts |
Quote:
On May 6, 2023, danny123 wrote: Yes |
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