I was out to lunch with a couple friends, brainstorming ideas for fun projects when one of them says “Wouldn’t it be cool if we could build a working gravity gun?”. We all immediately concurred that while it would in fact be cool, it is also a silly proposition. However, only a few seconds later, I realized we could do a display piece that emulated this concept very easily. Floating magnetic globes have been around for quite some time.
I determined I would tear the guts out of a stock floating globe and mount it on a portal gun, since they’re easier to find than a gravity gun. I would also build a custom companion cube to be the correct size and weight necessary.
The Levitation System
I started off with a StellaNova magnetic levitating globe. I chose the larger version that is roughly 8″. My assumption was that this one would be able to hold a little more weight than the smaller version.
Prying the coil out of the metal frame turned out to be difficult and actually resulted in a damaged coil that I had to repair. If you were to replicate this, I’d suggest cutting the entire metal case that contains the coil from the frame instead of trying to remove just the coil.
Once I had the coil out, I tore the strong magnet out of the top of the globe. This globe actually has a magnet in the base that helps stabilize it during levitation so I knew I was going to have to tweak my companion cube to get the weight just right. As you can see, my process is purely scientific and extremely precise.
The portal gun
I really wanted to make my own portal gun for this. My schedule and my ego fought hard on this subject and ultimately my schedule won. While I feel like I could have built a fantastic portal gun, there’s no way I could have done it in a reasonable amount of time and gotten as nice of results as just buying the portal gun props available at toy stores.
When initially mounted the coil on the gun, I found that the “arms” were far too flexible. I had to reinforce the arm somehow. The option I chose was simply to bend a piece of steel to the correct shape and strap it to the underside of the “arm”.
I made a cardboard model to test weight and size of the companion cube and got the system working on the portal gun.
At this point, the entire thing is working. I’m far too excited to wait for some kind of store bought cube to arrive and attempt to get it to the correct weight. That’s assuming I could find one the right size. So, I made my own out of foam. Admittedly, it isn’t the best looking companion cube in the world. If I were to take this further, I’d probably sculpt one and make a mold so that I could make my own solid foam companion cube.
A single huge improvement:
I started off thinking that the final product would be a portal gun that you could hold while it levitated a cube. This meant that I needed to actually mount the coil that suspends the floating cube on to the portal gun. As you can see in the video, it is a fairly visible modification. You can see the coil, wires, and reinforcement on the top arm of the portal gun. Once it was built however, I found that I couldn’t hold it still enough to maintain the levitation.
Since holding it is officially not going to happen, I realized I could have done this in a more aesthetically pleasing manner. Instead of using the type of floating globe that dangles the magnet below a coil, I could have used one with a magnetic base that floats the magnet above the coil. This would have left the portal gun completely un-modified.
I wanted to give a special thanks to Vintage Stock in Springfield Missouri (the one on Glenstone), who let me bring the system in and show it off until the hall effect sensor finally got smashed too many times and the cube wouldn’t levitate.