Many of you may have read the full sized ROMP instructable, but those of you who didn't, here's a link: https://www.instructables.com/id/E7343C85JWERIE2RED/
As you can see Stormed and I had a nice conversation about the "Random Oscillating Magnetic Pendulum", and he came up with the idea to make it portable. So then we started coming up with ideas on how to do this. Apparently I finished my design first though, so if you see another instructable much like this one posted by Stormed, don't say that this has already been posted, since his design varies from my own and without his comments, I may never have actually thought of this.
After much trial and error, my Pocket ROMP is complete. Now when I go to the DMV and the batteries in my handheld goes dead (cause we all know how long it takes), I can take this out and perhaps even inspire other people there to make their own.
Here's how I built my Portable.
Warning: Do this in a well vented area due to fumes. The soldering iron also becomes hot, so be careful with it.
Step 1: Materials
Time to gather your materials.
1. Goop or rubber cement (also a small nail to spread with)
2. A round disc magnet
4. Box Cutter (sharp knife)
5. Strong Wire
7. Altoids Container
8. Soldering iron and solder
10. 9 volt battery (or a small flat piece of metal)
11. Foil insulation or piece of cardboard.
Step 2: Cut the Magnets and Make the Pendulum
1. Take the disc magnet and hold it in the pliers (if you have a second disc magnet, use it to find which sides attract and which repels). Now cut it in half.
2. If you didn't have a second magnet, follow this step. Use the half magnets on each other, do your best to discover which areas attract and which areas repel. Cut the disc so that each smaller magnet only repels or attracts on each side.
3. After you have cut one half of the magnet into smaller magnets, cut another one out of the other side to be used as your pendulum.
4. Now use your marker to mark which sides of the main magnets will repel the side that you've chosen to be used for your pendulum.
5. Cut the pendulum down to size and make a slight cut half way into the magnet (so that one side of the cut is at the bottom, the side that you've chosen to repel off the others, and the other side of the cut is at the top). Cut a piece of thread about 5 inches long (makes it easier to tie the knots).
6. Using the small cut you've just made, insert the thread into it and loop it back up around the magnet and tie.
7. Now take the wire and bend the tip up. Tie the thread (so there's about an inch and a quarter) around the dip in the tip and bend the tip back. Goop up both the tip of the wire and around the magnet's sides and top (not the bottom though).
Step 3: Make the Case
1. Solder the wire into place (mostly in the corner) in the bottom of the case.
2. Take the foil or cardboard (if you use cardboard only use enough to fill the center, about an inch by two should do) an cut it to fit. Goop it into place. The foil allows the cover to close, so I decided to use it.
3. Take the 9 volt battery and take just the casing ( https://www.instructables.com/id/EOGAE2LXOUEP287E6N/ ), cut the casing and flatten it. Now trim it down, so that'll fit into the center of the lid. Goop it so it'll stay there.
Step 4: Finishing Touches and Then Play
1. Now the only thing you need is something to help keep the lid at a level and flat position. I cut a piece of the unused half of the disc magnet and used it on the top of the lid to support it. After I'm finished playing, I just place the magnet inside with the others.
Now you have a completed pocket sized ROMP (I suggest keeping it away from things such as cell phones and ipods).
All you have to do is open the lid and bend the arm into position. Then take the magnets and place them where you feel like it on the platform. Swing the pendulum and watch as it repels through the fields. After you're done, bend the arm back down and position the magnets in a group in the center of the lid (or in with the arm) and close the lid.
As always, improvement ideas are welcomed.