I know I did, so I finally got tired of wishing at the well and just up and made one. Unfortunately, I didn't take pics of the steps, so some things are going to be represented by simple drawings (they'll be easier to get the gist of, anyway).
The nifty part about this one is that no one but you and your wizardly hand can activate it, because you are wearing the power source in a pocket or sleeve, with the wires running to a pair of rings, one positive and one negative, on your fingers. You *must* wear them with at least one finger between them, so you don't short out your battery pack. :-) It's perfectly safe, as long as you don't forget you're wearing it and grip a metal post for very long (it'll damage the batteries and overheat them), because you're only dealing with three AA batteries in series.
What you'll need to make one of these:
A small battery powered (or USB-powered) plasma ball. I got mine for less than $5 at http://www.geeks.com quite a while back along with a number of other "useless" toys in their clearance section, but they don't seem to have them anymore. http://www.thinkgeek.com/homeoffice/lights/964e/ does, though they sure cost a bundle (it's exactly the same as the one I had, from the pics they show). Betcha you can find one cheaper.
Some clear, some black and some white silicone sealant (buy one tube of each if you have none yet). I use this stuff a fair bit, so I get it at Home Depot in the cartridges for those grease-gun style tools, though I rarely actually use the gun to apply it; I squirt some out on a cottage cheese container lid and then use various tools to apply it to the surfaces in question.
A suitably gothic, wizardly, or at least halloweeny looking cup that's at least a few inches deep, andjust a bit smaller than the diameter of the glass globe of your plasma ball. I used one from a cheap set of plastic halloween party cups found at a Fry's grocery store some time back, kind of like the one in the images below. I couldn't find one online to link to, but you can likely find something suitable anywhere you look right now.
Some copper wire. Preferably lots of unininsulated stuff, For mine, I ended using mostly wire out of an old vacuum cleaner cord that'd been chewed up by a dog. I stripped the entire length of all three wires of all insulation, and got quite a lot of thick stranded wire.
A 3-AA battery holder, preferably with a goodly length of wire attached. Radio Shack sells them (well, many still do) at an exorbitant price, but you can possibly find them in things you already own. If you want a little brighter light, use a 4-AA and put a diode in series with one wire to a ring., to cut the voltage down to prevent possible damage to your nominally 5V-powered plasma ball.
Some insulated cable with two wires (like speaker wire), or simply twist two separate insulated wires together . Make sure to use something with two different colors so you can easily tell positive from negative.
A couple of cheap brass rings that fit the fingers of your staff-holding hand on either side of the middle finger. They don't have to be brass, as long as they're conductive and look spiffy for a wizard to be wearing. It's better if they are a solderable metal, and acquired just for this project, so you don't have to worry about the power wires coming loose while you're dressed up.
A cool-looking knurled stick . Or whatever suits your style for your wizard staff itself. Make sure it's something you can hack into a little bit.
If you have leather or fur scraps around, these can be used not only to add ambience to the stick, but to make a carry bag for plasma globe guts if they won't fit in your chosen cup.
For tools, you'll need the common electronics manipulation tools of:
Soldering iron and solder
small screwdriver set
I recommend having a dremel and bits handy, but they're not required if you are creative with other tools, including utility knives and the like.
Some tools you might find needed that aren't listed here, depending on your choice of staff materials and the like.
In the pics, you can see the light even in a lit room, but barely. It works way better at night:
Sorry the video is sideways, for some reason the camera would fade in and out if I videoed it the other way--something wierd in it's autoiris, I guess.
Step 1: Take Apart the Plasma Ball
However, it's highly likely that yours will have a few small philips screws holding the base cover on. Undo those, then carefully remove the cover plate.
Inside will be the electronics for the plasma ball, which may have very long wires or very short ones. Mine had long enough ones to move the entire PCB more than a foot away from the ball! Yours may not. If you don't have long wires, you're going to have to have room inside the cup under the ball to secure the PCB.
I didn't have that kind of room in my cup, but since the wires were long enough, I siliconed the high voltage areas of the PCB to prevent electrocution, and let that cure for an hour or so (long enough to get a good skin on it), as I was in a hurry to make this for a party. :-) While it was skinning over, started work on the rest of it.
The globe is delicate, so be careful while handling it, especially where the nipple comes out at the base. This is where the red HIGH VOLTAGE wire on mine attached, simply by friction-fitting the stripped-bare wire as a little bundle inside the recess in the middle of the ball's base. I simply gently pulled it out, and set the bulb aside to begin attaching it to the cup in a little bit.
On mine, it had a standard little DC input jack for 5V, and a cable that came with it converting that to a USB device cable. I didn't need either, so I unsoldered the DC jack and simply spliced the wires that had been on it to a pair of red and black wires about 2 feet long. Those are going to go to the contacts down around hand-height on your staff later. I saved the other parts (and the plastic base and such) for later, as I am sure I will use them for a different project. :)
Step 2: Prepare Your Staff and Cup
My cup is plastic (styrene, specifically), and had a fairly wide base, about 3.5". I had no need of the base, but rather than cutting it off, I used the dremel to cut quadrants out of it, so I was left with a plus-sign shaped base, essentially 4 tabs sticking out from the bottom of the stem of the cup.
First I put on a leather work glove, and filled the kitchen sink with cold tap water.
I gently heated these over the electric stove on medium (if you have not done this before, I recommend NOT experimenting on your cooking surfaces, and don't use a gas stove as the flame will probably ignite the plastic) until they began to sag. Once they're workable but not molten, I placed the bottom of the stem on top of the staff at about the angle I wanted it at, then squeezed the VERY HOT plastic base tabs to conform to the top of the staff's shape (mine is pretty irregular). Still holding this, I then I dipped the whole end into the sink full of water to quickly cool it all, and let go. It worked better than I had imagined on the first try. Don't forget to turn your stove off.
Since the cup is not yet actually attached to the staff, just conformed to it's shape, it's not going to stay on it's own. First set the staff aside so it can dry off, and dry out the cup. You'll need to drill a hole in the bottom of the cup portion, somewhere above the (probably solid) stem. If your stem is hollow, then just drill a hole thru it wherever it needs to be to get wires thru from the cup itself all the way thru the stem, big enough for your battery wires, or for the HIGH VOLTAGE wire if you are placing the PCB outside the cup. If the stem is solid, just drill a hole above the stem into the cup--you can conceal the wires later with some silicone. No one will see them in the dark, anyway.
Once the hole is drilled, if you are putting hte PCB in the cup, run the battery wires from the PCB out thru the hole, and tack down the PCB in it's position with some silicone, stuffing papertowels or a sacrificial rag in there to hold it in place for a while. If you are putting the PCB outside the cup, run the high voltage wire from the PCB into the cup thru the hole, and temporarily tie the PCB to the cup's stem with the battery wires. In either case, put a little silicone into the hole and on either side of it to keep the wires in place. If your cup, like mine, has a texture to it, you can work the silicone as needed to sculpt a quick replica of that, to make it feel or look a little less like a blob of goo leaking out. :-) Again, it's dark, nothing to see here. You can use whatever color silicone you like, but if possible blend some white and black together to make gray--you'll use more of this later anyway.
At this point, I had decided that the little face on my cup begged for lighting up, but it was solid dark plastic, so no light would go thru it. I cut out the eyes and mouth by drilling many holes in it, then using a file to expand the holes and connect them until I had them clear of plastic. Then I promptly filled them up with clear silicone. The silicone is viscous enough it does not run, so it'll stay in reasonably thick layers filling gaps like this. Takes a while to cure, though, so don't touch it at least until it has skinned over, which probably will take at least an hour or so.
My plasma ball is only a hemisphere, and doesn't emit light on the underside, so I needed something else to light up the face, and had in the Geeks.com assortment a little squishy egglike thing that had a 3-color LED with it's own pulsating chip built in, and ran on, guess what? 3 AAAs.
I put the LED (still attached to it's power wires) in a glob of silicone, then put that glob against the spot right between the eyes and mouth (no nose on this cup), with more silicone (clear) to help diffuse the light between them all as evenly as possible. It's not very bright an LED, so I wasn't expecting much, but it worked well enough to see in room lighting, though certainly not daylight.
Those power wires I simply ran out the same hole as the HIGH VOLTAGE wire, though I had to splice on some extra length to them to reach the PCB, and then I simply soldered them to the PCB's power wire inputs, so I only have to run one set to the batteries. There's also a power switch on the PCB, so I can turn them both on and off with that, if I later chose to put batteries in the bag with it instead of on my person.
The power wires from the PCB can be run down to hand-height in a variety of ways, depending on your staff material and shape, and your design preference. Mine, being driftwood, already had a nice long worm-eaten channel from the top down most of the way to the middle. I ran my wires in that, with a dab of silicone in the channel first to keep them in place. You can see them in some of the pics, pretty clearly, but again, not in the dark. :-) Leave the excess dangling below hand-height.
Remember that bare wire you gathered? Now here's where it comes in first. This is an important step for comfort, so do this with patience. Stand up, take the staff in hand, and place the end of it on the floor next to you as you will be holding it while gabbing away at a party. Stay there a minute and see if your hand is comfortable there. If not, move it around till you find a good comfy spot, and then mark or remember where your pointer and ring finger are touching at their base, where rings would be.
Wind the copper wire around there enough times that you have a wide enough band to ensure contact even if you move your fingers a little, but nowhere near touching each other. If you want to, for style, you can also wind more wire around other places on the staff, but remember that hardly anyone is going to see anything but the top of the staff, after they see it lit up. :-)
Run the power wires you left dangling to the bare copper wire, so the positive is on the top windings, and the negative on the bottom. No, it doesnt' really matter, but this makes it easy to remember, since if you set a AA battery on it's end so it stays in one place like your staff, positive is on top of that, too. You do need to remember which is which, either way you do it, so you can put the appropriate ring on the finger to contact the corresponding winding. If you do it backwards later on, it depends on the design of the lighting in your staff whether it will be damaged or destroyed by that backwards connection. Mine happens to have a diode already in there to prevent this, and the LED appears to be hardy enough to take a short misconnection (as I found out by accident once during testing). There's no guarantee yours will, so be careful.
Connecting the wire to the windings should be as simple as stripping the ends of the power wires, then weaving them between the winding wires. Soldering to them is also an option with many staff materials, including wood. If your staff is plastic, don't do that, cuz you'll melt the plastic of the staff and it's smelly. :-P Probably harmful to you as well. :-(
Now that the wires are in place, you should secure the cup to the staff (not done before because you might have to change things as you run wires around). Mine I siliconed to the top of the staff, with some wood screws thru the plastic on two tabs to keep it in place while the silicone cured. Since that looked ugly, I did some other covering too.
I had some fur scraps laying around from costuming, so I used some to make a bag to hold the PCB, and then to wrap around the siliconed base of the cup. I did that while the silicone was uncured and unskinned on purpose, to help the leather of the fur stick to it and stay in place. I figured it probably would peel off later if I didn't secure it better, so I stylishly wrapped bare copper wire around the whole furry joint as decoration, then ran the last few inches down to the top of the fur bag and tied it shut. The bag itself was simply the corner of the collar from an old coat I found at a thrift store for a few bucks, falling apart at the seams and torn in quite a few places.
Step 3: Attaching Ball to Cup, and Decorating
Mix up some black and some white silicone to make your favorite shade of gray. Gray is nice because it isn't black, so it does reflect some light, but not too much, and doesn't really look quite so plasticy in darker light, compared to just white silicone. If you want a different color, such as something matching your cup, go ahead and mix it up, if you have the right colors available. There are silicone pigments available from Reynolds Materials, but unless you do a LOT of this, it's very expensive. You only use a tiny tiny bit, so they last practically forever if you don't do much, but it's between $15 and $20 a jar, PER COLOR. You only need 5 colors, really: red, blue, yellow, black, and white, to mix up pretty much any other color, but $100 for pigments is a bit much for the average DIYer. :-)
Put a little bead of the silicone around the lip of the cup, on the inside edge. Carefully seat the ball on that and press down gently, so it makes complete contact all the way around.
Now is the time to test this, before it's alldry and impossible to take apart, so put some AAs in your battery holder and touch the red wire to your positive staff winding, and the red wire to your negative staff winding. It should light up. If not, recheck that any power switch on the PCB is ON, and that all the connections are good. A multimeter will help, but there aren't many ways for something to be wrong that aren't just plain visible, in this setup. If you used an LED for interior lighting of the cup, and it comes on but the plasma ball does not, disconnect the battery power and gently pull the ball off the cup, to make sure it's HIGH VOLTAGE wire hasn't come loose. If it has, you'll need to push it back in. If it's in there good, there's not really much besides the PCB end of the wires you can check. If they're ok, then you might have a damaged or defective plasma ball (assuming it worked when you took it apart).
If it's all ok, then disconnect the batteries and start putting some silicone build up around the edges of the cup onto the ball. This both helps secure it in place further, and provides a bit of bumper so if you lean the staff on the wall it won't bang the glass directly on it, as long as the staff isn't tilted too far. See the closeup pic for what I mean.
I chose to extend the silicone up on mine so it looked like the ball was a crystal held in by claws. I used dabs and draws of silicone to make fingers around it, like perhaps a dragon's foot, then clear silicone for claws on the end of that (if they're clear, they coruscate with light as the plasma shifts inside the ball).
Anything you put on the surface of the ball will tend to attract plasma lines, so they're going to generally illuminate these claws fairly well, if you have a preferred illumination pattern, make the silicone fit that. But don't obscure too much surface, or people can't stare at the pretty colors. :-)
Step 4: Battery Holder and Rings
Take the batteries out of the holder if they're still in there from testing.
Solder the 1/4" end of the black wire to the negative wire or terminal of your battery holder, then the 1/4" end of the red wire to the positive of the holder.
Loop the 1" stripped end of each wire around a separate ring, ensuring that you can still put the rings on and take them off without discomfort. If these are rings just for this costume, solder the wire to the rings.
For my rings, I simply used some brass rings out of an old hospital-room-style divider curtain. They're ugly crimped-on junk, but they fit my fingers comfortably, and were easily solderable.
Now this part I don't have any pics of at all, because I set the battery pack and rings down somewhere at the event and lost them. :-(
Fortunately, it's the simplest part of the whole thing, and very easy to imagine. :-)
You can also skip the whole part involving this, and simply wire the battery holder right to the PCB, and put it in the same bag or spot as the PCB, so the staff works all the time it is turned on (or has batteries in it, if no switch is built-in). But I think it's cooler that it only works for the person who brought it. :-)