PENny Change is a great visual illusion. Here is a simple tutorial explaining how to make the gimmick inexpensively at home. Alternatively save yourself the trouble and get one in my Magic Store HERE.
YOU WILL NEED:
1. Any multi-purpose filler
2. Black marker pen (sharpie)
3. Two black ball point pens
5. Magnet (4mm dia x 10mm)
6. Super glue
This gimmick is fairly easy to make but you may waste a few pens trying to get it perfect, that's ok.
Buy a whole pack of cheap pens and you are set. The type of pens you need have ends that can be screwed off. Once the magnet is in place this will be glued on so spectators can't unscrew and tamper with the magnet. The magnet embedded in the end is what makes this trick such a visual illusion. It looks like real magic right under the spectators noses!
STEP 1: Take a pen and unscrew the end. You then need to hollow out the pen end with a pair of scissors, I find pushing one of the scissor blades into the end then twisting in a circular motion hollows it out nicely (pic A). Be careful when handling scissors in this way!
Do not hollow the top out too much or the magnet will be too loose. Hollow it out slightly then try the magnet, if you need to hollow more, do so then try again. Do this until you get a nice tight fit (pic B).
Push the magnet into the end not flush but slightly further down. You can at this point add a small amount of super glue to hold the magnet in place, this is not necessary.
You will probably need to trim the inner ink tube down slightly to accommodate the magnet inside the end. Again trim a small amount off with scissors then try screwing the end back on again. If the inner ink tube starts to push the magnet back out you need to trim more off.
You need to get a nice tight fit so when the top is screwed on, the magnet touches the inner ink tube to keep it from rattling. You can then add the multi-purpose filler into the top of the pen end and level it off (pic C).
Once the filler has dried (about 10-20 mins) you can colour it with a black marker pen to blend in with the rest of the pen top (pic D).
All that is left for you to do is unscrew the top slightly and add a small amount of super glue, then screw it back on. This will stop any spectator examining it and removing the top, exposing the secret (pic E).
Once the gimmick is complete it should look almost identical to a normal pen, but one you can perform a highly visual illusion with. You can switch the gimmicked pen for a normal one in your pocked and a spectator will not suspect a thing!
TIP: You will need a magnet that is 4mm dia x 10mm approximately.
You can get some cheaply on the net - try a Google search below or Amazon.