CustomArcade was kind enough to share with us one of the secrets they use in making their outstanding joystick consoles and cabinets.  The following is their writeup...

One of the biggest questions I get is What is VDT or Vibration Detection Technology? And it’s a simple one to answer. It is meant for Pinball games. When you are playing along in any of the pinball games in MAME, (and this works for any other pinball game not in MAME as well), you have the option of Tilting or Bumping the table.  You can usually achieving this by hitting the “T” button on your keyboard. Wouldn’t it be nice to bump your New Control Panel?

If your buying a CustomArcade Control Panel then stop reading Cuz all this is included already, but if you have built your own Control Panel or Cabinet, well here is how you can implement this simple little device.
 

You need:	Wire
	A Drill
	A Vibration Detector (VD).  No. 49-521a available at Radioshack
	An encoder (or keyboard hack with the "T" key available)

Once You Have Ordered and Received your Vibration Detector from radio shack (fig.1) Immediately Rip it from the package.  Unscrew the Top plate from the VD ant Throw away the top. It will serve No Purpose from here on out. On the back of the VB is a “peel-&-stick”. Remove it. You don’t want anything that may act as a cushion.

Ok, Now for the Fun… If you already have a control panel/box I recommend mounting this inside toward the back of the box. Just run a screw Thru the Screw Tower (The small piece of plastic that held the cover & screw on before). You may want to Drill this hole all the way thru first. Your goal here is to screw the VD as tight to the bottom of your controller as possible. (If you are mounting this in a cabinet, I suggest attaching it inside the coin door, anywhere.)

Inside you will find a Vibration Sensor, A sensitivity screw, and two wiring terminals.  Take the vibration sensor and bend it up toward you a little, just enough so that it is NOT making contact with the plate underneath it.  The rest is easy if you look in Figure Two the blue wire at the top is connect (in our case) to a pin on the KE-72, and the black is connected to ground. You have made a button that presses itself, so to speak. Now that you have this button “inline,” program it to the letter “T”. You may have to play with the sensitivity screw to get it more or less sensitive. Now as you play pinball, *BANG* your controller -- it will “Tilt” the Machine. Remember this is in the spirit of pinball, so it isn’t an exact science. Meaning sometimes you’ll have the “touch” and sometimes you’ll lose your Ball.

One thing of note, if you are concern about having an errant keystroke when you play other games either disconnect the VB or just slide a piece of paper between the vibration sensor and the metal plate. I hope you enjoy this little enhancement.