Armadillo - Clear plastic device for determining a bowler's positive axis point. This device has a series of lines on it, which get matched up to a bowler's initial track. When the device is aligned with the ball track, the device points to the bowler's axis point.
Added by JohnP, 2/14/12
To locate a player's PAP, mark the initial track on the ball with a white or yellow layout pencil. Match up one of the track lines on the 'dillo with the line on the ball (if none of them match exactly, estimate between the lines) and mark the PAP at the locator end of the 'dillo. To lay a ball out, let's say a 4 x 5 layout -- place the 4" line on the 'dillo on the pin AND the 5" line on the cg or mb. Mark the PAP for the layout at the locator end and proceed as usual from there. To draw a true perpendicular line to an existing line, line up the dashed line on the 'dillo with the line on the ball, placing the straight edge of the 'dillo where you want the line and draw it.To find tilt, when you line the 'dillo up to locate the PAP, count how many track rings the line you're using is away from the dotted line. The dotted line is a full roller track or 13 1/2" diameter. The first ring away from the dotted track is a diameter reduction of 1/2", or 13" diameter. Each subsequent ring is a reduction of 1" in diameter, so the next one would be 12", then 11", etc. When you have the diameter you just go to the chart for diameter versus tilt (Figure 1).