These APDs can be used on wooden or fiberglass shafts. They can be used for arrows and crossbow bolts, although the flared design is only used with arrows.

This type of APD must be made from either 75 or 80 psi Polyethylene tubing or equivalent as described on the Siloflex Equivalents page. The minimum outside diameter of the APD must be 1.25". If the outside diameter of the tube is less than 1.25" but greater than 1", the tube must be flared to expand the back end (end nearest the nock) to 1.25" as long as the flaring does not weaken the APD by causing stress cracks or breaks.

The back end (end nearest the nock) of the tube must be cut straight (perpendicular to the axis of the tube). If the front end (end away from the nock) is cut straight, the minimum length of the tube wall is 1.25". If the front end is cut at an angle, the minimum length of the top wall (wall away from the shaft) is 0.625" and the minimum length of the bottom wall (wall nearest the shaft) is 1.875".

All edges of the APD must be rounded and free of sharp edges. Using tape to cover the edges of the tube is not sufficient. Melted edges must also be free of sharp edges.

The APD must be securely attached to the shaft of the arrow within 0.50" of the back end of the nock. The attachment mechanism must include at least one wrap of fiber/strapping tape running through the tube of the APD along its bottom side and around the shaft in font of and behind the tube. Another strip of tape must go around the back end of the tube and the shaft; this must go around at least two times. Additional tape may be added to enhance the attachment. Glue or other adhesives may be used but do not remove the requirement for strapping tape.

 The attachment to the shaft may be enhanced by a routing a channel to help with the placement of the shaft. The depth of the channel may not be more than 3/4 of the thickness of the APD. The APD tube may also have tabs cut into the wall or extending out of the wall along the shaft to provide additional surfaces for taping. None of these methods remove the attachment requirements listed in the previous paragraph.

The APD must return to a round tubular shape after it has been squeezed. Be aware that this ability may vary with temperature and APDs that pass on cool days may fail on hot days or during the heat of the afternoon.

The APD should be firmly attached to the shaft. There should not be any significant movement of the APD on the shaft. If the APD is loose and rotates around the shaft or moves forwards or backwards on the shaft it will fail.

 These designs were tested and passed using the help of many archers. In particular, I would like to thank Sir Jon Fitz-Rauf and Master Thorvald Grimsson.

 Instructions: