Flexible Disk APDs (suction cups)
This design will only work on 1/4" solid fiberglass shafts and 5/16" or 11/32" wood shafts. They will not work on crossbow bolts.
Requirements:
These APDs shall be made using 2.5" suction cups (catalog number SC250P) manufactured by Suction Cups, Inc., which have been cut down to 1 3/4" diameter. Only those specific suction cups (catalog number SC250P) manufactured by Suction Cups, Inc are approved for APDs. The 2.5" suction cups are thicker than the smaller sizes. A 1 3/4" suction cup, which has not been cut down to size from a 2 1/2", diameter cup is not approved because it is too thin and flexible.
These shall be attached by punching or drilling a hole in the center, then glued in place on the nock of your arrows using liquid (not gel) super glue and a glue gun. Since they are slightly flexible, they shall be glued into place .25" from the end of the nock. In other words, they are glued into place just pass the slot in the nock.
**Warning: wait a day between using the super glue and hot glue, otherwise noxious fumes result**
This APD can not be twisted around the shaft. If it does it fails. This usually means that the hot glue broke the bond of the nock to the shaft and this means the APD can fail.
You can purchase this APD, please see the list of suppliers.
Thanks to Sir Erika Bjornsdöttir and her household for coming up with this design and doing the majority of the testing.
Diagram: to be added later
Thanks to Sir Erika Bjornsdöttir for samples of this APD.
Back to the APD page.
If anyone has any questions, comments or suggestions, please let me know.