"SLOX: Slider Stowing Lock"
Posted January 24,
There are many reasons to bring the slider all the way down to the bottom of the risers on modern gliding parachutes. The improved performance noted on high performance canopies in particular is quite noticeable (see fig 5). It is important to note that skill level and situational specifics may make this task inappropriate or even dangerous at times. However, the benefits most often outweigh the risks for most experienced jumpers.
The reason for this invention is to provide an option for stowing the slider at the bottom of the risers without necessitating an additional attachment point between the jumper and the parachute. This increases the likelihood of a safe cutaway, while offering a faster method of stowing the slider than other methods.
The slider locking mechanism described in this article is one involving a fabric keeper on the bottom of the risers. The fabric used in the photograph is CSR pattern #3511, 600 lb Dacron, finger-trapped inside itself to create double thickness. Other fabrics have been used successfully, including the larger diameter 1000 lb Dacron, as noted in the diagram to the right. The sewing machine used was a Brother B430-E bartacker, with size "E", #69, using a number 21 needle. The ends are hot knifed off, although it is possible to finger-trap the selvage if you want to make more work for yourself than is necessary. SLOX are 51 mm or 2 inches long (Fig 3), sewn in the inside of the front riser, 51 mm up from the confluence wrap (fig 4).
Fig 1: If you sew the SLOX in place in the upside-down configuration shown here, the sometimes unsightly bobbin side of the sewing will be on the inside.
Fig 2 Pre-sew a foot or more of the bartack or zig-zag-stiffened double thickness Dacron, and then hotknife into 51 mm segments.
Fig 3 Two inches at the start may result in a big smaller following the hot-knifing.
Fig 4 Two inches up from the confluence wrap.
SLOX in action on Big Air Sportz Lotus 170
* Note the reduced anhedral arc of the wing allowed by the increased riser spread. Coupled with a chest strap loosened after canopy inspection, this can reduce the risk of self-induced line twists while performing aggressive maneuvers such as turn reversals and stalls.