The Crank Cage: A Backyard Lacrosse Training System
Jonathan Winne
Figure 1: Side view of the entire completed backstop attached to the lacrosse goal
Figure 2: Side view of the top portion of the completed backstop attached to the
lacrosse goal
Summary:
Once a nearly unknown sport, the game of lacrosse has enjoyed a tremendous
growth in popularity over the past decade. Due to the increased popularity of the sport,
lacrosse goals have become more commonplace in backyards, many of which are located
in suburban neighborhoods where yard space is limited and houses are close in proximity
to one another. The setup of goals in many backyards poses many issues; if a ball misses
the goal it has the potential to cause a substantial amount of damage, including property
destruction and personal injury. While there are lacrosse backstops available to provide
protection to property by stopping errant shots, few options are available to the consumer.
Today’s lacrosse backstops are pricey, oversized, cumbersome, unattractive, and illsuited for the average backyard where many backstops are either used or needed.
In order for a backstop to be a viable option for practical use in the average
American backyard, it must meet several basic customer requirements. First and
foremost, the backstop must be affordable; a price tag of no more than $180 would put it
at about 50% of the cost of the average backstop. The backstop must also provide a large
protection area and remain rigid to help minimize the likelihood of causing property
damage and personal injury. Because the consumer will invest an ample amount of
money in a backstop, the backstop must have an average lifespan of two years without
the need for parts replacement to make it a worthwhile investment. Lastly, the backstop
must not require any modification of the goal it is used in conjunction with and must be
customizable to the meet the specific needs of the consumer.
All of the concepts considered operated under the same basic principles; each
proposed design utilized the 36 square feet of the lacrosse goal itself as part of the
backstop to maximize coverage area while reducing the physical size of the backstop
itself. Each concept also made use of adjustable panels of netting surrounding the three
sides of the goal to provide protection to the surrounding elements. The concepts varied
in the number and orientation of support beams used to support the netting, the manner in
which the netting was supported around the goal, the materials used, and methods used to
adjust the position of the backstop.
While the general shape and operating principle of the final design of the
backstop was very similar to all of the concepts considered, several unexpected issues
were encountered while selecting parts and prototyping required various modifications to
accommodate these issues. The locking joints chosen to adjust the position of the
backstop panels, while in existence on many consumer products, do not exist as standalone units available for purchase. This required the exchange of copper tees used in
plumbing for the desired joints. Because the tees do not provide an adequate amount of
counter-torque to ball impacts, several large supports were added to the side panels while
the top panel was soldered in place to provide sufficient counter-torque. While the side
panels of the backstop remain adjustable, the top panel is fixed in place, thus limiting the
customizability of the backstop to a small degree.
Despite the unexpected modifications needed to address various issues with the
design, the backstop performed as originally desired. The total cost of the project was
approximately $167, or $13 under budget. Including the coverage of the goal itself, the
backstop covered approximately 114 square feet and managed to block the majority of
missed shots during testing. The backstop was not quite as rigid as was desired, but the
movement of the backstop was minimal. While some of the mobility of the backstop was
lost due to the redesign, it still had a large range of movement. The only disadvantage to
the prototype was the tendency of the balls to experience a rebound effect when they
struck either of the side panels, indicating that the nets were too taut. Although there
were several setbacks, the backstop performed well as a whole.