The Overcomer Upper Extremity P17047 Net Catch > Rail Net Catch/Throw Functions: Catch, Throw Flow Revisions Owner(s): Elizabeth Nicolas, Robert Henry, Jamie Moore CAD Owner: Robert Henry
Rev 1 as of 10/8/16
Rev 2: 10/11/16 Rev 3: 10/14/16 Starting Concepts
An adapted version that used a horizontal rail to move the velcro pad across the user so that they could catch a velcro ball Pugh Chart Additions An adjustable vertical pole was added so that the user could move the catching device up and down and rotate at least 90 degrees in rotation. It was also adapted so that a net could be used to catch a propelled object Combined Concepts The net used would be adjustable for different sizes The net would be elastic so that it could be pulled back and propel the ball much like a slingshot Full System as of 10/6/2016 Horizontal rail Net attached to vertical bar Adjustable and elastic net Adjustable vertical bar System Architecture How it works? A vertical bar is attached by a u shaped rail mechanism. This has a handle attached that allows the user to move it in the horizontal direction. This vertical bar is similar to an antenna in the sense that is is retractable and extendable. The net attached to the vertical bar is made of an elastic material so that it may be used as a slingshot. When the ball is caught in the net the user can reach up and grab the hook on the back of the net, pull back and let go. Flow of Energy Moving the handle left and right moves the vertical bar and net in the same direction. Pushing the handle up extends the vertical bar, pulling the handle down retracts the vertical bar. Once the ball is in the net, pulling the small handle on the back of the net should propel the ball forward in the direction the net is facing.
Material Properties/ materials we are thinking of Vertical bars/rail/handle: Acrylonitrile butadiene styrene (ABS) plastic- this is ideal, what legos are made of, for durability and flexibility in molding Net: similar material to bungee cord (thinner than actually bungee) durable, flexible Handlebar grip: foam covered with tourna grip overgrip Forces acting on the components Friction between rail and bottom loop of horizontal bar Bending moment that may occur between the bottom of the net frame and the vertical bar. System constraints Requires user to have decent arm strength/coordination. Limited range of motion in rotational directions Requires the user to have quick reaction times List of subsystems and subsystem interfaces Attachment Device/Rail Interfaces with both end of rail to attached to vertical bars of arm rest Rail/ Vertical bar loop Interfaces with each other Handle bar Interfaces with user Net handle Interfaces with user Interfaces with net Engineering Analysis How far that the net needs to be pulled to get small ball to go mid range of the ER (pull force) Friction between the rail and loop Moment that the pull force can cause on the bottom of net frame
FOR EDGE As of 10/17/2016 Overview The Elastic Net/Rail System is an attachment that can that can both catch and throw and object. A vertical bar is attached to a u shaped rail mechanism that sits at the front of the wheelchair, looping around to the back. It will hopefully attach to the vertical bars of the arm rests. The unit is controlled by a handlebar attached to the vertical pole that the net is attached to. This vertical bar is similar to an antenna in the sense that is is retractable and extendable. The net is made of an elastic material so that it may be used as a slingshot. When the ball is caught in the net the user can reach up and grab the hook on the back of the net, pull back and let go. Moving the handlebar left and right moves the vertical bar and net in the same direction. Pushing the handle up extends the vertical bar, pulling the handle down retracts the vertical bar. Once the ball is in the net, pulling the small handle on the back of the net should propel the ball forward in the direction the net is facing. System Constraints Requires the user to have decent arm strength/coordination. Limited range of motion in rotational directions Requires the user to have quick reaction times
Bill of Materials Part Name Description Material Vertical retractable bars Rail Extend and retract much like an antenna Allows for horizontal movement around the user Acrylonitrile butadiene styrene (ABS) plastic ABS plastic
Handle User interface ABS plastic Handlebar grip User interface Polyurethane foam wrapped in tourna grip overgrip Net Elastic, able to catch and propel Neoprene wrapped in nylon yarn Feasibility of velocity and distance obtained from net with current design