Posted by Laurie Sullivan at 11/16/2014
Thisyear retired mechanical engineer Dr. Stu Jessup is working with Barrett 4thand 5th graders in the Discovery Lab. Dr. Jessup is a volunteer with the Scientists in the Schools program.
RecentlyDr. Jessup challenged the students to design a cantilevered support for acarport using a 1/5 scale model. Engaging props such as a groovy 70’s vansheltered under a wooden carport were employed to capture the students’interest in the project. Materials used for the engineering challenge includedscaled down “2×4″‘ beams and “4×4″ columns along with”2×4” braces. The children fastened the pieces togetherwith screws, washers, and wing nuts.
Byshowing the students photos of typical cantilever structures, such as streetlights, shelf brackets, and even tree branches, theyhad sufficient knowledge, and their own free thinking ingenuity toarrive at truly innovative design solutions….and everyone learnedwhich way to turn wing nuts and screws!
Overtwo class periods, four iterations were assembled and tested for verticalend deflection with an applied 4 lb weight. By viewing where the beams andcolumns flexed under load, the junior designers were able toattach appropriate braces to reduce the deflection toas little as 0.03″ over a 23″ span and 18 “columnheight. It was very exciting when every little handwas working the hardware simultaneously.The immediate jump from idea to hands on action made this learning exercisequite special.