{"id":359,"date":"2019-03-31T01:19:58","date_gmt":"2019-03-31T01:19:58","guid":{"rendered":"https:\/\/commons.princeton.edu\/epics\/?page_id=359"},"modified":"2019-05-06T20:19:43","modified_gmt":"2019-05-06T20:19:43","slug":"blades","status":"publish","type":"page","link":"https:\/\/commons.princeton.edu\/epics\/about-2\/2019-2\/blades\/","title":{"rendered":"Folding Pocket Knife"},"content":{"rendered":"

[vc_row][vc_column][vc_zigzag el_border_width=”8″ css=”.vc_custom_1553988634650{margin-bottom: 20px !important;}”][vc_column_text]<\/p>\n

Students<\/h3>\n

[\/vc_column_text][vc_row_inner][vc_column_inner width=”1\/6″][vc_single_image image=”683″ img_size=”medium” css=”.vc_custom_1557172599321{margin-bottom: 0px !important;border-bottom-width: 0px !important;}”][vc_column_text]Andre Griffin
\nCOS, 2020[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/6″][vc_single_image image=”682″ img_size=”medium” css=”.vc_custom_1557172609955{margin-bottom: 0px !important;border-bottom-width: 0px !important;}”][vc_column_text]Ramzi Haddad
\nHIS, 2020[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/6″][vc_single_image image=”681″ img_size=”medium” css=”.vc_custom_1557172621026{margin-bottom: 0px !important;border-bottom-width: 0px !important;}”][vc_column_text]Alex Deters
\nCLA, 2020[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/6″][\/vc_column_inner][vc_column_inner width=”1\/3″][\/vc_column_inner][\/vc_row_inner][vc_zigzag el_border_width=”8″ css=”.vc_custom_1553988638130{margin-bottom: 20px !important;}”][vc_column_text]<\/p>\n

Project Description<\/h3>\n

This project began in the Fall Semester as we created knife prototypes made entirely out of wood. We tested out a variety of handle set-ups, blade shapes and orientations, and locking mechanisms. After going through this trial phase of our project, we settled on our current handle and blade shape, as well as our locking mechanism of choice. Using the Fall semester as time for an experimentation process, our group settled on the liner lock mechanism because we felt it was the safest of the available locks, and it would adapt the most readily to a variety of handle and\/or knife patterns. Furthermore, we felt that we could more easily produce the liner lock than other mechanisms given our material and production restrictions. While our first semester knives were wooden, their production gave us opportunities to test the optimal locations on the knife handle for the placement of metal pins to fasten not just the sides of the handle together, but also the handle to the knife blade itself. Using these lessons learned from the Fall, this Spring, we constructed an ergonomically designed handle on a Carvey machine from Crosscut Wenge Wood. In addition, we add inlaid wood detailing to the handle. As for the blade, locking mechanism, and fastening devices, we took apart several pocket knives, and then selected the necessary components from each for the construction of our knife. Upon the completion of this project, we produced a fully functioning, durable, and safe pocket knife that can pass a standard battery of tests.[\/vc_column_text][vc_zigzag el_border_width=”8″ css=”.vc_custom_1553988641874{margin-bottom: 20px !important;}”][vc_column_text]<\/p>\n

Technical Background<\/h3>\n

[\/vc_column_text][vc_row_inner][vc_column_inner width=”2\/3″][vc_column_text]The basis for the scientific and technical background for a pocket knife lies in the mechanics behind the actual cutting of some object. While one imagines the physics behind the simple cutting of an apple or a piece of wood to be relatively self explanatory, there is actually a wealth of experimental findings and scholarly inquiry surrounding said subject. The bulk of the information behind our group\u2019s scientific background came from two studies in particular: The Mechanics of a Shear Cutting Process and Slicing Softly with Shear. From the former experiment and accompanying literature, our group gained several crucial insights to the cutting process. First and foremost, Meissner states the obvious: that knife sharpness, which he claims to be the \u201cradius of its cutting tip\u201d not only affects the level of force required to cut an object, but it also affects the \u201ccut-edge quality\u201d as well (Meissner, 31). Accordingly, a sharper knife requires not only less force to complete its cut, but also leaves the cut object with a better physical result (Meissner, 31). Finally in a study of his experiment\u2019s fracture morphology, Meissner concluded that it was \u201cindependent of speed and dependent on preload (ii, 60, 74, 77). From the latter study, our group came to understand that the most efficient way to cut organic materials is done through \u201cslicing action, i.e., dragging the sharp blade over the soft surface without pushing too strongly into it (Reyssat, Tallinen, Le Merrer, and Mahadevan, 244301-1).\u201d They go on to characterize this \u2018slicing action\u2019 as a \u201ccombination of normal and shearing deformations (Reyssat, Tallinen, Le Merrer, and Mahadevan, 244301-1).\u201d Accordingly, the authors state that for \u201ca giver critical fracture\u201d or successful cut in layman\u2019s terms, \u201ccutting by slicing action requires only a fraction of the force association with pure normal loading (Reyssat, Tallinen, Le Merrer, and Mahadevan, 244301-3)[\/vc_column_text][vc_column_text]Meissner, Stephen C. \u201cMechanics of a Shear Cutting Process.\u201d 1997.<\/em>
\nReyssat, E., et al. \u201cSlicing Softly with Shear.\u201d Physical Review Letters, vol. 109, no. 24, 2012.<\/em>[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/3″][vc_single_image image=”283″ img_size=”full”][\/vc_column_inner][\/vc_row_inner][vc_zigzag color=”black” el_border_width=”8″ css=”.vc_custom_1553988646466{margin-bottom: 20px !important;}”][vc_column_text]<\/p>\n

Design Drawings<\/h3>\n

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Fabrication Process<\/h3>\n

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We used the first semester as a bit of an experimentation phase. Accordingly, we tested a number of locking mechanisms, fastening arrangements, and handle types. In the creation of these early prototypes, we used the scroll saw, the Carvey, and both of the dremels. Once we had the handles cut out and dremeled down to size, we then crafted mock blades out of wood using the scroll saw to cut out the general shape, and then the dremels to bring the blade to a point and smooth over any rough edges. Again, this stage was used to experiment with various setups and formats. Ultimately, with all these materials in hand, we fastened the prototypes together with pieces of a brass rod that we cut into appropriately sized segments with a file. With an idea of where we wanted to go with our project after our trial phase in the Fall, we began the second semester with the goal of creating one pocket knife that was secured with a liner lock mechanism and made with a wooden handle. In order to pursue this goal, we first took apart several pocket knives to acquire the necessary components that we were unable to craft. With these parts in hand, we then set out to craft our handles on the Carvey machine, and after several runs of prototypes, we finally settled on our Crosscut Wenge handle with an inlaid \u201cARA.\u201d Once the handles were cut out from our piece of wood, we used the large, handheld belt sander to shape the handle down to size. Finally, we used resin to fill in our inlay.<\/div>\n<\/div>\n<\/div>\n

[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/3″][vc_gallery type=”flexslider_slide” interval=”3″ images=”646,685,686,687,688,689,690,691,692,693,694,695,696″ img_size=”360×360″][\/vc_column_inner][\/vc_row_inner][vc_zigzag css=”.vc_custom_1553988664868{margin-bottom: 20px !important;}”][vc_column_text]<\/p>\n

Final Result<\/h3>\n

[\/vc_column_text][vc_media_grid grid_id=”vc_gid:1557172972674-06c7a7c6-148d-3″ include=”697,698,699,700″][vc_row_inner][vc_column_inner width=”1\/2″][vc_video link=”https:\/\/youtu.be\/7j2M8MzhDD4″][\/vc_column_inner][vc_column_inner width=”1\/2″][vc_video link=”https:\/\/youtu.be\/y7n_aGtOzbA”][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

[vc_row][vc_column][vc_zigzag el_border_width=”8″ css=”.vc_custom_1553988634650{margin-bottom: 20px !important;}”][vc_column_text] Students [\/vc_column_text][vc_row_inner][vc_column_inner width=”1\/6″][vc_single_image image=”683″ img_size=”medium” css=”.vc_custom_1557172599321{margin-bottom: 0px !important;border-bottom-width: 0px !important;}”][vc_column_text]Andre Griffin COS, 2020[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/6″][vc_single_image image=”682″ img_size=”medium” css=”.vc_custom_1557172609955{margin-bottom: 0px !important;border-bottom-width: 0px !important;}”][vc_column_text]Ramzi Haddad HIS, 2020[\/vc_column_text][\/vc_column_inner][vc_column_inner width=”1\/6″][vc_single_image… <\/i><\/a><\/p>\n","protected":false},"author":1379,"featured_media":695,"parent":212,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-359","page","type-page","status-publish","has-post-thumbnail","hentry","category-12"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/pages\/359","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/users\/1379"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/comments?post=359"}],"version-history":[{"count":4,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/pages\/359\/revisions"}],"predecessor-version":[{"id":706,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/pages\/359\/revisions\/706"}],"up":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/pages\/212"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/media\/695"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/media?parent=359"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/categories?post=359"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/commons.princeton.edu\/epics\/wp-json\/wp\/v2\/tags?post=359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}