Cutting board for single-handed use

Amputee
Hardware
Cooking
Single hand

In development
  1. Ideation
  2. In development
  3. Final reviewing
  4. Finished

Summary

A cutting board that could stabilise food so it could be used with one hand with an attempt to minimise the decrease in usable board are.

Table of Contents


#Purpose The overall purpose of our project was to design a cutting board that could stabilize food so it could be used with one hand. The cutting board must optimize keeping the food stable while not reducing food area able to be cut. #User Needs Our codesigner, Ellen, has a shoulder level amputation of her right arm. Ellen told us that she enjoys cooking and would like a cutting board that could allow her to cut with a wide variety of food and techniques with only one hand. The cutting board must also be designed to be operated by Ellen’s left hand. The cutting board needs to be food safe and easily washable. #Constraints The constraints of our project were: limited time, a $50-$150 budget, and material limitations. Our time constraint was that we only had a couple days and didn’t have enough time to order anything off of amazon, which restricted our materials. --- #Prototypes ##First Prototype Our first prototype tested the layout of the board, feasibility of the gear system, and the operartibility of the nail system. ![First prototype](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.28.40%20pm.png#center) Our design has two workflows designed to help cut different foods: the gear system and the nail system. The gear system consists of a rack and pinion system with a sliding gear to adjust the width between gears to allow for cutting food of different widths. The rack is pushed with the users hip so the user doesn’t need to put down the knife, manually move the food forward, then resuming cutting. This system can cut foods like carrots, herbs, and celery. The nail system is used to cut foods like apples, potatoes, and onions. The system slides out for safety and washability, but utilizes a slot design so food can be pulled off. ###Steps ####Cutting Board Base 1. Cut one 14” x 11” rectangle of cardboard as shown in [Sketch 1](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.11.21%20pm.png) 1. Cut the top left rectangle into the second rectangle of cardboard 1. Superglue the cut rectangle on top of the second rectangle but leave about an inch unglued around the top right slot 1. Stab a 1/4” diameter, 2” long bolt through the center of the circle 1. Superglue the bolt head to the cardboard on both sides. 1. Superglue the uncut rectangle to the bottom of the cutting board ####Nails system 1. Cut a 4.25” x 3.25” x 0.2” rectangle (RS) of cardboard and another one bigger 5.25” x 5.” x 0.2” (RB). 1. Hot glue the two rectangles, making one of the shorter edges of RS align with one of the shorter edges of RB, leaving at least 1.25” from one long side to another. 1. Considering only the top 2.5” of RS, draw the hole for the three nails, so that they are 0.8” distant one to another, in an equilateral triangle shape with its incenter corresponding with the centre of the rectangle. 1. With the nails, penetrate the surface on each hole, in order that they come up from the big rectangle side just with their tips; now let them go all the way through in the opposite direction, so that their caps impede them to come out. 1. Superglue the caps to the surface of RB. ![Figure 2](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.17.01%20pm.png#center) 1. Cut two more rectangles of the same shape and attach them together in the same way. This is what will substitute the first system when the nails are not requested. ####The Gear System 1. Then design a 10-toothed gear using Figures 3 and 4 Page 4. Each gear has a total diameter of 2”(38.1mm) with a .35”(25.4mm) diameter hole in the center. Each tooth has a .25”(6.35mm) height and width with filets of .03”(.762mm) radii on the outward edges. It is suggested that a circular pattern tool is used to ensure precision and accuracy of dimensions. ![Figure 3, Figure 4](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.27.27%20pm.png#center) 1. Set the units of measurements to millimeters (mm) and export the sketch to a .dwg, which should download as an Adobe Illustrator file. 1. After downloading the file, access it on Adobe Illustrator, copy and paste the drawing to print two, and set the outline to hairline and make the lineart red. 1. Send the command to the laser printer to print 4 gears, and calibrate it, making sure to turn on the fan, the air compressor, and focus the laser. 1. Once the gears are printed, superglue two of them together so you end up with a total of two gears with double the original width. ![Figure 5](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.28.40%20pm.png#center) 1. The next step is to make the slider. It has 16 equal teeth and is 8” (203.02mm) in length. The base height is .25” (6.35mm) while the tooth’s height and width is also .25” (6.35mm) with filets at the topmost edges with a radius of .03” (.762mm). The dimensions are shown in Figure 6 and 7. ![Figure 6](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.29.42%20pm.png#center) ![Figure 7](https://www.humanistic.app/resources/files/projects/4/screenshot%202020-07-07%20at%2011.33.25%20pm.png#center) 1. Repeat steps 2, 3, and 4 to laser cut the slider, and assemble the slider as shown in Figure 5. ####Final Assembly 1. Slide one of the gears over the bolt and use a nut to ensure it stays on the cutting surface 1. Cut a 1” x 0.5” rectangle out of cardboard 1. Stab a bolt through the center of the rectangle and superglue them together 1. Insert the cardboard rectangle between the top and middle layer of the cutting board so the bolt sticks out of the board like the other one. 1. Put the gear on the bolt and use a nut to ensure it stays on the cutting surface. 1. Slide the nail system into the top left slot of the cutting board ###Testing Results Through testing, we determined that our gears needed to be taller for more contact with the food. We also found that our rack didn't turn out pinion well, so we needed to design a better rack. Due to time constraints, our first prototype ended up being our final design. ##Our 1.5 Prototype This prototype was supposed to be laid out on a wooden board to test out how well the systems work on a more rigid surface. However, due to time constraints and issues with the milling machine, we were not able to finish the wood cutting board by the project deadline. Even though we weren’t able to attach anything to our wood base, we did finish milling it which shows that the board design is feasible from a manufacturing perspective. --- #Results and Future Planning As a first prototype, our device was a success. Through talking we Ellen, we determined that the layout of the board, the nail system, the overall idea of the gears, and washability were successful elements. For future prototypes our most immediate actions would be ensure functionality of the gear system by redesigning the rack and increasing the height of the gears and installing the non slip silicone to the bottom of the board. Then, we would switch out cardboard for wood and ensure the system still worked before ensuring all parts are food safe. --- #Lessons Learned Through this process, our team learned a lot about time management, planning, and communication. At the start of the project, none of us really realized how limited the time was for the project. We also did not establish a clear plan on what we were going to do. Because of this lack of planning, we all worked mainly separately, and didn’t communicate well. The lack of planning also led to an inability to overcome issues with the milling machine, forcing us to use our first prototype as our final design. For our next project, we will be sure to fully comprehend our time limitations, plan ahead, and ensure better communication through team meetings.