OSAT Protractor and Spirit Level

Project developed by Jacob Huss

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Abstract

  1. Paragraph description of the OSAT - why is it Appropriate? What need does it fulfil? Are there case studies you have found of a technology being used successfully?
  2. Picture of completed print using
    Wood WorkingClamp Parts.png

Bill of Materials

  1. At least 13 grams of PLA filament - $0.20
  2. 1 clear straw - $0.05
  3. A small amount of rubbing alcohol - $0.10
  4. 2 pieces of gum or anything else that can seal the ends of a straw $0.15
  5. The following files - FREE
    1. OpenSCAD file if you would like to change the width of the spirit level's straw: File:Protractor.scad
    2. STL file for printing the default size: [1]

Tools needed for fabrication of the OSAT

  1. Jellybox or similar RepRap 3-D printer
  2. Access to everything on the Bill of Materials
  3. Some kind of 'snippers' that can cut through a straw or other thin plastic.
  4. A rolled-up piece of paper that can be used as a funnel

Skills and Knowledge Necessary to Make the OSAT

  • The default model perfectly fits the straw from a Silk Almond milk box, which is about 2 mm smaller than the average straw. To change the radius of the straw holder, you must change the value of the variable 'levelradius' in the .scad file. You must then export this into a new .stl file.

Technical Specifications and Assembly Instructions

  1. Print the .stl file. This should take about 2 hours and 45 minutes.
  2. Use the 'snippers' to cut off the circles at the corners of the protractor.
  3. Fit a straw through both ends of the straw holder.
  4. Use the 'snippers' to cut the straw even with the outside edges of the holders.
  5. Use 1 piece of gum or other sealing material to seal one end of the straw.
  6. Use a piece of paper as a funnel to pour rubbing alcohol into the open end of the straw. Do not completely fill the straw. Leave roughly an eighth of the straw's volume unfilled.
  7. Assembly should take roughly 10 minutes.
  8. Protractorlevel.jpg

Common Problems and Solutions

  • If the straw holder is not a good fit for your straw, adjust it in the .scad file using the instructions given in the 'Skills and Knowledge' section.

Cost savings

  1. The total estimated cost of this protractor is $0.50
  2. Commercial equivalents sell protractors and spirit levels separately, for a total of about $7.50 on the cheap end.
  3. Printing one of my protractor/spirit levels saves about $7, which yields about 93.3% savings.

References

  • The sources of information (e.g. engineering handbooks, journal articles, government documents, webpages, books, magazine articles etc.). References should use the <ref> </ref> and <references/> tags and can be in any format but should include all the information necessary for someone else to find the same information you did. For example: [1]
  1. web page: Department of Energy (DOE) Landscaping and Energy Efficiency, DOE/GO-10095 (1995) Available: http://www.eren.doe.gov/erec/factsheets/landscape.html

Based on the developmental needs addressed (e.g. food, heat, electricity, clean water, health care, etc.) be sure to label your device in the proper categories e.g. use [[Category:Water]]. Be sure to categorize your device so that it will be easy to find – for example “Low voltage connection basics” is categorized in [[Category:How tos]] [[Category:Electricity]] [[Category:Electric lighting]].

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