Shipwright's Compass

draw a curve when the circle's center would be in your neighbour's house!
  • The angle ACB is always the same.
  • 2014 D70 8058
  • 2014 D70 8060
  • I glued on a piece of 80 grit sandpaper to increase friction when tightening the screw. This is important becaiûse otherwise the compass could change its opening too easily while drawing the curve!
  • The three pins for setting the radius. Here you can download a spreadsheet which does the math for you: http://www.straordinaria.ch/taller/matematica1/radius.xls The same spreadsheet in OpenOffice format: http://www.straordinaria.ch/taller/matematica1/radius.ods
  • Tighten the screw.
  • Pull the center pin.
  • Draw the curve.
  • Done.