Coins or Pendants
by pmoews, published
I find these coin-pendants a pleasing way to display the plane curves from thing:26973, Decorative Disks. The coins have milled edges and curves on each face. They can be used as key fobs or pendants and are about the size of checker pieces.
The coins can be printed without holes or with two different types of holes. A hole through the face of the coin makes it suitable for use as a key fob. A hole through the edge allows a ribbon to be threaded through making the coin a pendant. See the image at the upper left.
Three pairs of stl files for two color printers are provided.
1) a key fob with devil and witch of agnesi curves -
coin_less_devil_witch.stl and devil_witch.stl
2) a pendant with 7 cusped hypocycloid and epicycloids -
coin_less_hypo_epicycloid.stl and hypo_epicycloid.stl
3) a simple disk with no holes -
coin_less_devil_form_evolute.stl and devil_form_evolute.stl
The openSCAD program that produces the coins is included below. There are hundreds of types of coins possible as most of the plane curve modules have adjustable parameters.
The coins are 35 mm in diameter and 5 mm thick. A 2 mm thick decoration occurs on the front and back face. Eight additional plane curve modules have been added to those from thing:26973 so that there are a total of 20 modules available.
The openSCAD program is similar to the one used for thing:26973. One chooses which type of hole to have by uncommenting the code producing the type of hole required or leaves all the hole commands commented out to produced a coin without holes. One decoration is chosen from each of two lists and the other members are commented out. The program is run once using the difference statement to make a file like coin_less_devil_witch.stl and a second time with the intersection command to make devil_witch.stl.
They look best printed with either no shells or one shell and are sturdiest with a fair amount of infill.