CCycloid

Last Updated: April 19, 2002
CCycloid is a program to generate graphs of Curtate Cycloids, which are the curves produced by a point within a wheel, when that wheel is rotated. The intended users of ccyclid are makers of stringed instruments, but the program is available for anyone to use. CCycloid creates the graphs in PDF or PostScript format.

For more information on cycloids, see one of the following web sites, which are just a few among many to describe cycloids:

Downloads

Click here to download the Windows executable (240k)
Note: This program has been tested on and runs on Windows ME and Windows 2000. It does NOT run on Windows 95 (although it might run on Windows 95 if the WinSock 2 updated patch is installed; this has not been tested, though).

This program has also been run on a MacIntosh G4 using Connectix emulation software for Windows 98.

To read PDF files, you will need a copy of Adobe acroread. ACROBAT READER

User Interface Overview

Here is an image of the user interface to ccycloid on the left, with a sample of the output on the right:

cycloid UI cycloid example
Create the curve Quit ccycloid Set the width of the cycloid Set the height of the cycloid Check to have file name automatically created Name of file where cycloid will be saved Status messages appear here Percent of full cycloid to use Check here to print caption (e.g., W=80.00, h=8.00) Check here for PostScript output Check here for PDF output

Typical use of the program would be to set the width and height, and click "Create Curve" to create a PDF file for the graph of the cycloid. In the case of cross archings of the violin family, it should be remembered that these curves

  1. need not originate at the edge of the plate. Many makers place the lowest point well inside the purfling.
  2. indicate the outside shape, and so the thicknes of the wood at the lowest point should be subtracted from the total height of the arch when calculating the dimensions of the graph.

What follows is a description of the entire user interface:

Hints on Printing

Depending on your printer, etc., you may need to select the print options "Landscape" and "Print as Image". Do not select "fit to page".

Credits

ccycloid was written by Stephen Mann for Quentin Playfair, with some help porting to Windows by Rick Leung. The user interface was written with fltk. This program is completed unsuported. A linux version is also available on request.