CURVE EQUATIONS

[alansimpson]

Know any sources on the web to find equations of curves (spirals, involutes, cam movements etc.) to be used to generate curves in parts?

 

[cadcamguy]

There are some equations here and some over at mcadcentral

http://www.mcadcentral.com/proe/forum/search.asp?KW=curves+from+equations&SM=1&SI=PT&FM=0&OB=1

 

[Guest0527211403]

This page has an involute formula:

http://www.cadquest.com/books/pdf/gears.pdf

Spirals can be created using a cylindrical coordinate system using the following format:

r = 5 + 2*t (5 is the base radius, 2 is the pitch times the # of turns)
theta = t * 3 * 360 (The number 3 represents the total number of full revolutions made by the spiral)
z = 0 (This just makes the spiral flat)



Cams can be created using a similar method.

Example: Simple sinusoidal cam profile

r = 10 + 3 * sin(t*360)
theta = t * 360
z=0