Join our MCAD Central community forums, the largest resource for MCAD (Mechanical Computer-Aided Design) professionals, including files, forums, jobs, articles, calendar, and more.
To draw spine curve for the "spring" part of this model
I use "curve -> from equation -> cylindrical coordinate system".
In relation discribing curve I use :
r - radius of the "spring",
theta - angle changing <0,360>,
z - ptich of the spring.
the most important is the value of 'z'. The sprint should be
tangent at star and end point to the rest geometry.
To do this the 'z' value should changing according to this (see image):
To discribe this function we use : f(t) = at^3 + bt^2 + ct + d
because : f(0) = 0, f'(0) = 0 (tangent to horizontal), f(1) = 1,
f'(1) = 0 (tanget to horizontal) (I use the domain <0,1> and multiple
value f(t) by the pitch value),
so, in the end f(t)= 2*t^3 - 3*t^2
and the curve equation loooks :
r = 2.75
theta = t * 360
z = -2.5*(2 * t * t * t - 3 * t * t)
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
