Continue to Site

Welcome to MCAD Central

Join our MCAD Central community forums, the largest resource for MCAD (Mechanical Computer-Aided Design) professionals, including files, forums, jobs, articles, calendar, and more.

Lamé Equation (function) to drive a curve?

vonhofs

New member
I have been asked if I could model a curve using a Lamé equation. The equation actually has two different equations with two missing values, one being the Z direction and the other being the radius (that is my belief so far).

Any ideas on how to get this into a model such that when the Z value is driven from 0 (or a negative number to start the curve on the correct trajectory) to say 7?

Rh=3.36
L2H=5.65
Rleh=2.1
n=3.5
A = L2H * (1 - (Rleh/Rh)^n)^(1/n)

Lame function:
(R / Rh)^n + ( Z / A)^n = 1

FYI: https://en.wikipedia.org/wiki/Lamé_function
 
We figured it out. There was an error in the equation that was preventing it from working.

In case anyone needs to know it in the future, here is what I put into the curve from equation (along with the notes to help):
/* Original Lamé function: (R/Rmid)^n + (Z/A)^(n = 1)
/* For Creo: T is the variable, we use this for the height in Z (CSYS based)
/* So, for a curve that goes to 5.65 high, Z = T*5.65 or Z = L2H*T (to use the L2H value as the height)
/* From the original formula, R is the radius, which we want to translate to X for cartesian coordinates
/* Rmid: Radius at midplane
/* L2H: Half length of the part
/* Rtop: Radius at the top of the part
/* n: exponent
/* So, change the formula such that: (X/Rmid)^n + (Z/A)^(n = 1)
/* Flip the equation such that we solve it for X = ((1-((Z/A)^n))^(1/n))*Rmid

Rmid = 6.742/2
L2H = 11.2874/2
Rtop = 2.1
n = 3.5
A = L2H * (1 - ((Rtop/Rmid)^n))^(-1/n)
Y = 0
Z = L2H*T
X = ((1-((Z/A)^n))^(1/n))*Rmid
 

Attachments

  • Lame.jpg
    Lame.jpg
    32.8 KB · Views: 12

Sponsor

Articles From 3DCAD World

Back
Top