I made a spring model under PRO/E (it still works under CREO).
On this spring you have parameters.
You enter the length, the outer diameter, the diameter of the wire and the number of turns directly.
It then builds it on its own (with the right relationships).
And of course it is flexible.
It just has one flaw, see below.
I'll explain the design principle and if you want, I'll give it to you on Thursday:
Start with a helical scan for the body. (we'll see later for the quoted values). Constructs the function to have the outside diameter dimension and to be offset from the plane (d5 below)
Do a 2nd helical scan for a joint coil. (start on the map). pitch = wire diameter
ditto for the second conjoined whorls.
The defect is between the body and the joined coils, the change of pitch is brutal and not in accordance with reality.
Then you make a cut for the 2 grinding wheels of the spring. (put the length rating well)
That's it for the functions.
4 parameters mentioned above real numbers to create. (Dia-Wire, Length, Dia-Exter, Nb-Turns)
Let's move on to the relationships:
For the length of the 1st function:
D1 = Dia-Wire (Wire Diameter Dimension)
d2 = length-(3*dia-wire) (side length function)
d3 = d1/nb-coils (steps)
d4 = dia-exter
d5 = 1.5*dia-fil
2nd function:
d6 = dia-fil
d7 = dia-fil (pitch)
3rd function:
d8 = dia-wire
d9 = dia-fil (pitch)
d10 = d5 (length helical function)
4th function:
d11 = length
And that's it. For flexibility, you change the length parameter in the assembly constraints.
Here is what I managed to do but there is still a value that I don't understand.
I created a helical scan protusion. Attributes: Variable pitch, Right hand, By axis. Scan profile: "see scan profile image" Not: "See graph-pas image" Section: 'see image section'
Then here are the relationships: X=(d49-1.9)*2000/20 /*X= FACTOR DETERMINING THE POSITION OF THE SPRING HEIGHT ACCORDING TO ITS COMPRESSION RATIO /*(IF d38=4.6 THEN X=100 AND IF d38=1.9 THEN X=0. IF d38=1.35 THEN X=50. \ /*4.6 = FREE LENGTH AND 1.9 = LENGTH OF JOINED TURNS)