variable helix to connect other helix curves 5

[JavadM]

Hello
i want to connect 2 helix using third one. it must be one turn and be tangent to both red and blue helix curves
i tried a few hours and applied trigonometric functions but didn't find solution
is it possible to design such helix in between?

Javad M.
NX 12.0.1

 

[JohnRBaker]

Is it's only a single turn, and it's important that the transition from one curve to the next be smooth and continuous, I would first try using a 'Bridge Curve' and apply whatever control is needed to emulate a true Spiral.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[SDETERS]

What if you model your helix as a straight lines with a fillet between your different helix angles, then wrap your curves onto a cylinder. See attached for a quick example. or thought.

 

[Ehaviv]

I built in the past
something like that 3 lines and fillets
but the problem was the fillet size.

its arbitrary ?

I call it : filling fillet.

 

[JohnRBaker]

You could do something similar with the Bridge Curve. Create a Cylinder the same 'size' as the spiral and after creating the Bridge Curve, Project it to the outer face of the Cylinder.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[cowski]

With a little work, you can create the entire helix in the same helix command. Attached is a quick example in NX 11.

 

[JavadM]

Hi john.
I appreciate and I’m glad to see your reply.
With bridge command the problem is that endpoints of helical curves are in same polar coordinate and they are on top of X axis. So bridge won’t create appropriate curve and projection is not applicable to form a turn. please correct me if i did wrong.

if there is any same thread with bridge I’m eager to looking at.

 

[JavadM]

Hi SDETERS and Ehaviv
can you give me more explanation? or useful thread about


best regards

 

[JavadM]

hello Cowsky

best regards
i used this method before, with linear along spine, Cubic along spine and by law curve the problem i encountered is that i cant control the correct height of helix. is any specific instruction?

I was interested to find a mathematical solution for creating this helix. Before this I modeled another helix with law curves that could be controlled with some parameters and quickly updates. It’s a good candidate for product template studio.its illustrated below.

I find that the use of math can bring the best results. but new model is too complicated for me yet to build suitable equations.

 

[Ehaviv]

Hi

After a digging in my computer I found this helix

See if this equation example can help

 

[Ehaviv]

Other more close to your needs
is here in photoes.

after I'l find the part I'l post it.

As you see in the firs picture ther are 5 equations.

 

[Ehaviv]

Hi Javad

My post is the solution you need
for your helix problem.

the difference between it and the
one that in photos is that the
3 lines for zt are replaced by equation.

Thank you.

 

[Ehaviv]

If you want
give me the 3 helix heights
and I build it for you.

 

[JavadM]

Hi Ehaviv
Thanks a lot
i like the methods you shared with me.

also last night i noticed that the helix height growth is completely linear. so i used the linear pitch law type in helix command and built the curve i wanted. the 3rd helix in between is fully tangent. also according to previous constant helix curves parameters, i wrote a simple equation and got the same result.
you can look at attached images and file.

 

[Ehaviv]

Hi Javad

Sory I'm uding NX11. can't load your part.

Thank you.

 

[Ehaviv]

Here's the second spring
It's more complicated. For his mathematics
I used the Internet and took a lot of challenge and time
To reach the result that is attached to the file in this post

If you succeed in tracking and understanding the file what is good
If not I myself will have to relearn it
Before I can answer any question that arise.

Best regards

 

[JavadM]

Hi again

i used two helix curves with constant pitches:
Red Helix
Blue Helix

variable pitch helix curves are in 2 methods and one of them may be used:
green helix is created using linear law type with illustrated values
magenta helix used an equation

I attached screen shots for you, so i hope you can follow along and create helical curves in NX11



best regards
javad

 

[Ehaviv]

I seen the pictures thats a good
solution connecting the two helix
with a variable pitch.

Thank you also for sharing me.

now I`l remember this variable pitch for future

 

[Ehaviv]

A Documentation for the flat smouth top and bottom helix
for any one that have interest.

This helix is verstile and can be changed by the A_xxx variables to
1. circular helix
2. circular conic helix
3. eliptic helix
4. eliptic conic helix

 

[Ehaviv]

and the internet help page