NX 9:Connecting two helix / constrain spline length

[gopisandy]

Hi All,

I have two helical pipes with same axis.

Each pipe is made up of two different helix: One large diameter(outer) and one small (inner) separated axially by some distance. The two helices are joined by a spline.

I am trying to join the helical parts of each pipe such that the lengths of both the pipes come out to be the same.

So the main question is, is there a way I can constrain the length of the joining spline and then adjust the curvature? The helical length on both pipes are same i.e. inner+outer, the only variable is the joining spline.
I have to adjust the curvature such that pipes do not intersect each other.

Any advice is greatly appreciated!!
Thanks Ya'll!!

 

[gopisandy]

images

http://files.engineering.com/getfil...1-cf49-4ea9-9644-354079166025&file=model1.png

http://files.engineering.com/getfil...feff-4508-80bd-e01cecda5edf&file=model1-1.png

 

[NutAce]

As far as I know, the only spline which can have a length constraint is the one created with Routing...So I would try that one...

Ronald van den Broek
Senior Application Engineer
Winterthur Gas & Diesel Ltd
NX9 / TC10.1.2
HPZ420 Intel(R) Xeon(R) CPU E5-1620 0 @ 3.60GHz, 32 Gb Win7 64B
Nvidea Quadro4000 2048MB DDR5

HP Zbook15
Intel(R) Core(TM) i7-4800MQ
CPU @ 2.70 GHz Win7 64b
Nvidia K1100M 2048 MB DDR5

 

[Toost]

can you manufacture this ?

 

[gopisandy]

Hi Ronald,
Thank you for your response. Sadly, I don't have license for routing application. Is there any other way where I could at least make the lengths as close as possible other than by trial and error?

Toost, yes. They make heat exchangers with multiple helical tubes. But I think it is very application specific.

 

[IvanNX]

Tools>Expressions>
make two new expressions with measure length (from measure drop down menu) of both curves. L1 and L2 for example.
expand User Expressions in Part navigator, and with right click add "value" column. This way you can see lengths (values update on changes) of both curves so you can easily edit one until they are almost the same length.
PS. This is much faster then to measure them after every change.

 

[gopisandy]

Thank you for that tip Ivan.