Creating a spring feature shape.. 1

[mechjames]

Hi Guys,
I have a single component with a spring feature in it I am working on that I can model without a problem in the compressed position. The component consists of basically a rectangular steel bar that is bent over in the middle 180 degrees so the two sides are then parallel, that is the compressed position. I need one side of the part to have a curve in it (the spring feature - the part is pushed into a pocket that compresses the single arm). How can I add this curve to the arm so that it goes back to the same compressed position? - I need to set the height of the arm with the curve in accurately - easy in the compressed position but the part needs to be manufactured in uncompressed position and then heat treated..

Any help received is gratefully appreciated!

cheers,
James

 

[JohnRBaker]

I suspect that we're going to need some pictures and maybe even a simple part model example before this thread is over.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[mechjames]

Hi,
of course! (sorry). Here is a small animation (.mp4 file). The solid body shows the spring in the desired compressed position. The sketch lines show where I would like the uncompressed position to be (approximately). This is a hack but I would like to know how to do it properly so that the top of the spring 'leg' will be in the known compressed position when compressed. How can I do this and how should I be thinking about it with regards to Nx functionality..

many thanks,
James

- using Nx6

 

[JohnRBaker]

If you only want to show the spring in the final assembly in either its compressed or uncompressed state what you will need to do in the original model file is create two separate solid bodies, one for each of the two compression states. Then I would create TWO Reference Sets, one containing one version and the other containing the other. Then when I'm building-up my Assembly and when I add the Component for the spring I just use whichever Reference Set is the desired one. This may be good enough as you can simply replace one Reference Set with the other anytime you desire. However, if this spring is part of sub-assembly which will be included in a larger assembly, it would best to at this point to also create an Arrangement, one showing the one Reference Set and the other with the other. This will make it easier later on if you need to quickly switch from one state to the other in your main assembly. Also, this will be mandatory if it turns out that there is a need for have more than one of the sub-assemblies containing the spring and if there is a need to show one compressed and the other not. In that case, then using Arrangements is the only practical approach.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[mmauldin]

Another option may be to use a deformable part. Attached is a model of the spring in its normal state. When you add this part to an assembly you will be prompted to give a value for the spring height as installed. With this method you can add the spring to as many assemblies as you like and each can its own value for its assembled state. Note that with this model, the value you give in the assembly must be greater than .18 or the model will fail. It will also fail if you give too large a value. At any rate add this part to an assembly and see how it works.

Also, this particular model will only give a reasonable facsimile of the part when deformed. You would have to run FEA to see how it actually deforms.

 

[mechjames]

Thanks for the answers Guys!
Each one gave me something to think about and I have now solved my problem..

many thanks,
James

 

[GPowers2]

People,

I have hooked this challenge onto this eMail thread being of a common Theme, springs.
in my case i have a deformable spring
this spring is preloading a spool
my objective is to create a screen animation with NX7.5.3.3 of the spool transitioning between two points and that the spring deforms accordingly during this move

any ideas where to start, ? - what NX functionality is best placed to tackle this

regards ... gary

 

[SiW979]

you are not going to be able to see the spring changing shape smoothly in NX at assembly level with out using the motion simulation software, however, if you were to model the the entire assembly in one model file an then have a sketch dimension that controls the position of the two spool locations an the length of the spring, then you can use the animate dimension command from within a direct sketch to show the model updating, however the results will not be as smooth as you might like.

http://screencast.com/t/FqI9JkLbA

Best regards

Simon NX7.5.4.4 MP5 - TC 8

http://www.jcb.com

 

[jnikolauk]

I've been searching for a way to live link "deformations" to a master part. Deformable part creates a copy which is not automatically updated and having "two copies in the "master" file can be confusing and lead to downstream errors. Are there other options I'm missing?

 

[JohnRBaker]

If you use the Animation option in modeling (not simulation) with deformable parts you can get simple examples of springs compressing and uncompressing, as seen in the video below.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.