Changing the length of a spring within an assembly?

[TechnicalConsultant]

Hi,

I have an assembly and within it I have a spring. The spring has been modelled with a helix and tube feature and has an expression controlling the length.

In the assembly I have a mating condition and the length of the spring is relevant to the distance between two objects. I can take a measurement of the distance, save it as an expression then interlink it to the spring which is fine.

However, if I want to use this spring in different assemblies(and release the part within TCEng)the length is going to differ from assemby to assembly.

Is there anyway I can do this without creating a different spring evertime?

Many thanks in advance

Mark Noyce
Senior Design Engineer/CAD co-ordinator

 

[vitulaaak]

have you tried deformable part?and change the spring pitch?

 

[TechnicalConsultant]

No I haven't used that before. Does it allow you to change the part in each assembly then? I'll have to have a look at it.

Mark Noyce
Senior Design Engineer/CAD co-ordinator

 

[hudson888]

Mark,

Deformable parts are the go. Under Tools>Define Deformable part.

I created an expression in the spring file for the length and used it to drive the pitch of the helix. I then defined the deformation nominating helix and tube as the deformable features, and the length as the variable expression.

Then I created an assembly and added a couple of springs to it. When you first add a deformable part you are prompted for the variable expression, in this case the length. So I was able to add two springs of different lengths.

In the assembly I created expressions for the spring length and I edited the expression values created in the list to support deformable parts such that they are now driven by those values.

It should work ok!

Best regards

Hudson

 

[TechnicalConsultant]

Superb! I'll give this a go and report back.

One more question, does this stop me being able to release the part within TCEng?

Mark Noyce
Senior Design Engineer/CAD co-ordinator

 

[hudson888]

It shouldn't do.

I can't see why it would, but knowing that one of the bigger users of Teamcentre are GM, who have recently implemented a new checkmate system you may have to experiment if they are your target audience.

Check that you can baseline at least the spring component, but in may not be proven until you have established you can also baseline the assembly.

Regards

Hudson

 

[scotty7]

Deformable parts creates the deformed shape in the parent assembly node and then supresses the original part (although this is not immediately evident to the user). The one thing to watch is STEP exporting the assembly. UG uses a protocol which is not universally recognised (by anybody) to control this, so you usually find that the defomed part has disappeared from the assembly when you import to a different system. This is definitely the case with NX2, and I think NX4 is the same.