Variable Positioning 3

[Ritmo2k]

I am having some issues with Variable Positioning relating to some sub assemblies. I have the following scenario:

1. Assembly of a shock absorber (consists of shock cylinder body w/ integral clevis and threaded shaft/piston components).
2. Assembly of a clevis pin (consists of clevis and tightening nut components).
3. Higher level Assembly with a lever arm that rotates 0 -> 90 degrees.

- The base of the shock body has an integral clevis that will center into a fixed component under the top level assembly.
- The lever arm is intended to be driven by an angular constraint. It has the clevis assembly separating it from the shock assemblies threaded shaft.
- I need the shock to swivel and extend with the clevis assembly as the lever rotates, and obviously swivels the clevis.

Where I am stuck is the order of constraints and what gets overridden? Possible constraints are components to assembly in each sub assembly, those components *or* their top level assembly being mated to the global top level assembly?

The cast does not have any examples, previously when animating an assembly in Visualization I wrote expressions for everything but it makes it more sense to build the constraints as they exist in real life for this project.

Any help would be appreciated!
Thanks

 

[hudson888]

Okay, but if I don't use it and I do override would I have less control over what moves in say your piston example and how does the need to use it manifest some benefit over just positioning the two components in space. In other words why do I want to use it? And/or is there any difference between bonding and just fixing two components?

Best regards

Hudson

 

[JohnRBaker]

If I had 'Bonded' all of the components inside of the 'Piston Assy' everything would still work as it did.

As for using a Bond rather than a Fix, a Bond is between components, so that 2 components Bonded to one another act as if they are part of the same component (they never move relative to each other) whereas Fix is between a component and 'ground'. It's like bolting something to the floor, it NEVER moves, period. Whereas the Bonded component can move, but as if it were a single object.

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[Ritmo2k]

@ JohnRBaker,

So after setting my assembly prefs to make 'Move Component' visible, following the first procedure nothing happened to the rod? So, undoing what ever may have happened, I attempted the next procedure and again nothing happened?

Any ideas?

Thanks for the example.
Ritmo2k

 

[JohnRBaker]

When you say 'the first procedure', what exactly are you refering to?

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[hudson888]

John,

Just for the feedback ...
I went back and tested according to your comments and filtering out some preconceptions and confusion made some sense of how this works. So now I get the whole bond and fix thing, and how they react when overriding is used in a variety of combinations.

The only problem that I could still find was that there is no align for spheres any more, the only way I could make it work is by using exactly the same diameter with touch align.

Best Regards

Hudson

 

[JohnRBaker]

Hudson,

For that unequal sized spherical constraining issue, try using the 'Infer Center/Axis' method as shown in the attached image?

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[hudson888]

Thanks John,

That works 100%. I had a bit of a tinker and see what has been done, you almost don't realize that method is available because the axis method for shafts is intuitive.

Best regards

Hudson

 

[Ritmo2k]

@JohnRBaker

My first procedure:
1. Make cyl assy work part
2. 'Move Comp.' -> cyl rod -> Look for both to move.

None moved?

My second procedure:
1. Undo any changes
2. Override position as described
3. @ Top Level, 'Move Comp.'

Still nothing moved?

Thanks!
Ritmo2k

 

[JohnRBaker]

My first procedure:
1. Make the part file 'cylinder_assy' the work part.

OK.

2. 'Move Comp.' -> cyl rod -> Look for both to move.

Just select the 'cyl rod' from the screen with your cursor. This should select the entire piston assy (it should say that in the status line). Now, accept the Dynamic option and the select the handle with the up arrow and drag the piston up and when you let go the other piston will also move to match.

My second procedure:
1. Undo any changes

Make sure that the top level assy is the WORK PART before you override the position of the Piston Assembly..

2. Override position as described
3. @ Top Level, 'Move Comp.'

This should now work.


John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/