using formulas/linked parts in distance assembly constraint

[teookie]

I'm using NX 6.0.5.3.

I am having some trouble figuring out how to make the position of one component change based of the measured distance between two other components. Let me explain in a little more detail:

I have a simple pulley setup; two pulleys with a single continuous rope around them. On one side of the pulleys I have a carriage attached to the rope, and on the other side joining the two ends of the rope together is a turnbuckle. Moving the carriage one direction should cause the turnbuckle to move the other direction with equal displacement. I currently have two arrangements set up, one with the carriage at each extreme of it's travel. But, the carriage has 1 degree of freedom and I can manually position it anywhere within it's travel range with the "move component" command.

How do I get the position of the turnbuckle to automatically update based on the current position of the carriage?

I've tried using the "distance" assembly constraint and setting a formula to correctly position the turnbuckle based on the measured position of the carriage, but NX says "the measurement can not be associative because it was made in the context of an assembly". I've also tried creating an associative measurement (both in the top level assy file and in the child assy which contains the carriage) and then using that in the formula, and this works -- although it does not update automatically. I have to double click the measurement to force it to recompute and re-position the carriage.

Anyone know how to do this? I'm convinced NX has this capability I just have not found it yet...

 

[MickyV007]

Hello, have a look at this thread,

http://eng-tips.com/viewthread.cfm?qid=308155

Or search the forum for assembly sequences/movement. There is a lot of info about this.

Best regards,

Michaël.

NX7.5.4.4 + TC Unified 8.3
Win 7 64 bit (Intel(R) Xeon(R) CPU X5650 @2.67GHz)
24.0 GB
NVIDIA Quadro 4000 + NVIDIA Tesla C2050

 

[JohnRBaker]

Without actually seeing (as in opening the file) your assembly it would be hard to provide any useful help in how you'd go about accomplishing what you're attempting to do.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
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To an Engineer, the glass is twice as big as it needs to be.

 

[jerry1423]

What you can do is put a sketch in you assembly file and have the pulleys or turnbuckle constrained to the sketch.
The dimensions of the sketch can be based of the distance measurements.