Inventor General Discussion

Inventor General Discussion

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Distinguished Contributor
barnadaniel
Posts: 135
Registered: ‎02-01-2010
Message 1 of 8 (631 Views)

Positional representations question

631 Views, 7 Replies
07-14-2011 03:27 AM

Hello,

 

I have the following problem: I have a part in an assembly, which can rotate around an axis. The extremes of its valid range (initial and final position of the movement) can be defined by two different Mate constraints, see the attached picture: an axis of the rotating part must be mated to two different axes in the model, indicated by the yellow work axes.

 

I want to put a stop-pin into the round part, which would define the end-of-the-movement of the rotating part in the real assembly. I made this adaptively in the assembly: I created the final-position constraint, and edited the round part adaptively.

 

Now if I create another positional representation, I can not create any more constraints. So still in the Master positional representation, I created another constraint for the initial position, which I suppressed there.

 

If I create now a new positional representation, I can suppress the final-position constraint, but when I try to enable the initial-position constraint, I get the error message

 

Errors occurred during update: Position1: compute failure in Positional representation. A cross part association has failed.

 

Can this problem be solved?

 

The documentation sais "In a positional representation, adaptivity is deferred", and when the positional representation Position1 is active, the "Adaptive" menu entry of the adaptive round part is inactive in the context-menu, so intuitively I thought that its adaptivity is only active in the "Master" positional representation, exactly what I would want. But it doesn't seem to behave that way....

 

I am using Autodesk Inventor Professional 2012

 

Thank you

Daniel

 

 

Valued Mentor
ravikmb5
Posts: 313
Registered: ‎05-30-2009
Message 2 of 8 (610 Views)

Re: Positional representations question

07-14-2011 08:28 AM in reply to: barnadaniel

Where is Screenshot

 

Adaptivity wont work with the combination  of positional Representation

Please mark this response as Problem Solved if it answers your question.
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Ravi Kumar MB,
i7 860 Dell Studio XPS Win 7 64 bit 12 Gb RAM
Autodesk Inventor Certified professional 2014
Email: ravikmb5@gmail.com
Distinguished Contributor
elise_moss
Posts: 361
Registered: ‎02-18-2003
Message 3 of 8 (601 Views)

Re: Positional representations question

07-14-2011 11:18 AM in reply to: barnadaniel

You may need to suppress some of the constraints to get the positional representations to appear properly.  you can set up different design reps with some constraints on and off.

 

elise moss

Distinguished Contributor
elise_moss
Posts: 361
Registered: ‎02-18-2003
Message 4 of 8 (585 Views)

Re: Positional representations question

07-14-2011 02:42 PM in reply to: barnadaniel

also I have a tutorial you can download from my website on view representations you might find helpful.

 

http://mossdesigns.com/Documents/Inventor2011_viewreps.pdf

Distinguished Contributor
cvbt-thailand
Posts: 125
Registered: ‎12-23-2005
Message 5 of 8 (563 Views)

Re: Positional representations question

07-14-2011 08:44 PM in reply to: barnadaniel

It seems you forgot to attach your screen shot.

To solve your problem I would set your pin to the length you need (using the adaptivity as a tool) and then take the adaptivity away, make it a fixed length. 

I use adaptive subassemblies in some positional representations.  Their adaptive lengths are set in their assemblies.  I use level of detail to work with different subassemblies that use the same adaptive parts.  I can have only one subassembly active (not suppressed) at a time.

Rebuild All is useful.

Geoffrey Wheeler
IV Pro 2011 64bit SP2; Win7 Ultimate SP1
ASUS MB Intel i5-3450 @ 3.10 GHz, 8GB RAM
ATI AMD Radeon HD 6600 Series, 1GB RAM
Distinguished Contributor
barnadaniel
Posts: 135
Registered: ‎02-01-2010
Message 6 of 8 (555 Views)

Re: Positional representations question

07-14-2011 10:55 PM in reply to: barnadaniel

Sorry, I forgot indeed to attach the screenshot.

Distinguished Contributor
barnadaniel
Posts: 135
Registered: ‎02-01-2010
Message 7 of 8 (550 Views)

Re: Positional representations question

07-14-2011 11:22 PM in reply to: cvbt-thailand

Hi,

 

I also did first what you suggested: make the length fixed (i.e. make the part non-associative after crating the pinhole). But the design was not 100% fixed, and I optimized some dimensions - and forgot to update the pinhole position.

 

In fact, the way I tried to do this DOES work with the following two annoying things:

 - When I activate the problematic initial-position positional representation, nothing happens, I need to slightly drag the part in question, and then it jumps to the correct position

- The quoted error message pops up, which I simply need to Accept, and that's it. The pinhole position remains in its correct place.

 

 

 

Distinguished Contributor
cvbt-thailand
Posts: 125
Registered: ‎12-23-2005
Message 8 of 8 (542 Views)

Re: Positional representations question

07-15-2011 12:53 AM in reply to: barnadaniel

It might be easier to constrain your motion with one angle mate.  You can set limits for the angle in the constraint dialog box.  Then set your positional representations; modify the constraint and set the angle to what you need for each position.  Choose your angle mating surfaces conveniently; you might need to create a work plane.

Geoffrey Wheeler
IV Pro 2011 64bit SP2; Win7 Ultimate SP1
ASUS MB Intel i5-3450 @ 3.10 GHz, 8GB RAM
ATI AMD Radeon HD 6600 Series, 1GB RAM
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