Discussion Groups

## Robot Structural Analysis

Product Support
Posts: 5,604
Registered: ‎04-26-2010

# Re: lifting the construction

04-20-2012 03:35 AM in reply to: mortel09

This was example how to properly rotate support.

As Rafacascudo said :  "No ,just Ux ,as long as you set the support local direction like I recommended"

Rafal Gaweda
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Valued Contributor
Posts: 56
Registered: ‎01-31-2012

# Re: lifting the construction

04-20-2012 05:31 AM in reply to: Rafal.Gaweda

why exactly just ux?

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Valued Mentor
Posts: 367
Registered: ‎05-16-2011

# Re: lifting the construction

04-20-2012 06:12 AM in reply to: tony.ridley
Hi Tony, If you have a small free height to lift the structure ,the angle the cable will do with the horizontal will be smaller and the horizontal forces can be very significant! For example if you have an 45 degrees angle(which is not rare) ,horizontal forces will be equal to the vertical force lifted on that point. Anyway , even if the angles are closer to 90 degrees, I believe this is the exact solution for the problem. Hard work?? I´m pretty sure an user as well skilled as you can set these supports in less than 30 secs!! And it is a fun solution!! If you change the lifting point coordinates ,you´ll will notice the 4 supports automatically pointing toward that single lift point/node. ;-)
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Valued Mentor
Posts: 653
Registered: ‎09-07-2011

# Re: lifting the construction

04-20-2012 05:23 PM in reply to: Rafacascudo

Agree with your thoughts.  However I'm lazy sometimes

Actually though, we normally add another member to the system, called a "spreader"  The additional beam takes a compressive force, and leaves the actual structure to be picked up with a vertical force only.

I can send you a picture if you're not sure what it is.

Tony

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Valued Contributor
Posts: 56
Registered: ‎01-31-2012

# Re: lifting the construction

04-23-2012 03:26 AM in reply to: tony.ridley

i would like a picture plz

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Valued Contributor
Posts: 56
Registered: ‎01-31-2012

# Re: lifting the construction

04-23-2012 03:37 AM in reply to: Rafal.Gaweda

When i calculate the file after i have added the supports on each corner I get a warning of instability on node 52... see the attached file. Should i take this to consideration or is it nothing to worry about?

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Valued Mentor
Posts: 653
Registered: ‎09-07-2011

# Re: lifting the construction

04-23-2012 04:52 AM in reply to: mortel09

can you post the model?

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Valued Contributor
Posts: 56
Registered: ‎01-31-2012

# Re: lifting the construction

04-23-2012 04:55 AM in reply to: tony.ridley

there

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Valued Mentor
Posts: 653
Registered: ‎09-07-2011

# Re: lifting the construction

04-23-2012 05:27 AM in reply to: mortel09

model attached

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Valued Contributor
Posts: 56
Registered: ‎01-31-2012

# Re: lifting the construction

04-23-2012 05:57 AM in reply to: Rafal.Gaweda

Why should I only cross off on the UX, and not UY? I attached my file, could you see if it looks like iam simulating a lift?

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