Inventor General

Reply
Mentor
safiredesignengineers
Posts: 581
Registered: ‎06-28-2008
Message 1 of 22 (329 Views)

inventor simulation testing counter balances on fabrications

329 Views, 21 Replies
12-05-2012 08:20 AM

hi group

 

in inventor 2013 simulation what is the way to test a fabrication for counter balanced weight stability?

if you see the enclosed rough assembly. I have been playing with variouse stuff and not getting the results i want.

the idea is to work out how much weight the arm will hold without tipping over. and then by increasing the base size and weight  or arm length i can then work out the ultimate design for my needs.

 

the way i want it to work is so that the base is just sitting on the floor as in real life with gravity and weight keeping it there and then as i apply weight to the arm see the tipping or load effect.

 

this upload is simple and i constrained the base via an axis on the edge put as soon as i run the symulation it just tips over and it shouldnt?

 

I have tried many other things but get a variety of results like the base suddely flying off and a thousand miles an hout due to the contacts used ?

 

any help on the best way to do this type of set up?

 

regards Adrian

*Expert Elite*
blair
Posts: 3,943
Registered: ‎11-13-2006
Message 2 of 22 (323 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 08:56 AM in reply to: safiredesignengineers

I might have my software mixed up (Mech Sim vs Inventor Sim), but I would think "soft-springs on the base corners. As soon as you get a negitive result on a spring it's begining to lift up and tip over.

Did you find this reply helpful ? If so please use the Accept as Solution or Kudos button below.

IV2015 up1 PDSU / Sim Mech 2015 /
Win7-64
EVGA X79 - Classified, iCore7 3930k 32Gb Quad-Channel
950Gb (2 x 500Gb Sata III SSD RAID0 Adaptec 6805E Controller)
Nvidia GTX-690 Classified - 335.23
SpacePilot Pro 3.17.7, 6.17., 4.11
*Expert Elite*
JDMather
Posts: 26,246
Registered: ‎04-20-2006
Message 3 of 22 (321 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 09:00 AM in reply to: safiredesignengineers

I think I would use Spatial and 3D Contact rather than Revolution or Cylindrical joints.

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
*Expert Elite*
blair
Posts: 3,943
Registered: ‎11-13-2006
Message 4 of 22 (314 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 09:14 AM in reply to: safiredesignengineers

I guess that as soon as the CG moves beyond the edge of the base it should become unstable and start to tip over.

Did you find this reply helpful ? If so please use the Accept as Solution or Kudos button below.

IV2015 up1 PDSU / Sim Mech 2015 /
Win7-64
EVGA X79 - Classified, iCore7 3930k 32Gb Quad-Channel
950Gb (2 x 500Gb Sata III SSD RAID0 Adaptec 6805E Controller)
Nvidia GTX-690 Classified - 335.23
SpacePilot Pro 3.17.7, 6.17., 4.11
Mentor
safiredesignengineers
Posts: 581
Registered: ‎06-28-2008
Message 5 of 22 (309 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 09:25 AM in reply to: blair

Hi Blair

 

but the centre of gravity is set low in the centre of the base?

 

regards Adrian

Mentor
safiredesignengineers
Posts: 581
Registered: ‎06-28-2008
Message 6 of 22 (308 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 09:27 AM in reply to: JDMather

Hi JD

 

using spatial can have funney effects on a test like this, like the base entering the floor, or the assembly suddenly flying off.

I have played with settings to adjust this but it should be simpler.

 

regards Adrian

*Expert Elite*
JDMather
Posts: 26,246
Registered: ‎04-20-2006
Message 7 of 22 (293 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 10:34 AM in reply to: safiredesignengineers

I think the key will be to get to correct properties for the 3D Contact.

It looked to me like your direction of Gravity was backwards.

3d contact.PNG

 

For the Cylindrical joint to act appropriately (if even possible) I think you will need to edit the Joint Torque Properties.

Cylindrical.PNG

 

Similar problems have come up here in the past (perhaps by you?), but I don't recall the solution.  Perhaps a search would turn up discussion the "Desker".

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
Mentor
safiredesignengineers
Posts: 581
Registered: ‎06-28-2008
Message 8 of 22 (287 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 10:43 AM in reply to: JDMather

Hi Jd

 

Yes sorry i did have the gravity the wrong way! this is just a quick test file that i could upload.

and yes the similer problem has come up posted by me, but this time i thought by uploading a simple assembly it might provoke a simple method by somone.

 

there must be a simple good solution as anyone that fabricates stuff usining inventor will want to run tests like this on the potential work.

 

A

 

*Expert Elite*
blair
Posts: 3,943
Registered: ‎11-13-2006
Message 9 of 22 (284 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 10:50 AM in reply to: safiredesignengineers

Is this a static item, where the unit is not moving, if so then there is not a stability triangle required for unit. As soon as the C/G moves beyond an edge or hinge point the unit will tip. If this is a dynamic unit that is in motion as the C/G moves outside of the stability triangle then the unit will become unstable and tip.

Did you find this reply helpful ? If so please use the Accept as Solution or Kudos button below.

IV2015 up1 PDSU / Sim Mech 2015 /
Win7-64
EVGA X79 - Classified, iCore7 3930k 32Gb Quad-Channel
950Gb (2 x 500Gb Sata III SSD RAID0 Adaptec 6805E Controller)
Nvidia GTX-690 Classified - 335.23
SpacePilot Pro 3.17.7, 6.17., 4.11
*Expert Elite*
JDMather
Posts: 26,246
Registered: ‎04-20-2006
Message 10 of 22 (278 Views)

Re: inventor simulation testing counter balances on fabrications

12-05-2012 10:55 AM in reply to: safiredesignengineers

Might be a bad time to ask questions like this.
There seems to be reduced participation here by the Deskers between AU and Christmas.

Maybe try over here http://beta.autodesk.com

or

bump this thread after the new year if they don't come along and respond before then.

 

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm

You are not logged in.

Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register

Announcements
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.

Need installation help?

Start with some of our most frequented solutions to get help installing your software.

Ask the Community


Inventor Exchange Apps

Created by the community for the community, Autodesk Exchange Apps for Autodesk Inventor helps you achieve greater speed, accuracy, and automation from concept to manufacturing.

Connect with Inventor

Twitter

Facebook

Blogs

Pinterest

Youtube