topic Re: Pivot Point in Inventor Forum

Pivot Point

Anonymous — Wed, 07 Sep 2016 12:45:52 GMT

How can I find the pivot point of a cover assembly ? I have attached the IDW file.

Re: Pivot Point

mdavis22569 — Wed, 07 Sep 2016 12:51:00 GMT

You didn't give the 3d so It's unresolved for however

here is one in my idw

find the view, then the solid for the view, Right Mouse Button ...COG and the point will come up in the IDW view

Re: Pivot Point

Anonymous — Wed, 07 Sep 2016 13:39:23 GMT

Here is the assembly that needs a pivot point.

Re: Pivot Point

mcgyvr — Wed, 07 Sep 2016 13:56:08 GMT

@Anonymous wrote:

Here is the assembly that needs a pivot point.

@Anonymous An iam file without including all the ipt/sub iam files is useless..

The iam just "links" to those files and does not include them in itself..

So you need to zip up all the ipt files (and any subassembly iam files) and include the main iam file too..

But searching help should get your answer..

https://knowledge.autodesk.com/support/inventor-products/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/Inventor-Help/files/GUID-81012CAC-CF33-401A-94E9-29DE44CABF81-htm.html

and more..

Re: Pivot Point

Anonymous — Wed, 07 Sep 2016 14:15:31 GMT

Sorry about that. Here is the zip file.

Re: Pivot Point

mdavis22569 — Wed, 07 Sep 2016 14:23:44 GMT

Did you see how I said to do it ...

O BROWNE PULL.ipt is missing.

I deleted it from the Assembly, here is here the COG/pivot point shows up

Mike

Re: Pivot Point

Anonymous — Wed, 07 Sep 2016 14:41:21 GMT

Centre of gravity does not help in this case . What I need is a pivot point that will allow the cover to be in position 1 when open and position 2 when closed. The parts would share a common pivot point location.

Re: Pivot Point

Anonymous — Wed, 07 Sep 2016 15:58:09 GMT

I have attached a model of the cover assembly. It is not exactly what I need but does show the intent. The pivot point was created by trial and error, not a good way to operate. The IDW view is what I need to pivot.

Re: Pivot Point

CCarreiras — Wed, 07 Sep 2016 19:40:49 GMT

HI!

Still missing "O BROWNE PULL"

You have to attach here all the files: iam, ipt, idw..... all the files... assembly files don't bring the ipt files with it!!!

Make a pack and go!! Check the video about wht you need to do.

Re: Pivot Point

mdavis22569 — Wed, 07 Sep 2016 21:14:27 GMT

let me ask you a question ..are you trying to get us to figure out where to put the pivot hole in this for you?

Re: Pivot Point

Curtis_W — Wed, 07 Sep 2016 23:40:51 GMT

Hi jerr72,

This is one of the few times I like adaptive parts.

What I would do is:

create a hole in the stationary part
change the dimensions to be driven
go a head and make the sketch that controls the position of the hole visible so you can edit it from the assembly.
edit the moving part in context of the assembly
project the hole from the 1st part to the 2nd making it adaptive
cut that hole in part 2

Now you're ready to figure some stuff out.

Create an insert constraint between the holes in the two parts
Delete other existing constraints if needed
Rotate your part and check the location
- Change your selection filter to Select Sketch Features
- grab the sketch center of the hole and drag as needed
- Change your selection filter to Select Part Priority
Rotate your part and check the location
- Change your selection filter to Select Sketch Features
- grab the sketch center of the hole and drag as needed
- Change your selection filter to Select Part Priority
Rinse and repeat, Etc.

When done:

turn off adaptively.
set sketch dims to be driven in part 1, and give them even dimension values (3.125" vs 3.11984685779")
edit part 2 and dimension it with proper dimensions

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

Re: Pivot Point

Curtis_W — Thu, 08 Sep 2016 00:09:28 GMT

not the best video but it should give you some ideas about the steps outlined above.

Re: Pivot Point

Anonymous — Thu, 08 Sep 2016 11:52:49 GMT

I was looking to find a formula or procedure to find the pivot point in this assembly. We do other types of assemblies which require a point also. I can do this by trial and error, however a better system would be great.

Re: Pivot Point

mdavis22569 — Thu, 08 Sep 2016 12:30:17 GMT

I do a little trial and error and I do adaptive like Curtis mentioned.

At first it sounded like you were looking from something different now I see what you're looking for.

The problem is no formula is perfect, it changes as the parts change. A lot of factors can come into play. Some might want it to balance in the pivot, so weight could come into play.

Re: Pivot Point

mcgyvr — Thu, 08 Sep 2016 13:11:13 GMT

I'm fairly sure there is some "geometry math" (gosh its been a while 🙂 ) that will give you the pivot point..

Probably something with circles tangent to the potential contact faces.. and then finding the common intersection point of those circles..

I'm not fully awake yet though and just don't love math the way I used to.

Re: Pivot Point

Anonymous — Thu, 08 Sep 2016 13:17:30 GMT

Yes. Geometry math is the likely solution. Just where to get the answer is the question.

Re: Pivot Point

mdavis22569 — Thu, 08 Sep 2016 13:43:29 GMT

time to start 2d sketching ...

Re: Pivot Point

Anonymous — Sun, 11 Sep 2016 13:41:17 GMT

Solved. I have created the geometric solution to the pivot point question . I have attached the IDW views . This procedure works well with all variations of roll covers we make.