error on flange formation when not at 90 degrees

[cjjatpuresilica]

I have noticed that an error is introduced when forming a flange that is not at 90 degrees to the primary face. The effect creates an offset i.e. the furthermost point of the flange face does not align with the original surface.

I have attached a simple image to illustrate the problem.

In practise of course, the error is far smaller than the very best of manufacturing tolerance.

The angle of the flange in the image is at 89.64705764 degrees.

The problem is that the error prevents from constraining multiple numbers of the components accurately.

Any help with perhaps a simple formula if available would be much appreciated.

Thank you.

cjj

 

[wyaro]

check the profile drawing and line constrains.

 

[cjjatpuresilica]

Dear wyaro,

Could I ask you to please expand on your kind response for my level of understanding of Inventor 2011 does not afford me the ability to understand your advice.

Since posing the question it has occurred to me that I can possibly apply a formula to one of the global sheet-metal bend settings!

Thank you,

cjj

 

[mcgyvr]

I don't understand the question. Are you saying you have a part that you cannot fold the flange at 90 degrees (so if you fold it at 89 degrees it works but if you enter 90 degrees you get an error? If so can you post the part.

Or are you saying that because you have a flange that isn't formed at 90 degrees you cannot constrain it properly. If so you need to find other ways to constrain the part (work surfaces/origin planes,etc...

Inventor does not have a constraint tolerance setting.

 

[cjjatpuresilica]

Dear mcgyvr,

I apologise for the apparent ambiguity in my question.
When I constrained multiple versions of the component, it produced an overlapping error.

When I measured the face of the flange and the original edge I found a discrepancy proportionate to the degree of variation of the bend angle from 90 degrees.

Thank you,

cjj

 

[mcgyvr]

So...um.. Inventor is working properly.
again Inventor does not have constraint tolerances.
If your flange is NOT 90 deg and your are trying to mate it to other 90 degree surfaces you WILL get an error.

If your flange must be a 85.3212366 deg flange and you must mate it to a 90 deg surface then you must find other ways to constrain the part in the assembly. Either use the origin planes or other work planes or other surfaces.

Inventor and all CAD programs SHOULD be exact. This same issue comes up when you have 2 holes in 2 different parts.. 1 part has the holes 1.000" apart. The other part has the holes 1.0000005" apart. You cannot use the insert constraint to put those parts together. because 1 does not equal 1.0005.. same as 89.5 deg does not equal 90 deg


I feel like I'm really missing something here though.. Can you not edit your part and make the flange 90 deg exactly?