what controls the auto (inferred) dim- in sketch?

[uwam2ie]

I like working in the sketch with the inferred dimension. Today I have a part with a wave linked body inside where I have placed a sketch on a plain face an used a edge for horizontal reference. I've drawn a line in the sketch with only horizontal contraint - using the infered dim between the line and the horizontal edge it is jumping into angle dimension 180 deg ? But why? - what controls this behaviour, the geometrie is clean, Ok using vertical dim. works - but it makes me insecure , maybe my glasses...
thx in ad

 

[JohnRBaker]

In your case, the 'inferred', for some reason, did not think that the line was truly horizontal and therefore it decided to add an angular dimension instead of a vertical or perpendicular dimension. Unfortunately, there is no way to modify or control that behavior. We just recommend that when the inferred is unable to capture what your intensions are that you then use an explicit method so that there is no question what it was that you wanted the dimension to control.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[uwam2ie]

... found it a difference of
0.000000036 deg.
only to measure with system accuracy

 

[JohnRBaker]

Unfortunately the constraint tolerances are not user controllable for the Sketch solver (although we do allow you to set the Constraint tolerances for the Assembly Position solver). I suspect the reason for that is so as to try to assure that the most accurate and geometrically precise models are being created, whereas with the Assembly Constraints the models are already what they are going to be and so forcing the same system level tolerances would be a waste of time and effort.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.