Overconstraining a Point

[Anonymous]

Hello all,

I have a hypothesis on the cause to a common problem, but my only evidence to support it is circumstanital at best.

In using AutoCAD 2013 and Inventor 2014, I have run into multiple cases where an over-constrained drawing error (or failure to apply a constraint occurs) when the constraints applied obviously still leave the drawing or sketch flexibile to some degree. There has not been a consistant quantity of constraints in a drawing or model when this happens, and is not releived when I delete constraints on geometry unrelated to what I actually want to constrain.

My hypothesis is that if a geometric object (point, line, arc, etc.) has a certain quantity of constraints to other objects, even if there is no conflict, then AutoCAD and other AutoDesk products begin having trouble computing the consequenses of adding more constraints to a sketch, block, or model.

It seems to me that if I am correct, then there should be more instructions about constraining, so that people don't have too many constraints on geometry like the origin point or a single locked geometry. However, since I have no evidence to this, I am willing to be proven wrong on this matter.

[hgasty1001]

Hi,

Can you post an example dwg file to look at?

Gaston Nunez

[Anonymous]

Gaston,

I attached a block definition files as an example where I ran into this problem, but was able to finish using satisfying constraints I needed using roundabout processes. (i.e. fixing points to objects rather than using a colinear constraint)

The nature of my subject is a rather general one however, and I was wondering if anyone had found contrary evidence to my observation.