CONSTRAINTS NOT WORKING CONSISTENTLY

[Anonymous]

I am trying to check the rotational clearance of a brace and leg, so I have drawn a simple centreline of both components, fixed the main pivot point, place a coincident restraint at the next pivot point, and a sliding coincident restraint at the final point.
It all worked first time but the geometry needed some adjustment. The leg refused to rotate back into the start position and when I removed the constraints Autocad will not re-apply them. I get a message saying
Command: _GcCoincident
Select first point or [Object/Autoconstrain] <Object>:
Select second point or [Object] <Object>:
The constraint cannot be applied. The two objects must reside in the same plane.
All lines start and finish on Z axis 0 and the UCS has been placed on one of the lines so how are they not in the same plane and how were the constraints applied the first time?
Is this an Autocad issue or am I doing something wrong?
Can anyone help here?

[Alfred.NESWADBA · Accepted solution]

Hi,

A lot of your objects have Z<>0 and are not parallel to plane XY. Set _UNITS to show 8 decimal places, then select the right line in the modelspace and look to the Z-values of that line:

please look to the smaller line of your block (within the block editor), you'll see this:

Adjust your entities within the block to Z=0, then make sure the block insertion point has also Z=0, then all should work well.

- alfred -

[Anonymous]

Thank you for that

I'll need to be more careful with the zero points.

[RogerTheShrubber]

Even at 8 decimal points, elevations of plines and endpoints of lines showed 0.000000000. Set those value manually to 0 in the properties and problem solved. Thank you!