Odd dimension behaviour when component is closed

Trying to dimension the edge lengths of an elliptical geodesic dome.

Component dome opened for editing:

Matching pair of edges (highlighted) both show the same dimension (3.783’) when I add dimensions with the component opened for editing.

Close the component, and both dimensions change, to different values, as they shift alignment.

They both shift back to the same original value when I re-open the component for editing.
Any way to avoid this?

Here’s the model:
Elliptical 2-freq dome.skp (573.0 KB)

Very odd. With the dimensions inside the component they change as you say.

I cut the dimensions from the component and pasted them in place outside the component and they stay put.

That seems like a good workaround, Dave. Thanks.

But they are no longer ‘attached’ to the edge. However, it would be good enough.

I found it quite hard to draw the dimensions with the component closed, so opened it, and highlighted the edge to dimension. Still sometimes difficult to get the dimension to align along the edge.

Will try it with Align to Dimension Line instead of Align to Screen to see if that makes any difference.

[After trying that]

Makes no difference, the dimensions still jump alignment, and change when the component is closed.

It does seem like a workaround but if I had to do something like that I might trace the edges I want to dimension outside the component and dimension them. I normally never use dimensions in SketchUp so I haven’t seen this before.

If you set the precision higher, you will notice a small difference. After scaling definition, the dimensions don’t jump around anymore:


Scaled objects might get dimensions rounded from their original (when created) definition, after the tranformation (one extra calculation that get’s rounded)

You are working with a scaled component without aligned dimensions.
You might get better results without jumping dimensions if you precisely tie each dimension to endpoints of the edge, without leaders. Only then they stay aligned with the measured edges between endpoints. Even when you scale the component.
Each placed dimension require two steps but can be done rather fast. (an extention might even automate the process for selections).
See: Dome.skp (243.7 KB)