Padding Effect on Position of Subcomponent

[jarvis393]

I am new to Sketchup Pro so have some real bonehead questions.
I will try to keep each one as it’s own topic.

I am working today on my very first dynamic component.
The component is a cabinet box that consists of 8 nested subcomponents.
These components consist of Sides - Floor - Apron - Back - Partition & Stretchers.

I am so far successful in working out the Size & Position Attributes with one exception.
I have a vertical partition that situates between two horizontal elements.
No matter how many times I tell the component that this partition is 18cm tall it displays and measures 17.8 cm tall.
There is a visible gap between the top & bottom of this element and adjacent elements above below.

What would cause this padding like effect?

[Box]

Without seeing the model it is hard to know, if you attach it here you’ll get a better answer.
But at a guess I’d check the position of the subcomponents axes, is the bounding box tight to the object or is there a little gap of .2cm

[jarvis393]

Thanks for the suggest Box.

I can’t explain how it happened but somehow some of the elements were not co-planer to each other.
When I zoomed in real close I could see a gap at the front but not at the back.
Some of the facets turned out to be oblique to each other.

I will have to, obviously, pay closer attention to the drawing.