unexpected behaviour redimensioning centred objects in sketch

[steve7C9EW]

Hi I've been having some major issues with editing centred objects in sketch.  For instance.  I have created a centred rectangle, then using its centre, created another centred rectangle construction) within it and used its corners as centres for circles (mount holes).

This all works fine, until I try to change the dimensions of the inner construction rectangle.  Rather than the inner (child?) rectangle changing size around its centre point, also maintaining its centre within the other rectangle, its changing its size in relation to one side rather than the centre.   this has the effect of moving the centre which is causing its (parent?) rectangle to also move as the centre shifts, which messes up everything drawn since.  

I'm not sure when this started, but pretty sure its a new issue.  It seems counter intuitive that when a centred rectangle is created it doesn't resize in relation to its initial anchor (the centre).   I've also found this in other instances, when a child drawing element, drawn fixed to aother element seems to have the power to move and disrupt its parent object when resized, rather than resize its own dimensions but stay anchored.

what are the rules for resizing, is the last element the parent or is this a bug where 'fixings' are not being respected?

[davebYYPCU]

Common workflow for the construction rectangle for Holes, 

unusual for that error, unless the sketch is not fully defined.

Might help…

[g-andresen]

Hi,

please show your process in a screencast and share the file

File > export > save as f3d on local drive  > attach to post

günther

[jeff_strater]

I don't believe that this is new.  Understand what a "center rectangle" is:  It is just a collection of lines and constraints that is solved along with the rest of the sketch.  There is no such object as a "center rectangle", just 6 lines, 5 points, and a bunch of constraints/dimensions.  There is nothing special, for instance, about that center point.  It is just a point with some coincident constraints to those diagonal construction lines.

So, yes, it would be desirable if we could guarantee that any size change would happen with respect to the center, but that is not in any way guaranteed, and even less so if there are constraints to other objects in the sketch.

[steve7C9EW]

Thanks for this. Perhapse then I need to create a centre line first then
build the centred stuff from that.