Sigh... Sorry to be such a pain guys. I'm really trying to do this on my own.
In this model, I need to offset two subtractive primitives - cylinder001 and cylinder002 under upper half - by 20mm. I can move cylinder001 along the X axis 20mm with no problem, but when I try to move cylinder002 along the same X axis by -20mm, the whole model goes screwy. Parts get reoriented and cylinder004 gets pushed off the model.
What am I doing wrong and can it be fixed without redoing every element under the cylinder primitives?
I think your problem is that if you don't pass the subtractive hole all the way through, you end up with different face names that change your file down the line. Because some of your other primitives are attached to faces, that breaks the attachment of those items. If you make cylinder002 30mm long, it doesn't break.
As you move cylinder002, the hinge pin also moves because of its attachment to a face. Here is your file update with the hinge pin hole attached to the XZ Axis002
You might also check https://forum.freecadweb.org/viewforum.php?f=3
They are blazing fast in solving such stuff...
I'll do that. Thank you.
Change y value in this way?
It's the X value that I need to modify, so that the holes move to the left and right. That is where I am changing the X value, though.