My blocks don't line up.

[Anonymous]

Using LT 2015 with 10.10.2 (actually 10.10.3 Beta, but this has been happening since long before this beta)

Outside of the block editor, if I create a box and then duplicate that box (Apple+C , Apple+V) and select a grip on one of the boxes, I can drag it and connect it to an end point on the original box and it lines up perfectly.  I verified this by zooming in some insane amount (I can't never actually tell what the current zoom level is.  Is there a thing for that?):

I have a block.  Within that block there is another block of a box.  If I do the same thing, duplicate the block of a box inside the other block (this is starting to sound like a Dr. Seuss poem!) using copy/paste and try to line them up, they just won't do it:

I've even gone ahead to make sure that the the top-left side of the box block is 0,0,0:

I just don't get what I'm doing wrong here.  It's wreaking havoc on my drawing because I expect the copy/paste/move grip to connect to an endpoint and align itself perfectly no matter if I'm drawing a box or using a block.

Thanks in advance!

[maxim_k]

I think you need to revise all your blocks, for example I noticed that in one of the blocks inside your drawing; FM - F1AS9N-1A12-10S, there are another blocks which seems lined up, but if I zoom deep enough to the object corners in this block (I explore this block in Block Editor), I can see this:

the objects doesn't lined up correctly.

So it is possible that when you use END object snap you accrue wrong endpoint inside your blocks - this gives an error in aligning blocks.

Maxim

[Anonymous]

Yes, I'm starting to realize that my entire drawing needs to be re-done.  I incorrectly assumed that the snapping was accurate, but it seems that's not the case at all.

Is there any way to make snapping idiot-proof or does it usually always require zooming in to the nth degree?

[maxim_k]

In the situation when you have a lot of identical points to snap to you need to be careful when using object snap. And yes, sometimes you need to zoom in in order to be sure about snap accuracy.
At the same time for ENDpoint object snap sometimes it is enough to position cursor over the line and wait for a half of second autosnap marker to appear at right endpoint of the line, than you can just click with mouse button and you will get right snap- it is not necessary to move cursor toward the endpoint.

Maxim