AutoCAD LT won't tim to block

[stephenP66RM]

Hi! And a Happy New Year to all!

AutoCAD LT user on Windows 10.

I think there has been a recent update on my AutoCAD LT, as this morning I have spotted a few things. For a start, when I create a new block, it automatically opens the block editor. Not an issue; I have since noticed a item in the New Block dialogue box that was checked (Open in block editor); removing the tick stops that.  But that isn't the issue...

On my last day of work before the holidays last year I was able to trim lines to blocks. This morning though, I can't. I have no idea why, but the lines will no longer extend or trim to lines within blocks. It doesn't matter if I have trim or extend set to select everything, or if I select the lines of the block as what I specifically want to trim things to: the trim and extend function ignores it.

Now, I can work around it by drawing a line over the top of the block, but why the expletive deleted should I have to do that?  And I am certainly not exploding the block, as that defeats the whole purpose of having a block.  I can't even select the anchor node of the line and use the object snap to align the line with the block, even though the lines are perpendicular.

I've had a look in the options, but I can't see anything on there that governs trim and extend, and there is nothing in the block options that I can see which has removed the functionality of the block.

Anyone else got this issue? And, even better, have a solution that doesn't involve me contacting the person who brought in this change (assuming it was done deliberately) and screaming incoherently at them for several hours till they undo this change?

[steven-g]

Can you post a dwg showing this behaviour, I just did a quick test converting a polyline into a block, and it works with trim for a line object, but we have no idea what objects are inside your block and what type of objects you are trying to trim?

[stephenP66RM]

Bizarre - it seems to be an error with this one block that I created today.  I've just tried other blocks, both ones I created last year and this morning, and they are working fine... I wonder what the z-value is?

[stephenP66RM · Accepted solution]

I've found the problem now, and solved it.  Thanks for checking, and assuring me that it isn't an update!  (And sorry AutoDesk for accusing you of a useless update...)

What had happened was that I had brought in some geometry from another drawing. Even though the properties for this geometry was showing a z value of 0.000, I don't think it was exactly 0. So what I did was changed the Z values of all the lines to 1, then changed them all back to 0. After that, the trim and extend function worked properly.

[steven-g]

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@stephenP66RM wrote:

I wonder what the z-value is?

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How do you mean the z-value are you getting an error message about that? Objects in LT can have a z-value if you are using external files that where created in full Autocad, or somehow accidentally gave the z field of a block scale a value other than 1. 

[stephenP66RM]

I had imported this geometry from another LT drawing, but I think that in turn might have been generated from a Solid Edge drawing. The start and end values for the lines were showing as 0.000, but as I have found out on another thread, if the value is less than 0.0005, it will still be enough to be out, but not enough to display as being out. I also learned in that thread that just over-writing the property value with 0 is not enough, as it won't change it (for some reason). The solution there (and here, as it happens) was to change to a definite non-zero value, and then change it to 0, which will make it exactly zero.

[steven-g]

Yeah correct, it depends on your settings in the units precision, but Autocad keeps the precision to a much higher degree than even you can see. And yes the only real way to return the values to zero, is first give it another value like "1" and then set it back to "0".