Insert a Dynamic Block

[bbankston]

Hello again,

 

I'm having trouble inserting a dynamic block. I get this message:

 

*Invalid*

Block SECTION CUT references itself

 

I've made the dynamic block saved the file as SECTION CUT.dwg and then I try to import it in a new file.

[Jadeous]

I have seen this when I name the block inside the Dynamic block the same thing. Inserting the Dynamic block then refferences the Block inside it and gets confused. Try naming them two different things.

[MaxwellEdison]

Or try using WBLOCK to save the dynamic block as its own file. Make sure to check the Block radio button under source at the top of the dialog. This way the block is brought in in its dynamic state and isn't nested inside another block, so no exploding necessary.

[bbankston]

WBLOCK did it! Thanks, MaxwellEdison. I didn't try your suggestion out yet, Jadeous.

[AlinOz]

One other thing to remember - this is not limited to Dynamic Blocks - any block can do it if the new name tries to reference a block name already difined 'inside' it. As you should appreciate, you cannot have 2 Blocks with the same reference (name) and in this case you have tried to have 2 different blocks with the same name.

 

Another option is if you have a Block nested within a block and they're named the same, you can explode the innermost block of the nesting. Be warned though that if you have other blocks of the same name elsewhere in your drawing they will be redefined to the new block definition.

[bbankston]

AlinOz,

 

I think I understand. Let me clarify for myself.

 

I saved the block in the document.

 

Then I saved that document as the same name as the block.

 

When I tried to import that file (block) it was telling me that I had nested it, correct? Because basically any DWG file can be block, you don't have to go into block editor to make a block. If you import any DWG or DXF you are automatically making that file a block in your current file.

 

Right?

[bbankston]

Second question. I making a dynamic block and I want all references of that dynamic block in other drawings to change if I change the original file of that dynamic block. But right now, it's not doing that.

 

I'll explain the process.

 

I create the dynamic block - save the block - then WBLOCK the block in model space. I then import that block in another drawing. But once I change the original block and resave nothing happens to that block instance in the other drawing. What gives?

[AlinOz]

To the first question, you're 100% correct - Any drawing can be a block and if there is a block within that Block/ Drawing with the same name, in simple terms, AutoCAD won't know which block named 'SECTION CUT' it should use. So, what is it to do- it warns you that the Block references itself...

[AlinOz]

OK, I think I know what you're talking about... It would seem that you are having difficulty grasping the difference between Blocks and XREFs. To define each, a Block is basically a drawing within a drawing - once it is inserted, it stays with that drawing. If you edit it in that drawing, it will only apply to that specific drawing - not the original Block. Likewise if you change the original block, it has no link to the ones in the drawing/s where you have used them.

 

This brings us to XREF's - these (as there title infers) External References. What this means is that the Block/ Drawing isn't actually inserted into the Drawing at all. AutoCAD just writes a link to the XREFed drawing and just displays the objects within the XREF file As such, if you change the original Block/ Drawing, all drawings that it is XREFed into will update accordingly.

 

Now, there is a downside to using XREFs and it is up to you to determine the extent of the potential damage. If you are to update the XREF drawing, all instances (including past drawings) will be updated. For example, if you XREF in a symbol and then you decide to change it - all drawings that reference that symbol will be updated. The Boss comes to you 6 months later and wants a plot of that 'old' drawing (exactly as it was perhaps for legal reasons or whatever) and suddenly all the Symbols are replaced with the new ones - Oops. So be creful where you use XREFs.

 

Now, let's say you want to 'force' the Blocks contained within a particular drawing to a new definition (I see this as closer to what you're trying to achieve) Here's the procedure. Firstly there are two criteria:

1. The Redefintion Drawing of the Block MUST be named exactly the same as the Blockname in the Drawing (i.e. Redefinition File: 'C:\Blocks\A Symbol.DWG' and the Blockname in the Drawing: 'A Symbol')

2. The Redefinition Drawing contains only the objects you want in the Block (i.e. it must be standalone). It cannot be a Block within (say) a symbol Library Drawing)

 

Now, to redefine the Block in the drawing:

1. Use the INSERT command

2. Use the Browse Button and locate the Redefinition Drawing

3. Choose OK and if the Block already exists, you will get a dialogue Box advising that Block XYZ is already defined, So many instances found and Do you want to update it. Naturally, Choose Yes if you do or No or Cancel will exit without the redefinition.

 

OK, doing it this way may be a little non-automated if you want to do this to several Blocks in several drawings, but you have control over it and it prevents those older drawings updating without your permission (so to speak)

 

Hope that helps you

[bbankston]

Holy crap, AlinOz! Thanks for all of the help. You're a AutoCAD book!

[MaxwellEdison]

Another point, there is also the BLOCKREPLACE command, which oddly enough, lets you replace blocks within a drawing. This can be useful if you need to update blocks with a block of a different name. For example, replacing "Pipe Detail-001" with "Pipe Detail-002". This is probably more detail than you were originally looking for, but one solution has a habit of sparking another around here.

[AlinOz]

Glad I could help... When you've used the software for 20+ years you tend to retain a few tricks along the way. OMG I think I need another interest!!!

 

Chalk it up that there's one beer you owe me if I'm ever in your neck of the woods:lol:

 

(gee, I hope I haven't confused with any Occarisms)