Have you ever tried to paste new edition of an existing block to a drawing, but instead of the new block you end up with the old one? Yes, this is normal because AutoCAD remembers the old definition and if the new block has the same name as the old one it won’t overwrite it.
There are many cases when we may want to replace an existing block like we want to create multiple versions of the same drawing with different block definitions, for example, landscape plan with different trees. Or our company decides to upgrade its title block and we need to paste the new one in an old drawing and so on.
Let’s see what options do we have:
Rename the existing block
We can rename the existing block and copy the new one in the drawing. This is Extremely useful if we want to save the old block instead of just replacing it.
To do that we will use the RENAME command. Just follow these simple steps:
- To start the command we just have to type RENAME on the command line.
- A new window will pop up called Rename. Here we have to click on the type of the object that we want to rename from the list on the left. In our case we choose Blocks.
- Now we have to select the block we want to rename.
- At the bottom, we can see Rename to: button. We just have to type in the new name in the box in front of that button and click on it.
- At the end, we click OK!
Cool, our _Dot block is now called DOT. At this point, we can just paste the new _dot block into the drawing!
Replace one block with another using Express Tools
Instead of renaming an existing block we can just Replace it. This method is fast but we need to have our new block already pasted in the drawing with a different name!
- First, we go to Express tools and under Blocks tab, we can see Replace Block button. Or we can directly type BLOCKREPLACE on the command line.
- A new window will pop up called BLOCKREPLACE. Here we have to choose the block that we want to replace from the list of blocks in the drawing.
- We choose the block that we want to use to replace the original block.
- Click OK, At the Purge unreferenced items when finished? <Y>: prompt we enter either Y or N.
That’s all now we have a new block definition for our block!
Note: You may need to do regen to see the changes.
Replace Blocks using -Insert command
To use this method first we need to use WBLOCK command to export the new block to a file.
- First, we type -insert in the command line.
- Secondly at Enter block name or [?] <block_name>: prompt, enter blockname=filename. Here Block name is the name of the existing block in our drawing and file name is the name of the file containing the block we want to use. Here we have to enter the entire path to our drawing, for example c:\users\user name\desktop\block_name
- At the prompt Block “square plate” already exists. Redefine it? [Yes/No] <N>: we enter “y” and press Enter.
AutoCAD will give us a message about redefined blocks and will ask us to specify the insertion point for the new block. If we don’t need to insert it in the drawing we can just hit Esc key.
Delete the old block and paste a new one
May be one of the first things that comes to our mind is to delete the old block and paste the new one into the drawing. This method will work anytime and is great if we don’t need the old block into our drawing. To learn how to delete blocks from our drawings just read our post about that: Delete blocks from drawing in AutoCAD (We offer 2 easy ways to do that!)