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Substitute one block for another

One of the advantages of blocks is that you can substitute one for another. Why would you do that?

  1. Your organization switches to a different part
  2. You need to create more than one version of a drawing, each with a different part

If you use blocks for this purpose, think how much faster it would be to substitute the block instead of deleting the existing blocks and reinserting new ones for each instance!

In order for this to work, you need a file that contains only the new block that you want to use. If the block’s base point isn’t at 0,0, use the BASE command in that drawing and set the base point to the base point you want to use for the block, perhaps somewhere on the block.

Follow these steps:

  1. Type -insert on the command line.
  2. Type blockname=filename, where blockname is the name of the current block in your drawing and filename is the name of the file containing the new block you want to use. (If the file isn’t in the support file search path, type its path.) Press Enter.
  3. At the prompt asking if you want to redefine the block (the current one in the drawing), type y and press Enter.
  4. Press Esc to avoid inserting a new copy of the file. The file that you specified replaces all instances of the current block.

If you think that you might need to replace certain components in your drawing, make blocks out of them so that you can use this technique.

Remember, however, that you now have a block in your drawing that has the same name as before but is actually defined as something different, based on the file you specified. For example, you could have a block, circle, that is defined as square.

Express Tools has a command, BLOCKREPLACE, that you can also use to substitute blocks.

Ellen Finkelstein

5 comments to Substitute one block for another

  • João Carlos Fonseca

    Como trabalhar em um desenho que é um ” bloco total “. Existe algum meio? pois já dei o comando “explode” várias vezes e não separa. Deve estar travado, mas mesmo assim será que tem algum alternativa? Se possível, me responda com urgência. Obrigado


    I have done this without issues in the older versions of CAD. I am using Arch Desktop 2012 and it asks me to redefine but then doesn’t update the blocks in the drawing. It just places the new block. So I have 1 name but 2 blocks associated with it… Argh! Any suggestions?

  • Enio

    Prezado João Carlos, provavelmente o bloco está com a opção de não explodir.
    Abra o bloco com o editor de blocos (selecione o bloco e digite na linha de comando “BEDIT” sem aspas e pressione ENTER – esse comando vai abrir o bloco no editor de blocos);
    Na toolbar PROPRIEDADES altere a variável “Allow exploding” de “No” para “YES”.
    Saia do editor de blocos salvando o mesmo ao sair.
    Pronto, agora o bloco pode ser explodido.
    Espero que seja essa a sua dúvida.
    Um abraço,

  • Here’s the answer translated by Google:
    Dear John Carlos, the block is probably with the option not to explode.
    Open the block with the block editor (select the block and enter the command line “bedit” without quotes and press ENTER – this command will open the block in the block editor);
    On the toolbar, change the variable PROPERTIES “Allow exploding” from “No” to “YES”.
    Exit the editor saving the same blocks to leave.
    Okay, now the block can be exploded.
    I hope this is your issue.

    Thanks, Enio!

  • Lakshmi

    why the results are not displayed in this block replace command even we regen, in some drawings.

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