Tuesday, February 24, 2009

Working with Blocks and Symbols in AutoCAD



In this project, you learn to create, place, and modify symbols as you lay out an interior floor plan for a residential building.

You learn how to:

  • Create blocks.
  • Place blocks in a drawing using the INSERT command, Design Center and Tool Palettes.
  • Edit blocks.
  • Add blocks to tool palettes.
  • Export blocked and unblocked to create stand alone drawing files containing just the selected geometry.

By the time you have finished this project, you should feel comfortable working with blocks in your own drawings, and in those you receive from other AutoCAD professionals

Creating Blocks with BMAKE

In this lesson, you create a block using the BMAKE command. The objects you block in this lesson were drawn on the Furniture layer. Once they become part of a block, they will always appear to reside on the Furniture layer.
    If the elements you are about to block had been drawn on layer 0, the resulting blocks would take on the linetype and color of any layer upon which they were inserted.

If you want a block to always appear to be on a given layer, draw its elements on that layer. If you want a block to be able to change layers, draw its components on layer 0.

Important: If you insert a block created on the Furniture layer on another layer, then Freeze that layer, the entire block will disappear. If you turn that layer Off, then the block will still be visible. That is the big difference between freezing layers and turning them off.

Prior to proceeding with his project, open 7201a.dwg.

  1. From the Draw menu, choose Block then choose Make.
  2. In the Name box, type BED.
  3. In the Base Point area, choose Pick Point.
  4. Select the corner of the bed, as shown in the following image.
  5. In the Block Definition dialog box, choose Select Objects.
  6. Select two points to put a window around the bed.
  7. Press ENTER to indicate that you don't want to select any more objects.
  8. Choose the Delete radio button to insure objects are deleted from the drawing after they are blocked. This will delete the elements of the block after the block is created. This will make it easy to see if all the elements of the bed made it into the block.
  9. Choose OK to exit this dialog box and create the block. The bed will disappear from the drawing.You don't have to do this every time you create a block, but its a great way to make sure that ALL the elements you wanted to put in the block got into the block. If something doesn't disappear and it should have, then type U to undo the BMAKE command. The create the block again with all the desired objects.
  10. Use the techniques just demonstrated to convert the objects identified in the image into a block called BIG-DESK.
  11. You will find our version of the drawing to this point in 7201b.dwg.

      The Retain option, found in the Block Definition dialog box, tells AutoCAD not to delete the individual elements of the block when the block operation is complete.

      The Convert to block option will convert the objects you select into an inserted block after the block is created. This is the most commonly used option.

      The Insert Units option allows you to specify the units in which the object is currently drawn, so that if you take this object into another drawing that uses other units it can be automatically scaled. Generally, you should leave this set to Unitless because you will always be drawing in the same units and scaling will happen automatically. You may want to select another option if you frequently work in multiple units and you want to place blocks created in one unit into drawings that use another.

      Note, this option only works if you use the INSUNITS command in every drawing to specify the drawing units.

This tutorial continues . . . .