The Explode tool
Fig. 9.13 The Explode check box in the Insert dialog
A check box in the bottom left-hand corner of the Insert dialog is labelled Explode. If a tick is in the check box, Explode will be set on and when a block is inserted it will be exploded into the objects from which it was constructed (Fig. 9.13).
Another way of exploding a block would be to use the Explode tool from the Home/Modify panel (Fig. 9.14). A click on the icon or entering ex at the command line brings prompts into the command line:
And the picked object is exploded into its original objects.
Fig. 9.14 The Explode tool icon in the Home/Modify panel
Purge
The Purge dialog (Fig. 9.15) is called to screen by entering pu or purge at the command line.
Purge can be used to remove data (if any is to be purged) from within a drawing, thus saving file space when a drawing is saved to disk.
To purge a drawing of unwanted data (if any) in the dialog, click the Purge All button and a sub-dialog appears with three suggestions – purging of a named item, purging of all the items or skip purging a named item.
Fig. 9.15 The Purge dialog
Taking the drawing Fig. 9.8 as an example. If all the unnecessary data is purged from the drawing, the file will be reduced from 145 Kbytes to 67 Kbytes when the drawing is saved to disk.
Using the Design center fig. 9.18)
1. Construct the set of electric/electronic circuit symbols shown in Fig. 9.16 and make a series of blocks from each of the symbols.
2. Save the drawing to a file Fig16.dwg.
3. Open the acadiso.dwt template. Open the Design Center with a click on its icon in the View/Palettes panel.
4. From the Folder list select the file Fig16.dwg and click on Blocks under its file name. Then drag symbol icons from the Design Center into the drawing area as shown in Fig. 9.17. Ensure they are placed in appropriate positions in relation to each other to form a circuit. If necessary either Move or Rotate the symbols into correct positions.
5. Close the Design Center palette with a click on the x in the top left-hand corner.
6. Complete the circuit drawing as shown in Fig. 9.18.
Fig. 9.16 Example using the Design Center – electric/electronic symbols
Fig. 9.17 Example using the Design Center
Note
Fig. 9.18 does not represent an authentic electronics circuit.
Fig. 9.18 Example using the Design Center
Wblocks
Wblocks or written blocks are saved as drawing files in their own right and are not part of the drawing in which they have been saved.
Example – wblock (Fig. 9.19)
1. Construct a light emitting diode (LED) symbol and enter w at the command line. The Write Block dialog appears (Fig. 9.19).
2. Click the button marked with three full stops (…) to the right of the File name and path field and from the Browse for Drawing File dialog which comes to screen select an appropriate directory. The directory name appears in the File name and path field. Add LED.dwg at the end of the name.
3. Make sure the Insert units is set to Millimetres in its popup list.
4. Click the Select objects button, Window the symbol drawing and when the dialog reappears, click the Pick point button, followed by selecting the left-hand end of the symbol.
5. Finally click the OK button of the dialog and the symbol is saved in its selected directory as a drawing file LED.dwg in its own right.
Fig. 9.19 Example – Wblock
Note on the Design Center
Drawings can be inserted into the AutoCAD window from the DesignCenter by dragging the icon representing the drawing into the window (Fig. 9.20).
Fig. 9.20 An example of a drawing dragged from the Design Center
When such a drawing is dragged into the AutoCAD window, the command line shows a sequence such as:
REVISION NOTES
1. Blocks become part of the drawing file in which they were constructed.
2. Wblocks become drawing files in their own right.
3. Drawings or parts of drawings can be inserted in other drawings with the Insert tool.
4. Inserted blocks or drawings are single objects unless either the Explode check box of the Insert dialog is checked or the block or drawing is exploded with the Explode tool.
5. Drawings can be inserted into the AutoCAD drawing area using the DesignCenter.
6. Blocks within drawings can be inserted into drawings from the DesignCenter.
7. Construct drawings of the electric/electronics symbols in Fig. 9.17 and save them as blocks in a drawing file electronics.dwg.
