engt 122 – cad i chapter 14 - blocks. what’s a block? block - a group of objects combined to...

ENGT 122 – CAD IENGT 122 – CAD I

Chapter 14 - BlocksChapter 14 - Blocks

What’s a Block?What’s a Block?

BlockBlock - A group of objects combined to create a single - A group of objects combined to create a single object.object.

Can be named and saved for later retrieval (Can be named and saved for later retrieval (BLOCKBLOCK).).

Can be repeatedly inserted into a drawing at any Can be repeatedly inserted into a drawing at any time (time (INSERTINSERT).).

Comprised of any number of objects, but treated as a Comprised of any number of objects, but treated as a single object that can be easily moved, rotated, single object that can be easily moved, rotated, scaled, and copied.scaled, and copied.

What’s a Block?What’s a Block?

Individual objects comprising a block can be Individual objects comprising a block can be “recovered” using the “recovered” using the EXPLODEEXPLODE command. command.

An inserted Block is referred to as a “An inserted Block is referred to as a “Block Block ReferenceReference”.”.

Once created, a block can be modified (Once created, a block can be modified (redefinedredefined), ), and all inserted block references will update and all inserted block references will update accordingly.accordingly.

Blocks can be “nested” within another block.Blocks can be “nested” within another block.

Some Advantages of BlocksSome Advantages of Blocks

Allows a previously created drawing or portion of a Allows a previously created drawing or portion of a drawing to be reused in the same drawing or another drawing to be reused in the same drawing or another drawing without recreating it.drawing without recreating it.

Allows extensive libraries of symbols and parts to be Allows extensive libraries of symbols and parts to be created, stored, and accessed at any time.created, stored, and accessed at any time. Reduces drawing time.Reduces drawing time. Assures standardized symbol conventions and part Assures standardized symbol conventions and part

dimensions within the organization.dimensions within the organization.

Some Advantages of BlocksSome Advantages of Blocks

Greatly simplifies drawing changes. Greatly simplifies drawing changes. Example: an assembly has 150 similar bolts. If Example: an assembly has 150 similar bolts. If

the bolt specification changes, the block the bolt specification changes, the block definition can be easily edited and the assembly definition can be easily edited and the assembly will update to reflect the change on all bolts. will update to reflect the change on all bolts.

Greatly reduces drawing file size. The objects Greatly reduces drawing file size. The objects comprising a block are only stored once, during comprising a block are only stored once, during definition of the block. Each block insertion is definition of the block. Each block insertion is merely a merely a referencereference to the original block definition to the original block definition (ex: 500 block insertions of a bolt require little (ex: 500 block insertions of a bolt require little more storage requirements than a single bolt).more storage requirements than a single bolt).

Block Example:Block Example:

Standardized electrical symbol library can be Standardized electrical symbol library can be created from Block entities and later used to created from Block entities and later used to create circuit diagrams.create circuit diagrams.

DEMO 1:DEMO 1:

Load file Load file Demo1.dwgDemo1.dwg..Show example of electrical symbol Block Show example of electrical symbol Block

insertioninsertion

Learning ObjectivesLearning Objectives

Create blocks with the Create blocks with the BLOCKBLOCK command.command. Insert blocks with the Insert blocks with the INSERTINSERT command. command.Split a block into individual objects using Split a block into individual objects using

the the EXPLODEEXPLODE command. command. Learn to redefine a block.Learn to redefine a block.Create drawing files using the Create drawing files using the WBLOCKWBLOCK

command.command.Redefine the insertion base point for a Redefine the insertion base point for a

drawing.drawing.Rename blocks and purge unused blocks. Rename blocks and purge unused blocks.

Creating BlocksCreating Blocks Step 1:Step 1: Create the objects to be grouped in the block Create the objects to be grouped in the block

using AutoCAD drawing commands, but note;using AutoCAD drawing commands, but note; When inserted, each entity in the block will retain the When inserted, each entity in the block will retain the

properties of the layer it was created in or inherit the properties of the layer it was created in or inherit the properties of the current layer according to table below:properties of the current layer according to table below:

If you want objects in a If you want objects in a block to:block to:

Create objects on Create objects on these layersthese layers

Create objects with Create objects with these propertiesthese properties

Retain original properties Retain original properties and layer when insertedand layer when inserted Any but 0 (zero)Any but 0 (zero) Any but BYBLOCKAny but BYBLOCK

Inherit properties and Inherit properties and layer from the layer layer from the layer current during insertcurrent during insert

0 (zero)0 (zero) BYLAYERBYLAYER

Retain original layer but Retain original layer but inherit specific individual inherit specific individual properties according to properties according to current property settingscurrent property settings

Layer you want Layer you want inserted block to inserted block to

be placed onbe placed onBYBLOCKBYBLOCK

Creating BlocksCreating Blocks Step 2:Step 2: Make sure the objects to be placed in the block Make sure the objects to be placed in the block

are visible. Then, issue the are visible. Then, issue the Make BlockMake Block Command using Command using command line, drop down menu, or toolbar.command line, drop down menu, or toolbar.

Command:Command: BBLOCKLOCK

All methods All methods bring up bring up Block Block DefinitionDefinition dialog box.dialog box.

Draw ToolbarDraw Toolbar

Block Definition Dialog BoxBlock Definition Dialog Box

DEMO 2:DEMO 2:

Open file Open file Demo2.dwgDemo2.dwg..Create some geometry.Create some geometry.Demonstrate Make Block Commands and Demonstrate Make Block Commands and

Block DefinitionBlock Definition dialog box; dialog box;BLOCKBLOCK

Exercise 1:Exercise 1: Start a new drawing using an English template.Start a new drawing using an English template. Set the current layer to Layer 0 and then create the Set the current layer to Layer 0 and then create the

simplified bolt shown (without dimensions). When simplified bolt shown (without dimensions). When inserted, this block will inherit the properties of inserted, this block will inherit the properties of whichever layer is current.whichever layer is current.

Using the bolt geometry, create a Using the bolt geometry, create a block named block named BOLTBOLT. . The base point should be at the The base point should be at the

location indicated.location indicated. Use the Use the DeleteDelete option for option for

the selected objects.the selected objects. Save your file as Save your file as Ex1.dwgEx1.dwg. .

You will need it later. You will need it later.

Base PointBase Pointat midpointat midpoint

Inserting BlocksInserting Blocks

Step 3Step 3 – Once created, the block is stored locally in the – Once created, the block is stored locally in the current drawing file. current drawing file.

To insert a copy of the block, the To insert a copy of the block, the IINSERTNSERT command can command can be used.be used.

Set the current layer and/or adjust settings in the Set the current layer and/or adjust settings in the Properties toolbarProperties toolbar before using before using IINSERTNSERT;; Each block object will be placed on the current layer.Each block object will be placed on the current layer. All block objects created on “All block objects created on “Layer 0Layer 0” will inherit ” will inherit

properties from the current layer.properties from the current layer. All block objects created with All block objects created with PropertiesProperties set to set to

BYBLOCKBYBLOCK will inherit specific individual properties will inherit specific individual properties according to current property settings.according to current property settings.

Inserting BlocksInserting Blocks

A Block is inserted using the A Block is inserted using the IINSERTNSERT command; command;

Command:Command: IINSERTNSERT

InsertInsert dialog box appears dialog box appears

Draw Draw Toolbar: Toolbar: Insert BlockInsert Block

Inserting BlocksInserting Blocks InsertInsert dialog box allows; dialog box allows;

A predefined block to be inserted, orA predefined block to be inserted, or A drawing file to be inserted as a block. A drawing file to be inserted as a block.

DEMO 3:DEMO 3:

Show the Show the INSERTINSERT command using block command using block made in Demo 2. Illustrate inserting;made in Demo 2. Illustrate inserting;A predefined blockA predefined blockAn external file An external file Demo3.dwgDemo3.dwg (title block) (title block)

as a block.as a block.

Exercise 2A:Exercise 2A: Use the same drawing file from Exercise 1 (Use the same drawing file from Exercise 1 (Ex1.dwgEx1.dwg) )

and create the geometry shown using a new layer and create the geometry shown using a new layer called called JOINTJOINT with color = Magenta (no dimensions). with color = Magenta (no dimensions).

Then create a new layer called Then create a new layer called BOLTBLOCKBOLTBLOCK using color using color = Green, linetype = continuous, linewight = 0.7.= Green, linetype = continuous, linewight = 0.7.

Set the current layer to Layer Set the current layer to Layer BOLTBLOCKBOLTBLOCK. .

Exercise 2B:Exercise 2B: Use the Use the INSERTINSERT command to insert 3 copies of your command to insert 3 copies of your

block named block named BOLTBOLT as shown below. as shown below. Notice the blocks inherit the properties of the Notice the blocks inherit the properties of the

current layer (current layer (BOLTBLOCKBOLTBLOCK ). Why? ). Why? Save your file as Save your file as Ex2.dwgEx2.dwg. You will need this later.. You will need this later.

Editing Block DefinitionsEditing Block Definitions A bock is treated as a single object, but is comprised A bock is treated as a single object, but is comprised

of multiple objects.of multiple objects. To make a change in a block, it must first be To make a change in a block, it must first be

““ExplodedExploded”” to divide it into its components. to divide it into its components. Use the Use the IINSERTNSERT command command

with the with the ExplodeExplode option to option to insert the block in an insert the block in an exploded state, or…exploded state, or…

Or use the Or use the EXPLODEEXPLODE command on a previously command on a previously inserted block.inserted block.

Command: Command: EXPLODEEXPLODE

DDMenu: DDMenu: ModifyModify > > ExplodeExplode

Modify Toolbar: Modify Toolbar: ExplodeExplode

Editing Block DefinitionsEditing Block Definitions

Once in the exploded state, the individual objects Once in the exploded state, the individual objects comprising the block can be edited and modified.comprising the block can be edited and modified.

After making the required changes, the block can be After making the required changes, the block can be ““RedefinedRedefined” as follows;” as follows; Reissue the Reissue the BLOCKBLOCK command. command. Reselect the objects comprising the block.Reselect the objects comprising the block. Provide the original block name Provide the original block name AutoCAD will AutoCAD will

issue a warning, “issue a warning, “Block is already defined, Do you Block is already defined, Do you want to redefine it?want to redefine it?” ” Select “ Select “YESYES”. ”.

The block is now redefined and incorporates the The block is now redefined and incorporates the changes you made. All blocks inserted previously with changes you made. All blocks inserted previously with this name will update accordingly! Wowee!this name will update accordingly! Wowee!

DEMO 4:DEMO 4:

Open Open Demo4.dwgDemo4.dwg.. Insert an exploded version of Insert an exploded version of diodediode..Redefine Redefine diodediode and view update. and view update. Insert a non-exploded version of Insert a non-exploded version of resistorresistor..Use Use EXPLODEEXPLODE to explode to explode resistorresistor..Redefine Redefine resistorresistor and view update. and view update.

Exercise 3A:Exercise 3A: If not currently open, reopen drawing If not currently open, reopen drawing Ex2.dwgEx2.dwg which which

you saved in the previous exercise.you saved in the previous exercise. Away from the existing objects, insert a copy of your Away from the existing objects, insert a copy of your

block named block named BOLTBOLT using the using the ExplodeExplode option. option. Use Use STRETCHSTRETCH to increase the length of the exploded to increase the length of the exploded

bolt by 2”. bolt by 2”. Then Set the current layer to Then Set the current layer to layer 0layer 0 and add some and add some

simple threads using simple threads using COPYCOPY or or ARRAYARRAY..

Exploded Exploded BoltBolt block block

Exercise 3B:Exercise 3B: Use the modified bolt geometry to redefine your Use the modified bolt geometry to redefine your

block called block called BOLTBOLT. Use the . Use the RetainRetain option for selected option for selected objects, and use the same base point as previously.objects, and use the same base point as previously.

Respond YES to the message Respond YES to the message Bolt already defined, Bolt already defined, do you want to redefine it?do you want to redefine it?

Your bolts should all update by increasing in length.Your bolts should all update by increasing in length.

Base Point Base Point at midpointat midpoint

End Lesson 30End Lesson 30

Block LayersBlock Layers

Review of Layers as pertaining to blocks:Review of Layers as pertaining to blocks:










DEMO 5:DEMO 5:

Open file Open file Demo5.dwgDemo5.dwg..Show how object creation layer affects Show how object creation layer affects

block insert properties and layer.block insert properties and layer.

Nested BlocksNested Blocks

Nested BlockNested Block If the If the BLOCKBLOCK command is issued command is issued to create a block, and another block is selected as to create a block, and another block is selected as one of the objects, a one of the objects, a nested blocknested block is formed (one is formed (one within another).within another).

The depth of nesting is unlimited.The depth of nesting is unlimited.

DEMO 6:DEMO 6:

Load Load Demo6.dwgDemo6.dwg..Show Nested block.Show Nested block.

Create a small circuit using existing Create a small circuit using existing blocks.blocks.

Convert circuit into a larger block with Convert circuit into a larger block with nesting.nesting.

WBLOCKSWBLOCKS Blocks are stored locally in the drawing file they Blocks are stored locally in the drawing file they

were created in and are not directly accessible in were created in and are not directly accessible in other drawings.other drawings.

The The WBLOCKWBLOCK command (called command (called Write BlockWrite Block) ) overcomes this deficiency.overcomes this deficiency. Any drawing file can be inserted as a block.Any drawing file can be inserted as a block. WBLOCKWBLOCK glorified save command that creates glorified save command that creates

a drawing file from a portion of your current file.a drawing file from a portion of your current file. selected objectsselected objects predefined blockpredefined block or the entire drawingor the entire drawing

These new drawing files can then be inserted as These new drawing files can then be inserted as blocks in any other drawing file.blocks in any other drawing file.

WBLOCKSWBLOCKS

To Create a WBLOCK:To Create a WBLOCK: Command:Command: WWBLOCKBLOCK Displays Displays Write BlockWrite Block

dialog box.dialog box.

DEMO 7:DEMO 7:

Load file Load file Demo7.dwgDemo7.dwg..Show the Show the WWBLOCK BLOCK command using; command using;

A predefined blockA predefined block Entire drawingEntire drawing Selected objectsSelected objects

Show Show WWBLOCKBLOCK insert. insert.

Exercise 4A:Exercise 4A: Open a new drawing.Open a new drawing. Create a layer called Create a layer called BLOCKSBLOCKS (any color & line type). (any color & line type). Make layer Make layer BLOCKSBLOCKS current, then set the Properties current, then set the Properties

Control for color, linetype, and lineweight to Control for color, linetype, and lineweight to BYBLOCKBYBLOCK.. Create the objects shown below without dimensions. Create the objects shown below without dimensions.

Exercise 4B:Exercise 4B: Create a Wblock named Create a Wblock named SmallBoltSmallBolt using the geometry using the geometry

and base point indicated. Save it where you can find it!and base point indicated. Save it where you can find it! Create a Wblock named Create a Wblock named BigBoltBigBolt using the geometry and using the geometry and

base point indicated. Save it where you can find it!base point indicated. Save it where you can find it! Create a Wblock named Create a Wblock named nut nut using the geometry and using the geometry and

base point indicated. Save it where you can find it!base point indicated. Save it where you can find it! Save your file.Save your file.


Wblock named Wblock named SmallBoltSmallBolt

WBlock named WBlock named BigBoltBigBoltWBlock named WBlock named NutNut

Base PointBase Point


Exercise 4C:Exercise 4C: Open a Open a newnew drawing file and create the geometry drawing file and create the geometry

shown below (without dimensions).shown below (without dimensions). Create a new layer called Create a new layer called BOLTBOLT (any color & line type). (any color & line type). Make Make BOLTBOLT the current layer. the current layer.

Exercise 4D:Exercise 4D: Set your Properties Controls as Set your Properties Controls as

shown below. Use shown below. Use INSERTINSERT to to Insert block Insert block SmallBoltSmallBolt shown in shown in greengreen

Adjust Property controls as Adjust Property controls as shown below and Use shown below and Use INSERTINSERT to to Insert block Insert block BigboltBigbolt shown in shown in yellow.yellow.

Adjust Property controls as Adjust Property controls as shown below and Use shown below and Use INSERTINSERT to to Insert two blocks Insert two blocks nutnut shown in shown in red.red.

Defining Base PointsDefining Base Points When a drawing file (i.e. WBLOCK created by When a drawing file (i.e. WBLOCK created by Entire Entire

DrawingDrawing option) is used for block insertion, the base option) is used for block insertion, the base point defaults to the drawing origin.point defaults to the drawing origin.

If the file is frequently used as a block, it’s desirable to If the file is frequently used as a block, it’s desirable to reset the base point to a specific location.reset the base point to a specific location.

BASEBASE command accomplishes this. command accomplishes this. Open the drawing file to be used as a block.Open the drawing file to be used as a block. Issue the Issue the BASEBASE command; command;

Command:Command: BASEBASE

DDMenu:DDMenu: DrawDraw >> BlockBlock >> BaseBase Select a new base point and resave the file.Select a new base point and resave the file.

DEMO 8:DEMO 8:

Open file Open file Demo8A.dwgDemo8A.dwg and show contents. and show contents. Then close it.Then close it.

Open file Open file Demo8B.dwgDemo8B.dwg and Insert and Insert Demo8A.dwgDemo8A.dwg as a block with original BASE. as a block with original BASE.

Edit the BASE in Edit the BASE in Demo8A.dwgDemo8A.dwg using the using the BASEBASE command, then save it. command, then save it.

Insert Insert Demo8A.dwgDemo8A.dwg as a block with new as a block with new BASE.BASE.

Editing WBlock DefinitionsEditing WBlock Definitions

Redefining an externally referenced block (one from Redefining an externally referenced block (one from another file) will update the block locally but not in another file) will update the block locally but not in the source file.the source file.

WBLOCKS and Drawing files used as blocks should WBLOCKS and Drawing files used as blocks should be edited directly in the source file and re-saved.be edited directly in the source file and re-saved.

Renaming BlocksRenaming Blocks A block can be renamed using the A block can be renamed using the RENRENAMEAME command: command:

Command: Command: RENRENAMEAME

DDMenu: DDMenu: FormatFormat > > Rename…Rename… RenameRename dialog box dialog box

displays.displays. Select the name to Select the name to

change.change. Enter a new name and Enter a new name and

pick the pick the Rename ToRename To button.button.

Select Select OKOK.. Rename can be used for Rename can be used for

other entities too.other entities too.

DEMO 9:DEMO 9:

Open Open Demo9.dwgDemo9.dwg..Rename some of the blocks.Rename some of the blocks.RENAMERENAME can be used for other entities. can be used for other entities.

Deleting Unused BlocksDeleting Unused Blocks To remove unused blocks from the drawing use the To remove unused blocks from the drawing use the

PUPURGERGE command. command.

DDMenu: DDMenu: FileFile > > Drawing UtilitiesDrawing Utilities > > Purge…Purge…

Command: Command: PUPURGERGE PurgePurge dialog box displays.dialog box displays. Expand the tree labeled Expand the tree labeled BlocksBlocks. .

Only unused blocks will be Only unused blocks will be visible. visible.

““Non-purgable” items can be Non-purgable” items can be viewed by selecting viewed by selecting view items view items you cannot purgeyou cannot purge..

Nested blocks can be purged by Nested blocks can be purged by selecting selecting Purge nested itemsPurge nested items..

PURGE can be PURGE can be used for other used for other entities too!entities too!

DEMO 10:DEMO 10:

Open Open Demo10.dwgDemo10.dwg..Delete all blocks then insert a couple blocks.Delete all blocks then insert a couple blocks.Show the Show the PURGEPURGE command. command.PURGEPURGE can be used for other entities. can be used for other entities.

Exercise 5:Exercise 5: Create the objects shown. Then generate a block for Create the objects shown. Then generate a block for

each using the name indicated and the each using the name indicated and the DeleteDelete option. option. Insert a copy of each block.Insert a copy of each block. Rename the blocks as follows:Rename the blocks as follows:

CIRCLECIRCLEROUNDROUND; ; RECTANGLERECTANGLEBOXBOX; ; HEXHEXPOLYGONPOLYGON Try to Try to PURGEPURGE the blocks. the blocks. Delete the inserted blocks, then try Delete the inserted blocks, then try PURGEPURGE again. again.

Block: Block: CIRCLECIRCLE

Block: Block: RECTANGLERECTANGLE

Block: Block: HEXHEX

The EndThe End

RETIRED RETIRED MATERIALMATERIAL

Creating BlocksCreating Blocks Step 1:Step 1: Create the objects to be grouped in the block Create the objects to be grouped in the block

using AutoCAD drawing commands, but note;using AutoCAD drawing commands, but note; When inserted, each entity in the block will retain the When inserted, each entity in the block will retain the

properties of the layer it was created in or inherit the properties of the layer it was created in or inherit the properties of the current layer according to table below:properties of the current layer according to table below:










Inserting BlocksInserting BlocksAffect of Scale Factor:Affect of Scale Factor: Block can be mirrored during insertion by using a Block can be mirrored during insertion by using a

negative scale factor. negative scale factor. If X-Scale negative If X-Scale negative mirrors about Y-axis. mirrors about Y-axis. If Y-Scale negative If Y-Scale negative mirrors about X-axis. mirrors about X-axis.

Basepoint

Nested BlocksNested Blocks Nested BlockNested Block If the If the BLOCKBLOCK command is issued command is issued

to create a block, and another block is selected as to create a block, and another block is selected as one of the objects, a one of the objects, a nested blocknested block is formed (one is formed (one within another).within another).

The depth of nesting is unlimited.The depth of nesting is unlimited. Special rules for how layers, colors, and linetypes Special rules for how layers, colors, and linetypes

are affected in a nested block:are affected in a nested block: If an inner block has objects on If an inner block has objects on Layer 0Layer 0, or , or

objects with linetype or color specified objects with linetype or color specified BYBLOCKBYBLOCK, the objects acquire the properties of , the objects acquire the properties of the first fixed layer encountered in a higher the first fixed layer encountered in a higher level nest.level nest.

If no fixed layers are found, the If no fixed layers are found, the Layer 0Layer 0 and and BYBLOCKBYBLOCK objects acquire color = white, linetype objects acquire color = white, linetype = continuous, line weight = default.= continuous, line weight = default.

engt 122 – cad i chapter 14 - blocks. what’s a block? block - a group of objects combined to...

Documents

block objects

block example

block commands

predefined block

block insertions

title block

block entities

make block command