The purpose of this tutorial is to produce a solid model of Bplate shown in System Settings
Special layers do not have to be created for this tutorial exercise.
Suggested Commands
Begin this tutorial by constructing the profile of the Bplate using polyline. Add all circles; use the EXTRUDE command to extrude all objects at a thickness of 0.75 units. Chamfer the top edge of the plate using the CHAMFER command. Use the subtract command to subtract all cylinders from the Bplate forming the holes in the plate. Perform hidden line removals using the HIDE command and create shaded models using the SHADE command.
Whenever possible, substitute the appropriate command alias in place of the full AutoCAD command in each tutorial step. For example, use “Co” for the COPY command, “L” for the LINE command and o on. The complete listing of all command aliases is located on pages 1-9and 1-10. s
Step # 1
Begin the Bplate by establishing a new coordinate system using the UCS command at the right.
Define the origin at2.00, 1.50. Use the UCSICON command to update the user coordinate system icon to the new coordinate system location on the display screen. Use the PLINE command to draw the profile of the Bplate. See Figure 9-57.
Command: PLINE
Arc/CloseHalfwidth/Length/UndoWidth/<Endpoint of line>:C(To close the polyline and return to the command prompt)
Draw the twelve circles of 0.50 diameter by placing one circle at “A” and copying the remaining circles to their desired locations (see Figure 9-58). Use the COPY-Multiple command to accomplish this.
Command: COPY
Select objects (for the last circle)
Select objects: (press ENTER to continue with this command)
<Base point or displacement>/Multiple’s (For Multiple) Second point of displacement: 2.50,0.50
Second point of displacement: 4.50,0.50 Second point of displacement: 6.50,0.50 Second point of displacement: 8.00,3.00 Second point of displacement: 8.00,4.50 Second point of displacement: 0.50,2.50 Second point of displacement: 1.50,6.00 Second point of displacement: 8.00,6.00
Second point of displacement: (Press ENTER to exit this command)
Command: CIRCLE
3P/2P/TTR/<Radius>:D (For Diameter) Dimeter:0.50 Step # 3
From the slot by placing two circles using the CIRCLE command followed by two lines drawn from the quadrants of the circles using the OSNAP Quadrant mode. See Figure 9-58
Command: CIRCLE
3P/2P/TTR/<Center point>:4.00,3.00 Diameter/<Radius>:1.00 Command: CIRCLE
3P/2P/TTR/<Center point>:4.00,4.50 Diameter/<Radius>:1.00 Command:Line
From point: Qua of (select the quadrant of the circle at “A”) to point :Qua of (select the quadrant of the circle at “B”) To point: press ENTER to exit this command) Command:Line
From point: Qua of (select the quadrant of the circle at “C”) to point:Qua of (select the quadrant of the circle at “D”) To point:press ENTER to exit this command) Step # 4
Use the TRIM command to trim away any unnecessary arcs to from the slot. See Figure 9-60 Command: TRIM
Select cutting edges: (Projmode = UCS, Edgemide = No extend) Select objects: (Select both vertical lines at “A” and “B”)
Select objects: (Press ENTER to continue with this command)
Select objects to trim>/Project/Edge/undo: (Select the circle at “C”) Select objects to trim>/ Project/Edge/undo: (Select the circle at “D”)
Select objects to trim>/Project/Edge/undo: (press ENTER to exit this command) Step # 5
The next illustrates the use of the EXTRUDE command to give the plate a thickness of 0.75 units. However, this command only operates on circles and polylines. Currently, all objects may be extruded except for the two arcs and lines representing the slot (see Figure 9-61) the PEDIT command to convert these objects into a single polyline. This command to convert these objects into a single polyline . This command is found under Modify>Object>polyline in the pull-down menu area.
Command: PEDIT
Select polyline: (Select the vottom arc at “A”) Object selected is not a polyline
Do you want to turn it into one?<Y>(Press ENTER to except this default value )
Close/Join/Width/Edit certez/Fit/Spline/Decurver/Ltype pen/Undo/eXit<X>:J (For Join) Select object: (Select the objects labeled “B” “C” “D”)
Select objects: (Press ENTER to perform the joining operation) 3 segments added to polyline
open/Join/Width/Editvertex/Fit/Spline/Decurve gen/Undo/eXit<X> (press ENTER to exit this command)
Step # 6
Use the EXTRUDE command to give Bplate thickness,. Use the all option to select all circles and polyline outlines. Enter a value of 0.75 as the height of the extrusion. Keep the default value
for the extrusion taper angle. When completed with this operation, turn off the UCS icon with the UCSICON command. See Figure 9-62
Command: EXTRUDE Select objects: All
Select objects: Press enter to continue this command) Paht/<Hight of Extrusion>:0.75
Extrusion taper angle <0>: (Press enter to execute the operation) Command: UCSICON place a chamfer of 0.12units along the top edge of the plate. The top surface may not highlight when prompted for the base surface; Use the next option until the top surface is highlighted.
After entering the chafer distances use the Loop option to create the chamfer along the entire edge without picking each individual edge along the top.
Command: VPOINT
Rotate/<View point><0.00,0.00,1..00>: 1,-1,1 Command: CHAMFER
(TRIM mode ) Current chamfer Dist 1= 0.50,Dist2=0.50
Polyline/Distance/Angle/Trim/Method/<Select first line>:(select the line at “A”) select base surface:
Next/<OK>: N (For the next surface which should be the top surface ) Next <OK>: (Press ENTER to accept the top surface as the base) ENTER base surface distance <0.50>:0.12
ENTER other surface distance <0.50>:12
Loop/<select edge loop>: (Select the edge along the top at “B”)
Edge/Select the edge loop>: (Press ENTER to perform the chamfer operation) Step # 8
Since all of the objects have been extruded a distance of 0.75 units. The holes and slot are considered individual solid objects that do not yet belong to the base. Use the SUBTRACT command to subtract the holes and slot from the base plate (see Figure 9-64). This operation will resemble the drilling of holes and the milling for the slot. This command may be found in the pull-down menu area under Modify > Boolean > Subtract.
Step # 9
To see the object with all hiddn edges removed, use th Hide command. This command may be found in the pull-down menu area under View >Hide. See Figure 9-65.
Command: HIDE Regenerating drawing.
Regenerating the display again will return the model back to its wire frame mode.
Command: REGEN Regenerating Drawing Step # 10
From Figure 9-65 in the previous step, the circles and slot look somewhat irregular after performing the Hide operation. To smooth out the circles and arcs representing the slot, use the FACTERES command. This stands for facet resolution and it controls the density circles and
arcs are displayed in Set FACETRES to a new value of 1, perform a hide, and observe the results. See Figure 9-66.
Command: FACETRES
New value for FACETRES < 0.5000>:1 Command: HIDE
Regenerating drawing.
Notice the circles are butter defined due the in creased density. Regenerating the display again will return the model back to its wire frame mode.
Command : REGEN screen, and observe the results. See figure 9-67
Command: ISOLINES addition to the shading being performed in the original color of the model. There are no features to control lights, materials, or shadows. This shading mechanism is merely to get a fast shaded image of a model before preparing it to be rendered. See Figure 9-68
Command: SHADE Regenerating drawing.
Shading complete.