ert3056 lab sheet

8/8/2019 ERT3056 Lab Sheet

1/43

Brains, Knowled ge, Wisd om : 10 Yea rs a nd Beyo nd

FACULTY OF ENGINEERING

AND

TECHNOLOGY

LAB SHEET

INTRODUCTION TO CIM

ERT 3056

TRIMESTER 3 (2008/2009)

IC 1 (CAD): Modeling by using CATIA

IC 2 (CAM): Rapid Prototyping

IC 3 (CAM): CNC Milling


2/43

2 Prepared by KJWong

IC1: Modeling by Using CATIA

Objectives:

- To introduce the Part Design , Assembly Design and Drafting modules of

CATIA.

- To model simplified components of a typical engine mechanism. Those

components are as shown below.

Engine Block

Piston

Conrod

Crankshaft


3/43


Lab I: Sketches

1. Engine Block

- File > New > Part > OK

Select yz plane > Sketcher (or vice-versa)

Or

Select yz plane > start > mechanical design > sketcher (or vice-versa)

- Select from Profile toolbar

- Sketch two rectangles

Excessive

lines


4/43


- To remove the excessive lines, go to Operation toolbar

Click which is located at bottom right of and you will get

Select and left click on the excessive line.

Repeat it once to remove another excessive line.

(You have to do twice because there are two excessive lines, one from each

rectangle)

You will get


5/43


-To add dimensions, go to Constraint toolbar

Select

- For example, you want to specify the dimension of 15mm, you may just select line

A.

- Double click on the number (value of the dimension) and you may change the

dimension.

70mm 55mm

15mm75mm

40mm

235mm

A

CB

D


6/43


- Another alternative is by selecting line B and line C to give the dimension on that

particular line.

- Similar steps are repeated for other lines.

- To specify dimension with respect to the origin, the dimensioning method is same,

just treat the H and V as lines.

- For example, select line D and V to specify the dimension of 70mm. Similarly,

select line A and H to specify the dimension of 40mm.

- To know whether the sketch is properly constrained, you may just observe the

color of the sketch:

White under constrained

Green fully constrained

Purple over constrained


7/43


2. Crankshaft



Or


- Go to Profile toolbar, click which is located at bottom right of and you

will get

Choose oblong

- To sketch oblong, you only need to define first and second center point. Locate the

first point at the origin and the second point somewhere to the right horizontally.

Move the mouse and click the left button of the mouse. The profile is done.

- Dimension the profile as labeled.

35mm

35mm

First

point

Second

point


8/43


3. Piston



Or


- Sketch a rectangular profile, where the vertical line on the left passes through the

origin. That particular line is actually an axis of revolution. Therefore, it should not

be a solid line. To convert it into an axis, select the line and click (or

vice-versa).

- Specifying dimension as according to the dimensions given in the figure below:

50mm

50mm

Axis of

revolution 35mm


9/43


4. Conrod


Select yz plane > sketcher (or vice-versa)

Or


- Select from the profile toolbar. Sketch two circles with center at the origin.

Then, sketch another two circles that are located somewhere vertically downward

from the previously sketched circles.

- Select from the Operation toolbar . Select

each outer circle and indicate a point to define the left fillet curve approximately.

Repeat the step for the right fillet curve.

- Dimensioning the sketch as shown in the figure below:

Center


10/43


Some tips: 1. If some of the toolbars are missing, go to View > Toolbars and activate the

toolbars.

2. To exit the sketch, just click on . To open the same sketch, go to the

specification tree and click on the + sign of PartBody. Double click Sketch.1 (or

some other name as you have renamed) and the sketch will be shown in the

sketcher.

R=25mm

D=25mm

R=140mm

150mm

R=140mm

D=50mm

R=40mm


11/43


3. Right click Part1, go to Properties, and Product tab to change the name of the

Part Number.

4. Some important icons on view toolbar:

fit to fit the geometric model to the screen.


12/43


pan to move the geometric model on 2D plane. (can also be done by pressing

the middle button of the mouse and move the mouse)

rotate to rotate the geometric model on 3D plane. (press the middle and right

button of the mouse and move the mouse)

zoom in/out to enlarge or reduce the size of the geometric model.

(press the middle button of the mouse, click the right button once and release, and

move the mouse)

normal view - to show the sketch where the plane is parallel to the screen.

(note: clicking the normal view icon for another time will show the backside of the

plane, where the horizontal axis is pointing to the left.)

5. To undo, ctrl Z;

To redo, ctrl Y;To copy, ctrl C;

To cut, ctrl X;

To paste, ctrl V.

Double click the icon if you want to use it for more than once.

6. FAQ

Q: I have already specified the necessary dimensions as given on the figure, but the

sketch is not turned into green, which indicates that the sketch is not fully constrained.

A: Check for other constraint definitions. For example, for the sketch of crankshaft, the

arc and the line may not be defined as tangent to each other.


13/43


If the = sign does not appear at the intersection of the arc and the line, it means

that the tangency constraint is not defined. To define the constraint, select the line

and the arc (click on the line or arc first, press ctrl button, and select the other

profile). Then, select constraint, right click and select tangency (or vice-versa). Do

not click the left button, it is for specifying the dimension.

Similarly, if you do not start the first center point on the origin, you can click on the

constraint button, select those two points, right click and specify coincidence to

locate the first point to the origin.

Sometimes, the lines are not horizontal or vertical. Select constraint and click on

the corresponding line, right click and define horizontal or vertical as desired.

Intersection

of arc and

line

Tangent


14/43


If it is horizontal, there will be an alphabet of H on the corresponding line. Similarly,V for vertical line.

Points to

be

selected


15/43


Lab II: Parts

1. Engine Block

- Open the sketch, press Exit workbench to exit the sketch.- Go to Sketch-Based Features toolbar

> Pad and you will get

Key in 70mm for the Length . If the arrow is not pointing towards negative x

direction, click Reverse Direction . Click OK after that. At this stage, you will get

- Next, we have to create the cylinder shaft. To do so,


16/43


- select xy plane > Sketcher

- Select Circle and sketch a circle centered at origin with diameter of

100mm.

- Exit workbench > select Pocket and in the Pocket Definition

window

Select Type as Up to last . Click Reverse Direction if needed. Now, you get


17/43


- The modeling is continued with creating crankshaft hole

- Select zx plane > Sketcher > Circle and sketch a circle centered at

origin with diameter of 50mm

- Exit workbench > Pocket > Type: Up to last


18/43


- This is the desired engine block!

2. Crankshaft

- Open the sketch > Exit workbence

- Pad > Length: 16mm in negative x direction

Front plane


19/43


- Select front plane > Sketcher > Circle and sketch a circle > Select

the semi-circular right-hand edge of the Pad and the sketched circle > Constraint

> right click > Concentricity

- Select the sketched circle > Constraint > D=50mm > Exit workbench

- Pad > Length: 20mm in positive x direction

Rear plane


20/43


- Select rear plane > Sketcher > Circle and sketch a circle centered

at the origin > D=50mm

- Exit workbench > Pad > Length: 60mm


21/43


3. Piston

- Open the sketch > Exit workbench

- Shaft > First angle: 360 o > OK

- Select bottom face > go to Dress-Up Features toolbar

> Shell > Default insidethickness: 10mm

- Select yz plane > Sketcher > Circle and sketch a circle centered at

the origin > D=25mm

Bottom

face


22/43


- Exit workbench > Pocket > click More >> Type: Up to last for both

limit

- Select the top surface of the piston > Chamfer > Length 1: 2mm & Angle:

45deg > OK


23/43


4. Conrod

- Open the sketch > Exit workbench

- Pad > Length: 16mm in positive x direction

Some tips:

- To apply material, select the Part, click (or View > Toolbars > Apply

material) and apply the material as desired.

- To check the properties, right click on the specification tree >

Properties > Mass tab and you can see the properties of the material applied.

- To change the background color, go to Tools > Options > General > Display and

change the background color as desired.

- To change the color of a surface, select that particular surface > right click > select

Properties and you can change the color.

- To change the color of the whole part, right click PartBody at the specification

tree > Properties and change the color.


24/43


- To hide/show (including sketches, parts and planes), just right click and select

Hide/Show.

- from View Toolbar allows the user to

generate different views.

- Play around with and see what happen to

the solid model.

- How about create multi view ?


25/43


Lab III: Assembly

- File > New > Product > OK

Or

Start > Mechanical Design > Assembly Design

- Insert > Existing component > select all the four part design files > Open

Or

Go to specification tree > right click > Components > Existing

components > select all the four part design files > Open

You should get

- Select Block part > fix (or vice-versa)

- Explode > OK > Yes (This step is optional. It is just to ease you in applying

the assembly constraints.)

Or

Manipulation > translate or rotate the components accordingly as desired >

Update > OK


26/43


Exploded View Manipulation Pad

- Go to Constraints toolbar >

Coincidence constraint > select the center lines of the piston hole and

conrod top hole > Update toolbar > Update all


27/43


- Coincidence constraint > select the center lines of the piston and block >

Update toolbar > Update all

- Coincidence constraint > select the crankshaft hole center line on the

engine block and the center line of 60mm length cylinder of the crankshaft >

Update toolbar > Update all


28/43


- Coincidence constraint > select the center lines of 20mm length cylinder of

the crankshaft and conrod bottom hole > Update toolbar > Update all

- Contact constraint > Select back face of conrod and front face of

crankshaft > Update toolbar > Update all


29/43


- Distance > Select zx plane for both piston and conrod > Offset: 8mm >

OK > Update toolbar > Update all

- Go to View toolbar >

select from Isometric View > Front View and you should get

zx plane for piston

zx plane for conrod


30/43


Note that the conrod is positioned at the middle of the engine block and the piston.

- If you want the crankshaft to be rotated at a particular angle, you may adjust the

distance between the top surface of the piston and the engine block by using

Distance .

Conrod

Engine block

Piston


31/43


- For example, specify it as -50mm (Remember to update the constraint by pressing

). Finally, you should get


32/43


Lab IV: Drafting

- Open any part. For example, crankshaft.

- File > New > Drawing > OK > Standard: ISO; Sheet Style: A4 ISO > OK

Or

Start > Mechanical Design > Drafting > Modify > Standard: ISO; Sheet Style: A4

ISO > OK

- Window > Tile Horizontally (to get both windows shown on the screen)


33/43


- On the specification tree, right click Sheet. 1 > Properties > Name: Crankshaft >

Scale: 1:3 > Projection Method: Third angle standard > OK

Front face


34/43


- Tools > Options > Mechanical Design > Drafting > go to Layout tab > untick

Scaling factor > go to View tab > tick Generate axis and Generate hidden lines >

OK


35/43


- Go to Views toolbar > > Front view > Select

the front face of the crankshaft > click on the sheet > drag the front view to be

located at bottom left corner.

- Click from > Projection view > position the cursor at the top

left location of the sheet. This is the top view.

- Repeat the step but now position the cursor at bottom right of the sheet. This

corresponds to the right view.


36/43


- In part design, Isometric View so that the crankshaft is being positioned in

isometric view. (If it is already in isometric view, the skip this step.)

- In drawing, Click from > Isometric View > select the part >

position the cursor at the top right location. To change the direction, use compass.


37/43


- Generate Dimensions > OK > OK

You will get

Compass


38/43


- We wish to get the final drawing as follow. To add necessary dimensions,

- Go to Dimensions Toolbar > Dimensions > adddimensions as shown in the figure above. Delete those unwanted dimensions as

well (by selecting the corresponding dimension and then press Delete key.). To

dimension radius, click of > radius > click on the corresponding

circle.

- To change the font size, select any dimension > go to Text Properties

> change the font

size (for example: 2.5) > select all other dimensions > go to Graphics Properties

> Copy Object

Format > click on the dimension that the font size is modified previously.

All the font size of the dimensions will be changed.


39/43


- Similarly, to change the color of the dimensions, select any dimension > go to

Graphics Properties and change the color > select all other dimensions > Copy

Object Format > Select the previously modified dimension and all the dimensions

will be changed accordingly. (Note: Those dimensions that are generated when

you apply Generate Dimensions may still appear to be green in color. Dont

worry, the color is actually changed. Just right click on the dimension and go to

properties and check.)

- Edit > Sheet Background > go to Drawing toolbar > Frame

Creation > Style of Titleblock: Drawing_Titleblock_Sample_2 & Action:

Creation > OK

- Change the text as desired by just double clicking the text box and type the text as

desired. You can also add text by using

- To change the font size and color, it is similar to changing the font size and color of

the dimensions.

- Edit > Working views and you can move the views to suit the frame. Finally, you

should get


40/43


Acknowledgement:

The author would like to thank Dr. Belal F Yousif for guiding the author to use CATIA

modeling software.

Reference:

CCARD, CATIA V5 User Guides , The CAD/CAM Partnership, 2001.


41/43


42/43


IC 3: CNC Milling

Tasks: NC programming, simulation and fabrication

1. You are given a raw material of dimension 909010mm 3.

2. Based on the raw material size, write a NC program to make the partshown in Figure 1.

3. Run program simulation before starting the job.

4. Tools and parameters used for the program.- Endmill cutter 6mm (T1)

- Approach point Z = 5.0mm- Depth of cut = 1.0mm- Spindle speed 1000rpm, federate 70mm/min (cutting contour)- Workpiece origin at center of workpiece

Evaluation:The students have to show their results by delivering both the NC programsand the workpiece within one lab session.

Note:How to operate the CNC milling machine is described in the documentOperation Manual.


43/43

ert3056 lab sheet

Documents