E-Formation charlyrobot V4

6.0 CAD module, exercise N°2

The second exercise proposed to you is the drawing of a «Tangram». The main purpose of this exercise is to make you use geometric constraint tools.

As you have already done exercise N°1, we don’t go into the details of each manipulation that you have already performed.

Just as earlier, you are going to define the properties.

Click on the icon «new file» and enter in the fields the following values :

X = 120 Y = 120 Z = 3, grid spacing would be : 10 mm.

Then click on the «drawing» tab and choose :

Color : black. Thickness = 0.25 mm Type : continuous. Plane : drawing

Validate the dialogue box of properties with the button «OK»

Now, you are going to start your drawing by constructing the outline.

Activate the link «magnetic grid» if not already activated.

Click on the icon «rectangle».

Place the pointer at position : X = 10 and Y = 10. Click on the left button to validate the point.

Expand you drawing until position : X = 110 and Y = 110

Validate the point with the left mouse button, and the drawing with the right mouse button.

You have drawn a square of dimensions 100 x 100.

Save your file by using the standard windows procedure. Perform this saving in the current repertory «CAD» by naming it : Ex2.CAD. Think of saving your drawing regularly as its construction goes on.

Click on the icon «polyline».

Place the pointer at the position : X = 50 and Y = 110. Click on the left button to validate the point.

Expand the created line until position : X= 10 and Y=80.

Click on the left button to validate the point then on the right button to stop construction.

Place the pointer at position : X = 90 and Y = 110. Click on the left button to validate the point.

Now, you are going to draw this line parallel to the one you have just drawn.

Click on the icon «parallel to».

During these manipulations, the line will follow the mouse pointer moves, which is normal.

Put the mouse pointer on the line previously drawn and click on the left button to validate.

Automatically, the new line follows a trajectory obligatorily parallel to the previous line. This trajectory is materialized by a dotted line.

Now, you are going to indicate a stop point by using the constraint «copy of X».

Click on the icon «copy of X».

With the mouse, point to a certain point situated on the left side of the drawing at position : X = 10 ; the magnetic coupling to the grid make these manipulations very easy.

Click on the left button to validate the point then on the right button to stop the construction.

Now, place the pointer on the last constructed point, X = 10 and Y = 40 ; click on the left button to validate the point.

Click on the icon «perpendicular to».

With the mouse, point to the previous straight line. Click on the left button to validate the intersection point.

The constraint is activated and the construction line is perpendicular to the previous straight line.

You are going to define the stop point of the straight line by a digital data capture.

Click on the icon «digital data capture».

In the data capture window, click on the tab «polar» and enter «40 mm» in the field: «distance» then validate the window by «OK» (it is useless to enter a value in the field «angle»).

Click on the left button to validate the point.

Click on the icon «parallel to»

During these manipulations, the line will follow the mouse pointer moves, which is completely normal.

Bring the mouse pointer on the previous drawn line and click on the left button to validate.

Automatically, the new line will follow a trajectory obligatorily parallel to the previous line. This trajectory is materialized by a line.

Now, you are going to indicate a stop line by using the constraint «copy of Y».

Click on the icon «copy of Y».

Point with the mouse to certain point situated at : Y = about 50 mm (the magnetic coupling to the grid will place it exactly at 40 mm).

Validate the position by clicking on the left mouse button.

You are going to define the last point of this polyline with the mouse, by placing the pointer at position X = 110 and Y = 50.

Click on the left button to validate the point, then on the right button to stop the construction.

Place the pointer on position : X = 90 and Y = 110 and click on the left button to validate the point.

Click on the icon «perpendicular to».

Point, with the mouse, to the reference line and click on the left button to validate.

The constraint is activated and the construction line is perpendicular to reference straight line.

Click on the icon «copy of X».

Point with the mouse to a certain point situated at X = about 110 mm (the magnetic coupling to the grid will place it exactly at 100 mm).

Click on the left button to validate the constraint on X and another time to validate the point then on the right button to stop the constraint.

Activate the icon «coupling to magnetic objects.

Click with the left mouse button on the bottom angle of the polyline that you have just constructed (see on the picture above).

with the magnetic coupling help, the pointer is perfectly placed at the two segments intersection.

Click on the icon «parallel to».

Point the reference line to the line you are constructing by pointing the cursor and clicking on the left button to validate it.

The constraint is activated and the construction line is parallel to the indicated straight line.

You are going to indicate the following point by using the constraint «copy of Y».

Click on the icon «copy of Y».

Indicate with the mouse pointer any point situated at position Y = about 10 (the magnetic grid coupling will place it exactly at 0 mm).

Click on the left mouse button to validate the point and another time to validate the constraint, then on the right button to stop the construction.

The basic drawing of the «Tangram» is now finished but the aim of this drawing is to realize a machining, you will have correct it in order to separate each part, To be able, after that, to create in CAM module tool-paths with outside machining.

Evidently, this operation requires, first of all, to increase the drawing volume.

Click on the icon «properties» (this function is accessible only if you are not in drawing mode. If it is the case click on «selection» to exist from it).

Enter in the fields the following values :

X = 150 Y = 150 Z = 3

The grid spacing remains unchanged.

Then click on the tab «drawing» and choose :

color : green Thickness : 0.25 mm Type : continuous Plan : plan 1

Validate the window with the left mouse button.

The fact of creating a new plane is going to permit you to use the drawing that you have just done as a tracing so as to reproduce each figure separately.

Now, you are going to center the drawing in the new surface.

Select the whole drawing (menu «Edition» «select all» or by simple press on the space bar).

Click on the right mouse button to call the contextual menu.

Click on the menu «properties».

In this window, you are going to enter the values : X = 25 and Y = 25 in the fields «position» of the tab «geometry» (don’t change the other fields).

Validate the window by «OK».

Your drawing is now centered in the new drawing volume.

Now, you will draw again each polygon of the «tangram» superposed on the existing drawing that we will call background drawing.

To avoid a selection, by mistake, of background drawing parts, you should lock its selection.

Click on the menu «edition» then on the sub-menu «selection lock».

The selection frame disappears and the lines become shaded. The whole background drawing can never be selected.

Now, you are going to draw again each polygon by relying on the background drawing. Check that grid and objects magnetic couplings are activated, because they are going to allow you to follow the contours with an exact manner.

Be careful: The most lines are common to two objects ; so it’s normal to draw it for each object.

Click on the icon «polyline».

Place the mouse pointer on the top left point of the background drawing, then click on the left button to validate the point.

Draw this first object by using the magnetic couplings to change direction (click on the left mouse button to define the point, and on the right button to stop the construction) (1).

Repeat this operation for all the other polygons, the drawing direction is not important (2) (3) (4) (5) (6).

Your drawing is now finished, the following operation will consist in selecting each polygon and displace it slightly in order to fit out a space that will allow the tool passage.

Click on the icon «selection».

The last polygon you have drawn is selected.

Place the mouse pointer near the contour of the selected object. It must be situated in 20 pixel zone of a selected object segments.

Click and slide the mouse in order to displace the object.

Displace it enough to fit out a space of at least 5 to 6 mm between each object.

Warning

If you click and release the button without performing a displacement, you activate the function «manual rotation». When this function is activated, the selection frame is accompanied by four circles at the frame corners. If this happened, just click a second time to go back to the selection standard.

Repeat this operation by selecting each one of the objects and displacing it in a such a way to get a space of about 5 to 6 mm between each object.

The last operation will consist in erasing the background image, that is no more useful.

Click on the menu «view» then on the sub-menu «tracing».

Inactivate the tracing plan 1 then validate by «OK».

You have, therefore, only the tracing «drawing» with the background image on the screen.

Unlock the selection with the menu «Edition» then «Unlocking».

Select the whole drawing then erase it by pressing the key «Del» or «Suppr» on your keyboard.

Now you are going to reactivate the drawing «tracing-plan 1» in order to find your final drawing on the screen.

Your drawing is now finished ; you can view it in different views by creating different windows (see exercise CAd level 1 on the last page) and you can of course print it.