To help you to get started with the CharlyGRAAL surface functions, we suggest you carry out two guided exercises. Remember to record the file and save it regularly. (You can call it " Ex6.CAO ")

For this exercise, you will use the functions of extruded surfaces smoothed surfaces and delimited flat surfaces.

To make the drawing more easily legible, you are going to place the surfaces in a different plane ( plane 1).

After opening the CAD module, give the following blank dimensions:

- X = 190 - Y = 160 - Z = 50

Set the grid parameters to steps of 5 mm.

The in the " surfaces " tab, choose " plane 1 ".

These dimensions correspond to the dimensions of the " LAB 50 " resin blocks available from the list of accessories.

As for the previous examples, arrange your screen with two windows attributing the perspective view to the small window and activate the " realistic rendering (window menu) !

You are now going to draw the external contour of the pen tray.

Click on the " shape, rectangle " tool.

In the window " digital entry absolute tab ", enter: - X = 8 - Y = 15

Validate then in relative enter: - X = 174 - Y = 130

Make four fillets at the four corners of radius = 2 mm.

You are going to design the pencil area of the tray.

Click on the tool: " Béziers curve« 

Enter in absolute the values : - X = 15 - Y = 40

Then after validating,

Enter in relative the values: - X = 80 - Y = 20

Then after validating,

Enter in relative the values : - X = 80 - Y = -20

Stop the construction with a right click.

Edit the points.

Select the left point and with the mouse move the tangent of the point with the " X " value from the left point and with the " Y " value from the center point.

Proceed in the same way for the right point.

Move into selection mode and make an " any axis " mirroring with duplication

Designate the horizontal mirroring axis at the base of the half shape.

You are now going to draw the paper-clip area.

With the " shape " drawing tool draw a rectangle, positioning the first point in absolute at: - X = 105 - Y = 95

Then in relative at: - X = 60 - Y = 40

Make a rounded shape of r = 10 at the four corners.

Select the unit and join it.

You are going to draw the first corner of the Post it block compartment.

With the polyline tool place the first point in absolute at: - X = 45 - Y = 73

Then successively in relative a point at: - X = -22 - Y = 0

Then: - X = 0 - Y = 22

Then: - X = 2 - Y = 0

Then: - X = 0 - Y = -20

Then: - X = 20 - Y = 0

Then: - X = 0 - Y = -2

Stop the construction with a right click.

To make the visibility easier, make a window z oom around the object you have just created.

Mak e a rounded shape of: r = 1.5 on the inside angle of the corner.

Select the unit and join it.

You will now draw the central band of the pencil area. As this band will have a profile following " Z ", you will activate the " 3D mode " . You will then use the three objects composing the pencil area as profiles on which you will create the smoothed surface.

Activate the " 3D " mode .

With the " curve " tool, click on the constraint " belongs to ".

Designate a point on the contour.

In " absolute " entry mode enter: - X = nothing. - Y = 40.

Then in " relative " enter: - X = 80 - Y = 0 - Z = -15

Select the constraint: " belongs to "

Designate a point on the contour.

In " absolute " entry mode , enter: - X = nothing. - Y = 40.

Stop the construction with a right click.

Place the principal view in " XZ " view

Edit the points of the curve you have just drawn.

Select the left point.

Select the setting handle of the tangent at this point.

Click on digital entry and enter in absolute the values:

- X = 15 - Y = 40 - Z = -15

Select the right point.

Select the setting handle of the tangent at this point.

Click on digital entry and enter in absolute the values :

- X = 175 - Y = 40 - Z = -15

Return to " XY " view

You are going to draw the profile of the pape-clip area.

Make a zoom at the position of the paper-clip area.

With the " curve " tool, enter in absolute the values: - X = 170 - Y = 125

Then in relative the values: - X = 10 - Y = -15

Stop the construction with a right click.

Edit the points

Select the top point, then its point of tangency and position it with the mouse at: - X = 170 - Y = 120

Select the low point, then its point of tangency and position it with the mouse at: - X = 175 - Y = 110

Thanks to the magnetic grid, this positioning is easy with the mouse.

Drawing of the profile of the Post it block corner.

Make a zoom in the area of the Postit corners.

With the " polyline " enter in absolute the values: - X = 50 - Y = 75

Validate the point with a right click

Then in relative: - X = 5 - Y = 0

Validate with a left click

Then in polar: - 83°

- do not complete the« distance " field , do not validate the point

Then in relative: - X = nothing - Y = 10

Validate with a left click

Then in relative: - X = 2.5 - Y = 0

Validate with a left click

Then make a fillet with two angles of: r = 1.5

Then select the object created in this way and ungroup it

Select the first segment on the left before the rounded part and delete it.

Select the profile (frame selection) and join it.

Drawing of the profile of the outside contour of the pen tray.

This profile will be drawn between the pencil area and the paper clip area on the right side of the workpiece.

Make a zoom in this area.

With the " polyline " tool, enter in absolute the values: - X = 125 - Y = 65

Then in relative: - X = 5 - Y = 0

Validate with a left click

Then in polar: - 83° do not validate

- do not complete the " distance " field

Then in relative : - X = nothing - Y = 25 Validate

Then in relative: - X = 5 - Y = 0 Validate

Then make a fillet with two angles of : r = 1.5.

Then select the object thus created and ungroup it.

Select the two segments, top right and bottom left and delete them without deleting the rounded corners.

Select the profile ( frame selection ) and join it.

All the profiles and guide curves are now created. Yu are now going to generate the surfaces.

You will start with the surface of the outside contour of the pen tray. It will be created by

the extrusion of the profile that you have just created on the outside contour that will be the guide curve.

To identify the surfaces, you are going to give them different colors.

Check that no object is selected.

Click on " properties "(keyboard shortcut = Enter) then in the tab " surface ", choose the color " yellow ".

Select the profile and click on " extruded surface " then select: " guide curve "

Then select the " guide curve« then the tentative point onthe profile (upper point of the profile).

After designating the tentative point of the profile, you go automatically into perspective view where the profile is represented in position. If the position is good, you must click on " yes ", if not you must click on " no " to reverse it and then only validate by " yes ".

If the profile is well positioned, click on " yes "(the slope must go towards the outside of the contour).

If it is positioned upside down, invert it by clicking on " no " then click on " yes " to validate.

Once the validation is made, the surface is created and is represented on the screen in line mode. You can if you wish activate the realistic rendering.

Then return to " XY «view.

If you click on " cancel ", the whole operation is cancelled and you return to " XY " view.

Creation of the surface of the pencil area.

It will be created by a smoothed surface on the three profiles that you have just created.

As indicated previously, you will attribute to this surface the color: green.

Select the three profiles, then click on: " smoothed surface ".

Designate first the profile of the top on the left quarter of this profile.

Then designate successively the other two profiles in the same way.

After the designation of the last profile, right click to launch the generation of the surface.

N.B.: it is normal for the pointer of the mouse to snap on the junction point of the three profiles. It is however imperative to respect the order of designation described above.

The surface is now created and selected .

Creation of the surface of the paper-clip area.

This will be created by an extruded surface of the profile on the contour which, because of this, will be the guide curve.

As previously indicated, you will attribute to this surface the color: magenta.

Select the profile and click on " extruded surface " then select : " guide curve ".

Then select the " guide curve " then the snap point on the profile (upper point of the profile).

If the profile is well positioned, click on " yes "(the slope must go towards the inside of the contour).

If it is positioned upside down, invert it by clicking on " no " then click on " yes " to validate.

Once the validation is made, the surface is created and is represented on the screen in line view, you can if you wish, activate the realistic rendering.

Then return to the " XY " view.

Creation of the surface of the corner of the Post it bloc.

It will also be made by the extrusion of the profile on the contour that will be the guide curve.

As previously indicated, you will attribute to this surface the color: blue.

Make a zoom in the area in question.

Select the profile and click on " extruded surface " then select: " guide curve ".

Then select the " guide curve " then the snap point on the profile (upper point of the profile).

If the profile is well positioned, click on " yes "(the slope must go towards the outside of the contour).

If it is positioned upside down, invert it by clicking on " no " then click on " yes " to validate.

Once the validation is carried out, the surface is created and is represented on the screen in line view.. You can, if you wish, activate the realistic rendering.

Then return to " XY " view.

If you click on " cancel ", the whole operation is cancelled and you return to " XY " view..

You are now going to carry out the mirroring duplication of the Postit corner.

Select the surface of the corner.

Open the " mirroring " menu of the contextual menu and choose: " any axis " and " duplication ".

Designate two points vertical to the absolute " X " dimension of : 55.

The duplication is made.

Now select the two corners.

Remake a mirroring duplication by designating two point s horizontal to the absolute " Y " dimension of: 103.5.

The four corners are now created.

You are now going to raise the four corners to place their bases at the high level of the pen tray.

Select the four corners.

Go into " XZ " view.

With the aid of the direction arrows , raise the corners by two grid steps of 5 mm

i.e. 10 mm.

Return to " XY " view

You are now going to create the " delimited flat surfaces " on:

- The upper parts of the four corners.

- The bottom of the paper-clip area.

- The base of the pen tray.

To do this, you will extract the edges of the surfaces, and to have a better visualisation of these edges you will create them in the N°2 plane.

Click on properties (keyboard shortcut = Enter) taking care that no object is selected.

In the tab " draw " click on " plane 2 " then " OK ".

So as not toconfuse the edges of the surfaces with the guide curves or the profiles, you will deactivate the plane: draw.

Click on the tracing sub-menu of the display menu.

Click on " draw " to unlock the draw tracing.

To make the work easier and even if you do not need all the contours, you will make a global selection of the surfaces to extract the edges.

Click on " global selection "(keyboard shortcut = space bar).

Click on the " extract the edges " sub-menu of the " tools " menu.

The edges are now created.

You are now going to create the four surfaces of the four corners of the Postit compartment.

N.B.: the flat surfaces can only be created inside closed, joined contours.

To make it easier to create flat surfaces, you are going to deactivate the plane of the surfaces, i.e. plane 1

Click on the " tracing " sub-menu of the display menu.

Click on " plane 1 " to unlock the tracing of the surfaces.

Select the inner square of one of the four corners, then join it.

Click on the icon: " delimited flat surface ".

The surface is now created.

N.B.: the surface will not be visible because the surface plane (plane 1) is locked.

Repeat this operation on the other three angles.

You will now create the flat surface of the bottom of the paper-clip area repeating exactly the same method described above for the corners of the paper-clip area.

And finally you will create the flat area on the top of the pen tray, but this surface must avoid the pencil or paper-clip areas. To ensure this, it is sufficient that these areas are selected at the same time as the contour of the surface.

Select the outside contour and join it.

Repeat this operation on the upper contours of the pencil and paper-clip areas.

Then select these three contours, and click on the icon: " delimited flat surface ".

The surface is now created and avoids the contours of the pencil and paper-clip areas.

You will now reactivate the plane of the surfaces (plane1) in order to reattribute to the flat surfaces that you have just created their colors (blue, yellow and magenta).

The drawing of the pen tray is now finished. If you wish to carry out the 3D machining of this exercise, you have to have a licence for the FAO GRAAL 3D software and, in this case, refer to the teaching manual of this software. If you have not acquired this licence, contact the sales department of the Charlyrobot company: