Making a 3D Model

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For this tutorial, we are going to take a basic 3d model that will help us get to grips with few of the 3D modelling commands in AutoCAD. By the end of this, you will be free to explore other commands that are not used here but have an idea of how they work.

We should never be afraid to experiment with new and exciting commands and making more and more complex models to challenge ourselves.

Let us start by looking at an isometric view of the 3D model with given dimensions.

The X shows that the front view is from the x-direction and we can start making the model with respect to that. Normally you will find sketches have different views and there is no isometric representation shown which makes it difficult to predict the exact shape of the model in some scenarios.

But this skill develops with practice, the more models you make, the better you will know where to start the drawing from and which dimensions to take. It is also suggested to have a basic knowledge of Engineering Drawing which makes working on CAD software easier and clearer ideas while designing in AutoCAD.

component to be design

Step 1: Making the Base blocks

Firstly, make sure you are in 3d modelling workspace, this will give us access to the top 3d commands directly and make the work easier. We also now move to work in 3d, which is having all 3 coordinates so you can click on the home icon on the top right to do so.

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Now we start by making the base rectangle, observe the figure carefully and see the dimensions that are given. We enter the coordinates ‘0,0,0’ for the first point so that it is easier to enter the later coordinates if required (this is a good habit so we can make any point accurately later).

Press Enter, give the length and breadth as shown and place the rectangle.

We use the Presspull command to give this shape the height given which is 12 and press Enter, we can also use extrude alternatively to give the same result.

For the second block, we make it similarly but this time, we make the rectangle on the base block with accurate dimensions and use presspull again and give height as 50 (Subtract 12 from 62).

Step 2: Sketching the middle loft

We see that the UCS is not at its origin, use the option as shown to place the UCS back to origin so we have a better idea of the position. First, we find the mid-point, you can press Shift+RMB and select mid-point from there.

Find the point and follow the line straight up by adjusting the view, we take this up to 40mm as seen from the figure and go 20mm to the left. Now join this line to the bottom one diagonally.

Similarly make the upper half from the mid-point, going 25mm this time and then 10 vertically downwards. Join the line to the previous sketch at the corner as shown.

Now delete the excess lines by selecting them and pressing delete or going to erase command.

After removing extra lines, we now mirror this sketch to make it whole. Do not forget to use join command to join both halves. Having a closed loop is important for using PressPull or Extrude if you want to make it a solid body.

Go to ‘Presspull’ now and select the cross section we just made and pull to 23mm as given in the figure.

Step 3: Cutting the Arc

Now we have to cut the semi-circle or the arc from the cross section and it needs to go through to the vertical base block as well.

First, select Right view from the view menu, so we can draw on the right plane. Make a circle by getting the mid-point selection as shown and give it radius of 15mm.

Make the middle line cutting it in half following the guidelines that come up when you hover the mouse over the points.

Trim excess parts of the line and the upper of the circle. You can see we used the press pull command without joining both the sketches, and it makes a surface with no thickness.

So now we select the two sketches and type join>press enter. Now select ‘Presspull’ again, select the cross section pull to the back edge by selecting that edge via snapping.

Now we use the ‘Subtract’ command to remove this solid cross-section form the base model. To do this, go to subtract from the solid editing menu or simply type ‘SU’ and press Enter. Select the model or part as shown, press Enter, select the part to remove and press Enter, the section is subtracted.

Step 4: Fillet

From the drawing, we can see that the corners are rounded or have a fillet with a radius of 12mm. For this, we use the ‘Fillet Edge’ command which comes in the solid menu from the ribbon. This command is similar to fillet in sketching but is for 3D models.

Select the command or just type normally ‘filletedge’>press enter. Select the edge or edges to fillet, press ‘r’ and press enter to give radius, give 12mm radius as shown, press enter twice.

Step 5: Making the Circular holes

To make the circular sections on the model, we need to select the right orientation so that the circles are draw on right coordinates. To do this, we select the top view from the view menu first, no need to remain in this view, we can reorient using mouse now.

Make the circles by taking the fillet’s center points as a reference and then giving them a dimension of 6mm radius each. We repeat the process for the second 2 circles, this time selecting the right view from the view menu.

Now, we loft these circles to 12mm for each of the 4 circles, this makes an extrusion which is a solid at first. To turn them into holes, we use ‘subtract’ again;

Enter the command, select the main body or the bigger body first, press enter then select the body to be subtracted or in this case bodies to be subtracted and press Enter to finish the command.

Step 5: Bottom cut and changing Visual style

To make the bottom cut, we can simply make a rectangle and extrude it, then use subtract to make a cut of that shape. But we can also make a box directly from ‘Box’ command seen in the modelling menu for a change.

We first go to bottom view and orientation, so that we can sketch on the bottom part of the model. Select ‘Box’ command > Select the first point by taking reference from the bottom corner and going straight at 25mm distance > press Enter.

From this point, we first give it a length as 60mm by selecting ‘Length’ from the command line, and then set the width as 45mm or select the endpoint of the model. Now we have to enter the height straight away to make it box, this height is 6mm from the figure and press Enter.

We turn the visual style to ‘Shaded with edges’ from the top left corner of the workspace. This gives a better view of the 3d solid model, and we can see that the rectangle is left to cut in our model to make it complete.

Go to ‘Subtract’ > Select the bigger part > press Enter and select the box > press Enter, the cut is now made.

And the model is now complete. feel free to look at it with different angles by holding both Shift+MiddleMouseButton and moving the mouse around.

Also, feel free to experiment with different commands and features available in AutoCAD, this is how they all work and the command line always shows what the next step requires.

Back to: Basics of AutoCAD

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