Modeling a 3D Object in AutoCAD 2014

by AwesomeChickenHacker

71K28116

Intro: Modeling a 3D Object in AutoCAD 2014

Hello everyone,

Today I will be showing you how to model an object in Autocad 2014. This is a beginners tutorial and no prior knowledge is required. I am 14 and am using the free educational version of Autocad. Have fun and I hope you enjoy.

STEP 1: ​What You Need

What you need

A computer with AutoCAD. As a student I downloaded my copy for free, so if you are a student you can too. You can also find free alternatives like SketchUp (but this tutorial is specifically aimed at AutoCAD).

Something to draw (I like to find stuff on Google images).

Some time and patience :)

You can also download the source files that I've modeled below :)

STEP 2: ​Work Out How to Draw Our Object

The first step is to look at your model or object and decide the order in which you will model the different parts.

Try to think about how you will model the different parts so you can get an idea about which parts will rely on other parts, as you will need to model these parts first.

I decided to model the rectangular prism in the middle of the object first, then model the top part out from it and finally to model the bottom part.

STEP 3: ​Navigation and Basic AutoCAD Features

I have put together a few important points to use as a reference when first using AutoCAD. Throughout the tutorial I will provide more detail:

  • use scroll wheel to zoom in or out of the model or press and drag the scroll wheel to move around the model
  • use the view cube to change the direction of the view.
    • click on faces, edges or corners to jump to different views.
    • click and drag the view cube to create custom views
  • change between visual styles (solid, line drawing) with the visual styles controls
    • use wireframe to draw most of the time, and realistic or conceptual to preview what it will look like in real life.
  • to find a command or tool just type the first few letters of the command's title and then select it from the drop down menu that will appear. If it is at the top of the menu you can just press enter.
  • important shortcuts:
    • ctrl + z = undo
    • esc = cancel
    • enter = accept
    • press esc before you press undo because you can't undo while using a tool.

TIP: after some commands some of the lines you have drawn seem to disappear. If this happens just use the mouse's scroll wheel to move the view a little and the lines should reappear.

STEP 4: Setting Up the Document

Firstly, start a new document in AutoCAD:

  1. press the plus (+) icon beside any open tabs or press ctrl + N
  2. choose acad.dwt as the template, and open it
  3. press ctrl + S to save the document

Now we need to choose which work space to work in:

We are drawing a 3D object so we will use the 3D modeling workspace.

  • in the very top bar, next to the save/print icons, press the drop down menu and select 3D modeling.

Choose what visual style to use

To choose how AutoCAD displays your model (solid, line drawing) choose from the visual styles menu.

  • Change the visual style to wireframe

We need to choose what view we will start with:

We can see the front, left and top sides of the object we have chosen to model, so we should choose a view with these three sides visible.

  • we can do this by going to the view cube and clicking the corner between front, left and top or we can use the view controls menu (beside the visual styles controls menu) and change it to SW isometric
  • if you just see a square that says TOP just click one of its corners and you will see a cube.

I like to work with the picture of the object we are modeling open, so I split my screen between AutoCAD and the picture. I recommend saving the image and doing the same while you work.

Now we are ready to start drawing!

STEP 5: ​Modeling the Middle Rectangular Prism

First, draw the cross section of the center rectangle. It needs to be rectangle 60x70 units. To do this:

  • type REC
  • select rectangle by clicking on it in the menu, or just press enter
  • type 0,0,0 to set the start point to the origin
  • press enter
  • press D to set the dimensions
  • press enter
  • choose the length of the rectangle – type 70
  • enter
  • choose the width of the rectangle – type 60
  • enter
  • click so the rectangle is formed in the SE corner – see picture

Extrude the rectangle up 20 units

  • type PRES
  • select presspull tool by pressing enter
  • select the rectangle by clicking inside the rectangle. It is important that you click inside the rectangle, not on one of its sides as this insures you extrude the face, not just the edges
  • press enter
  • choose the height that you wish to extrude – type 20
  • press enter

STEP 6: ​Modeling the Upper Part

Extrude the back rectangular prism

  1. Copy the upper Eastern edge
    • select copy edges tool from the solid editing panel. It is in the top right hand corner of the panel and may be hidden under the extract edges command.
    • choose the upper Eastern edge of the rectangular prism you have just created and click it – see picture
    • press enter to confirm the selection
    • select the southern end of the line you just clicked to – click when you can see the blue square
    • move the mouse along the negative X axis (the way you are going to paste the copy of the line). You can tell you are along the X axis if you see a thin green line.
    • type 10
    • press enter to confirm the copy
    • press esc to exit the copy edges tool
  2. Extrude the new area 50 units up
    • select presspull tool (extrude won't work) – type PRES
    • press enter to select the tool
    • click inside the new face
    • drag up along Z axis
    • type 50
    • press enter to confirm the extrusion
    • press esc to exit the presspull tool
  3. Create the big cylinder at the top of the part:
    • Copy an edge to use as guide – see pic
      • change UCS (universal coordinate system) to Left. This will allow us to easily draw objects orientated to this plane. To do this:
        • select the view tab at the top of the screen
        • inside the coordinates panel, click on the drop down menu where it says world and change it to left
      • copy edge with the copy edges tool just like you did before. Copy it in 30 units.
    • Draw the cylinder. We will draw two cylinders and join them, as this is the easiest way of doing it. One cylinder will go towards the left, and the other one will go towards the right, they will both start at the same place where the guide meets the top side of the rectangular prism. When we have drawn them both we will join them with the union tool.
      • Draw the left cylinder:
        • type CYL
        • press enter to select the cylinder tool
        • choose the center of the cylinders first face. Click where the new guide line and the top line meet. You will see a green square.
        • move mouse along X axis and click at the end of the rectangular prism to set the radius. You should see a blue square.
        • Set the depth of the cylinder. Type 25
        • press enter to confirm cylinder
      • Draw the right cylinder:
        • again, click where the new guide line and the top line meet. You will see a green square.
        • move mouse along X axis and click at the end to set the radius. You should see a blue square.
        • Set the depth of the cylinder. As we want the cylinder to extrude to the right, and we are in the left UCS we must use a negative number. Type -15.
        • press enter to confirm cylinder
      • join the two cylinders together
        • type UNION
        • press enter to select the union tool
        • select both cylinders. You can do this by clicking one cylinder and then the other, or draging around both.
        • press enter to merge both cylinders into one.
  4. Select the guide line and press delete as we don't need it anymore
  5. Temporarily change view to realistic to see how the project is coming along
  6. Change the view back to wireframe
  7. Make the bore hole on the left side
    • draw a circle. Type CIR
    • press enter to select the circle tool
    • select the center of the circle. Use the center of the cylinders end face and click. You should see a small green circle.
    • type the radius of circle. In this case it is half of 30 which is 15
    • press enter to finalize the circle
    • type PRES
    • press enter to select the presspull tool
    • click inside the newly created circle – it won't work if you click on the actual circle
    • type (-6) to intrude the bore hole
    • press enter to finalize the intrusion
    • press esc to exit the presspull tool
  8. Change UCS back to world
  9. Change to SE isometric view
  10. Change UCS to right
  11. It is easiest to do the hole that goes all the way through next, before doing the right bore hole
    • it has a diameter of 20, so draw a circle with a radius of 10 on the near face of the cylinder centered on the center of the cylinder's face
    • use the presspull tool and press the circle more than -40 (-100 is safe and make sure to click inside the circle) to press a hole all the way through the cylinder. Note: If you click inside the circle it will just cut out a hole, but if instead you click the circles edge it it will extrude the edge and you will end up with a big bar sticking out the left side of your model.
    • Press esc to exit the presspull tool. You will also need to change the UCS from unnamed back to right, because whenever the presspull tool is used it automatically changes the UCS to the face it is "presspulling"
  12. Draw and presspull another circle with a radius of 15 and a depth of 6 on this side
  13. Change to realistic to see how your work is progressing and don't forget to save it.
  14. You may notice that the second rectangular prism you created before sticks up into the hole we have pressed through the cylinder. If you do, follow the following steps:
    • change the UCS to left
    • redraw the guide line in the same place we had it before.
    • Use the intersection between it and the top edge of the top rectangular prism as the centre for a circle with a diameter of 10.
    • delete the guide line
    • use the presspull tool to intrude the lower half of the circle to the right at least 10 units
    • delete the circle
  15. You will also notice that the bore hole on the right hand side has a small lip in the bottom half. This is because the cylinder comes out from the rectangle 5 units but we have pushed the bore hole 6 units, therefore this lip is part of the second rectangular prism. To fix this problem we will again use the presspull tool.
    • Change the UCS to world, view to right, and then change UCS to right (now the view cube will say top).
    • draw a circle from the centre of the cylinder with a radius of 15
    • presspull this circle -1 along the -X axis
    • press esc to exit presspull tool
  16. change UCS back to world

STEP 7: Modeling the Bottom Part of the Object

  • On the view cube, select the corner between left, front and bottom and change the UCS to bottom
  • Change the visual style to hidden. You don't have to do this but I find it makes it easier to work as you don't get muddled by all the lines in the top part of the object.
  • Extrude the main bottom rectangular prism. The next part is hard to explain so please use the screen shots to help you work out what I am trying to say.
    • copy the line in 20 units – see picture
    • copy both adjacent lines in 10 units – see picture
    • press esc to exit copy edges tool
    • trim off excess lines to create a rectangle 40x20 units – see picture
    • type TRI
    • press enter to select the trim tool
    • click all three newly drawn lines or drag around them
    • press enter to select these lines
    • click all segments you need to delete – see picture
    • press enter to confirm trim
    • extrude new rectangle to a depth of 50 units
    • type PRES
    • press enter to select the presspull tool
    • choose depth of extrusion – type 50
    • press enter to confirm extrusion
    • press esc to exit the presspull tool
  • To create the lower (and larger) fillet
    • type FILLET
    • press enter to select the fillet tool
    • select one of the short edges of the lowest (and newly extrude rectangle) – see picture
    • type the radius of 20 units
    • press enter to confirm radius
    • select the other short edge – see picture
    • press enter to confirm fillet
  • To cut out the lower hole
    • change the UCS to left
    • draw a circle on one face of the lower part
      • type CIRCLE
      • press enter to select the circle tool
      • use the center of the fillet to use a the center of the circle. You should see a small green circle.
      • type the radius of the hole. It is half of 15 = 7.5 - type 7.5.
      • press enter to draw circle.
    • presspull circle to create hole
      • type PRES
      • press enter to select the presspull tool
      • click inside the circle just created and type a number greater than 20
  • To create the upper bevels. Again, the next part is hard to explain so please use the screen shots to help you work out what I am trying to say.
    • On the front side:
      • select copy edges tool from the solid editing panel
      • copy edge up 20 units – see picture
      • select presspull tool – type PRES
      • press enter
      • extrude new face 10 units – see picture
      • change UCS from unnamed to left
      • select circle tool – type CIRCLE
      • press enter
      • make the center of the circle the corner of the newly extrude part – see picture
      • set the radius – type 10
      • press enter to confirm circle
      • type PRES
      • press enter to select the presspull tool
      • click inside the quarter circle
      • type -50
      • press enter to accept the intrusion
      • select the original circle
      • press delete
    • set the UCS to world
    • click the corner of the view cube between left, back and bottom
    • set the UCS back to left
    • repeat the proces to create the upper fillet on the back side

STEP 8: The Upper Triangle

You might have noticed that I have not talked about making the triangular prism bellow the upper triangle. I decided to leave it for you to work out. If you need some hints try using some of the tools we have learnt about including copy edges, and presspull tools. I also used the line tool (type LINE). Also make sure to change the UCS to the face you are working on.

STEP 9: ​Exporting

3D printers use STL (STereoLithography) files. Read more on Wikipedia. To export a STL for 3D printing:

  • Go to the output tab
  • click send to 3D print service
  • drag around the whole object
  • press enter to export the selection
  • set the scale (usually just leave all the defaults and press OK)
  • choose where to save the STL file
  • now you can send the STL file to a 3D printing company or import it into the software that you use with you 3D printer

You can also import you STL into blender to animate it.

  • all parts that you want to animate separately must be separate
  • just export STL files in the same way as above and you can import them into blender by going file -> import -> STL

STEP 10: Conclusion

Thanks for reading my instructable and I hope you got something out of it. If you still have questions please leave a comment and I will try to answer them as soon as I can.

12 Comments

david.makkers 5 years ago

Can someone please provide instructions on how to create the triangle. Thanks in advance

bsbcadd1 8 years ago

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bsbcadd1 8 years ago

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Edbed 8 years ago

Great in depth instructable.

james.lister.184 9 years ago

Thats really good, i studied autoCAD last year at a college and we didn't go into as much detail as this, awesome instructable.

You can also download auto cad REVIT software free on the same website, which is similar but for designing buildings and creates a 3D image of all the componants of a build project.

AwesomeChickenHacker 9 years ago

Thanks, I'm glad you liked it.

The REVIT software certainly looks cool. I will download it and have a go when i get a chance.

seamster 9 years ago

Great tutorial, thank you!

ewoco 9 years ago

Great tutorial!