Auto. CAD Tips Blog Auto. CAD tips tutorials to help you work faster smarter. This is a guest post by Viktor Rask, founder of CAD Mode and author of the e book 1. CAD Exercises Learn Improve Your Skills. He is a mechanical engineer BSc. CAD and 3. D He also loves to help others grow. When I first started to learn CAD a few years back, I had a major problem with my learning process. I couldnt find any exercise material. I searched and searched but couldnt find anything useful. I decided to create the 1. CAD Exercises book to help others speed up their learning process and make it more hands on and fun. If you want more exercises like this, you can get them here. The exercises are 2. D and 3. D drawings without instructions so that they are not specific to Auto. CAD. In this tutorial, you will learn how to create a piston using 3. D geometry in Auto. CAD. To do this you will use the 2. D drafting and annotations and the 3. D features. I assume that you are already a bit familiar with the basic 2. D drawing commands such as LINE, CIRCLE, TRIM, etc. The final model should look something like this in 3. D. Here are the 2. D drawings Remember that using gridmode F9 and snapmode F7 can be helpful between drawing tasks. For this exercise, Ive been using Auto. CAD 2. 01. 7 but it will work with previous versions as well as other CAD software. Your commands and shortcuts might differ with other versions, though. The dimensions that are used in this exercise are originally metric but since its all proportional you can use the same values but with imperial units instead. Ive decided to keep the measurements unitless for this exact reason. Start a new drawing in Auto. CAD. Draw a circle with a diameter of 6. Draw a horizontal line that starts at the origin and a length of 2. This line will be used as a reference length for the next step. Draw a rectangle using the RECTANG command as shown on the right side of the image below, using the endpoint of the line as a guide to place the rectangle. The dimensions of the rectangle dont need to be exact but they must exceed the circle perimeter as we use it as a cutter. Then mirror the rectangle using the start point of the line or the center of the circle for the mirror line. Remember to erase the reference line that you used to create the rectangle. Autocad Set All Z To 0 Table' title='Autocad Set All Z To 0 Table' />Now draw a concentric smaller circle with a diameter of 5. Also, draw a vertical line 1. As with the rectangles, the lines need to exceed the circle perimeter. Autocad Set All Z To 0' title='Autocad Set All Z To 0' />Now use the TRIM command and use the vertical lines as edges to trim the inner circle. Resize the 2 vertical lines so that they end at the top and bottom arcs. Then use the JOIN command to make the following shape in the center. Click the gear Workspace Switching icon on the bottom right of the screen and choose 3. D Basics instead of Drafting and Annotation. Also choose a 3. D viewpoint so you arent looking at plan view. Now use the EXTRUDE command to extrude the shapes to make a 3. D model. The Z dimensions shown below are 4. This image is using the X ray visual style. Now start the SUBTRACT command and subtract every shape from the main cylinder. Remember that first you must select the main cylinder, press Enter and then select the objects you want to subtract from it. You might need to change your viewpoint or visual style, especially to subtract the central shape. Now you should have a model looking like this Now you should go back to the 2. D Drawing and Annotation and return to a top 3. D view such as SE Isometric if necessary. Draw a concentric circle with a diameter of 5. RECTANG command with a height of 7. The length of the rectangle should exceed the cylinder diameter, which is 6. You can isolate hide the main body by right clicking on it and choosing Hide or Isolate Hide. Then use the COPY command to create two more circles, 4. B8GHdunOzQ/U2RBckiMk3I/AAAAAAAACJM/G6c4PGW_fmI/s1600/Screenshot-%2528146%2529.jpg' alt='Autocad Set All Z To 0' title='Autocad Set All Z To 0' />After this, delete the base circle. Go back to the 3. D Basics workspace. Use the EXTRUDE command on the 2 circles the lower circle should be 4. Image1.jpg' alt='Autocad Set All Z To 0' title='Autocad Set All Z To 0' />How to Set up an AutoCAD Drawing. Millions of civil engineers worldwide use AutoCAD to help create visual representations of important projects. Buildings, bridges. Then use the REVOLVE command on the rectangle to make another cylinder. Specify the X axis as the axis of revolution and use the default 3. Now right click and end object isolation Unhide. Using the MOVE command, bring the thin cylinder 2. Z direction and move it towards the main body of the piston so that it extends on both sides. Now subtract the 3 cyllinders from the main body. You can use the Bottom view for easier access. In the 2. D Drawing Annotations workspace, draw a concentric circle with a diameter of 2. Use the EXTRUDE command to create a cylinder that is higher than the main body. Then subtract it from the main body. Now use the CHAMFEREDGE command pick the outer edge of the top face of the cylinder, press Enter and type d to give it a distance from the edge. Choose 1 unit as the distance and then press Enter. You must enter the distance twice to give it the same distance from both edges. Start the FILLETEDGE command and then pick the inner edge of the top face of the cylinder, press Enter, and type r to give the fillet a radius. Choose 1 unit as the radius and press Enter. Next task is to fillet the side faces. Autodesk Beta Testing on this page. Use the same command as in the previous step. We will now create the ring pockets on the pistons outer wall. In Excel we can access the data in a worksheet by using Sheet1. CellsRow, Column. We can loop through Sheet1. Cells and take action in AutoCAD based on the content. Use the TORUS command. Set the center of the torus to the origin 0,0 and then use 6. Make three copies of the torus using the COPY command with the following values in the z direction 7. You should delete the first torus. Remember that you can isolate hide the main body for this step. Finally, subtract the tori plural of torus from the main body. You should now have a 3. D model that looks like the one at the beginning of this post. For more drawings that you can use to practice your skills, be sure to check out my bookIf you have any questions you can also email me at email protected and Ill do my best to help you out.