3D AutoCAD Tutorial: Create a 3D piston

When I first started to learn CAD a few years back, I had a major problem with my learning process. I couldn’t find any exercise material. I searched and searched but couldn’t find anything useful. I decided to create the 101 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 hereexercises are 2D and 3D drawings without instructions so that they are not specific to AutoCAD.)

. (The
In this tutorial, you will learn how to create a piston using 3D geometry in AutoCAD. To do this you will use the 2D drafting and annotations and the 3D features. I assume that you are already a bit familiar with the basic 2D drawing commands such as LINE, CIRCLE, TRIM, etc. The final model should look something like this in 3D.

Here are the 2D drawings:

Remember that using gridmode (F9) and snapmode (F7) can be helpful between drawing tasks. For this exercise, I’ve been using AutoCAD 2017 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 it’s all proportional you can use the same values but with imperial units instead. I’ve decided to keep the measurements unitless for this exact reason.

1. Start a new drawing in AutoCAD.
2. Draw a circle with a diameter of 60 and place its center on the origin (0,0).
3. Draw a horizontal line that starts at the origin and a length of 23. This line will be used as a reference length for the next step.

 4. 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 don’t 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.

5.Now draw a concentric smaller circle with a diameter of 52. Also, draw a vertical line 19 units to the right of the center of the circles as shown below and mirror it. As with the rectangles, the lines need to exceed the circle perimeter.

6.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.

7. Click the gear (Workspace Switching) icon on the bottom right of the screen and choose 3D Basics instead of Drafting and Annotation. Also choose a 3D viewpoint so you aren’t looking at plan view.

8. Now use the EXTRUDE command to extrude the shapes to make a 3D model. The Z dimensions (shown below) are 40 units for the rectangles, 44 units for the central shape,  and100 units for the circle. This image is using the X-ray visual style.

    9. 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:

   10.Now you should go back to the 2D Drawing and Annotation and return to a top 3D view such as SE Isometric if necessary. Draw a concentric circle with a diameter of 52 and a rectangle (using the RECTANG command) with a height of 7.5 and one of its sides on the x-axis as shown in the image. The length of the rectangle should exceed the cylinder diameter, which is 60.

বিস্তারিত পড়ুন

• Share
• Tweet

Dealing with gaps

Hatching

If you need to hatch an open area, use the DIST command to find out the length of the break. Then start the HATCH command. If you don’t see the Gap Tolerance section, click the right-facing arrow at the lower-right corner of the Hatch and Gradient dialog box. This section controls the HPGAPTOL system variable, which you can also specify on the command line. In AutoCAD releases with the Hatch Creation tab, click the Option panel’s drop-down arrow to find this setting.

Enter a number larger than the gap. Then place the hatch by clicking the Add: Select Objects or Add: Pick Points button. However, these two methods of placing the hatch don’t always work the same way. Sometimes one button won’t work at all or won’t give the right results. In this example, only picking points worked properly.

By selecting objects

 

By picking points

However, in the example below, selecting objects gave acceptable results, picking points displayed this dialog box and wouldn’t hatch at all.

Therefore, before giving up, try both options! Also, in some cases, you can fill with a regular hatch, but not with a solid.

Joining objects

You can use the JOIN command to eliminate gaps. The command requires lines, polylines, arcs, or elliptical arcs. (However, it combines splines and helixes if they touch each other, but are separate objects). Although AutoCAD’s Help on this command doesn’t explain this, the objects must be on the same linear, circular, or elliptical path. Therefore, JOIN works best for objects that you broke with the BREAK command and were therefore once one object.
A nice feature of JOIN is that you can close arcs to make circles and elliptical arcs to make ellipses.

Joining polylines

The PEDIT command has its own Join option. Start the PEDIT command and at the first prompt, choose the Multiple option and select both objects. Then use the Join option. At the Enter fuzz distance or [Jointype] <5.0000>: prompt, enter a number larger than the gap to close it, and end the command.
Use the Jointype suboption to specify how the gap is closed. The Extend method extends or trims segments to the nearest endpoints. The Add method adds a straight segment between the two nearest endpoints. The Both method tries to extend or trim, but if it can’t, adds a segment.

বিস্তারিত পড়ুন

• Share
• Tweet

How to create multicolored lines in AutoCAD

Now the preview shows a white line because the element on top is taking its color from the layer which previews as a white line.

Note: We’re using the dashed line type for both elements. The line types can be loaded in the case you don’t see them when you click on the “Line type” button.

By default a “Standard” profile is defined for regular line drawing. This is also set to the current profile in selection. At any time, this one profile will be available if there are no other. Create a new profile as shown below.Step 3: Create a new Multi-Style profile

By default design, AutoCAD’s line is a single entity. This singularity of the line allows it to be treated as a simple drawing element without the leverage of more complex types. However, for those of you who may require such a feature, there is a way other than grouping different colored lines into one.
As said, by default the line is a simple element hence to replicate functionality not built-in, we need to setup the proper environment before we proceed with the actual development. See the below screenshots for a step by step explanation of the prerequisites of sawing multicolored lines.

Preparation

Step 1: Command: MLSTYLE. Use the command MLSTYLE to access the Multi-Style menu. When you press enter, the dialogue box should open up.
Step 2: View current profiles
 Give your profile a name and press continue for the configuration menu.
 





Set up your profileStep 4: 
The name that you entered is on the top of the current screen. That’s your profile configuration screen where you can define your style.

• Line type – Define the kind of line you want this element (segment of the final line) to be.
• Caps – For a multi-colored line, we’re going to select the Line option for Start & End. The angle doesn’t matter for now. Experiment with it on your own when you want the line to start/end with an arc.
• Fill – This is the background color. If this is set to none, then where you assign the line to inherit the color from the layer, the line will be drawn transparent. There are two functions here, we’ll cover both later.
• Display joints – Whether to display the joints where the intervention is defined.
• Elements – Just as on your canvas, the elements section refers to the elements you will be drawing when using this style. The properties are shown below.
• For multi-colored lines, the offset should be kept to 0 for all elements defined. This is because the offset is vertical in nature and displaces the lines from each other placing them upon one another. Add another element with the properties as shown below.
• Color – Self explanatory

Load line types if you can’t see the ones you need by clicking on load and selecting from the list as shown below.
Using the Dashed line type we set up both lines to contain dashes within them. Here the two features of the Fill option come into play.
As can be seen below, the first element’s color is inherited from the layer. Which basically means that one Magenta colored line with dashes will have yellow behind it because that’s the base layer. This can be left to colorless so you can have a line that alternates between opaque and transparent after the same interval.
Step 5: Set the new profile as current.
Click the Set Current button. And then click  OK. (see below)
With that, you’ve prepared your default environment for some workaround-fashioned multi-colored lines. Let’s draw!

Drawing

Step 1: Draw the line
The line needs to be drawn using the MLINE command. 
This selects the line tool with the current multistyle profile. Now draw the line. This is pretty basic, but just to rid everyone of confusion, the colors will only show once the drawing is committed. So don’t be disheartened if you don’t see two hues after the first click. (See below).

First click –



Second click –






Zoomed in –

If interested in more tutorials, check out these AutoCAD exercises.




Do you have another way to create multi-colored lines? Leave a comment!

বিস্তারিত পড়ুন

• Share
• Tweet

What is 3ds Max?

Formerly known as "3D Studio," 3ds Max is a 3D modeling, animation and rendering program from the Media and Entertainment division of Autodesk, Inc., San Rafael, CA (www.discreet.com). Widely used in the areas of interactive games, visual effects for movies and industrial design models, the software lets you create 2D shapes that become the cross sections of the 3D models. The application includes an animation module that uses inverse kinematics, which links components so that they move together, adding to the effect of bringing a character to life. 3ds Max carried Autodesk's Discreet brand name until 2005. See Character Studio.

বিস্তারিত পড়ুন

• Share
• Tweet

What’s New in AutoCAD 2017? PDF Import

Welcome to the first entry in my “What’s New in AutoCAD 2017?” blog series. (For a quick overview of all the top new features in AutoCAD 2017, see “AutoCAD 2017: It’s … Alive!“)
With AutoCAD 2017 you can convert PDF to AutoCAD geometry, TrueType™ text, and raster images—either from a specified page in a PDF file or from all or part of an attached PDF underlay. If you’ve already attached a PDF file to your drawing, you can select it and choose the new Import as Objects tool from the PDF Underlay ribbon tab. You can then import everything or pick a polygonal or rectangular selection around the geometry you want to import.
To see PDF Import in action, check out the PDF Import overview video.
Pretty cool, huh?
Below we take a quick look at how AutoCAD got here. If you’d rather get right to the meat of the feature, skip to the next section, “AutoCAD 2017 PDF Import: A Walkthrough.”

PDF and AutoCAD: A Shared History

PDF files are a common way of publishing and sharing design data for review and markup.
AutoCAD 2007 was the first AutoCAD release with PDF support; it included a PDF plot driver that enabled you to easily print your AutoCAD drawings to PDF file format, no additional software required. AutoCAD 2010 gave you the ability to attach PDF files as underlays to drawings. Since then Autodesk has continued improving the quality and performance of the software’s PDF output and underlays.
We previewed the AutoCAD 2017 PDF Import functionality at Autodesk University 2015 and then polled the audience to gauge their interest. The response was overwhelmingly positive: About three-quarters of attendees strongly agreed (and overall nearly 95 percent agreed) with the statement “I will use the PDF Import feature.”

Poll results for using PDF Import

So here we are at another milestone… the much requested ability to import geometry from a PDF file.

AutoCAD 2017 PDF Import: A Walkthrough

Import selected objects from a PDF file

Use the Settings option to control how the geometry is imported.

PDF Import Settings dialog box

For example, you can specify:

• The type of data imported from the PDF (geometry, solid fills, text, and raster objects)
• How layers are assigned to imported objects
• Different post-processing options for imported geometry

If the PDF file includes raster images, you can extract them as .png files and automatically attach them to your drawing. Since those images are referenced from the AutoCAD drawing, choose the Options button to ensure the new PDF Import Image Location is appropriately set for your workflow.

PDF Import image location

After selecting the geometry to import and specifying the appropriate import options, you can choose what to do with the PDF underlay when the import is complete: Keep the original PDF underlay, detach it, or unload it.

PDF Import options

When completed, the selected geometry is imported as native AutoCAD objects.

Imported objects from a PDF underlay

You can also import PDF geometry directly from an unattached PDF file. Use the new PDFIMPORT tool, or even the regular Import tool, which now includes PDF as a supported file type.

PDF Import and Import tools on the ribbon

If you use the Import tool, you’ll need to choose PDF Files from the File type list.

PDF file type in Import File dialog box

If you use the PDF Import tool, you’ll need to select the File option. The PDF Import default behavior prompts you to select a PDF file that is already attached, as I described previously.

PDF Import command line

With either method (Import or PDF Import), the Import PDF dialog box displays after you select a PDF file. If the PDF file has multiple pages, you can visually select the one you want to import or you can enter the page number. All the objects on that page will be imported based on the settings you specify: Insertion point, scale, and rotation in addition to the settings that control how the geometry is imported, which I described previously.

Import PDF

Note: Objects imported from a PDF file will lose some accuracy because, well—PDF ain’t no DWG™ when it comes to the accuracy it can support. If you’re using PDFs for visual purposes, such as for importing catalog items, the loss in accuracy may not be significant.

বিস্তারিত পড়ুন

• Share
• Tweet

How to Use Google Earth and AutoCAD Together

Looking to take advantage of Google Earth in AutoCAD?
Available on the Autodesk App Store, CAD-Earth “is designed to easily import and export images, objects, and terrain meshes between Google Earth and AutoCAD,” as well as create dynamic contour lines and profiles.

The app boasts a wide array of additional capabilities, including:

• Import command fully optimized for speed and performance
• CAD entities exported to Google Earth grouped by layer name
• Drawing previews in the real world; move, scale and rotate in real time until they match the exact location
• Insert of geo-referenced images
• Slope zone analysis
• Profile and cross-section from mesh
• Extensive help section in each step

বিস্তারিত পড়ুন

• Share
• Tweet

Tips for AutoCAD Customization

What do an architect, a mechanical or civil engineer, a product designer (and the list goes on) all have in common?

This isn’t a set up for a cheesy joke. It’s AutoCAD, of course! But what they don’t have in common is the workflow—and that’s why AutoCAD customization is crucial to getting each individual job done.
Customization is the key to efficiency and automating specific processes or accessing frequently used tools. By tailoring it to your specific workflow, AutoCAD becomes personalized to you since it’s much different designing a part or product versus a building or structure.
Here are some great resources to aid in customization so you can be more productive and save even more time.

AutoCAD 2017 Customization Guide

This in-depth guide takes you through a variety of customization options, including user interfaces; migrate and transfer settings; custom linetypes and hatch patterns; DIESEL; programming interfaces; shape and shape fonts; and much more.

Top Ways to Customize AutoCAD

Just getting started with AutoCAD customization? Check out this list of customizations that may surprise you.

AutoCAD Customization Boot Camps

At Autodesk University 2016, Autodesk’s Lee Ambrosius presented two AutoCAD customization boot camps for both beginners and more advanced users. You can download the entire presentations and all of the in-depth supporting materials; it’s almost as good as being there. (Almost!)

• AutoCAD Customization Boot Camp—Basic (No Experience Required)
  Discover tools and tool palettes. Learn how to create custom desktop icons and command
  aliases as well as modify the ribbon and Quick Access toolbar.
• AutoCAD Customization Boot Camp—Beyond the Basics
  Learn how to write and run script files; record and play back action macros; create and load small AutoLISP programs; and manage user settings with profiles.

বিস্তারিত পড়ুন

• Share
• Tweet

What Is AutoCAD?

 AutoCAD is a computer-aided drafting software program used to create blueprints for buildings, bridges, and computer chips, among other things. Discover how AutoCAD is used by drafters and other professionals.

AutoCAD: An Overview

AutoCAD is a 2-D and 3-D computer-aided drafting software application used in architecture, construction, and manufacturing to assist in the preparation of blueprints and other engineering plans. Professionals who use AutoCAD are often referred to as drafters.

Training Programs

Training in AutoCAD software and computer-aided drafting can be found at technical and community colleges, including certificate or associate degree programs in AutoCAD, drafting, or engineering technology. Most of these programs feature courses that focus on the hands-on use of the AutoCAD software package. Some programs may even prepare students for AutoCAD industry certification.
Bachelor's degree programs in related fields, such as engineering, may also require students to take AutoCAD courses.

Career Information

While drafters work in a number of specialties, the five most common specialization areas are as follows: mechanical, architectural, civil, electrical, and electronics.

• Mechanical drafters prepare plans for machinery and mechanical devices.
• Architectural drafters draw up plans for residential and commercial buildings.
• Civil drafters draw up plans for use in the design and building of roadways, bridges, sewer systems, and other major projects.
• Electrical drafters work with electricians to prepare diagrams of wiring electrical system layouts.
• Electronics drafters also prepare wiring diagrams for use in the making, installing, and repairing of electronic gadgets.

According to the U.S. Bureau of Labor Statistics (BLS), in May 2015, the median annual salary for drafters in general was $52,720. As reported by the BLS, drafters in general as well as architectural and civil drafters could expect a 3% decline in employment from 2014 to 2024. During this same ten year period, employment opportunities for mechanical drafters may decline by 7% while job opportunities for electrical and electronics drafters are projected to increase by 5% from 2014-2024, which is about average when compared to all other occupations.
AutoCAD drafters use 2-D and 3-D computer-aided drafting software applications to prepare blueprints and plans for architecture, construction, and manufacturing projects. As reported by the U.S. Bureau of Labor Statistics in May 2015, drafters in general earned a median annual salary of $52,720.

বিস্তারিত পড়ুন

• Share
• Tweet