AutoCAD Drawings & PDF Files: A Perfect Combination
AutoCAD Drawing Files and PDF’S – What A Team.
AutoCAD’s DWG format is universal, easily imported into many popular design software packages. Often, however, the data we would like to bring into an AutoCAD DWG is in a format which is native to other software packages.
I am an opportunistic CAD designer; I will admit it. If I can get CAD data on something that is needed for my drawing from an external source, I will certainly do so (with a degree of caution, of course). Commonly, when looking for drawing data on a component or device that will be used in a design, the first thing that a designer will look for is native AutoCAD in format.
Native DWG files as well as DXF files are available when searching many vendor websites. Care must be taken when working with the available files. Often, vendors do not actively support 2D formats. If they do, the file is often a converted 3D file, which is a completely different animal.
The screenshot below looks like a typical 2D drawing of a PLC. Things are not what they seem, however. I imported the module on the left from the vendor website. The vendor took a 3D component and created a 2D DWG.
As I went to add wires and connections to this drawing, I found a few hidden “bonuses,” as seen in the screen shot below.
*TIP* when you suspect that a DWG has 3D embedded in it, click on the home icon of the view cube – you may be surprised!
As the screenshot below shows, the vendor data had a few extras included! The captured data which, when visible from this perspective, is obvious, had caused a few challenges. Notice how the wires to the terminals are not parallel to the drawing border. Also, trying to mate components with this data can be challenging when I have several end points that can be selected erroneously.
This detail was edited to attempt a clean-up of the drawing, without much success. I have since taken a different approach to the importation of vendor data when I need to include a component, as this unseen data also adds to file size and drawing complication.
PDF’S – Valuable Sources of Data if you Do a Little Digging.
PFD data is a treasure trove of information available to the CAD designer. It is available in many locations, some of which people frequently overlook. Think about how many documents a vendor includes image data in. Everything from cut sheets to full manuals for components, and recently as a link to the file on the vendor website.
There are some vendors who will configure their PDF data in a way that makes image data unavailable, I have found, however, the number of them is low.
Product manuals are a great place to get clear and accurate data for my drawings. The images typically included are basic, allowing component wiring, yet providing enough detail to easily identify a component. The screenshot below is a prime example. I have enough data for the component to be clearly identified, yet I can do all my design work with the included data.
A word of caution when working with this data is the scale factor. Manuals, as well as product cut sheets are formatted to fit letter size paper. In the image below, the breaker is 17.6mm wide by the dimension showing. This size restriction applies to any size component! When using this image as a PDF import it will be (obviously) out of scale. The screen shot below is how the PDF came into my drawing.
The dimension is referenced in metric. This is not really an issue, as you will need to scale it anyway. However – take note of the dimensions that I put on the copied data. Doing the math, the view is drawn at .78 = 1 scale, if you have your dimension style properly set. Before working with this data, I recommend doing a “distance” command to verify the actual size of the entity. Using this data, you can determine how to accurately scale the entity to match the drawing settings.
Another point to remember is that the data will contain many small entities, in this case 173 of them. If you miss a line or two this could be interesting.
*TIP* - always select the desired portion of the detail and “cut with base point” using a practical base point. This will remove the individual pieces from the drawing, and provide a pratcial base point. Next “paste as block” back into your drawing. One entity is a great thing…
When this single entity is selected, it can easily be manipulated without losing important detail. I will typically save my original PDF uneditied, to our server to preserve all the data. When inseting into a DWG, edit the scaling and cetail content you wish to keep. Also add a note to the original file with the proper scale, for future reference!
By creating a reference directory of original data files, and an alternate for cleaned up data , the source data can always be referfnced as necessary.
PDF’S – Not Just One Trick Ponies.
As often as I use a PDF reference in my schematic design and enclosure design, the benefits of including a PDF extend to many other aspects of my design work. As part of my work, I need to add track data for our AGV integration into a plant. As customers are sometimes hesitant to send me a DWG, they will send a PDF. I will then put this into my file as an import, cleaning up the layers and locking them to avoid errors.
One of the caveats of PDF imports is the uncetainty of the layer structure.
In the image below, the plant layout is a PDF import. I will typically lock its layers for accuacy.
Conclusion
As a CAD designer, I am always looking to save time on my work. PDF files and their proper handling can make a designer more efficient and accurate. Too often the sources of said files get overlooked, resulting in extra time and work.
Always check online, and not just the vendor’s website, for a PDF manual or cut sheet before you invest too much time and start from scratch on a project.
