Drafting is a craft, and sometimes even an art. Architectural drawings by the old masters of the profession are sold as art works, and displayed in museums. Drafting with CAD is also a craft, but something of an invisible craft - people looking at the plotted drawings pinned up on a wall don't know if they are looking at the result of a well crafted, elegant CAD file, or not. But, the people who work in the files know the difference because poorly crafted files slow them down, and cause problems. I have known many a drafter to give up, and redraw entire buildings because sloppy, haphazard drafting in CAD is slowing them down so badly that they can't make progress.
Like any craft, it takes time, and practice to achieve mastery. But, even entry level drafters can draft with care, and avoid the common pitfalls that result in bad cad. Listed below are ten guidelines - basic standard practices that should become second nature for anyone working in CAD. Following these may not raise your files to the level of art, but at least they won't be trash.
1. If something looks like one line, it should be one line...
...not a series of short lines all in a row, touching each other, and not a stack of lines all on top of each other. Likewise, Corners should really be corners - not two lines that end near each other. Use your OSNAPS, so that things meet exactly. If you are filleting, or chamfering, don't use tiny radii, use a 0" radius. (note that AutoCAD 2002, and earlier use a ½" fillet radius by default, you have to set it to 0" yourself!). Of course you can use a fillet radius if a rounded corner is what you mean, but the point here is draw what you mean, not some close approximation.
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Drafting is a craft, and sometimes even an art.
2. Remember your audience
Drawings intended for millwork contractors are not the same as drawings intended for site grading contractors. Yet, I have seen drawings of large scale urban planning projects drawn at 1/32" increments. Be precise, be accurate, but also be aware of what you are drawing, why, and for whom.
3. Draw somewhere specific!
You can't imagine how many drawings I open and find that the building is just placed randomly off in the middle of nowhere. This actually causes more problems than you can imagine. So, draw starting at 0,0,0. Make all of your drawings x-ref together nicely, with no craziness required. If you are working with Site Drawings that place the building off of 0,0, and at some angle, then get the whole team together, agree to a coordinate system that makes sense, and stick to it. The same logic applies to blocks - use insertion points that make sense!
4. Use X-refs sensibly
I recently described a drawing's X-Ref scheme as a "Bowl of Spaghetti." It was the best analogy I could think of at the time. For many of our drawings "bowl of spaghetti" falls short, because it implies that all of the X-Refs were somehow contained, as if in a bowl. A better description for some drawings might be "a pot of spaghetti that's been thrown on the floor by a two-year old." So, insert your X-refs at 0,0. Put them on layer 0 (or create a dedicated layer - but don't put them on A-Anno-Dims-96, or something like that). "Overlay" x-refs, rather than "attaching" them most of the time. Don't x-ref one sheet file into another. Detach your x-refs when done, instead of simply unloading them - or worse, erasing them. Also remember that raster
images, when used in drawings, are referenced. If you erase them, they are
still linked to the drawing, they simply aren't referenced. You have to detach them.
5. Use layers properly
Put stuff on the right layer, and let the layer properties work for you. Name your layers according to the offices layer naming standard. I find it odd that the thing people complain to me about the most is people not drawing things BYLAYER. Everyone complains about this, and yet everyone keeps finding non-BYLAYER stuff in their drawings. Why? If everyone hates it, who's doing it?
6. When starting a new drawing, start a new drawing
Sounds silly doesn't it? But people routinely start new drawings by opening up some drawing from another project, and then erasing everything in it. This is a horrible, abhorrent, and inexcusable practice. I frequently open up drawings for new projects to resolve problems, and find that the drawing was actually started sometime in 1995, and has months of accumulated editing time. There may be 1,000 objects currently in the file, but there have been tens of thousands of objects deleted over the years. And people wonder why their files have become corrupted. Start with a clean, fresh new file, and you will have fewer problems.
7. Don't leave extraneous garbage in your files
Really, it is amazing what people leave in files. If data in drawings occupied some sort of space in the physical world, the office would have burst at the seams. If you are working on multiple options, keep them as separate files - not lined up side by side. (And, as per my point above, give them all the same base point, so you can swap them in and out of sheet files easily&) Don't leave whole floor plans of other buildings in your drawings, just because you looked at them for reference. Make each drawing a neat, clean, easy to understand drawing of one thing - whether that thing is a single floor, or a set of door jambs.
8. Don't explode stuff
I find drawings with exploded hatches, exploded dimensions, and dashed lines exploded into lost of short, separate lines. Don't do it. Explode blocks, on occasion, but not hatches, not dimensions, and not dashed lines.
9. Name your files appropriately
This isn't rocket science, and our naming standard is not that cryptic, but still, a lot of people can't seem to manage. Personally, I find it extremely annoying that people keep re-inventing the standard abbreviations that are defined in the CAD Manual - Why do we have to have "Plan," "FlrP," and "FLP" when everyone understands FP to mean Floor Plan? But, more than just an annoyance, drawings named "Drawing1" or "Version2" or "Current" always lead to confusion.
A dozen more good practice guidelines come to mind, several of which deal with units, accuracy and precision (why would anyone draw something in fractions of an inch increments when working at an urban planning scale? I don't get it!). But I promised myself I would limit this email to just ten items, to keep it short enough for you to read. So, I will wrap it up with this one, which is, perhaps, the most important.
10. Remember that you are part of a team
Drawings you produce here are not your drawings, they are the offices, so you have to stick with the offices standards - it's not an option, it is part of what you are paid to do. No offices standards are perfect - I could give you a list of things I don't like about my office's standards. But that isn't the point, standards provide for a common way of working, and address the largest possible range of things that are done in an office. So, your own preferences, and your feelings about the way layers should be named, or the way files should be named, etc., are things that you can discuss with with your offices CAD Manager. Work together to improve the standards for everyone. But, hey are not things that you should change on your own, because everyone else in your company needs to use the work that you create.
Article Submitted by Charles Prettyman CADD Manager at Robert A. M. Stern
Architects. You can contact Charles at c.prettyman@ramsa.com
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