Wednesday, May 23, 2012

Dynamic Hold Lines

(Click the little gear and set 720p HD for the best view)

Tonite I rolled the calendar back to a deferred (and self-imposed) project to see if I could make something of it. Several months ago while working on a "real" project at work I discovered that many of the airfield hold lines in our airports CAD files had been done pretty much, "the hard way". They had been built with a mixture of lines, solid hatches, not a lot of accuracy, and are pretty cumbersome to modify. I don't get upset about these things when I find them because most finds are legacies of far older work, and because of lot of this is as new to me as anyone around here. This particular problem felt like it might become a nice update however, especially if it could be done with a dynamic block or two. So I suggested as much. The thing is that I'm the only one who ever messes with dynamic blocks! So the whole idea was bound to sit idle until I could find some time to have a shot at it. The video above shows the solutions I came up with after a couple hours of messing around tonite.

These are custom AutoCAD (2012) dynamic blocks that I've created and stashed on a tool palette for easy access. They include linear stretch and array actions, and an alignment setting. To use them I've drawn disposable construction lines where the hold lines are needed (the cyan lines in the video - typically they might be on a non plot layer) and then dropped the blocks on them. I made three different types of line blocks tonite as shown. Once placed they are stretched to complete the line work. This is considerably faster than anything done by hand. And all of the widths and spacings are in conformance with the most current FAA Advisory Circular 150/5340-1K for Standard Airfield Markings.

I've made dynamic blocks with the linear parameter/action before, but this was my first shot at anything using an array or the alignment parameter. It's all kind of cool.

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