Learn how to draft lines and arcs with precise coordinates in AutoCAD. This comprehensive guide explains how to use relative polar coordinates, apply line type scales, zoom in and out, and much more to design clean and accurate diagrams.
Key Insights
- The article provides step by step instructions on how to draw and scale lines accurately using relative polar coordinates in AutoCAD. It explains how to define the point of beginning, how to input the degrees, minutes, and seconds, and how to understand the direction of the line relative to the last point drawn.
- In addition to creating straight lines, the guide also shows how to create arcs with specific angles and radii. It details how to use the start-center-end command to create a precise arc and how to manipulate other line segments to achieve the desired outcome.
- The tutorial also offers tips on how to maneuver around potential issues within the AutoCAD program, such as zoom limitations and correct alignment of designs. It demonstrates how to adjust the view size to overcome zoom lockups and how to orient your design correctly on the canvas.
Note: These materials offer prospective students a preview of how our classes are structured. Students enrolled in this course will receive access to the full set of materials, including video lectures, project-based assignments, and instructor feedback.
Let's begin. If you look up here at the layers, you can see that we're already on the proper layer. If you orient your handout on your 11 × 17 paper so that it's horizontal, you can see the point of beginning, or POB, at the bottom right-hand corner.
So I'm going to start off drawing a line. My first value will be 00. My next point will be at 116.11 in the direction of N for north, 51, D for degrees, 10 minutes, 13 seconds east.
Now, look at how I keyed it in. I started off at 00, so my first point, the point of beginning, was 00. I'm using relative polar coordinates.
So I'm saying relative to where I'm starting, I'm going to go at 116.11. So that's representing feet. That's the decimal units. And then the in the direction of is the less than sign.
And you can see looking at the handout, it's saying go north, 51, I type in D for degrees, 10 minutes, which is the apostrophe, 13 seconds, which is the quote marks, and then E for east. Because if you remember, degrees are broken down into minutes and seconds. I'm now going to roll back, and you'll notice as I roll back that we already have our line type scale being presented.
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So again, I've drawn my first point. My second point will be at, meaning relative to the last point. So I'm going at 128.87 in the direction of north, 38, D for degrees, 30 minutes west.
And I'm just going to hit ENTER to stop it. I'm now going to do a zoom extents, and one thing you'll see is that when I do a zoom extents, I can't get out any farther than I can right now. AutoCAD for some reason tends to lock up certain zoom factors.
So how I get around this is typing Z enter for zoom, and I will type in.25X, meaning my next view will be 25% of this image size. So I hit ENTER, and now you can see what we have. So I have the first line down here, I have the second line segment up here.
I'm going to continue, so I'm going to type L enter for line, and it says specify first point, and I could say go to the end of this segment, or I can hit ENTER, and that will continue the line segment from where I was. So I'm back in the line command, so I'm going to say at 23.02 in the direction of N for north, 49, D for degrees, 16 minutes, 59 seconds east. Enter, enter.
Now you can see this segment went to the right as opposed to going down to the left, which is what we needed. So what that tells me is that when the surveyor did his input, that one person was standing here, someone else was standing here, and they were taking the measurement going this way. Now remember that if I have a segment going north so many degrees towards east, that's the same as saying south so many degrees towards west.
So since I can see that this has happened going in that direction, I will simply say move this line from the end of here to the end of here, and save the file. I'm going to have a similar kind of situation happen down here, but I'm going to say draw a line from the end of here, point of beginning, I will say at 70 in the direction of south, 25, D for degrees, 30 minutes east. Enter, enter.
Now I'm going to pan back, and I will move this segment from the end of here to the end of here, zoom back, control S to save. Now I know that we have two handouts. There's the one where the image is represented horizontally on the sheet.
There's one that shows it on the actual sheet image. If you position your handout so that the north arrow is going straight up, you can see this kind of configuration as far as the alignment of the actual site relative to where we're going. Now, let's look at this next part.
This is going to be an arc, and if you look right about here in the handout, you can see that the arc has an, it says A for angle, R for radius, and L for length. So what's going on is that the angle being represented by this arc fills a circle, and it's 78 degrees of a circle, but the radius of the arc is 78 feet. So here's a nice way to do it.
I'm going to draw a line from an arbitrary point to a point perpendicular, P-E-R, enter, to here, and I'm now going to move this line from the end of here to the end of here, control S to save. So this is going to be one of the radial lines that will be dealing with this arc. This segment, the radius of the circle, the radius of the arc, is 78 feet, or 78 units.
So I'm going to say offset by 78 this line and go up, enter. I'm then going to fill it with a radius of zero these two segments, and I will now erase out this segment. What I know though is that this is the center point for the arc that will be going right along in here.
So what I'm going to do is I'm going to take this line, copy it on top of itself, and then rotate the last item. So watch this, copy this line, enter to say I'm done, the base point is the end of here, destination at the ampersand, enter. It's asking for another one, I hit escape.
If I were to say erase crossing, you can see up here it says two found. I'm now going to say rotate the last item, L enter for last, enter to say I'm done. My base point will be up here.
Now remember that positive rotation is counterclockwise, so I'm going to say rotate it minus 78 D for degrees, enter. So you can see now I have what I need. So I'm now going to draw an arc, so I'll go to arc, start center end, here's my start, here's my center, here's my end down here, and I now have the arc that I need.
Now if you'd like, you can take these line segments and migrate them to the see no plot layer, hit escape and save. Now we have all of our property lines in the drawing. So let's save the file, if you would please get caught up, and then we'll start working on labeling information on the drawing.
