Develop a deeper understanding of the usage of AutoCAD's built-in construction geometry tools in creating precise designs. Learn the flexibility and precision of the ray tool, the subtleties of polar tracking, and the effective usage of fillet and trim tools to achieve an accurate representation of your intended design.
Key Insights
- The ray tool in AutoCAD is a valuable tool for creating lines that start from a central point and extend an infinite distance in one direction. It is particularly useful for creating angles as it does not require the specification of the distance of the line.
- Polar tracking is a useful feature that allows locking or snapping the cursor to specific angles. This can be particularly helpful when creating designs that involve precise angles or directions.
- The fillet tool is used to create a sharp corner by adding a curved radius to two lines. The trim tool, on the other hand, facilitates the removal of unwanted geometry. It's important to remember that with fillet, you maintain the geometry you click on, and with trim, you remove the geometry you click on.
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The detail hat symbol will eventually be a triangular shape on top of the circle. However, in order to find those two final lines, we have to use some construction geometry. AutoCAD has two built-in construction geometry tools, although you might see some people just using lines for these tools.
I'd like to introduce you to these tools for the next couple of symbols, and then we might go back to using lines. This is fully a personal preference, but please follow along with the construction geometry we draw for this video. This construction geometry can be found in the flyouts under the Home tab, the Draw panel, and click this arrow to access the flyout.
Here we can see two types of construction geometry. This is called an X line or a construction line, and this is called a ray. A ray starts from a central point and draws a line an infinite distance in one direction.
An X line or a construction line does the same thing, but in two directions. For this example, let's choose ray. I can see on my command prompt that it says ray, specify start point.
Of course, that means click or type, and in this case, I want to start from zero comma zero. Enter. Now, I cannot see how I could find a good angle.
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I need to click or type something on my screen or on my keyboard that lets me point this line in a 45 degree angle in this direction. This is where polar tracking comes in very, very handy. Down on the bottom right of your screen, you can see this image, this icon, which is a circle and a little pie shape.
This is the polar tracking button. Click this to turn on polar tracking, and then the arrow to the right, if you click it, will show a flyout of different angles that we can track. The tracking settings dialog box will have more options, but in this case, let's choose 15 degrees, and with that image on, now when I move around the screen, you can see that my cursor is locking in or snapping in to certain angles.
Because we are using the ray tool, it does not matter what distance this line is, although our cursor will show the distance value. What's more important is that I come over and see where it says 45 degrees at any distance and click once. The ray tool will not automatically end, so I can also come over to this side and find where it says 135 degrees and click again.
When I have drawn my two rays, I can click enter, and now that I know I started at zero comma zero and drew my two lines at 45 degrees and 135 degrees, I have made a perfect 90 degree angle. This is exactly what we want. And now we can do the same thing, but connecting our points back together.
I will go back to draw and choose ray, and this time I need to find this point right here. I do not know the coordinates of that point, so I need to use our object snaps, and we can access those by shift right click. So I'll go shift right click, and I will find intersection.
Intersection is where two pieces of geometry meet, and in this case, it's our ray and our circle. I can come down and I'll see it snap into place and read intersection, so I can click to start, and now I will come back to 135 degrees, click enter to say that I'm done. I'll go draw ray one more time, shift right click, intersection, and then from this point, this intersection, I can draw my line at 45 degrees and click, enter to say that I'm done, and now you can see this shape in here represents our detail hat.
Now we have to do some cleanup before we get to our final shape. To start, we can erase our original two rays. This is why this geometry is often called construction geometry.
It is used in the construction of our final symbol, but it is not necessary for the final product. I will go up to the eraser tool, and I will see that I have a pick box. This pick box will allow me to click on objects that I want to add to the selection set.
So I can select this line and this line, but in order to fully erase the objects, I need to complete the command by hitting enter. If I hit escape, the command will be canceled, not completed. I'll hit ENTER to finish erasing those objects, and now we need to clean up this geometry.
In order to clean up the geometry, it is best to use fillet and trim. Fillet will add a curved radius to two lines, although you can specify a radius of zero, which allows you to create a sharp corner. Let's use the fillet tool on the top two lines.
I will hit fillet, and I will check my command prompt. I can see in the second line above that it says radius equals zero. If that radius reads any other number, or if we just want to make extra sure, we can go R, enter to enter a new radius value.
So I'll hit zero, enter, and now I need to select my objects. It's important to know that fillet is what you want to keep. When I click on geometry, I want to click on the bottom left of this ray, and the bottom right of this ray, and I will keep both bottom sections.
If I undo and do fillet, and I choose the top objects, it will keep the top lines, and it will fillet at this point. So once again, I'll go fillet, make sure my radius is zero, and I will click and click. Fillet automatically ends the command.
For the bottom circle, I will use my middle mouse to pan, we can use trim. Trim cuts away geometry that you do not want to keep. I can come up here and see trim, and in order to trim, it is best to find your cutting edges.
If I move down automatically, I can see that it has set all edges as cutting edges for my drawing. We will talk about how to assign cutting edges in the future but for now, we will simply click the bottom of the circle to erase, to trim away that geometry, and enter to complete our process. Remember that fillet, you click on the geometry you want to keep, and trim, you click on the geometry you want to trim away.
I will do a double middle mouse wheel click for a zoom extents, and control S to save. The final bit of geometry we need to add is our fill color, or as AutoCAD calls it, a hatch. The hatch button can be found on the home tab, draw panel, hatch, and when I click hatch, it opens a contextual tab.
This is the contextual hatch creation tab. This tab is only available when you are creating or editing a hatch. In this case, it is a fairly simple hatch.
It is a solid pattern, and we can pick points, which allows us to click inside of a region as if it were a coloring book, and we are simply coloring within the lines. In order to pick points, we need to click inside the space. Do not click on the edge.
We are coloring in the lines while we use pick points. So I will hit pick points, click in my space, and hit the check mark to close hatch creation. Now I can control S to save, and in the next video, we will work on our next symbol.
