Creating the plate outline in 2D AutoCAD using circles and polylines - AutoCAD Tutorial

- We're going to start a new chapter now which is going to be like a little mini project for you to do. So we're going to start off with a drawing from the library called metal plate dot dwg. When you open it up in the model tab you'll see a simple rectangular polyline on the objects layer. So see there's the objects layer there. We're in the 3D modeling workspace as well. Remember that too. Don't change your workspace. Now what we're going to do we're going to use some arcs, circles, and a bit of offsetting to create a nice outline that we can then generate into regions and convert to a 3D solid. Now we're starting off in 2D at the moment you can see we're in the top view on the view cube and this is a flat rectangle with the Zed value equaling zero. If I do a quick isometric, you'll see that's all it is. Look it's just a rectangle flat on the XY plane with the Zed value at zero. I'll jump back to the top view now on the view cube. Now, it is a closed rectangular polyline. If I hover over it, it's a polyline on the layer objects. So the first thing I'm going to do is I'm going to go up to the modify panel on the home tab on the ribbon and I'm going to go to the fill it command. There's the fill it command there, and this is just as if you were doing this in 2D as well. So I go to fill it and I right click and I select radius. Now my radius is going to be 50. I'll type in five oh and press enter. And then I'm going to right click again and use a little trick with polylines. I'll select polyline there on the shortcut menu, click on the rectangle, and lo and behold I've got some lovely filleted corners with a radius of 50 straight away. Quick and easy. Then we're going to go back up to the modify panel. Click on the offset command, come into the drawing area, the offset distance will be 25. Press enter, select your polyline, click on it, and move inside it. So you should see a red outline inside the purple outline. Can you see that? So the red outline is whichever side you offset. When you move the mouse. You want the red outline inside, not outside and click for direction. That confirms it. And then press enter to finish the offset command. Now the reason I've done that little offset is I need to utilize that now to create some circles as well. So, very quick and easy. The the inner outline allows me to snap easily. You'll see what I mean in a minute. I'm going to go to the circle command now on the draw panel on the home tab on the ribbon. And I want circle center radius. And this is quick and easy. Make sure your 2D object snaps are on. So I go midpoint on the outer outline and then come down and click on the midpoint of the inner outline like that. There's my first circle and all I'm going to do now is copy this. So I select the circle, right click, copy selection, use the midpoint there which is also the center of the circle, and we'll just pop that on each midpoint going around our outline like that. So we get it to there like that. Now I've put that one in the wrong place. Don't worry about it. Just hit escape a couple of times. Click on it, click on the grip, just move it out to the other midpoint like that. And then just hit escape like that. So some little 2D trickery there like so. Now, the next bit is a bit more interesting. We're going to do another circle. So we're going to go to the circle center radius again and we're going to use the center of this circle which will also be a midpoint snap. Click and come outwards, and this time you want the radius to be 50, 5 0 and enter. Can you see that? It forms a bigger circle. So the bigger circle kind of crosses everything. Don't worry about that. We'll tidy that up in a minute. Again, select the bigger circle. It's a right click. Copy selection. You want the center of your circle which will also be that midpoint snap. Same as before. We're going to go around, use the center of each of the smaller circles that we've just placed like so and then press enter to finish the copy command. Now it does look a bit untidy at the moment but everything we've got here right now is in fact a closed boundary. That means they can be converted into regions. Now before we do that, we need to just tidy up a little bit. So in a offsetted rectangle with the curve corners, click on that, right click, and erase. We don't need that anymore. And what we're going to do now, can you see? We're trying to create a metal plate with little outstands that are hemispherical with a little hole in the middle. So ideally, what we need to do now is we need to make sure that when we tidy this up that we lose all the lines that we don't actually need. So it's just a case of doing a little bit of trimming now. So all we need to do is go to the trim command that's in the usual place, modify panel, little pair of scissors there. So we're going to trim what we don't need away from the drawing. So ideally that one, that one, that one, and that one. So that tidies that up. And then we need to cut in the middle of the hole. So we go one and two and we do this four times each time, as you can see. And then we just need to tidy up where the holes are. So we use these little lines here like this. And you can see we've developed a nice simple boundary for a metal plate, just using circles, arcs, and a bit of trimming and a bit of tidying up, a little bit of offset as well. Once you get it to that point just press enter to finish the trim command. And what you want to do now is save the drawing. Ready for the next video.