Now I'm just going to zoom in a little bit and I'm going to just create a line. And then this is where the crown of the fork connects to the head tube of the bike. So this is where the fork connects to the front wheel. We're then going to come over here and select on this line again, and we're going to bring up back to this head tube line and stop that. So it's just very important to know that it's a fully sealed shape. So we could use this in an extrusion to extrude a 3D box from it, we could do it to create a surface if we wanted to. And that's really important because when it shades it in, it means that it's a sealed object, it's a sealed shape. Now, you'll see, as soon as I did that, it actually shades in the shape. We're then going to go ahead and snap that over to this center line that we built. We're then going to come up here to the top tube and select the end point. There's many things that reference this line. This is a reference line that's really important because we reference how high the bottom bracket is from the ground, which we reference by the center line of the wheels, and we also use this as a reference point for the fork of the bicycle and the head tube angle. Now, this line is very important to the bicycle because this is the center of where the front and rear wheel are. So I'm just going to go here to this check mark and hit that. And then I don't need to continue drawing, which the line tool allows you to do if you select two points. Again, we're going to make this snap to parallel to the Z axis, or ground axis. So we're going to go ahead and pick a point in space over here, and another one over here. The next thing we're going to do is draw the center line of the wheels. So if you double click, you can go to 560 millimeters, which makes a little longer, and go back to 555.

I can do that also with these down here and with this angle as well. Now, I don't like where this dimension value is. We are then going to give it a value of 555 millimeters. So we're going to let it do that so that it's parallel to the ground. Since we're really close to being parallel to the Z axis, it snaps to that. And then we're going to select along this line and you'll see, once we start drawing the line, it automatically snaps here. In this case, we're going to use the keyboard shortcut to pull up the line tool, and that's just simply L. The next thing we're going to do is we're going to create another line that's going to represent the top tube. If you just hit the scroll key, which is the center button, we can then pan and see our entire line. And then to pan, and we can also use the scroll key. We can simply use the scroll key to do that. You'll see that we can't see the whole line, so we want to zoom out. We're then going to use the tab key and go over to the angle and do 73.5, hit enter. So for the length, we're going to do 555 millimeters. And then you'll see, once we start creating this line, we get two dimensions that it gives us. We're going to go ahead and select the origin. So, let's go back over here to the left, and we're going to select that the line tool up here. So we're going to go ahead and create the bottom bracket as the origin, and we're going to create the seat tube first. It just makes a life really easy down the road. I could also create a mirrored plane, mirrored components, referencing the origin. I could also create symmetry on a three dimensional part from the left and right side, referencing an origin. So I can use that origin construction planes to bisect the part, if I needed to, if I was for instance, making a mold. One of the things I always like to do, and why I like to select from the origin is to allow the origin of the model to be essentially the center of the model that we're building. So we can go ahead and select this construction plane, which is our Y Z plane. And so this center point right here is zero, zero, zero. Now you'll see that this has highlighted the origin of the part, of the model. So let's go back over to the left side of the screen and select the create sketch tool. So we are ready to create our sketch now. Now, I like to be on the left side when designing a bicycle frame, since we're looking at the drive side where the chain rings and chain are. So we're going to go over here to the right side of the screen, and we're going to select on the view cube so we can kind of move around and go to the left side. The next thing I really want to do is I just want to change the view that I'm in so that I can be in the left view. So if we go to the left side of the screen here and select the arrow for the document settings, I just want to make sure my unit is millimeters.

Since this is the beginning of a brand new project, I just want to make sure that my document settings are correct. In this video, we're going to be drawing a sketch for the front triangle of a bicycle frame.

Fusion 360 mirror sketch