Creating 3D Sketches for Lampshade Power Cord Placement

In this video, we will continue to sketch for our lampshade power cord. You will see that I am still in the Step 13 file, and if I open up my Power Cord and Cord components, I will activate my Cord component, and I will not edit Sketch 1. Instead, I would like to make a new sketch.

This sketch will be directly in the middle of this arm, running right through these holes. So, I need to create some construction geometry. Specifically, I would like to create a construction plane.

I will go to Construct > Midplane. This will place a plane between two faces. So I'll select this face and this face, and you will see my construction plane preview.

I'll click OK, and now I know that this plane is directly in the middle of this arm. So, I can now create my sketch. Again, with my Cord component active, I will go to Create Sketch and select this plane.

I would also like to slice my model so that I can see my sketch more clearly, and if I would like to, I can hide Sketch 1 so that this geometry is not involved. You may notice a slight optical illusion between this arm and this arm. They don't look like they are at 90-degree angles, but they really are.

So let's begin to sketch. I know that I want to draw the cord for this part that goes through here, down my arm, and back through here. So I'll go to my Line tool, and this time I'm going to sketch the shape, and then add my constraints.

I'll come out into space with my Line tool, and I will click once to start my line, and then I will click and drag to add an arc to the end of that line. When I release, it draws my endpoint. Let's do that again.

Click and drag to draw an arc, release, and draw another line. You will notice that there is a Tangent constraint applied at this end, but not at this end. Same here.

So I will go to the Tangent constraint and apply it from here to here, and here to here. These points are already perpendicular. You can see that as I drag it, so I do not need to add any Perpendicular constraints.

Before I can place my constraints, I need to bring in my projected geometry. I will press P for Project, and zoom in and select this line and this line. I'll click OK, and now I can begin to place my constraints.

I will go to Coincident and snap this endpoint to the Shift-midpoint of my line. Let's do that again. Point to Shift-midpoint.

Now those lines are black, and I can begin to dimension my lines. Press D for Dimension, and I'll change this to a radius of 5, and this one to a radius of 5. Now I need to dimension from this line to this line, and this will be a distance of 10. Again, I'll press Escape a couple of times, and then drag across my model, and press X to turn this line into construction geometry and remove my profile.

I want a couple of lines to extend off the end here, 5 millimeters. So I'll go to Line, zoom in, click and drag straight out, which will automatically place a Perpendicular constraint, and now I can press D for Dimension, and type 5. Let's do that one more time. I'll go to Line, select the endpoint, and drag straight out.

The Perpendicular constraint is automatically applied. Press D for Dimension and set it to 5. This is all I need for this sketch, so I'll click Stop Sketch and orbit my model. Remember we turned Sketch 1 off—we can turn it back on now.

We can see now that our sketch looks like this: comes up, around, through this arm, up again and around, and then there's a break, and it comes down to the arm here. I'm going to show all of my components, so I'll activate my top component, and then I will go through and unhide all of my components in my model. Notice I may need to unroll and check my subcomponents in my assembly components.

Again, I can turn off my Fastener Assemblies—I don't really need them while modeling right now. Now that we can see the full model, we can understand what else we need to do in this sketch. I want to place a sketch that connects the point here to here, this point here to my switch, and my switch to my plug.

I will use a series of sketches in 3D to build these. Remember, under Preferences, that in Design we have "Allow 3D Sketching" checked on. If you would like to work in 3D sketching, you may—but for now, I'm going to draw this sketch off to the side and then move my points.

So, I will activate my Cord component one more time, and I will leave these two sketches on because I am going to reference them in this sketch. So I will go to Create Sketch and just select the bottom plane, because it doesn't matter where I draw these components—I will move them into the appropriate positions. Once you have selected your plane, we can begin to draw our sketch.

I will sketch a spline like this and click OK—a simple two-point spline. I will sketch another spline down here and click OK—again, a simple two-point spline. Then, here, I am going to sketch a four-point spline and click OK. If I orbit my model, we can see that they are all flat on the ground plane, but we can move them up into place.

Before we do that, I found it helpful to change their grips to more closely resemble how they will appear once positioned. So I will turn this grip to the side, and I will turn this grip up vertically. Let's move over here and do the same. This one will be horizontal, this one will be vertical, and these two we will edit once they are in position.

This one, we know exactly where it should go, so I will move it into the midpoint there, and into the midpoint here, and their grips have adjusted accordingly. Notice that it is constrained to the midpoints, so I will delete those midpoint constraints so that my line appears blue. Again, those were snapped to the bottom plane, but I want to move these into 3D space.

So let's move our points. For this, we need to use the Move command. I will go to Modify > Move, and we’ve been using Free Move until now. I can select my point, drag it up a specific distance, and click OK.

This time we will use Point to Point. Make your selection first—I will select this point. Then, my origin point will be here, and my target point will be the middle of this face (a small square). Now we can see the point move into place.

When I click OK, that point is in place, and its grip is still oriented correctly. Let's do the same to this line. I will select my point, go to Modify > Move, choose Point to Point, define the first point, the second point, and click OK.

Now that spline has moved into 3D space and is ready to go. We can also place Coincident constraints when snapping to exact geometry. Since I have a point here in this sketch and one here in another, I can snap these lines directly to them.

I will go to Coincident, select this point and this point, then this point and this point. Let's zoom in, and we can also apply Tangent constraints. You may need to orbit the model for better access.

I will go to Tangent, select the spline, then select the arc—you will see the constraint apply. Next, I will orbit around, zoom in, select this small line, and then the arc.

Now I have Tangent constraints applied across the entire shape. Press Escape to exit the command. Let’s move this final line now.

First, I know I can use a Coincident constraint to go from here to here, and then move it using the Move command.

Go to Modify > Move, select your object, this point, and go Point to Point—from here to the center of this face. Click OK. Now, if I go to my right view, I can see that my line is not exactly where I want it to be. I will go to Modify > Move again and use the plane slider to fine-tune its position.

This doesn’t have to be exact—adjust it as needed. Click OK and return to the Home view. We’ve now placed three splines in our model in 3D space.

Go to the top view, and I’ll refine the shape using Modify > Move. I’ll check the side view—it still looks good. Click Stop Sketch and save the file.

In the next video, we will create a profile and sweep that profile along these sketches.

I’ll see you in the next video.