Explore advanced sketching techniques used to create a 3D model of a power cord, including strategic hiding of unnecessary components, the use of projected geometry, and the importance of constraining and dimensioning features accurately. Understand the downside of using a single spline for complex shapes and the benefits of using a series of splines, arcs, and lines to create a parametric model that can be updated when the model is moved.
Key Insights
- Advanced sketching includes hiding unnecessary components in the model to ensure a clear focus on necessary components such as the power cord.
- Rather than using a single spline for complex shapes, it's better practice to use a series of splines, arcs, and lines to create a parametric model. This allows the model to be updated parametrically when certain sections are moved or changed.
- The use of projected geometry and the careful constraining and dimensioning of lines are crucial for accurate and professional 3D modeling.
In this video we will use some advanced sketching techniques to create the power cord for our model. If you will please let's scroll down and find step 13 and open it.
Once your file is open you can go ahead and hide your data panel and let's look at our power cord component. I need to add a component inside of my power cord component for the cord. So I will right-click on power cord, new component, and I will name this cord.
Also I want to hide some features in my model because they are not necessary. Specifically my fastener assemblies component, we don't need any of that information, and the lampshade I also don't need. I will need my lampshade cap assembly because that's where my cord is going into.
I'll need my arms here and here, but I don't need this arm or my base. So I will go into my arm assembly, hide my lampshade arm, my lower arm, and I can hide my base component. Now that I have all the components I need I can begin sketching.
So I'll create a new sketch and I will host it directly to my middle plane. This is because my lamp is symmetrical and I'm only creating the first part going through the middle of my arm. When my sketch is hosted I'll zoom in and let's talk about what our sketch will look like.
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For now I will do a spline, but please do not do this. We are going to run our model through this arm, up through this arm, and around like this. This is the rough shape for our model, but using a spline like this is very bad practice.
This spline has so many points and it is not able to be updated parametrically. Instead I will use a series of splines, arcs, and lines to create a parametric model that will update when we move our lamp. So I will delete this spline, just remember the shape, and let's begin sketching.
Notice I have no projected geometry on my screen, so the first thing I would like to do is to create some projected geometry that we will be snapping to. You will notice that I cannot directly select this hole in my model, so again I will go to slice and this will slice my model right down the middle. We can clearly see the guts of our lampshade cap assembly and we can go right through the middle of our model.
Now I will go P for project and zoom in and I can grab these two lines in the top and bottom of my holes. I will do the same down here and grab those lines. Now we will be able to snap to the midpoints of each of those lines.
I also want to snap to specific parts of my lampshade cap, but instead of using the slice geometry, I would rather grab the outside. So I will uncheck slice and now I can grab this horizontal line here, hitting P for project, and I will grab this line here. I can also click directly on the face to grab all of the surrounding geometry.
When that's done, I no longer need my lampshade cap assembly, so I can hide that component and the projected geometry will stay. I will keep my arm here for now so that I have a better understanding of what I'm drawing to. If you accidentally hid your lampshade cap assembly while you were still in the project command, you may need to hide it again.
So let's begin drawing. I want to start down here because this is where all of my lines and arcs will be and I think this is the easiest part to draw. Let's go line and I'll zoom in and simply go from the endpoint here down to the endpoint here.
Notice that it stopped my line command and my two points are black and my line is black. This means it is fully constrained. I'll go line again and do the same from here to here.
Again, fully black is fully constrained. Now I'll draw a line out in space and hit escape. Let's constrain and dimension this line into place.
I will go parallel this line to the bottom side of my arm and I will go D for dimension and dimension this distance as 10. Now I'd like to connect these two and these two lines, so I will go sketch, fillet. I can select my lines and I'll place a radius of 5. Your radius may be different depending on your zoom level.
Notice that my fully constrained line has now become unconstrained because the endpoint is no longer coincident with the midpoint of this line. Placing a simple perpendicular constraint will fix that and my line will become fully constrained. Let's do that one more time.
I'll go sketch, fillet this line to this line. Again, making sure it says 5 and here's my warning, constraints or dimensions were removed during the operation. Again, I'll go perpendicular and go from this line to the bottom of my arm.
Notice that I created a profile because this line was projected in. This is okay. I'm not super worried about it, but I will select with a crossing window and turn on construction to make the bottom of my arm construction geometry.
This will remove my profile and let's review our sketch. I now have a piece running like this which looks like the rough shape for my lampshade arm. I'm pretty happy with this, so I will stop my sketch and save my file.
In the next video, we will place some splines. Let's do one more thing before we end this video. I will double click to edit my sketch again and I want to place some small geometry here in my model.
We will use this in the next video when placing our splines. I will create a line. Make sure that it is completely blue and has no constraints.
Now I will go P for project and project in this circle. Now I can place a coincident constraint from this line to the center of the circle. Now my line is constrained on one end and the other end is free.
Let's select this line and make it construction geometry. I will dimension this line using an angled dimension and make it 10. And that's all I need to do for this geometry in this video.
Notice I've simply placed a line that's constrained at one end and unconstrained at the other so that it can freely rotate with our model. The reason why we are doing this is I want to create a spline that runs around our model like this. And I want to connect it to the end point there.
But we will do that in the next video. For now, zoom out, stop your sketch, and save your file. I will see you in the next video.
