Discover how to build a lower arm for a lamp using a step-by-step method. This article guides you through creating new components, building sketches, dimensioning and constraining sketches, modeling and copying components, among others.
Key Insights
- The tutorial begins by creating a new component named "Lower Arm" and then proceeds to build a sketch on the same face used in the previous creation of a hole.
- After the sketch is complete, the dimensions and constraints are added, a horizontal vertical constraint is placed to keep the geometry from moving side to side. The resulting project geometry is either purple (projected) or black (fully dimensioned and constrained).
- Lastly, the arm is modeled by extruding the sketch and the whole process is repeated to create a second arm on the opposite side of the lamp. This is done by copying and pasting the existing component and moving it along the X-axis.
In this video, we will build the lower arm for our lamp. I will go to my data panel and open Step 02: Lower Arm.
Remember, you can open with a double-click or right-click > Open. When my file is open, I will close my data panel, and we can begin to build our lower arm. The first thing we need to do is create a new component.
Again, I can go to the New Component button here or right-click on this component, choose New Component, and that will make a new component nested inside. I will double-click on the name and rename it Lower Arm, then hit ENTER.
You will notice that all of the objects in my base component have become grayed out, and this is because they are not in the active component. So let's build our first sketch. With Lower Arm 1 active, I will create a sketch, and I will choose the same face I chose earlier to create my hole.
My view will reorient to this view, and let's create a rectangle. My arm will go somewhere like this, so I'll draw it roughly to shape. Next, we know that there will be a second hole here, but instead of drawing a new point and creating a separate hole command, we will build our hole using the Extrude.
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So I will go to Sketch > Circle > Center Diameter, and I will draw my circle here. Again, I will not worry about the dimensions yet; I will add them in a minute. The last circle we need is the circle that will go on top of this object.
Because we are building our geometry in place, we can use projected geometry. If I go to Sketch > Project/Include > Project, which is the keyboard shortcut P, you will see the Project window appear. I can select specific entities or entire bodies.
I will select specific entities, zoom in, and select this circle. It may be hard to see on your screen, but you will notice that the circle has now become a dark purple color. This means that sketch geometry is now present in my current sketch and is non-editable because it is projected directly from my 3D geometry.
I will hit OK, and now we can begin to dimension and constrain our sketch. First, I will press D for Dimension, select my circle, and let’s make this 5, then hit ENTER. Next, my rectangle will be 30 millimeters wide
And 285 tall. If your geometry is moved, that’s okay. Click and drag your geometry to move it back into approximately the right location.
Next, let's dimension our circles to the edges of our rectangle. I will zoom in, select the center of this circle and this endpoint, and I will make this 20, then hit ENTER. And I will do it for the top circle as well—20, Enter.
Notice that my geometry can still move side to side. So instead of dimensioning this geometry, I will place a Horizontal/Vertical constraint. If I zoom in with nothing selected, I will select the Horizontal/Vertical constraint.
When I hover over this circle and click the center, you can see that I want to snap to the midpoint of this line, but I can only select the endpoints. By holding down Shift on my keyboard, I can open up my object snaps. As I hover over the midpoint of the line, you will see the midpoint snap appear.
By clicking while holding Shift, I can snap a Horizontal/Vertical constraint from the midpoint of this line to the center of that circle. Let's do that one more time for the circle at the top of our arm. I will select Horizontal/Vertical, select the center of my circle, and holding Shift, I will select the midpoint of this line.
You can see that my geometry is either purple (as it is projected) or black, which means it is fully dimensioned and constrained. We can now click Stop Sketch, go to our Home view, and click Extrude. Notice that when I hover over this rectangle, the bottom portion is not selected.
This is because my projected geometry has split this face and this profile into two separate sections. I will need to click once here and once here to select the full rectangular face. I can now drag out 15 and hit ENTER, and we will see that the arm with the holes already cut out has been modeled.
I am done modeling in this component, so I will activate my main component. And to finish this video, I would like to create a second arm on the other side of my lamp. We can do this by simply copying and pasting our existing component.
If I go to my Lower Arm component, right-click > Copy, I can then right-click > Paste, and it will paste a copy of my component directly on top of the original. When it pastes, the Move command automatically opens. In the Move command, I can use the sliders to move the object along three directions, use the Rotate tool to rotate the object about its axes, and use the square grips to move along two axes or within a plane.
I will hit Cancel and delete my old component, and again go to right-click > Paste. I will now slide along my X-axis, type -45, and that will place my other arm directly opposite the first arm. I will go to my Home view and save my file.
Again, feel free to write whatever description you would like. I will leave this as “User Saved” and hit OK. In the next video, we will build the upper arm and create an assembly component.
I’ll see you in the next video.
