Learn how to build the lower and upper arms of a lamp using various tools and components in a 3D modeling program. This article provides a step-by-step guide on creating, mirroring, and dimensioning the components to fit seamlessly into the lamp design.
Key Insights:
- The process involves creating a new component named Arm Assembly, which will house multiple components for the different arms of the lamp.
- The modeling process includes creating sketches, projecting geometry into the model, and using constraints and dimensions to create symmetry and to set specific measurements.
- Once the lower arm is created, a mirror of this arm is made on the other side of the lamp base. An upper arm component is then created, following a similar process as the lower arm, but hosted to the center plane.
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In this video, we will build the lower and upper arms for our lamp. I will open up Step 2 and hide my data panel.
You will see that this file looks identical to the file that we finished in the last video, including our user parameters and our group at the bottom of our timeline. The new steps will begin exactly where we ended the previous video. Feel free to go through the entire workshop using your file.
But if you get lost or your file doesn't seem correct, go ahead and use one of the steps. So let's get started. I will go to the browser, right-click > New Component.
And I will rename this component Arm Assembly, because I know that I'm going to have multiple components for multiple arms. Again, right-click > New Component. And I will name this Lower Arm.
Now we can start modeling. I will click Create Sketch and host it to this face on my vertical body.
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We can now begin to create our arm. I will go to the 2-Point Rectangle and draw a rectangle like this. Press C on my keyboard for Circle and draw a circle here.
Then press P on my keyboard for Project, and select this circle to project it into my model. Now that all of the geometry is sketched, we can begin to constrain and dimension it.
First, I will go to Constraints > Horizontal/Vertical, select my two circles, and then apply a constraint from the circle to the Shift-midpoint of the line.
Now the geometry is symmetrical. I will use the Equal constraint to set my two circles equal to each other. Because this geometry is referenced from the body behind it, we know it will update parametrically as we change our user parameters.
Since an Equal constraint is applied, the second circle will also update. Now press D for Dimension, and dimension the distance between the circles.
This will be 20, as it is a static dimension. I want this dimension to match the bottom one, so instead of typing a value, I will click the existing dimension.
You will see that Fusion calls that dimension’s reference number. When I press ENTER, a function appears, and it says Function: 20.
If I change that reference to 25, the linked dimension will update to 25. I’ll press Undo so that they both read 20 again.
Now two more dimensions. Press D again for Dimension. The height of our rectangle will be 285.
And the top will be W (for width). Our arm is now fully dimensioned and constrained—it is all black. I will click Stop Sketch and return to the Home view.
Now click Extrude to create the geometry. I’ll select these two profiles and drag out using the T parameter (for thickness). We can now see that the Lower Arm has one sketch and one body. I will activate the Arm Assembly component and go to Create > Mirror.
I want to mirror this arm on the other side of the lamp base. I’ll change my pattern type to Components and select the Lower Arm component.
For the Mirror Plane, I’ll use the origin plane, and we can see that the mirror occurred. I’ll click OK.
Now we have two bodies mirrored about the base. Let's finish up. I will right-click > New Component and name this Upper Arm.
Let's create the sketch, and this time, I will host it to the center plane. We could host it to the inside face here, but as an example, I want to host it on the center plane. I will draw a rectangle, press P to project the circle, and then draw another circle here. Again, I’m not going to dimension it right away.
I’ll use the Equal constraint to set the circle sizes. Now let's use the Horizontal/Vertical constraint—from the circle to the Shift-midpoint, and from the circle to the projected circle.
Then press D for Dimension. The dimension at the top will be 22.5. The vertical distance will be 45. The overall length of the rectangle will be 340. And the width will be set to T (for thickness). This body is made in the opposite direction, so T will define our width and W will define the length.
I’ll click Stop Sketch, then extrude the sketch. I’ll select the profile and drag out. Notice that we’re dragging in one direction. Under Direction, I’ll change this to Symmetric.
Now as I drag, the geometry will extend equally on both sides of the sketch. I will type W divided by 2 so that each side is half of the width, and when symmetric, it reaches a total width of W. I’ll press ENTER and activate my main component. All of our arms are created, so I will go to the timeline and group these features.
Right-click > Create Group. I’ll collapse this and save the file. In the next video, we will build our lampshade arm.
I’ll see you in the next video.
