Create the contour

First you’ll need to sketch something like this on the front plane. Please note that all the dimension lines are centre lines and the poly line is not. The vertical line is our axis in the next step.

You can also add this sketch is a part that you have inserted like I described in the previous article about springs Pressure springs in SolidWorks.

For the next step you’ll need the surfaces toolbar. If you don’t see this toolbar in your interface you can add this by right clicking on a empty space in the upper command bar and select the surfaces tool bar.

Add a Revolved Surface to the sketch.

Line 1 is the centre line we’ve defined in the sketch.

This is what we have now

Create the path

Add another sketch on the front plane (or the same plane you’ve created the first sketch).

Draw a simple line in this sketch from top do bottom.

Add another sketch on the front plane an this one contains a horizontal line. The length of this line is not important, as long as it intersects the cup we’ve already made with the revolved surface.

Now we need a surface sweep. Select this feature in the surface toolbar. Sketch 2 is the rotation axis, Sketch 3 is the profile that needs to be swept. Choose in the options ‘Twist Along Path’ and specify the turns.

This is what we have at the moment. Two surfaces that are totally a mess, but there is a logic behind these two surfaces. The first one is the contour of the spring and the second one is the path of the spring.

Project path on contour

We’re almost done and we’re up to the point were the magic happens. Now we need to project the path of the spring on the contour. Select the two surfaces.

And choose ‘Intersection Curve’ and select the contour (cup) and the inner line of the path.

You’ll get a curved 3D sketch that looks like this. Select the two surfaces and hide them for a better overview.

Create the profile

Create a sketch on the front plane and draw the profile of the spring.

Make sure that the centre of the circle is pierced by the 3D sketch.

At last we’ve got to add a swept boss/base to these two sketches.

Define the profile and the path and you’ll have a tapered or curved pressure spring!

The result

We’ll start with a shock absorber assembly without a spring. We’re going to add this part to the assembly.

Add a new part to the Assembly with the top down method in SolidWorks. Read more about this in the article 10. Top down modelling in SolidWorks.

Select the Assembly front plane to define your first sketch plane.

A new part is added to the feature tree and the rest of the parts are displayed as outlines. This means that the assembly is in the ‘edit part’ mode.

Draw a centre line trough the centre of the assembly. This is the rotation axis of the spring.

Add some dimensions to it. In this case I’ve added some extra length to the spring to flatten the outer ends of the spring. Make sure the smart dimensions points to the contact points of the spring.

Create a new sketch on the front plane.

Draw a circle on the sketch. This will be the contour of the material the spring is made of. Add a horizontal relation to the end of the centre line and the centre of the circle.

Now just add a Swept Boss/Base to these two sketches.

And put some attention to the options of this feature. Define the turns and the apply the modifications.

Here you are, a top down pressure spring. Drag the piston to change the stroke of the shock absorber and hit the rebuild button. You’ll see that the spring is changing in length.

Just use the Cut Extrude feature to modify the outer ends of the spring!

The result

This is how it looks like when you’re creating a animation of the assembly!

Create your 3D model

I’ll start with a render of a couple of steel balls also known as the witch is also used in the logo of this blog. I’m not showing how to model these, it’s just a standard modeling process.

Tips:

• Add a fillet over all the sharp edges (a custom curve is even better)
• Make sure you have a small space between seperate

Add a camera

Camera’s are great to create a nice view. You can play with the focus so you can make nice blurry effects.

Materials

I’ll choose for the materials orange plastic and chromium plate for the balls. The cords are made of black low gloss plastic. To add these materials to the parts you’ve got to select the parts, and apply your appearance.  In this case its a three step process.

The appearances are shown in the feature tree beneath the PhotoWorks tab.

The first render

When you don’t change anything in the PhotoWorks options and press the render button for the first time you will see something like this:

Uhr… Not perfect right? Go to the next step of this tutorial.

Scene selection

When you’re rendering chrome it’s important to see that is chrome. Not only by the color, or the shine but chrome is like a mirror. It reflects the environment. So lets add an environment to our assembly. On this step you have to play with the scene. Some things witch influences the render:

• Room tab: The floor offset
• Room tab: The floor rotation
• Environment tab: The reflection (amount of environment detail witch you will see in the products)
• Environment tab: The Diffuse Appearance Brightness (the higher, the lighter the products)

In this case I’ve chosen the conference room because of its great light fall and not to much details in the room.

Do mention the war floor!
Occasionally when you’ve build up your model and start rendering the floor of the scene is cutting up your model.

Variables

To make a really sharp render you’ll have to set the PhotoWorks options. Go to “Document Properties” and set the “Anti-aliasing quality” very high.

Change the tab to Illumination. Enable indirect illumination. Here are to renders with this option on and off. Can you tell me where it’s on?

Yes… the image on the right is rendered witch indirect illumination on.

Adjustments

Now add some motion into the image. In this case I simply blurred the orange ball with Photoshop and here we are. A nice render with chrome balls.