Basically, what you need to do is to draw a zig-zag line in Inkscape using the pen tool . This is fairly easy to do, so I’ll leave that part up to you. Just turn on the grid by pushing SHIFT+3 first, as this will make it easier to draw it symmetrically. Have a look at the picture below:

A simple zig-zag line in Inkscape

The next thing is to select all the nodes on the sharp edges of your spring as in the image below:

Select all the nodes on the spring, except the outer parts.

Afterwards, push the button outlined in the screenshot to make the selected nodes smooth.

Push the "Make selected nodes smooth" button in the toolbar.

We’re soon done, all we need to do now is to turn each of the node handles on either the top or the bottom of our wiggly line 180 degrees. This is where it’s really nice to have the grid enabled to make sure all the handles are turned just the same amount.

When all the lower handles are turned, my wiggly line became a beautiful spring!

And we’re finished! Below you see my finalized spring:

Look at that spring twisting around itself again and again.

You may put this into whatever physical context you want. Connect it to boxes, power grids or horses – just remember to show off that you have now become a worthy spring master! I decided to go with a good old sports car.

I guess we're looking at a couple of kilonewtons here!

If you like to, you may download the source .svg file here.

I’ve been working on some free-body diagrams lately, and in my last paper I needed to draw a spring. Since I didn’t find any simple way to do this, I thought I should give a quick tutorial here.

First of all, turn on the grid by clicking SHIFT + 3 on your keyboard (the # key).

When your grid is turned on, enable the bezier curve editor by clicking this button:

Now, draw a shape similar to this. I’ve enabled the grid so you may see the distance between the points:

If you’re having trouble with the handles you may want to enable cornered points by clicking this button:

Next, you should make a copy of your newly drawn curve and open this for editing (double click on it).

Select the two leftmost points (as shown above) and delete these. Then move the new shape next to the other.

As you see, in my drawing the shapes don’t really fit. We’ll fix this by editing the second curve.

Now we’re soon done. All we need to do now is to exit editing mode by clicking the arrow tool:

Then select the second curve and copy + paste it as many times as you like:

Copy+paste the first shape and flip it

Now, move this to the end of the spring:

I did some final editing on the last part, but all in all you should be finished now! If you want to reuse this string, save it in a folder and import it when you need it or use it right away in your new diagram. Or just download the source here: Spring model.