Resizing and scaling 3D objects in Cura: a visual how-to is now available

So, you want to request a 3D print job? Awesome! We’ve got some info on the process on our website that you should likely have a peek at first.

I’ll warn that it’s a pretty popular service and it takes quite a while to process all the requests, get them printed, etc. Want to help us get through your print job a little faster? Here’s what you can do for us (and for yourself)!

1. Download Cura

Cura is the software that allows us to prep the .stl files for our 3D printer (Ultimaker2). It is free to download for Mac, PC or Linux. Cura will show you a nice blue checkerboard space which represents the build plate / space on our 3D printer which will help you in seeing if your item is too large, too small, etc. for our printer.

2. Open your .stl file in Cura

At the top left corner of Cura, you will see three buttons. The first one that looks like an open file folder with an object hovering over it is the “Load” button. Click on that to navigate to your .stl file.

A screenshot of the "load" button in Cura.You will then see something like this:

A screenshot of a Stormtrooper pen cup object loaded in Cura.

The yellow object in the middle of the checkerboard space is the object stored in the .stl file. In this case, it’s a pen cup in the shape of a Stormtrooper helmet from Star Wars. You will see the approximate printing time show up in the upper left corner beneath the Load button. In this case, it’s over 18 hours, which is well over the 5 hour max guidelines that we require.

Click on your object so that three buttons show in the lower left corner. The second one is used for scaling the object (to make it larger or smaller). This is where we punch in the measurement values (in mm) and where you can get the measurements from to input into the print request webform. But as this is over 18 hours to print, we want to scale this back a bit. A pen holder doesn’t need to be 10 cm tall and can certainly be scaled back.

A screenshot of the scaling function in Cura.If you look at this image, it’s currently at a “1.0 scale“, or the file’s regular scale, as is. If you change that scale, it will resize the image. You can do this either by changing the scale (where it says Scale X, Scale Y and Scale Z), or you can punch in different measurements into the Size area (Size X(mm), Size Y(mm) and Size Z(mm)). Be sure to keep the Uniform Scale locked to keep your objects proportions when scaling, or it will end up skewed (image below):

A screenshot of the Uniform Scale being turned off in Cura.

Instead, make sure that Uniform Scale is locked (click on the lock icon) and then change the scale:

Another screenshot of Cura, showing what happens when the Uniform Scale is locked.You will now see a new approximate print time in the upper corner, new Size measurements (which you could then input into the webform) and a resized version of the original object (so you can see the physical change in the object size).

A screenshot of Cura, showing the changes made by scaling the object back.

As you can see, this print job is much more manageable at a 3 hour 22 minute print time estimate, rather than 18+ hours. Looking at the measurements, you can see they are currently 52.52 mm x 47.36 mm x 49.5 mm, or approximately 5.3cm x 4.7cm x 5cm. In this case, it might actually be a little too short for a pen cup and could be scaled up to 0.6 scale, but this is just an example of how the scaling mechanism works.

Recommendation: Once you have figured out the exact size that you want, input the measurements, in mm, as Cura shows them into the webform. Then in the Description area, tell us you’ve looked at it in Cura and that it’s a 0.5 scale (or whatever scale you are asking for). This will help us because we’ll know you’ve already looked at it in Cura and that the measurements are accurate and not an estimate. A lot of our time is spent emailing people back to talk to them about measurement expectations vs realities. If you mention you’ve looked at it in Cura, we will know that you are on the same page as we are. 🙂

To compare, let’s see the original object and resized object side by side so you can see the visible difference between the original and scaled items more clearly:

A side by side view of the original object and scaled object.

The difference in colour just represents which object is currently selected (brighter yellow is the selected item). But as you can see, there’s quite a difference in size between these two objects.

Happy scaling!

~ Kelly, Library Media Specialist






Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s