What is gear ratio? It’s actually a simple formula that shows how gears can work together. I will show you how it works in this blog. Or if you want to see a more tangible example, you can watch the linked video!

A gear is designed to transmit movement to other gears. A set of gears will result in a specific gear ratio. To keep it simple, we will calculate the gear ratio between two gears only. So there’s one drive gear and one driven gear.
You can visualize those involute gears in FreeCAD by generating them on your screen. You can do that in the Part Design workbench. They must both have the same Module to work together. The Module is the unit that defines the size of a gear.

When positioning two gears, you can calculate the correct distance between them with the formula below. T is the number of teeth.

Module * (T1 + T2)) / 2 = (2.50 * (10 + 8)) / 2 = 22.5. 
In this example one gear has 10 teeth and the other 8.

The gear ratio can be defined as: Teeth (green driven gear) / Teeth (red drive gear) = 8 / 10 = 0.8. A gear ratio lower than 1 means that it’s an overdrive gear transmission with a higher output speed. If the gear ratio is higher than 1, the output speed is lower than the input speed.

With FreeCAD you can generate involute gears in the Part Design workbench. A perfect free tool for simulating (3D printed) gears together.

If you want to see a visualisation of the steps above, the video below will show you how i generated gears in FreeCAD and 3D printed them to get a real example.

Parametric CAD design is now also available for Blender! It’s still in an experimental phase, but you can use it already. You only have to install the CAD Sketcher add-on. How? It will be explained here!

If you walk through all steps below, you should be able to use the CAD Sketcher add-on in Blender.

1. Go to the CAD Sketcher website
2. Below ‘Addon installation’, click ‘ZIP_archive’ (don’t unpack)
3. Below ‘Dependency installation’, click ‘solvespace python module‘
4. Click ‘Download files’
5. Select a version (on your own risk)
6. Open Blender (at least 2.92)
7. Go to ‘Edit’, then ‘Preferences’
8. Click ‘Add-ons’ and then ‘Install’
9. Select the CAD Sketcher ZIP file (packed)
10. The add-on will now be visible in the ‘Community’ tab
11. Check the box
12. Select the .whl solver file in the ‘Solver Module’ space
13. Click ‘Install from file’
14. Restart Blender when needed
15. Now you got extra tools on the left side

With the CAD Sketcher add-on for Blender, you can also create parametric designs, like you can do in FreeCAD.

If you prefer a visualisation of the steps above, just click on the video below to see how i install the CAD Sketcher add-on for Blender.

Here’s how to apply a dark theme to FreeCAD! You can change it easily by changing the preferences. Then you can enjoy a dark version that gives a calmer picture to your eyes.

When you are in FreeCAD, click on ‘Edit’ and then select ‘Preferences’. Then go to the ‘General’ tab and select ‘ProDark’ as the style sheet. You have more dark options, but this is my favorite. Then in the ‘Sketcher’ tab, select ‘Colors’. Change all black colors to white for the right contrast. Finally change the background color to black. You can do that by selecting ‘Colors’ in the ‘Display’ tab.

A dark mode will give you a calmer picture when using FreeCAD. It’s also better when you’re using it on a TV screen, because there’s a bigger chance you prevent burning in. Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

If you like a visualisation of the steps described above, just click on the video below to see how to configure this dark mode in FreeCAD!

You can create bodies and parts in FreeCAD. With bodies and parts, you can also assemble in FreeCAD, instead of using a specific assembly workbench. This all works with the Part Design workbench in FreeCAD.

When you create a new sketch in the Part Design workbench, a new body will be created automatically. Features you add to this sketch later, will also be placed inside this body. After you create an object inside this (first) body, it’s possible to create another body. Objects you create inside this new body, will stay here. So multiple bodies can act as assemblies in a larger object.

I think bodies and parts are a great way to make simple assemblies in one document. Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

In addition to bodies, you can also create parts. Then you can group multiple bodies inside (multiple) parts.  I made a video where i demonstrate how bodies and parts can work together. The box and one lid act as one assembly inside a part in this video. Just click on it to watch the video!

FreeCAD has the option to scale objects. You can do that in the Draft workbench. Here’s a short explanation, but if you want a full guide, you can watch the video on my channel. It’s also visible in this article!

When you selected the Draft workbench, you can click on a button that makes it possible to scale your designs in FreeCAD. You can scale original objects into a new single one (clone) or only modify the original. But you can also copy an object. Then you will keep the original model to the original size, but a new scaled one appears.

Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

I made a video where i demonstrate scaling an object. Just click on it to watch me scaling sunglasses, which i also designed in FreeCAD!

FreeCAD has a lot of great features to add custom text labels to your designs. It’s possible to engrave text into flat or curved surfaces. I will quickly describe how FreeCAD makes it possible to do this. 

In the Draft workbench in FreeCAD, you can create a so called ShapeString. This is where the text will be generated. Together with the Part Design and Curves workbench, it’s possible to create text on (curved and flat) surfaces. After putting text on a surface, you can extrude it or cut it out.

Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

I made a playlist of videos where i demonstrate different approaches of adding text to 3D designs. Just click on it to watch all videos and start learning about adding text to your designs in FreeCAD!

Did you know that you can create sheet metal objects in FreeCAD? You can do this with the Sheet Metal workbench that you can download and add to FreeCAD!

When in FreeCAD, select the ‘Tools’ tab and click on ‘Addon manager’. There you can install many workbenches, making FreeCAD even more usable. I also published an article about how to do this. You can read it here.

Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

In the first video, you can see how i created a sheet metal object in FreeCAD. It’s a simple bended plate. Just click on it to watch.

A cool feature in FreeCAD is that you can create datum planes very easily. In the Part Design workbench, you can click the datum plane button to create a plane on the position you want. Then you can work from positions under an angle or a specific height.

When you select the built in Part Design workbench, there’s a button with an oblique rectangle on it. When you click on it, you can create a plane as you want. It can be referred to another plane for example or it can also be a so called deactivated attachment. Then the plane is independent from any other object.

Check out my videos on the AllVisuals4U channel to learn more about FreeCAD! I’ve been uploading a lot of tutorials there.

In the video in this article, i demonstrate how i created an independent datum plane under an angle. I also show you how to create an object on this plane. You can click the video on this page to watch it!