In this tutorial, we’re going to take a look at the steps I used to design prop guards for the IRIS autonomous multicopter using FREE cad software, Autodesk 123D Design.

In order to print out the full size of the prop guard, I designed it in two parts. This mounting clip will allow you to securely attach the prop guard to the mount using phillips screws.

Here’s what the complete prop guard looks like. In the final design, the guard is apart of the LED mounting system. It’s layered in between the ring holder and mounting clip. Two phillips screws will securely join the three pieces together.

To create the base shape, I started with a 140mm x 4mm cylinder primitive shape. This size should be enough to guard the 10′ propellers yet small enough to fit on our MakerBot Replicator 2 build plate (250mm x 150mm).

Using the Polyline tool, I drew two sketches that intersect the center cylinder in the X and Z-axis.

Using the Split Solid function, I used the polyline sketch to chop the cylinder in half.

Using the second polyline sketch, chop the cylinder again, making it a quarter of the original cylinder.

Add a small cylinder to the center of the quarter cylinder. We will use this second primitive subtract from the guard so that it can fit under the prop arm.

Subtract the smaller cylinder from the large quarter cylinder, the result is the shape above.

Round off the corners by highlighting the object and selecting each of the corners you want to round off using the Fillet feature.

Highlight the object and select the top and bottom face and apply the Shell feature. I made the guard 4mm thick.

To rotate the prop guard in the position we want, we can reorient the object manipulator by clicking the “start reorient” icon.

Click on the object you’d like to the object manipulator to reference, in our case it’s the mounting adapter.

In order to save the new position of the object manipulator, you need to click the icon again to “stop reorient”.

With the object manipulator reoriented, you can rotate the prop guard frame relative to the mounting adapter clip.

Make a duplicate of the prop guard by copy and pasting it into place. Use the same steps to reorient the object manipulator and rotate the prop 30degrees. This will cover and protect more area.

Once you’re satisfied with the coverage of the prop guard, merge the objects together.

Select the edges on the top of the prop guard and apply a Fillet on the edges to smooth it out. Now you can export it as a STL and print it out!

Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!

Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!

The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!