In this lesson we're going to focus on measuring mass properties. After completing this lesson, you'll be able to measure mass properties and create a comment. To get started with the engineering section of our course, we want to make sure that we have all the appropriate supplied files. If you want to carry on with your design from the previous sections, you can do that and just simply follow along with our steps. If you want to start with our supplied file, go ahead and upload the X star version 35 that's supplied with the course. I've done this by making an engineer folder, and under a week one, I've uploaded extra version 35. I also have a component's folder which we'll be using shortly. Inside of here, I've uploaded all the data set supplied files. I have my battery, my video transmitter, I have my power distribution board, my camera, my receiver for the controller, my flight controller, my ESEs, and so on. So all these files are going to be used to create a distributed design, and help us design the mounts that hold all of our components. So make sure as you get started with this section of the course that you upload the supplied files as needed or carry on with your own version. The first thing that we want to do in this section is analyze the mass properties. So in the browser, I'm going to expand my X star component, going to expand the bodies, and I'm going to go to my X star body. Right click, and select properties. Inside of the properties, you'll note that the mass is 225 grams, and the physical material is Nylon 6. I want to record this by placing a comment at the bottom of the browser. So I'm going to say, initial mass 225 grams. I'm going to take a screenshot. And post this. We can go ahead and okay the properties, and take note in the comments section, that we have a screenshot, and it says initial mass 225 grams. Now this is great because at any point in time, we can come back and view this note, so we'll know what the mass was at the starting point. We can click to view this. It will open up our snapshot of the position of our, in this case our drone. Noticed that it says V1. Now because this file was supplied and uploaded, there's only a single version. If you carry on with your file, there'll be a version number that represents whichever version you made it up to. If you saved it all the same points that I have, it will be version 35. So again this is a great way for us to sort of record some of this information, make sure that we know the starting point that we're working with. That way any changes that we make we can understand how they're going to affect the overall design. If you made any changes to the design, go ahead and save your file, and we can move onto the next step.