You can build the posts using an extended primitive called a Hose object. This makes it simple to create nice looking posts.
Now you can adjust the hose parameters to modify its appearance.
Hose object used to create a post
Shift+Rotate to create the other posts.
With the post created, you can now clone it using one of several ways. In this case you'll align the hose object's pivot point to match the pivot point of the chamfer cylinder. Then you'll useThe pivot is now positioned as shown in the following illustration.
Align the hose pivot with the chamfer cylinder.
Rotate the hose 90 degrees.
Four posts are now displayed in the viewport.
Clone using Shift+Rotate.
Now that you've built a basic hourglass, you'll add some materials to give it some realism. After making the glass chamber transparent, you'll create the sand contained within the chamber.