Once we had the table top built, Nate got going on the base. The first tricky thing was the main post. We needed two, three sided, bulky posts since we wanted the posts to expand with the table. We achieved this by screwing two 2x10's together and then using the table saw to create the two angled cuts.
Next came attaching the the support pieces. We built support pieces on the top for the table and on the bottom so the whole thing wouldn't tip over. The first layer of the supports attached to the top and bottom of the main post
Then we attached the diagonals to the second layer of the supports. This allowed the screws to be buried between the two support layers. This was a tricky step since there were a lot of degrees of freedom and no 45˚ clamps are readily available at any of our home improvement stores.
The second layer got attached to the first layer and then the other side of the diagonal was secured to the post.
Once one side was built we realized that we missed on thing. The supports had a tendency to flair out and so the base didn't sit flat and there were different size gaps between the diagonals at the middle of the post.
After using our clamps to straighten everything out and re-secure the diagonals with bolts, Nate plugged the holes.
The other side was built the same way and it was pretty awesome to see the two side sitting next to each other perfectly level (and no more awkward gaps).
Since the base isn't something we'll be touching every day, I just did a quick sand on it to smooth any sharp corners and then hit it with some stain and poly.
Up next: Finishing the Top