Friday, February 4, 2011

Extension Table

10:20 AM Comments 6

Extension Table – Stained Alder

A few months ago Suzie Hall, owner of Cornerstone Interior Design, came to us and ask for a 51″ diameter round dining table that could extend to 108″ total!  An extension of 57″, which is greater than the diameter of the original table, seemed like a tall order, but we figured most anything is possible if designed correctly.

After some internet searching, we discovered metal and wood table extensions that confirmed our hunch that it was indeed possible and is actually quite common.

Sun Valley Table A

The 3D model above is the overall look of the table in the closed position.  Each half will have a leg assembly that is able to hold itself upright and slide along the floor when the table is opened up.

Sun Valley Table B

When the table is pulled apart, the user can install up to three 19″ leaves, allowing the table to extend to lengths of 70″, 89″ and 108″.

We began by milling the two half-round tops, the three leaves, and the skirt that wrapped around the entire underside of the table.  With the tops and skirts milled, cut to length, sanded, and screwed together, it was time to join all five table top pieces using table pins and alignment locks.

In the picture above, after installing the table pins into the edges of the table tops, we laid the table tops upside and added the alignment locks.

The table pins ensure perfect alignment between two tops since the pin fits perfectly into its corresponding hole without any play.  The perfect fit is great when it comes to the finished fit and function of the table, but aligning and drilling the holes perfectly opposite each other is incredibly difficult!  Thankfully we were having a very good day and all 12 pins were perfectly aligned!

The alignment locks were quite a bit easier to install. Just lay the top upside-down, center over the seam, and attach with four screws.  The alignment locks, as the name implies, provides some alignment benefit, but we decided they were not good enough to be used on their own for that purpose, which is why we used the table pins for the alignment issues.  The alignment locks were mostly used to lock the tops together and prevent them from pulling apart once they were brought together.

Alder Extension Table 2

With the pins and locks installed, it was time to turn our attention to the star of the table, the piece of hardware that was going to make the entire table function, and that was the table extension.

I mentioned earlier in the post that we found metal and wood table extensions online, which showed us that this kind of project was indeed possible. It also showed us that we would probably have to make our own extensions because none of the metal units would fit in the space we had available and we did not trust a wood-only extension to provide enough vertical support or stiffness.

So we made our own table extensions from three 20″ 200lb. rated ball bearing drawer slides. The resulting assemblies were incredibly heavy, silently smooth, and functioned perfectly!

Alder Extension Table 3

We attached the legs and gave the table a test run!

Alder Extension Table 4

The final table was stained a beautiful, warm, rich brown and finished with two coats of dull-rubbed conversion varnish.

Alder Extension Table 5

The final table with all three leaves installed.

The table is sitting on a sheet of melamine to help even out some of the inconsistencies of the concrete shop floor.

Alder Extension Table 6

The final table with one leaf installed in the clients home.