In an attempt to eliminate carrying table extensions up and down the stairs, I am building a butterfly extension dining table. It's my first attempt at a dining table. My wife and I looked at different dining tables and she wanted a 4-leg table base. I bought a geared table extension mechanism from Lee-Valley. https://www.leevalley.com/en-ca/shop...able-extenders I am planning on having a retracted table length of 68" and extending it to 92" with a 24" butterfly extension in the middle. I have the butterfly extension "axle/pivot mechanism" also purchased from Lee-Valley. https://www.leevalley.com/en-ca/shop...ount-mechanism he table width is to be 36"

My thoughts are to run the grain of the walnut across the tabletop and breadboarding the edges, pinning the breadboard edge to each board with a slotted hole in all but the middle board's tenon.

The front and rear rails will be topped with either an aluminum or steel 1/8" flat stock covered by some HDMW tape to reduce wear and friction though the opening and closing for extension use won't be operate that often.

By breadboarding the edges and with the grain perpendicular to the plane of the extension mechanism the tabletop should be supported and should have less opportunity to warp.

Any opinions on the plan as I described it? Inputs appreciated!