DIY coffee table that converts to dining table. Free plans by ANA-WHITE.com
3 - 1x6 @ 8 feet long
5 - 2x2 @ 8 feet long
2 - 2x4 @ 8 feet or stud length
4 4" L brackets or additional cross bracing for open bottom side
9 - 1x6 @ 29-1/4"
2 - 2x4 @ 46-1/2" (approx)
4 - 2x2 @ 18"
4 - 2x2 @ 46-1/2"
4 - 2x2 @ 26-1/4"
Layout the tabletop boards. You can pocket hole them together with 3/4" pocket holes and 1-1/4" pocket hole screws if you choose. Then add the back supports and attach with 2" self tapping screws and wood glue.
Build the rectangle base with 1-1/2" pocket holes and 2-1/2" pocket hole screws and glue. Remember to hide pocket holes on side that will be less visible. Use one pocket hole per end, use glue to secure.
Scribe cut the cross supports and attach to the frame, using the 2" screws and glue to attach.
Place frame on tabletop and attach remaining cleats in place with 2" screws and wood glue.
My coffee table needed additional support, so I purchased four L brackets in 4" length, and attached flat to the underside of the coffee table frame. This was sufficient. You could also add additonal cross bracing to the bottom (when in coffee table position).