Farmhouse Bed with Arch

Lay two 1x4 trim pieces down and line up the 1x6 panel boards across them. Nail through the panel boards into the back of the trim with glue and 1-1/4" brads. Do all 11 headboard boards onto their two trim pieces, then repeat with the shorter boards for the footboard. Check each panel for square as you go — a panel that racks now fights you at every later step.

Set both finished panels flat and check them for square across the diagonals. This is the last easy moment to fix a racked panel before it's buried under caps and posts — measure corner to corner both ways and adjust until the two diagonals match.

Draw the arch on the 1x10: start the curve 5-1/2" in from each end and rise to 6" at the center. Use a flexible batten or a string sweep to get a fair curve, not freehand. Cut just outside the line with a jigsaw, then sand the curve smooth — a lumpy arch looks like an error, a faired one looks designed.

Flip the headboard panel over and attach the arched header across the top with 2" nails and glue, keeping all outside edges flush.

Mark each 4x4 post 5/8" in from the edge on the face that meets the panel, and center the panel on those marks. Predrill halfway through the post, then drive 4-1/2" screws through the post into the panel — aim for where the panel is three boards thick, so the screw bites into solid material. Do the headboard with the tall posts and the footboard with the short posts.

Set the 2x6 top caps over the panel top rails on both the headboard and footboard, leaving a 1" overhang on all sides. Fasten with glue and screws. The cap frames the panel and covers the top edge of the boards.

If you're building the full frame rather than using a metal one: attach the cleats to the inside faces with the bottom edge 9-1/2" from the bottom, predrilling and using four long screws each. Add the footboard end rail (J) inset to the cleats, three screws per end. Then position the footboard so the end rail sits flush with the panel and screw through it into the footboard.

Finally add the 1x10 side rails, keeping their bottom edge flush with the cleats, screwing from the inside of the cleat out into the rail with predrilled 2" screws down its length. Sand and finish the whole bed.