Captain's Bed with Trundle Bed

Drill two 3/4" pocket holes on each end of the 1x6 top rail boards, and three on the ends of the 1x10 bottoms. Attach to the 2x4 legs with 1-1/4" pocket hole screws, flush on the inside face, pocket holes facing in.

Glue and nail the 1/4" plywood end panels into both end frames.

Cut the ladder's top legs at an angle with a circular saw or miter saw — about 30° works well — leaving 3/4" flat at the very top. Build the ladder frame with 2-1/2" self-tapping wood screws, then attach it from the back of the corresponding end assembly, also with 2-1/2" screws.

Drill 3/4" pocket holes on one end of the small 1x6 top-rail pieces for the ladder side and attach to the legs with 1-1/4" pocket hole screws. Attach to the top of the ladder with 2-1/2" self-tapping wood screws. Finish both end panels as desired before continuing — it's easier to get into every corner now than after the sides are attached.

Build two identical drawer support frames from 2x4 stock. They must match each other exactly — any difference and the drawer slides won't run true between them. Use 2-1/2" self-tapping screws or pocket hole screws.

Paint or stain the drawer frames and side rails before installing them — much easier to reach every surface now. Drill 3/4" pocket holes in each end of the 1x6 siderails, plus a few facing downward on the bottom rail for attaching to the 2x4 framing. Attach the siderails to the end assemblies with 1-1/4" pocket hole screws and glue, then attach the 2x4 drawer framing to the end panels with 2-1/2" wood screws, and the bottom siderail to the 2x4s with 1-1/4" pocket hole screws.

Attach the drawer support rails to the insides of the 2x4 framing — 3/4" pocket-hole setting and 1-1/4" screws for 1x material, 1-1/2" setting and 2-1/2" screws for 2x material.

Before going further, check the whole bed frame for square: measure both diagonals corner to corner. If they don't match, the frame is out of square even if it looks fine — adjust now, not after the slats go in. Once square, cut the 1x2 top trim to fit and nail and glue it to the top of the bed.

Recheck for square, then add the bed slats, nailing or screwing them down. Screws (about 1-1/2" long) are more work than nails but easier to remove later if needed.

Lay the trundle's 2x4 supports on a flat surface and set the slats on top. Adjust until the diagonal measurements match exactly, then nail and glue the slats to the 2x4s.

Drill 3/4" pocket holes on the top end of the trundle side pieces and attach them to the frame with 1-1/4" pocket hole screws, along with the back panel.

Attach three caster wheels to the front and three to the back of the trundle's 2x4 frame. Slide the trundle into place under the main bed, then position and attach the trundle front over the assembly.

Check your drawer slide packaging for its exact clearance requirement — this plan assumes 1/2" per side (1" overall) and 23"-wide openings, but if your slides differ, adjust the drawer width before cutting. Measure your actual openings to confirm before committing.

Build the drawer boxes with pocket holes on the outside faces (they'll be hidden by the drawer face later), check each one for square, and glue and nail the plywood bottoms in. Install into the openings inset 3/4" from the front edge of the 2x4 framing, to leave room for the applied drawer face.

Cut each drawer face 1/4" smaller than its opening. Set the face in place over the installed drawer and tack it with a couple of 1-1/4" nails, avoiding the spots where handles will go. Then pull the drawer and attach the face from inside with 1-1/4" screws for a permanent, secure fix. Add handles last.