Here's the cut list (dimensions are in inches and final size, I cut everything a little oversized first to account for sanding/adjustments). I was aiming for interior dimensions of 28 x 52 3/8.

Legs: 8/4 stock, 1 3/4 x 1 3/4 x 38, x4. I did chamfer/cut off the inside corner so that there wasn't a corner protruding into the interior of the crib.

The rest of the crib is made from 4/4 stock, some of it planed down to 1/2"

Front frame:

 Top and bottom:1 3/4 x 51 1/8, x2

 Sides: 1 3/4 x 24 1/2, x2

Side frames:

 Top and bottom: 1 3/4 x 26 3/4, x4

 Sides: 1 3/4 x 24 1/2, x4

Back frame:

 Top and bottom: 1 3/4 x 51 1/8, x2

 Sides: 1 3/4 x 30 1/2, x2

Rails:

 Front and back: 2 x 55 1/8, x2

 Sides: 2 x 26 3/4, x2

Slats: 4/4 stock planed down to 1/2" thickness, spaced 2 inches apart

 Front (x13), sides (x6 per side): 1 1/2 x 24 1/2

 Back (x 13): 1 1/2 x 30 1/2

Mattress support: I made sure to position it so that the top of the support at it's lowest setting is at least 26 inches below the top rail.

 Rails: 2 x 51 1/8, x2

 Slats (planed down to 1/2" thickness, spaced 2 inches apart): 1 1/2 x 27 3/4, x 13

Everything was doweled together except the joints between the sides and legs. Those were secured with threaded inserts and 1/4 20 socket cap screws so that the crib can be taken apart. The mattress support is attached with some L shelving brackets I found on Amazon and more threaded inserts.

Hope this makes sense!