Adapted from the Sliding Three puzzle, J. A. Storer, 2020.
(Planned construction for 3d print, 2.7" x 4.7" x 3/8" thick, with cardboard sleeve.)

A variation of the Sliding Three puzzle puzzle where all interior and exterior rounds have been eliminated, except for the two discs.

The start is a large piece containing Square U-shaped pieces, each covering half a disc, with along the bottom three square pieces. The discs and squares are all 2 units high and wide, the U-pieces are 2 units high by 4 units wide, the big piece is 4 units high by 10 units wide, and the tray interior is 6 units high by 12 units wide.

Problem 1: Exchange the discs. A solution that is identical to a Part 1 solution for the Sliding Three puzzle of 34 rectilinear moves (43 straight-line moves) is shown on the following page.

Problem 2: Exchange the Square U-pieces. A 40 rectilinear moves (54 straight-line moves) solution is shown on the following pages.

Problem 3: The combination of Problems 1 and 2 to exchange both the U-pieces and the discs. It can be done in Square steps by first solving Problem 1 and then Problem 2; the following pages show a shorter combined solution of 52 rectilinear moves (66 straight-line moves).

All three solutions have some steps that involve moving the big piece while containing other pieces, and can be performed by pushing with a single finger on one of the pieces.