Step 1
Start with a regular piston facing upward on the ground. Stack 2 slime blocks on top of it and place one more slime block on the side of the top one. Place a redstone block under the slime block that hangs on the side.
Start with a regular piston facing upward on the ground. Stack 2 slime blocks on top of it and place one more slime block on the side of the top one. Place a redstone block under the slime block that hangs on the side.