Just basic tools are needed. A saw, a drill, a grinder or hack saw & that's about it.
3- boards (I bought 8x6' cedar fence boards)
2- 3/8x36" all thread
4- 3/8 nuts
4- 3/8 flat washers
20- used baseballs
Optional brackets to hang
Step 2: Drilling Baseballs
Drill a 3/8 or 1/2 hole through 16 baseballs (1/2 is easier to slid on the all thd later) I made a little jig with some PVC bushings 2 1/2" female socket fits the newer baseballs perfectly the real old ones were a little loose & tend to spin. Set the other 4 balls aside for now.
Step 3: Wood
Cut your wood to desired length. I cut mine at 30" ea. I used a cedar fence board that had some nice dark streaks & is rough on one side I wanted the shelf to look kind a rough & old. Also go a head & drill two 3/8 holes in each board. I put mine 2 1/8 from each end & centers them on the width.