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.
Assembly is pretty easy. I started by sliding 4 balls on each all thread so I didn't have to slide them on the whole length. Then I slid the all thread through the 1st boards holes that we drilled earlier and put a washer & nut on the all thread that was sticking out. Leave about half a baseball length of all thread sticking out. Now with the 1st board down slide the next board onto the all thread (make sure if your wood has different finishes that you put them all on the same way) then 4 more balls on each side & finally the last shelf. Secure the top with the last 2 washers & nuts. Tighten the nuts evenly some of the balls squish more then others do to different fillings & use. Mine ended up at 23 1/4" from top of top board to bottom of bottom board.
Step 5: Optional
If you don't want to see anything holding the shelf up you need to hang it on the back edge of the board. So I got these little brackets that are really suppose to mount vertical but I mounted them horizontally (hopefully it works but it ain't hanging in my house lol) I just drilled 2 holes next to each other then put the bracket on with the provided screws. I also taped them done a little with a hammer to get a flush finish then tightened the screws a little more. I put some on the top board & bottom board so she can make either end the top depending on which wood finish she likes to see more (rough or smooth). Make sure all the big holes are pointing the same way.
Step 6: Finish Up
Almost done! Cut off the extra all thread on the top leaving about half a baseball length! Now drill a 3/8 hole half way through the last 4 balls. Then you need to boar it out to fit over the nut & washer. I used a small hole saw a little bigger then the washer to remove the cover which wasn't really necessary cause the washer sunk in to the board but who looks when you already have an idea in your head in how to do something! Then I used a knife to boar it out for the nut. Now you just have to glue the balls on to the all thread! I had one that wouldn't stay on so I had to clamp it with my poor clamp selection & the wood scrap & a giant bolt.
Step 7: All Done
All finished! Hopefully she likes it & hopefully all you robots liked it make sure to check out some off my instructables. http://m.instructables.com/member/Petergottm