I used 9 8′ long 2×4′s and two 4×8 pieces of 1/2″ plywood.

Framed up a rectangle of 2×4′s to frame under the sheets of plywood and cut an additional piece for the center.

I saved the longer halves of the 2×4′s cut for the frames to make the vertical supports. What I had left determined the height of the top shelf. I mounted the bottom about 1′ off the ground.

I’ve found I didn’t need diagonal bracing, but then again, my shelves are only about 51″ tall and the 2×4 frame under the shelves provide a pretty rigid structure.

It’s strong enough I can get up on them, and I’m about 240#.

I can build two of these for the same price as some pre-made units.

I could make the movable by using different hardware to assemble them. The wood screws installed with the drill could be replaced with lag bolts, nuts and washers to make this something that could be disassembled.

-buy some #8 wood screws in 3″ and 1 1/4″ lengths
-buy 2, 4×8 plywood sheets (5/8″ works well and is most cost-effective for price vs. sturdiness) cut lenghtwise into thirds (each approx 16″ wide) (to save time and ease transport I always had the hardware store cut these for me)
-buy 10, 8′ 2×3′s, and cut 16″ off the top of 8, and cut the last 2 into 16″ lengths
-using 2 of the long 2×3′s, make a ladder-shaped box structure by fitting 5 of the 16″ 2×3 cut-offs in between them like ladder rungs (make sure the top and bottom “rungs” are fastened at the very top and bottom ends of the 2 long 2×3′s) (make 4 “ladder” box structures in total) (the “rungs” determine shelf heights, so use less rungs if you want more space in between shelves, and ensure the rungs are all the same height as each corresponding rung in each “ladder” box) (fasten using 2 of the 3″ screws for each side of each rung, screwing through the side of the upright 2×3′s into the ends of the horizontal 16″ pieces between them)
-now the shelf is ready to be put up – and it is very easy for 1 person, but even easier with 2 – stand the 4 “ladder” boxes up together and slide a plywood strip between them at the bottom and then the third level up – spread the “ladder” boxes apart until there are 2 at each end of the plywood strips, and 2 evenly spaced in the middle
-fasten the plywood down to each rung with the 1 1/4″ screws (2 for each rung)
-slide the other plywood sheets into place on the other shelf levels, and one at the very top (you will have 1 16″ wide plywood sheet leftover (in total I made 3 of these, so this leftover was not wasted) and fasten down just like the others

These have always been sturdy, and have never tilted sideways. It takes 5-10 minutes to put them up and take them down once the “ladder” boxes are made (in the military I move a lot, so I wanted shelves that could survive multiple set-ups and take-downs). In total, for 1 shelf, the project costs (in Canada):

-plywood and 2×3′s = $40
-screws = $10

I already have something like a Gorilla rack; I like it, but it doesn’t hold nearly as much and it’s not nearly as stable. (Bolting it to the wall would fix the stability, but would be difficult in my basement, which has cinder-block walls.) Pricing Gorilla racks at Amazon, I found that $70 would get me five 30×12 shelves, rather than the five 96×24 shelves I have. Not the best deal! Or there’s the 72×24, three shelves, for $190…not for me either.

of course, i’m biased; i practically grew up in my dad’s shop. wouldn’t give that up for the world. and now i can do my own repairs at home – it’s win-win.

http://www.bignmorn.net

Not to put a cold wash on the idea but it guesstimates at about $50 just for the 27 support pieces. Then the cost adds up with plywood if you do not keep such things hanging around. Nails and screws. Then there are the men among us who will also get a new tool or two for such a project, God is pleased by a fine working tool, as we all know.

A Gorilla rack at Costco was about $80, takes way less time, and can be easily dissassembled/moved/customized.

Not EVERY thing is about money, a Gorilla rack leaves no sense of accomplishment. But it IS biblical to count the costs. AND I cut my hand the other day taking it apart, leaving a pride-boosting humbling yet manly injury, that I did NOT complain to anyone about. AND my wife hit the thing with the car so a steel support corner got bent. THAT was pretty manly pounding it straight, lots of cool shop sounds, sweat and blood.

A prefabricated steel rack is a lesser thing, but I managed to get some testosterone out of it anyway.

And thanks for the excellent 30 days to a better man series. That was top rate!

with regard to the measurements of the 2x2s, etc., that is perfectly normal. lumber is sold under the dimensions it is originally cut (say 2 inches by 4 inches), but then it is milled so that the finish will be more smooth and the size more uniform, which shears a half-inch off of each dimension (lengthwise). hence the 1 1/2 inch 2x2s. of course, as you say, always measure ’cause that’s just a general case. and some more craft-oriented woods will be exactly the size they say!

also, one thing i’ve found helpful for stabilizing bookshelves is to add a “kickplate”. It’s not really something you can add after the fact, but it’s not hard if you plan it in. Simply get a 1×4 the width of your shelves, make the sides extend 3 1/2″ (the height of the 1×4) below the bottom shelf, and screw/nail in the 1×4 in the space below. if you set it back – like, “inside” – about a half-inch it won’t be very visible and will add greater stability. plus, for bookshelves it gives it a somewhat more “finished” look.

i hope that made sense – hard to explain hands-on without visuals!