This garage is way cluttered, it's all due to me having too many hobbies but for years I had this plan to put everything in the garage on wheels. There were six large shelves and a small one. Two desks and a narrow cart I store a chopsaw on. Anything else is just spilling over and no one here's happy about it. Why have I procrastinated? Well basically the volume of the task is heavy on my mind, getting all the materials, the time to build all of it and at the same time having to shuffle everything from the existing shelves onto new ones and then what to do with those old shelves. Ugh, why start today on something you can put off until tomorrow?

A few months back I went ahead and grabbed a couple of sets of casters, a good start but they just collected dust. I'd need at least three more to really make an impact. Well along comes this crazy pandemic and guess what I suddenly have: a ton of free time and hanging out around the cluttered garage anyway. Good recipe for lemonade when you have lemons. First job was to go ahead and get more mover dollys and draft a design.

I decided the break the overall plan down into a few phases. Making the large project into several easy projects gave me a focus and more clarity to see the light at the end of the tunnel. I'm happy to report that I've replaced all six large shelves, a smaller shelf and at the same time tackled the chopsaw bit too. I'm left with the two desks and will replace one with a new/better workbench and the other with an extra shelf since that's really needed more than a second desk. Bonus I sold five of the shelves which offset a chunk of the total cost here.

All this stuff in the garage is basically still there but my new shelves are a bit bigger and that makes it easier for everything to have a place but the best part is that now all my shelves are portable. Anytime I need space to work on a large project I can roll everything aside and viola - SPACE! Follow along and you'll see.

Supplies

Mover dolly, one per shelf (yields 4 casters)
level and/or straight edge, better if you have a small one and long one
tape measure & pencil
drill
saw (chopsaw and circular saws are best)
sockets
prying tool
box cutter
square or framing square (optional)
1 1/4" flathead wood screws (large box)
3" construction screws (large box if you are doing multiple shelves)
#14 2" screws (12 screws per shelving unit, size may differ based on the casters)
Nine 2"x3"x8' boards per shelf (you can use 2x4 but if you're store sells the 2x3 they cost/weigh a bit less but are strong enough for most projects.)
at least one sheet of plywood, (4'x8') 3/8" thick is great, go thicker if you'll store really heavy items.
wood glue (optional)
clamps (recommended)
hammer (you always need a hammer to persuade something along the way)
a helper (at least for a few minutes near the end)

Step 1: Start With the Mover Dolly

Let's get cheap and dirty! You can buy casters of any size and type but it's cheaper to pickup these mover dolly's at the local cheapo shop and disassemble them. For $8-9 you get a set that are rated for 250 lbs each (1000lbs total) and we'll also use half of the wood parts as well. The quality isn't a priority here, just a simple need for basic garage storage. You can always opt for something better or upgrade when you have some extra cash and time.

The prying tool can be used to remove staples and the carpet, then grab a socket sized right for the nuts on the casters and remove those too. Lastly finish removing any carpet, go ahead and tap those bolts out of the wooden frame. Save them and the nuts for some other project.
My shelves need to be 18" deep so get dollys that have a similar dimension as your need and this means you can reuse those boards when making the base.

Step 2: It's All About That Base!

Grab your saw and three of the 2x3 boards. Get your plywood ready too along with all the screws. The simplest design is to make the shelves four feet wide just like the plywood. Of course we're working with wood so change up any dimension to suit your own needs, go ahead and make them different sizes for a perfect fit in what ever nook you have. We'll use four foot here for the general instructions.

measure the 2x3 and make two four foot sections
the next 2x3 you'll cut two 15" sections
rip the plywood end off so you have 4' x 18" piece for the shelf.
snag two of the 18" planks from the disassembled dollys

Save time: go ahead and repeat the first three steps so you have parts for the total number of shelves in your plan.

Now you're ready to assemble a frame, you can screw the 2x3's together but I find it fastest to start with the longer boards and set the plywood on top. Fit in the 15" piece on each end between those and see that everything is shaping up correctly. Tip: start with the first 4' board up against the factory edge of the plywood and use this as the base of your unit. It will help as a reference for lining everything else up. Use a square if you're going for perfection but for a simple beginner project with basic dimensions it's not really necessary. After you're happy with the fitment take a few 1 1/4" screws and attach the plywood to a 4' piece, four screws should be fine. Line up the other 4' piece and snug it up to so the 15" piece is tight. Go ahead and screw through the plywood into each end of the 15" bits then finish up the last 4' board. Lastly take four 3" screws and drive them into the front/back corners to the long boards are tied to the 15" ones.

Congrats, first shelf is done. Repeat this so you have enough for one whole unit. Mine are about 6' tall and will have five shelves counting the top. You can always add more or go with only a couple for a short unit.

Step 3: Let's Get Rolling!

In the last step you created a basic shelf like millions of others but we want to be able to move these units around. It helps make your garage or shop dynamic, push all the shelves to one side for a bigger work area, roll them away from the wall so you can clean every nook and cranny. And also I plan to be able to move these into positions so the shelves can also be used to support a work piece.

Flip the shelf over so the plywood is on your work surface, take the 18" strips from the dolly, casters and the #14 screws. I lined up the label side so if I ever forget how much weight the casters support I can still read it. Match the edge of that strip to the edge of your shelf and screw the dolly into the frame you made in the last step. The holes are already in the strip so you have an easy guide if you need to pre-drill. The innermost hole doesn't have anything under it so just use three screws. It will be fine but if you have any concerns feel free to block that in with some scrap wood and use another screw. If you choose to do that then glue and/or screw the block to the plywood.

In one picture the plywood isn't on but you can clearly see how just a frame with casters looks. It seems best to build it out with plywood first and then do the wheels. It's not heavy flipping it over.

Step 4: Get Up, Get Upright

My shelf units will be six feet tall (72 inches) you can make them any dimension you want but if you have a maximum height in mind don't forget the casters and that 18" strip from the dolly added in the last step. For me those two parts totaled four inches so I will subtract that from 72, so I sawed off four 2x3s into 68" lengths.
Picture one shows a clever way to hide your screw by inserting it from the inside if you want to be fancy.

Best here is to have a helper support one shelf while you attach the base and top shelf, add a second 2x3 to the other corner and flip the unit over. We'll add the other shelves later. I found after firmly screwing the base and top into two uprights that it had no problem supporting the open end when I flipped it over. Your mileage may vary but your assistant can help.
After it's flipped over add the last two 68" planks. You should be ready to stand this up. But beware: if you only use one screw in each corner the top can easily pivot over. Have your assistant keep control while you check the uprights so everything is vertically level. When you're satisfied with all upright edges add an extra 3" screw about 3/4" away from the first, repeat on each corner. Keeping them spaced out a bit prevents the wood from splitting. Now your unit is stiffened up. Double check all your base corners before proceeding, add extra screws to other shelves as you see fit in the following steps.

Your helper can assist with installing the rest of the shelves or maybe you let them go and just use clamps (see pics) to support the shelve temporarily while you add the four screws through the upright into each shelf. Add as many as you like, make taller shelves for your bigger items, come back later and change them up. Wood is infinitely versatile. Just keep that level handy and double check before inserting the 3" screws. Check the front edge and back edge with a long level, use a smaller one to check each side.

With one unit built you can see in the last picture I've already started getting things off the floor and onto the new shelf as I go, also a lot of the parts for the other units are piled on there too. Feels good to see space getting clear already and this spurred me on to return the next day and keep going!

Step 5: Final Words

As I did these units I also knocked out the chopsaw stand and will show that in my next Instructable. Clearing out the old plastic shelves revealed years of dirt and bugs under them even a mouse, ick! My portable shelves will never have this messy problem. The space under the shelf is 4" so the robot vacuum fits nicely under it, so long as I have no screws or such laying around I don't even have to sweep much. That's a huge boost for me.

I cleaned up the old ones and posted them online, I got about six calls wanting them within 30 minutes and the first contact Paypal'd me the asking price so I would hold them. Sale done in under an hour, I probably could have asked for more $$ but hey I got new and better shelves out of the deal and my garage is freed up and cleaner.

This project is great for anyone starting out or who needs basic shelves and maximum functionality done fast. You can add many shelves if you have small items to store or double the depth and have 4' by 3' shelves. If you want to paint them that's great and if you're proud of them maybe you take a router and round off all the edges. Add a plank just for holding drill bits, easy. Need an angled shelf for your family's hiking boots, just change a shelf. There's almost no end of possibilities!

My first customization was adding a broom hanger on one so I'm ready to sweep up the next pile of sawdust or whatever. Another shelf will probably have a power strip and cord hangers too.

I still have some organizing to do since there is more shelf space than before and also need to do the workbench (phase 2). You can see the improvement in the pics and I moved things around, easy to reach the backside or rearrange the room. My motivation is high, procrastination is over and amazingly I even happened to get the final push to write up the instructable.
Thank you, I look forward to hearing from other builders and ideas for customizing these basic units. P.S. please vote for this project in the Finish It contest, button below. :)