Introduction: IPad or Chromebook Cart for School

About: I like to explore with my hands, but I trouble choosing one area of focus. I have completely renovated my house, but nothing I do is craftsman quality. I want to build an electric car, hack computer hardware…

Like many schools, ours is trying to put an iPad into the hands of every student (update: after two years, we replaced iPads with Chromebooks and re-utilized the cart for those). For our seventh grade, that's over fifty iPads. As our middle school is multi-age, in a year we will have iPads for every seventh and eighth grader. Soon, we will have to store and power over one hundred iPads.

The cost of an IPad cart is anywhere from over a thousand to three thousand dollars. Looking at their capacity, we would need to buy anywhere from three to five carts that are currently on the market, depending on the cart. While various grants have allowed us to stock up on iPads, they won't pay for the cart. Or five. Our school's budget is shrinking, so we needed a solution that was practical and cheap.

I would have thought that, with the popularity of iPads, cart plans would abound. No. There is one plan, which was very helpful in organizing the Ipads. John Umekubo is the Director of Technology at St. Matthew's Parish School in Los Angeles and writes this very helpful blog entry here. It will teach you the guts of the beast. Other sites talked about using dish racks and such, but they weren't secure and middle-school proof (I did adopt an old desk organizer for my own personal electronics).

This design is four cabinets, each of which holds nearly 30 iPads while charging ten at a time (more on power and syncing later). They are designed to sit on a counter, although caster wheels could be added and be secure from crimes of opportunity (anyone who really wanted our iPads could get them, and you can make them more secure, I'm sure).. The total cost was $400.00, including locks.

Throughout, I offer up considerations and lessons learned. On the last page I have included other brainstorms. I am sure you will only improve on what I've done with these prototypes.

UPDATE: As stated above, after two years we moved from iPads to Chromebooks. The slots I had made happened to fit in width, although I did need to drop the shelves about an inch as the Chromebook on its side was taller than an iPad on its side. Fortunately, the dividers, when turned, happened to be tall enough so that I did not have to re-cut a whole new batch. Measure with your device in mind--and the next generation!

UPDATE: There were some concerns about heat combined with the wood construction. We tested the temperature over the years and found no problem. Still, results vary. And our insurance carrier ultimately expressed the same concern--we no longer use these. They worked for our needs, though, with no problems.

Step 1: Materials

I built four carts. Adapt to fit your needs.

Four 19/32 CDX plywood. If you plan well, you can actually get away with three sheets. CDX is cheap, but pretty ugly sitting on the counter. If I had it to do again, I'd spend the extra $80 and upgrade to AC or something with a nicer finish, or have planned better and used only three sheets.

Five 1"x10"x10' pine boards

Two 1/4" Luann 8'x4' sheets. Nice stuff.

1lb of 1 1/2" finishing nails.

1lb of 2" sheet rock screws (wood screws would be fine, but I had these already).

100 1/2" #6 wood screws. The hinges and latches came with screws, but the screws were a tad too long for the thickness of the wood so I had to buy the wood screws. Your results may vary.

Wood glue.

Eight hinges. Note that some hinges have a removable pin, which is not what you are looking for if security is an issue. I went cheap and got 3" narrow hinges. They came in two-packs for under $5.00 each.

Four latches.

Pack of four locks that have a common key.. Master Lock sells them and it allows for other teachers to open any of the iPad carts.

Step 2: Cutting Lumber for the Box

Mistakes were made, but here's what I did.

A box has six sides, so I needed that. Stock plywood comes in 4'x8' sheets, so I figured I'd make each side of the box 2'x2'. Or, 8 sides per sheet. If you are making four boxes, that works out to exactly three sheets of plywood (6 sides by 4 boxes requires 24 sides, which, divided by 8 sides per sheet is three sheets). Because I figured a few would be ugly, I cut up a fourth sheet. In retrospect, I should have gotten three sheets of higher grade plywood.

So, cut the sheets into 2'x2' squares. You will lose an 1/8 of an inch to the width of the saw blade, leaving two slightly smaller squares for each sheet. These can be the back.

Separate the squares into matching piles. You should have a pile close to 2'x2' and a smaller pile a half an inch shorter on one side; these will be the back. But you don't want to mix the two or they won't fit.

Step 3: Put the Box Together

Pull four squares that match in size. Choose the ugly sides and make sure they are inside the box, with the ugliest bits to the "back" (yes, this is subjective).

Because I wanted the interior of the boxes to be slightly higher than wide, the sides of the box rest on the bottom square and the top square sits on top of the sides. When we do the interior you will why I wanted the space.

Lay down some wood glue along the edges and nail them into place using the 1 1/2 inch finishing nails. I used seven nails every edge and it seems pretty secure.

To keep the whole thing from racking, I wanted the back of the box to fit inside of the sides and top. So, it had to be a bit smaller than 2'x2'. That's where the second pile of slightly smaller squares come in. Put the box on its side so the "back" is no on top and lay the "back" square on top. Note where the excess board is and cut it off. Now it should fit. Glue and nail it in place.

You now have five sides of your box.

Step 4: Put a Door on It

Take your last 2'x2' square. Measure the half way point and cut it in half. You now have "French" doors.

I placed mine so that the top of the doors were flush with the top of the box. Because the box is a 2'x'2' side stacked on a bottom square and topped with another square, the entire box is higher than two feet. Your doors will have a gap of about half an inch.

On the plus side, they won't drag on whatever counter you put your cart on. On the other, it's not very secure and simply a poor structure. But we'll fix that later.

Place the hinges and screw everything in place.

My packets of hinges came with screws, but they were a tad too long. I had to use 1/2" wood screws instead. They hold fine.

Then, I put a latch on the outside that's made to take a lock. Again, I used 1/2" wood screws instead of the screws that came with the packet.

If security is your concern, simple Phillips head screws should scream alarms at you. My school is concerned with crimes of opportunities, not master criminals. You might have greater concerns, and there are security screw heads you can buy, or pre-drill the holes and put superglue in them, or use bolts and lock nuts. I'm sure others have ideas.

You now have a secure box worthy of a Boy Scout troop.

UPDATE: There were some concerns about heat combined with the wood construction. We tested the temperature over the years and found no problem. Still, results vary. And our insurance carrier ultimately expressed the same concern--we no longer use these. You could, if security is not an issue, leave the doors off for more ventilation.

Step 5: Create the Rack: Part 1

Again, let me direct you to John Umekubo's blog. He is the Director of Technology at St. Matthew's Parish School in Los Angeles and writes this very helpful blog entry here. He has no security issues, just storage. When I asked, he said that if security had been an issue he would have put his model into a cabinet they already had. If you already have a cabinet, you might consider this.

I estimated the inside to be about twenty-two inches. If I was going to have two rows of racks, I'd need about fifteen slots on each rack. Roughly, I figured I'd make each slot about 1 1/2" wide.

For each box, I measured the width of the inside of the box. I then cut five lengths for each box from the 1"x10" boards. You will only use four of these boards for notching.

Using a table saw, I set the guide at 1 1/2". Then I set the height of the blade to 1/4" (if that). I cut a notch.

The 1/4 Luann that will become the dividers is thicker than my blade, so I had to move the guide over one saw blade so that the notch was two blades in width. After this cut, I resent the divider 1 1/2" from the last setting--so it's not at 3" but at 3 1/8" inch. You will get blade creep, and that's okay. If you require wider slots, or are okay with thinner, great. Be careful: You are pairing up boards, and the notches on the one need to line up with the notches on the other so that the dividers are vertical.

A word about boredom. After my prototype box, I cut up enough rack boards for all of the boxes. I then set the first cut and cut all of the twelve boards I needed, flipping the board around so I cut ta notch at the other end of the board. In short, two notches for each setting. Then, I moved the guide and did every board again. This is a tedious step, and saws do not mix well with day dreaming. If you flip the board as I did, you'll get to the middle and have to fudge where to put the final notch.

Take the fifth board. Cut it in half the long way. This is the back of the shelf, so that the iPads don't get pushed too far and fall into the back of the box. I make them half so that the iPads can breath out the back of the slots.

Place them at the back of two of the four notched pieces you've made for each box. Use wood glue and 1 1/2" finishing nails to hold them in place. These are the shelves. The other two notched pieces will be at the top, holding the dividers in place.

UPDATE: After two years we moved from iPads to Chromebooks. The slots I had made happened to fit in width, although I did need to drop the shelves about an inch as the Chromebook on its side was taller than an iPad on its side. Fortunately, the dividers, when turned, happened to be tall enough so that I did not have to re-cut a whole new batch. Measure with your device in mind--and the next generation!

Step 6: Create the Rack, Part 2

How high does each rack have to be? For my iPads, I estimated 8 inches, as they would be laying on their sides with their charging port facing the door.

I cut 8" high strips from the sheet of Luann. Then I used a miter saw to cut them into 9" lengths (a tad shorter than the shelf is deep).

Taking a suggestion from John Umekubo (have you checked out his blog yet!) I cut corner tabs so that students could easily grab their iPads.

Then, they just slid into place. I have not glued them in place. If it comes to that, I will, but I want to be able to take things out to have access to back if needed.


UPDATE: After two years we moved from iPads to Chromebooks. The slots I had made happened to fit in width, although I did need to drop the shelves about an inch as the Chromebook on its side was taller than an iPad on its side. Fortunately, the dividers, when turned, happened to be tall enough so that I did not have to re-cut a whole new batch. Measure with your device in mind--and the next generation!

Step 7: Power!

John Umekubo seemed to use three surge protectors located in the back of his rack. Okay, but power concerned me and I wanted it to be concealed and neat.

I did a big search for surge protectors that allows for many, many plugs and found.... none. In the end, I choose a Belkin 10 plug. Although there are nearly thirty iPads in the cart, they don't need the same amount of charging that laptops do. Our students were aware last year when they needed it and when not, and shared nicely. You could just as easily get two of these Belkin plugs, for twenty outlets.

When you look for surge protectors, be aware of the space needed for the iPad adapter. The plugs cannot be stacked as the adapter is taller than a plug.

Another concern is syncing. My tech people say they can sync without wires. There are 22 USB hubs (and more!) that will allow you to sync that many iPads with wires, but they do not charge. I have also heard differently.

If people have solutions to this power issue please make suggestions in the comment section. I went with the Belkin 10 plug surge protector with the fifteen foot cord.

Step 8: Air!

Electronic things get hot.  They need to breathe.  A wooden box is not, without modifications, conducive to this.  So, mod we will.

In the end, I just took a drill attachment I had that cut big holes in wood and made Swiss cheese on the sides.  It's easy and, to me, whimsical.

I had thought of cutting patterns that matched our subject areas (i.e., a Pi symbol for the cart going into the math room).  By the time I got to this part of the project, I wanted simple (cutting those notches for all of those shelves numbed my mind beyond belief).  Upon reflection, I realize that, with the way the shelves are, the whole back of the box could be missing and it would be difficult to get at the iPads if the front was locked.  Secure enough, anyway.

The back of the box fit the power supply, and to have easy access I cut a largish hole in the back with a jigsaw.  That alone should let a lot of heat out.  You can argue its compromises security, but it does a good enough job for my school.

But the cart will need plenty of air to breathe.  I put about ten holes in the top and sides of each box.  I'm going to speak with our tech guy to see if more are needed.

Step 9: Make It a TARDIS

Sure, having iPad boxes are good.  But why not make them into TARDISes?

To keep it simple, I used tape and paint to make the windows and Police Box sign.

First, paint where the windows and Police Box sign would be white.  A second coat makes it pop.

When the white paint is dry, put painter's tape where the windows and Police Box sign would be.  This will keep the areas you want to keep white (windows, Police Box sign) white when you paint the whole thing TARDIS blue.

Then, paint the whole box.  True Value Hardware calls it 31B7 Thrill Seeker.  The color of the TARDIS changes over the seasons, and this looked close enough.  Again, a second coat makes it great.

When the second coat dries, carefully peel off the painter's tape.  You will reveal the white paint, aka the windows and Police Box sign.

Because the CDX plywood was rough, the edges of the painted area did not come crisp.  I had dumped half a gallon of TARDIS blue onto my garage floor, so I used the floor as a roller.  That meant an overly quick, sloppy job.  Oh, well.  I might go back and clean it up.  Might.  You can do better.

Finally, I bought a few cheap solar pathway lights.  Measuring the diameter of the light's stem, I drilled a slightly wider hole in the exact center of the top.  I cut off the stem, leaving half-an-inch to stick in the center hole.  It should have enough light to charge up during the day, and then glow when students need their iPads but the room is dark (for, say, a video).  I'm sure a clever individual can come up with a way to make it fade in and out, but I wouldn't want that in my classroom.

Please, don't make comments about size and details of a "real" TARDIS.  I know.  Pretend it materialized halfway into the floor.  This is more whimsical than anything, to give kids a bit of something different and offer a nod to the geeks in our group.

Step 10: Other Thoughts

The original plans for shelves by John Umekubo is the heart of this.  The secure shell is very flexible.

Other Ideas

Filing Cabinet: I toyed for awhile using a filing cabinet.  They are plentiful (as everything goes digital, some really old, sturdy filing cabinets are gathering dust in storage) and strong.  I also like metal things more than so much wood. 

I figured if I removed the drawers, I could build the shelving inside and fix up some type of door. 

Casters: One of the teachers wanted her cart to be mobile.  She wanted to slide it under a table when not in use.  Casters are easy to add.  I could recommend flipping the box on its back, though, be it the TARDIS box or filing cabinet.

Kitchen Cabinet: When I was pricing stuff out at Home Depot, I noticed that kitchen and bathroom cabinets are less than $100.  If you don't feel handy, these cabinets are a lot easier to put together than the boxes I made.  I find them a tad dull, though.  Put the shelves inside and you're all set.

Be creative.