the industrial cd rack.
© 1999 Jamie Zawinski <jwz@jwz.org>


Well, I didn't learn my lesson last time, and I built yet a third set of shelves out of galvanized steel pipe, this time to hold my CD collection.

I used to have these nice black wooden shelves that I was fairly happy with: they were thin and non-imposing, and were modular so that you could stack them. They came in blocks of three shelves, about three feet wide and high, and so I just bought more shelves as my collection grew. Until, that is, the day that the store I bought them from stopped carrying them. Not only that, but nobody at the store remembered having ever carried anything like them. And of course I didn't have a model number, or even a manufacturer name.

So, my new CDs sat in piles on the floor until I got around to building this new monstrosity.

Design.

The design I came up with is for a bookcase of ten shelves, measuring 5'3" x 4' 8" x 6". The shelf space is slightly over 5" high and 6" deep. Which, coincidentally, is just the right size for a CD. These shelves have room for somewhere between 1,400 and 1,450 CDs, depending on how tightly you pack them in.

Unlike the last set of shelves, this one is a skeleton only: it doesn't require any horizontal shelving material at all, because I had the idea of simply arranging for the horizontal pipes to be close enough together that the CDs would sit on top of both pipes and not need any support in the middle. This works out quite nicely if the shelves are flush up against a wall (so that you can push a CD all the way back without having it fall through.)

Shopping.

The parts list for this project:

This one took a lot longer than the last one, because it took me months to gather all the necessary parts! I designed the thing on paper, counted up the pieces I needed, and headed off to the same store as last time. I had them cut the long pipes for me, and the flanges and 4-way joints were in stock.

The first problem was getting the various short pipes (which, as we learned last time, are known as ``nipples'' for no adequately explored reason.) It turns out that their pipe-cutting machine can't handle pieces of pipe that small: the short pipes they sell come from their distributor pre-cut and pre-threaded. And of course they didn't have enough in stock, so I had to go to a second store to gather all 66 of them.

Now I hit a major problem: they had none of the 4-way pipe joints (which I learned are really called ``side-outlet elbows.'') And -- get this -- their distributor claimed that that product had been discontinued. It seems that the modern plumbing industry no longer has a need for 4-way half-inch pipe connectors.

So, I checked at least half a dozen other hardware stores, including a plumbing supply wholesaler. It seems that they all have the same distributor! Imagine, one company with a strangle-hold on the plumbing supply industry of northern California.

Well, finally I found one store that had a different supplier who still stocked this part. They had eight in stock when I first visited. I asked them if they could order 32 more for me. ``Oh, those get automatically re-ordered when we run out, so just come back next week. We re-stock on thursdays.''

``Ok,'' I said, ``but how many do you order at a time? Like I said, I need 40, and you have 8.''

``Just come back thursday,'' he repeated. I tried several more times, but I couldn't make him answer my question or show any evidence of understanding my problem. Apparently the hardware store just didn't pay him enough to care.

So I came back the next week, and as I expected, they only had 10 pieces. I tried again to get them to order them for me, and even though it was a different guy, we had the same conversation. This guy seemed even more confused than the last guy. ``They get re-ordered automatically, sir.'' He thought I just didn't get it.

I went back the next week. They had 10. I repeated the conversation, with no luck.

I went back the next week. They had 2. This time I asked the guy, ``wait, when you re-stock, how many do you order? There are only two here!'' He didn't know. But he did assure me that ``we re-stock every wednesday.'' Wait, the other guy said thursday. ``No sir, it's wednesday.''

I went back the next week. This time they had 9. I needed 10. ``Please,'' I said to the guy, ``I've been coming here every week for five weeks. I only need one more piece. Please don't make me come back next week for it. Can you just sell me that one?'' I pointed at the ``demo model'' that was strapped to the bin with a cable-tie. I watched the gears turn in his brain, he pondered, and and at last! Sanity! He clipped it off and handed it to me. Finally I had all the raw materials! And there was much rejoicing.

Construction.

The process for constructing these shelves is exactly the same as for the last one, so I won't repeat the whole thing here. In summary:

That sounds pretty straightforward. Here's the part of the story where I tell you the difference between theory and practice.

Trouble.

First, the act of constructing the ladders was a nightmare. As you'll recall, the technique for installing the horizontal segments is to screw them in extra tightly into one side, then un-screw them so that while coming part-way out of one side, they screw in to the opposite side. It was insanely difficult to do this, and the reason is that these pipe segments were so much shorter than on the other shelves. That means that they don't flex. At all. It took me hours, lots of sweat, and lots of swearing to get the things attached.

Then, when I finally got the ladders constructed, they were notably non-identical. In particular, one of them curved visibly to one side, because apparently one of the poles turned out to be shorter than the other. Oops. That means the shelves will be crooked. Well, I thought, hopefully they won't be so crooked that it matters... because I sure can't do anything about it now.

On the plus side, when they were in place, they were in for good. I didn't have trouble with many of them turning freely, so I didn't have to use much thread-locker.

Attaching the ladders together involved similarly copious amounts of swearing, again due to the non-flexibility of the ladders. I did get it eventually, though, and it wasn't dawn just yet.

Somehow, one of the long horizontal pipes ended up not being long enough, due (I presume) to the curvature of the ladders, since I know all the pipes themselves were exactly the right length. But if it was screwed in to one side, there was no way I could make it reach the other side. This meant it jiggled around, and wouldn't actually provide any support at all to the back of an entire row of CDs. This would not do. I finally solved this problem by wedging a large hex-headed screw between the pipe and the joint! I did this by sticking the threaded end of the screw into the pipe itself, then rotating the joint out of position, and then rotating it back with the screw-head between it and the pipe. And when I say ``rotating it back'' what I really mean is ``wailing on it with a large rubber-headed mallet until it moved far enough.''

I broke the mallet. But I made it fit.

Now it's time to stand it up and strap it to the wall! (Since it's so tall and thin, it wouldn't be stable if free-standing, and besides, I live in earthquake country. Of course, if there's a quake, all these CDs will be on the floor, but at least I won't have to worry about 160 pounds of metal falling on me.)

More Trouble.

As I mentioned earlier, a key part of this design is that the back of the shelves be right up against the wall, so that there is something to push the CDs against so that they don't go back too far and then tilt forward and slip into the gap between the pipes.

Well, when I stood it against the wall, I noticed the first problem. The wall where I intended to put it is where the TV cable comes into the room. And whoever installed the thing had, for some reason, attached an inch thick block of wood over the hole, with the cable face-plate mounted on top of that. And of course, it was positioned just so, so that it bumped into one of the horizontal pipes rather than fitting into the gap between them. This meant that the shelves were flush against the wall at the top, and were about an inch away at the bottom. Well, that should be ok, I thought. I hoped. I dreamed.

I intended to use these two pre-molded pipe straps to attach the top bar to the wall: these are roughly C-shaped bits of metal with holes drilled on the outer flanges. The wall in question is drywall, so I needed to use wall anchors to attach screws.

Now, if you've ever used metal wall anchors before, the way they work is this: you drill a hole; you hammer the wall anchor into the hole; and you drive a screw into it. As the screw goes in, it makes the ends of the wall anchor pull together, expanding out in the middle, so that it flattens out on the other side of the wall and can't pop out. Then, you can un-screw the screw and screw it back in later, with the anchor in place.

So I held up the shelves, marked the spots I intended to drill, and put in the first anchor. Well, it seems that with the wall anchors I got, that trick doesn't work. After the screw has gone in, it won't come out. I guess something broke off on the other side, because after having gone in, the screw simply turns freely instead of coming out. Great. So now I've got a wall anchor in place that I can't get out at all.

So I re-positioned the holes (to work around the useless anchor now in place) and screwed them in with the shelves and the pipe straps already in place. I verified that, yes indeed, all the anchors behave the same way: these screws are not coming out. This means that this shelf is never coming off the wall. Not unless I figure out some way to saw the screw-heads off...

Even More Trouble.

I loaded it with CDs. When I got to the third-from-the-bottom shelf, it became apparent that my fantasy that it would not be a problem for the bottom shelves to be slightly away from the wall was just not the case. I had to position the CDs very carefully to make them line up on the front and back pipes, and the slightest bump would cause them to slip backward and tilt forward into the gap, which just looked terrible.

I tried to think of some way around this. Maybe I could attach a back to it somehow? Maybe I could get some chicken-wire and strap it behind the shelves? This was going to be difficult, given that it was no longer possible to take the shelves down off the wall! I had to find a way to slip something in there from the side...

Oh, screw it. Time for bed.

Fix!

Weeks passed. I thought more about attaching a back, and nothing I came up with really sounded very feasible. Finally I decided on the square-peg-in-round-hole approach, which is to say, violence. That wooden block behind the cable faceplate had to go. Basically, I just chiseled it off, from the side. Then with a good deal of whacking with a hammer, I was able to dislodge it from its position behind the shelves.

Then all I had to do was push the shelves back against the wall, and... uh oh. They won't move. They're screwed in tightly at the top, and the weight of the CDs being on them for weeks had made the feet take up permanent residence in the carpet below.

So, I repeatedly hurled my body into the shelves from across the room. They moved a few millimeters each time, and eventually were flush against the wall.

Perfection! More or less...

Next Time?

That sucked. If I ever do this again, I'm going to spend the extra money and get Kee Klamps instead of plumbing joints. I only learned about these recently; had I known about them years ago, I probably would have built all the shelves that way.


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