Sunday, January 21, 2018

Woodworking project: CD cabinet ... drawer ... rack ... thing

This thing.... this thing was one of those projects, if you know what I mean.

And if you don't, well, I'll try to explain. (I make no apologies for the length of this post. Get comfy.)

This started, as most things do, with a complaint from the War Department. (This is patently false, by the way. None of this is her fault at all. Except the part where she encouraged and suppported me.  But it makes a better narrative in my head if I can blame it all on her, so let's just go with that.) She has a really good Bose stereo that sits on the counter in the kitchen, and we use it all the time - especially when we're cooking or entertaining, and even if we're just hanging out in the family room. It's got amazing sound and a nice little remote (and it hardly ever skips at all now that we got the moths cleaned out of it), but it only takes one CD at a time.

We also have a perfectly cromulent CD rack that I "inherited" a long time ago from a friend who was moving and didn't need it anymore. It's a free-standing floor unit with enough room for pretty much every CD we own, but there's nowhere near enough space for it anywhere near the kitchen, so it hangs out at the far end of the room - exactly as far from the stereo as it can get. This meant, of course, that there was always a big stack or three of loose CDs teetering precariously on the edge of the counter or on top of the "junk drawers". It was really starting to get on our nerves, and it was hard to find a particular CD. (We really did need a better solution, but it's still Amy's fault for pointing it out first.)

After a lot of thought and futzing about (months, actually), I drew up a model of what I had in mind in SketchUp, and even built a full-scale mock-up of the drawer "mechanism". There were a couple of minor details that I didn't have worked out entirely yet, but I figured I had enough of a plan that I could get started.

Which, as usual, was where things started to go wrong.

See, I had an idea in my head of how this thing was going to work, and I was convinced that it WOULD work. Unfortunately, it was kind of my own stubborn devotion to this imagined design that made the project more difficult than it really needed to be. (Hey, stop me if you've heard this story before.) I probably could have just nailed a few boards together and piled the CDs on top; as long as they were out of the way, we'd be happy. But I just had to make it challenging... (Though, to be fair, we did look at a fair number of CD racks and whatnot online and didn't like any of them.)

The first problem arose when I went digging around in my copious piles of scrap and offcuts, looking for the wood to build it with. Sadly, this was before I got my new woodshed (have I posted about that yet? No? I should do that soon...) and I didn't really have the material I wanted/needed to implement my design. I wasn't even really sure what wood I wanted to use, I just knew that if I was going to make something that looked really nice, I wanted to use some decent wood - not just whatever scraps I had on hand. Finally, after solving some design issues I'll cover in a minute, I went up to the store and paid way too much money for some 3/4" edge-grain fir. 

A quick note about my final design (you could put every single word in that clause in quotation marks to denote ironic usage, and you'd be right): I had worked out a design that looked a bit like a horizontal version of my Scotch cabinet - one of the reasons I went with fir, in fact. But instead of doors, it would have two drawers that tilted outward to show the spines of the CDs. I found an old Fine Woodworking article online that showed a similar style of drawer to what I had in mind, and co-opted the design for my own use. I did have one problem with their design, which is why I built the protoype of the drawer, and it's a good thing I did because I was actually right, and the drawers might not have worked at all had I just followed their layout.

Actually, you know what? I'm kind of proud of myself for figuring this out, so I'm going to explain what it was that I did. Or try to anyway.

Here's what their design for a tilting drawer looked like:



There's a rounded groove cut in each shelf, and a matching rounded lip or bead on the bottom of the front of the drawer that rests in the channel. This allows the drawer to tilt forward while resting in the channel. The issue I spotted with their design was that the pivot bead is at the back of the drawer front. When the drawer tilts forward, the front of the drawer acts as a lever, lifting the bead out of the channel - you can kind of even see it happening in the cutaway diagram on the right.

This didn't make any sense to me - the channel and bead should be on the front edge of the drawer. That way, when the drawer tilts forward, the bead pivots in the channel and maintains contact throughout the opening process. And what do you know? When I built my mock-up, I was right! (I also figured out that it would work a lot better if the groove was cut closer to the front of the shelf.)

Of course, I also needed to alter the original drawer from the article in a rather more substantial way: it needed to be a fair bit deeper to accommodate the height of a CD case. As I quickly figured out, however, the deeper the drawer, the bigger the radius, and the taller the front of the drawer would have to be. I spend a lot of time fiddling with my prototype, making two-dimensional mockups, and double-checking the results in SketchUp. In the end, instead of an 8-inch drawer front, I needed something that was a lot closer to 9-and-a-half. But the material costs for 10" boards was astronomical - no way I wanted to spend that much money on a design that I wasn't even sure was going to work!

Then I thought I'd take another cue from the Scotch cabinet and make simple frame and panel "doors" to use as drawer fronts, but that presented a couple of problems: first, all of the material was going to be 5/8 thick, which would make for some very small, and therefore very weak, tenons. Second, a standard frame-and-panel construction would not leave a flat surface on the back of the drawer front for the CDs to rest against.

My solution was to create a wide, flat drawer front that looked like it was frame-and-panel, but used half-laps to create stronger glue joints and a flat surface on the back. I also left a slight reveal between the pieces on the front as a little design detail.

Of course, gluing these panels together required a very specialized glue-up jig:


And a few miscellaneous pieces of heavy stuff to keep it all flat while the glue dried:


But damn it, it worked! Back of the drawer front on the right, front of the drawer front on the left:


The carcass was fairly straightforward - just some stopped dadoes for the top and bottom, a through-dado for the sides, and a lot of double-checking that the channels for the pivot beads were facing the right way. Of course, I actually messed up this step - I didn't do a very good job of squaring it up during the glue up - and I paid for that later when it came tip to fit the drawers:


After a fait bit of swearing and a lot of sanding, I managed to get the drawers fitted in the case, and actually opening as intended:



Which brought me to my next design challenge! I needed a way to keep the drawer from falling forward out of the case when it was opened. Also, for some reason, I always felt that the drawers should be removeable. In retrospect, I'm not sure why.

The article I was using as a starting place had a simple enough suggestion: a wooden stop, mounted on the shelf above the drawer. The stop would fit through a slot in the rear of the drawer, and then pivot to lay across the slot once the drawer was in place. If you needed to remove the drawer again, simply rotate the stop so it fit through the slot, and the drawer would lift (or fall) right out.

This system was easy to set up and worked like a charm... except that it kept the drawer from opening all the way. No matter the thickeness of the stop - even if I used a simple pin, it meant that the leading edge of the back of the drawer couldn't go any farther forward than the rear edge of the front of the drawer. (I wish I'd taken a picture, because I know that's confusing to explain, but I was so frustrated by this oversight that I just forgot.) I did take a picture of the repair I had to make to the drawer after I realized it wasn't going to work:


What this meant for my purposes is that it kept me from being able to slide the CDs straight out of the drawer - I had to tilt them to get them out. Obviously, this wouldn't work if the drawer was anywhere close to full.

This became one of those moments where I vacillated between chucking the whole thing in the fireplace and starting over, and frantically scribbling down possible solutions. Eventually I settled on a system where brass pins, inserted through the sides of the case, would ride in grooves along the sides of the drawers. This meant performing a little router surgery on the already-assembled drawers, AND drilling holes through my beautiful case, but it turned out all right in the end. Mostly. (I supposed that it's still theoretically possible to remove the drawers, but I wouldn't advise it.)

After all the fiddly bits of drilling and checking and sanding and bluffing in the drawers and cutting brass rods and whatnot, it was finally time to apply some finish. For that, I went with the old favorites approach of a coat of Danish oil and two coats of poly:


That's actually not a bad shot of the grooves that I had to rout in the sides of the drawers and the holes in the carcass for the brass pinss - well, sort of. Nothing's quite facing in the right direction, but whatever.

Oh, and I was originally going to put a back on it, but decided it was really just more weight that the  project didn't need, so I added a French cleat for wall mounting and left the back open.

And then I hung it on the wall right next to the stereo (and directly below the Scotch cabinet). Admittedly, it's a temporary location and not ideal (the damn thing turned out a little bigger than what I originally had in mind) but it works!



Except.... yeah. I don't know if you've noticed (I didn't until after I'd already installed it), but there's a rather huge flaw in the overall design. A bad one.

You see, in my eagerness to make a cabinet that could hang on the wall or sit on the countertop, I had changed the structure so that the long sides (the ones with the horns) were on the top and bottom instead of on the sides. Unfortunately, this meant that the dadoes were now vertical instead of horizontal.

The entire weight of the cabinet (and all of the CDs inside) hangs from the two dadoes in the top shelf. And the bottom shelf is hanging from the sides while supporting the weight of the bottom drawer. (The middle shelf is the only one with decent structure as the dadoes fit into the sides of the case, providing material support underneath the joint. Though it's all still just hanging from the top shelf,...) As if that wasn't bad enough, the drawers aren't exactly soft-close. If you're not really gentle when closing the drawer, you're basically smacking the shelf with a large, heavy hammer.

Despite this, we left the cabinet in service for a few months and it was working okay. That is, until I showed it to a friend of mine with some experience in making fine furniture. (Ironically enough, the same friend that gave me the CD rack we're not really using anymore! How's that for parsimony?!) I didn't even need to point out the flaw to him because he spotted it right away. That was really all the confirmation I needed - time to finally do something about it.

I took the cabinet off the shelf, added some nice long screws to each of my dadoes in the top and bottom, and cut some plugs to fill in the holes:



Heh, you can tell from that last shot that I had the "foresight" to use screws and plugs when attaching the French cleat to the back of the case - the one joint that really didn't need them!

Anyway, this also required sanding off the finish on the top and bottom, but it was easy enough to reapply, and I felt a whole lot better about filling it with 30 pounds worth of music afterwards.

So, it's done!  Thanks for reading this far, and allowing me to vent a little. Despite all my complaining, it was actually a fun thing to build. Though I'm not 100% happy with how it turned out, I'm pretty proud of myself for coming up with the solutions to some of the problems I faced. Like so many other projects, it would be a lot easier to build the second time... like anyone anywhere would ever need a cabinet like this for anything.




And, hey: with a little luck, I can use the lessons I learned to avoid making the same kind of design and build mistakes with my next project. Yeah, right. I can always find new and exciting ways to screw it up. Stay tuned!

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