Cable control for a pull-out shelf

Step 5 Mount the arm and start using it

Finally, we'll attach the arm and wire everything up.

Before attaching the arm, it's a very good idea to do a test fit. You want to know that the arm--when the shelf is closed--won't hit the shelf tracks or the back of the cabinet. You also want to know that the arm is long enough to not pull loose when the shelf is all the way out. If there's a problem, now's the time to know about it. Note that you can have the arm articulate from either the left or the right by flipping it upside down. In my case, I needed the arm attached on the right side of the cabinet and the shelf because of where the cables were entering in the back. Your mileage may vary.

BEFORE YOU START: take a moment and check what wires and cables you're threading through there. You've got an opening in the arm that's at most 3/4" x 1". If your cables won't fit--because the fittings on the ends are too big or there are too many of them--you'll have to take all of this apart to fit the cables through before attaching them again. For example, if you've got a VGA cable going through there (like I had), it will not fit through that hole. In this case, I had to thread them all through in advance before I bolted the arm down. You've been warned.

ALSO BEFORE YOU START: if you took the route I did and added those zip tie mounts, take a few minutes and pre thread the zip ties through the appropriate holes. As you'll quickly discover, they're hard enough to get in there when the arm isn't mounted. Doing that while hunched over, half in the cabinet, with your arms nearly over your head will cause you to exercise your considerable four-letter vocabulary (if you don't have a considerable four-letter vocabulary, contact me ... I seem to have some to spare).

OK, test fit is done and everything fits. It's easiest to start by mounting the arm to the shelf. Find the position of the arm on the shelf and, with a bit slightly larger than 1/8" (large enough for a #8 machine screw), drill completely through the shelf at the two mounting holes. Next, with the #8 machine screws and nuts, fit each screw through the top mounting hole of the arm, the shelf, and the bottom mounting hole of the arm. Attach the the nut to the bottom and tighten. Repeat with the other screw and nut. At this point you may notice that getting these things fit in here requires a bit of twisting, shoving, and holding your head at just the right angle. Depending on how accurate you were in drilling all those holes, this part will be either very easy or the most difficult part of the whole effort.

Next, with the drawer in the closed position, take two of your small wood screws and mount the top-most of the "shoulder" hinges. Once that's firmly mounted, pull the drawer back out--to give you better access to the bottom mount--and attach it. My cabinet had thin enough material in the back that I didn't need to drill pilot holes. Again, your mileage may vary.

The last thing to do is attach your cables. This is an exercise in trying to satisfy conflicting goals. You want enough cable so that when the arm is fully closed the cables aren't pulled too sharply around the elbow corner. However, you don't want so much that when the drawer is open that the cables have too much of a bend at the hinge (see the diagrams to see what I mean). This will also be complicated if you've got cables that have to be sized from two different ends. For example, some of the cables I was attaching couldn't have much extra slack on the drawer side, so I should attempt to tie that side down first. Some of the other cables couldn't have much slack on the back wall attachment, meaning that I should probably tie them down first. What worked for me was to tie all of them down, but not to cinch the zip ties in snug. Then I could work the individual cables to where I needed them cinching the zip ties down once everything was satisfactory.

One last thing that you'll probably note from the pictures. I had more cables than would fit into the arm mount. Specifically, I had the power cable for the drawer that I needed to tie down. I found that the easiest thing to do was to use velcro ties to tie that cable to the top of the arm. Obviously, this will work for any type of cable if you've got too many cables to fit in the arm.