Make717 Hardware Caddy Part 3: One More Prototype

In Part 2, I detailed how to mount those drawer slides on the thin plastic sides of a Stanley hardware organizer. Now, it was time to make one more prototype to check that everything is going to work right. I made it out of cheap MDF (medium density fiberboard), but I used the same joinery techniques I plan to use on the real thing. Here's the finished prototype:

When building a cabinet to hold drawers, you need to work from the inside out. That is, you analyze the space needed to hold the drawers, and then build a cabinet around the hole, so to speak. I had determined by direct measurement that the width should be 18 inches, which is the distance from one drawer slide (including the part that mounts on the cabinet) to the other.

In the last post, I talked about the utility of expressing the height of each drawer plus the gap below it in 16ths of an inch. For this set, the taller drawer plus 1/2" gap measured 71/16, and the short drawer 41/16. Since I had 3 tall and 2 short drawers, and wanted a 1/2" gap above the top drawer also, the math looks like this:

      (71 * 3) + (41 * 2) + 8 = 303

That is the height of the drawer space in 16th of an inch - the final 8 represents the 1/2" (8/16") top gap. Divide by 16 to get the size in feet. 303 / 16 = 18.9375, which is 1/16" short of 19". I just rounded to 19 to make the drawing easier.

That was the next step - a measured drawing. I use drafting pads from leevalley.com, which have segments divided into quarters. Here's the drawing - click it if you want to see it in detail:

As shown in the drawing, I elected to capture the top in a dado (a groove) and the bottom in a rabbet (a one-sided groove). There was an addition rabbet to hold the back panel. Here's one side with the joinery cut on the router table:

In Part 2, I gave measurements for some spacers that align the drawer slides. The first one aligns to the top of the bottom's rabbet, and then each subsequent slide aligns to the slide below it. I made the spacers and carefully labelled them so they don't get thrown out as scrap:

Then it was just a matter of working my way up each side, installing the slides. I used a small adjustable square to set the slides back 3/4" from the front edge:

Since it was a prototype, I tried to save time by just forcing the self-tapping screws into the MDF. Of course, I was rewarded with off-center holes and squirming slides. I went back to the correct technique of using a Vix-style centering bit to pre-drill the holes. It went perfectly after that - funny how doing things the right way is often faster than taking the shortcut!

After that, I used a pneumatic nailer to put everything together. It all fit gratifyingly well. The 16" slides are exactly the right size to allow the organizers to extend fully and open the lid:

This afternoon I took the prototype to the Make717 Innovation Center. Our hope is that members will make suggestions on where the units should be in the space, and how they should be accessed and used. Feel free to chime in with suggestions!