Installing Drawer Slides

[Tom Bender]

The instructions for installing are clear enough but sometimes there are complications. Here's one that I struggle with.

Suppose my cabinet or drawer is not perfectly square. It happens. I have shimmed to perfection (within 1/64") and had no problems but it is fussy to measure and shim. Any suggestions?

[andy bessette]

Drawer slides do not require perfect squareness. If your build is so far out of square that the slides cannot accommodate that, you need to perfect your building methods; either by taking a finish cut to "square" the drawer, or using a scrap plywood form to hold the cabinet square at assembly. Or switch to center slides.

[johnny means]

What type of slides are we talking about?

[Jim Becker]

As others have eluded to, there is generally a little leeway in most drawer slides for side to side operation so unless your drawers or carcasses are really out of square, they should work as long as you're within the specification parameters.

[Tom Bender]

So I'm talking about side mount full extension slides like Accuride. They must be screwed to the drawer and the case. They are 1/2" wide. If the space is 5/8" at any point they will fail.

For kitchen cabinets and the like built from flat plywood etc it is reasonable to build close enough to perfect. For one-off furniture built from imperfect real wood, I allow a little wiggle room and shim as required.

Where does the variation come in you ask? How about this bow front tool cabinet. The drawer fronts are 1 1/8" steambent ash. Springback was not all exactly the same and the cabinet sides were almost perfectly straight, but not exactly so. Sure I could have designed it differently but once done it has served well for many years.

Tool Cabinet.JPG

hmm, I must have been standing on the wall when I took this shot. Have to reset the gravity again. Clocks twice a year, gravity every 26,000 years.

[Jim Becker]

1/8" from the nominal 1/2" is right at or maybe beyond the limit, if I'm not mistaken. That's pretty much a meaningful out of square, too. You may be left with shimming and the easiest way to do that may be to adhere something to the outside (cabinet contact surface) of the slide prior to putting it in place and screwing it down.

[Steve Jenkins]

I haven’t used those slides in some time but if I recall correctly the mounting holes are on tabs that can be bent out prior to installation. When you install the drawer and move it in and out a few times the tabs should settle in where they need to be.

[Jim Becker]

I haven’t used those slides in some time but if I recall correctly the mounting holes are on tabs that can be bent out prior to installation. When you install the drawer and move it in and out a few times the tabs should settle in where they need to be.

I forgot about that, Steve...many slides have mounting holes available on bendable pieces. Good tip!

[andy bessette]

...Where does the variation come in you ask? How about this bow front tool cabinet. The drawer fronts are 1 1/8" steambent ash. Springback was not all exactly the same...

Tool Cabinet.JPG
...

Presumably these bent drawer fronts were cut to size after steam bending and spring-back. So this should not contribute to any non-parallel condition of the drawer sides.

[Jim Dwight]

I put in 10 sets of drawer slides just today. Only 8 of the drawers are made but those are installed (I ran out of plywood). It is a utility cabinet for a room off my garage so I am not using fancy materials. 3/4 pine plywood carcase and 1/2 inch plywood drawers, both from BORG. I made blocks from pieces of scrap to position the slides in the carcase but I was off on the length of the next to the top drawer. Others were right. Except I had to shim that same next to the top drawer on the bank of drawers where I had the positioning stick the right length. Not sure what happened but the gaps are reasonable (I designed it for 1/8) and the drawers work smoothly (the 8 that are in).

I was worried when I got the slides because they are not 1/2 inch thick. They are a little thinner. I allowed at least 1 inch clearance between the drawer and carcase. I might be 1/32 over in a few places. But everything works without shims.

I made essentially all of the cuts for the carcase with my tack saw and a lot of the drawer cuts were made with it too.

I haven't used a lot of ball bearing drawer guides but they always seem to give me some trouble. Today it was mostly a math error. Some day I will get smarter and install the guides in the carcase before assembling it. I suspect that would be significantly easier. But does anybody have a better way to position the guides in the carcase than sticks of scrap under them while you screw them on? I've seen the commercial jigs but they seem to be just to get it level, not get it at the right height. The height is my issue.

[Bruce King]

Don’t build the drawers until you have the side mount slides mounted.
I glue wide wood strips on the carcase sides about a half inch above where the drawer bottom will be. The thickness of these strips is thin enough to keep them mostly hidden when the drawer is open. Screw on the slides using two screws for now. Measure the available space between the slides and build the drawer that size or slightly smaller if your dovetail jig produces proud tails or pins on the sides. This was my method recently after wrestling with some not long ago. Then the setback on the slides depends on the thickness of the drawer front and any drawer front inset you might want. Once it’s all good, add more screws.

Instructions that come with the slides never applies to my projects.

[Tom Bender]

Jim and Bruce

Thanks for being helpful. I have considered bending the tabs but think shims are more certain. Washers can be a little thick so I have made some with aluminum flashing.

The fasteners that take the most load are at the front so I save those spots for after test fitting.

Aligning the drawer fronts is affected by shims so when possible I finish these after fitting the drawers, but it is fussy work on inset drawer fronts.

Tom

[Jim Becker]

Try to jigger things so that the drawer fronts are ultimately parallel with the face of the case...it may take you awhile to get there, but in the end the time is worth it. Using a square with a long leg or shop-made equivalent will help you ascertain "which side" of the drawer needs more adjustment to get the drawer box square referenced to the case front. Be sure to measure both sides as you may even need to shim both sides, but at different amounts, etc.

[Bruce King]

Are you putting drawer fronts on the drawer boxes or is it part of the box?
Separate ones make it easy, just a dab of caulk on each corner, line it up and screw it down later. The double sided tape will change your inset or flush line.

[Kevin Jenness]

Accuride side mount tolerance for side space is typically 1/2" +0 -1/32", meaning a little loose is ok but too tight is not. Better to have the drawer box a little too small and shim if necessary.

To mount slides in an assembled carcase, cut a piece of ply to fit between the floor and top slides, screw them on then cut the ply down for the next slides down.

If the face of the drawer is not parallel to the cabinet face, taper it on the jointer or set the drawer box back and shim between the box and applied front.

With Accurides, the cabinet members have horizontal slotted holes and the drawer members vertical ones. Use only the slotted holes until the drawer is fitted, then add fixing screws.

Blum Tandem and similar slides are much more forgiving and adjustable in three dimensions with the right clips, so if you have more money than time...