Undermount drawer slide tolerance question
rtilghman
| Posted in General Discussion on
Finally getting around to making a bunch of drawers for a new cabinet I’m building. Using undermount accuride slides with 5/8 poplar boards.
Cutting down the poplar I had milled I decided to do a test measurement on the width of a drawer. After calculating in various pending cuts (lock rabbets, etc) I was finding that my drawer was 1/32 too wide. This was strange, because I’m 100% certain my math on the test piece and measurements was correct.
Decided to check the material itself… bingo, 1/32 over 5/8 (so material is 21/32, not 20/32 or 5/8).
I don’t have a planer, so the question is whether I take all the new cut panels back to my lumberyard and have them milled to the proper 5/8. I’m sure they’ll make things right, it’s just a time and effort suck to haul the now 28 boards over to their shop and wait for them to be milled down.
So, the question is if anyone knows what the tolerance is for undermount slides (Blum, Accuride, etc) and whether an extra 1/32″ of material thickness will be an issue (i.e., binding, fit, etc)?
Thanks,
Rick
Replies
Your post left me with many questions.
First and foremost are the drawers already assembled or at least cut? The fact that you are considering having them remilled implies they are not and you mention many "pending" cuts. If you haven't made the final cuts yet why don't you just trim the front and back pieces 1/32"? If you have the wood remilled you will end up 1/32" short just as likely. Setting up a planer to remove 1/64" from scratch is very difficult to do.
If the drawers are already assembled removing such a small amount is relatively quick with a belt sander or even an aggressive RO since you a really talking about 1/64" on both sides.
Regardless most drawer glides can accept a 1/32" but I can't picture why it's important at all in an undermount drawer glide... Unless you really are referring to the nylon bearing side mounts that that attach to the drawer box on the bottom using a right angle piece of steel and sometimes referred to as bottom mounts although the track is actually a side mount.
I haven't used Accuride, but use Blum undermount all the time. 1/32 will not make a difference. And as esch wrote, sanding off 1/64 is easy. Make your box, and see how it fits.
I always make drawers a hair oversize, and then take off a few shavings to creep up on the fit. It's better than having a drawer too small, and trying to stretch it.
Hi there, thanks for the replies. To clarify, I've cut my material to length... the pending cuts are the lock rabbets... the dadoes on the sides, the locking part on the cross members. All the wood is otherwise cut to the "exact lengths" needed to assemble the drawers... meaning once I do make the cuts for the locking rabbets they will fit together to make exactly the size box needed.
So, I could just take all that cut lumber (28 pieces) back to the mill and have them planed down the extra 1/32 if needed.
While I could just account for that 1/32 by cutting my fronts and backs that much shorter, that solution won't address the issue (and might compound it). The reason is that the thickest material you can use for the slides (as prescribed by Accuride's literature) is 5/8". Cutting down the wood won't impact that number. Beyond that, the box itself has to be 1/2" less than the width of the cabinet, and if I cut down the fronts and backs I will reduce the width of the drawer which will take me over that 1/2". Given that the under mound slides sit just inside the drawer sides it seems risky.
So, all of this is the reason I'm trying to get some kind of definitive insight on whether undermount slides have a "tolerance"... like, they anticipate variability in stock, so the wood should be "5/8" but could be a little bigger. In other words, the slides have 1/8 or so of forgiveness at the top and bottom ends (as long as the outer and inner dimensions are as prescribed).
Make sense? Lmk any thoughts.
Thanks,
Rick
I'm going to spit ball here, having never used the Accuride undermount glides, but it my be that the thickness of the stock issue is not related to the sides but the front. My thinking is that a 5/8" thickness is what is needed to keep the drawer box flush with the frame anything more and it might stand proud. If that is the case I don't think a 1/32" gap is going to create a significant issue, but I don't know the other details of the cabinet construction. I will say I have never worried about that degree of precision with the Blumotion glides I use.
Great point. I've decided to just go with it and sand out anything that proves to be an issue. Here's to hoping you're right! :)
What model are the slides , there are many undermount accuride models and many are not dependant on material thickness or drawer width.
I've got two models. Most of the drawer are using Accuride's 3135EC slides (22" depth). However, I have one very wide drawer that's using Accuride's 3160EC (21" depth). That drawer is 50"+ wide, so it required a special slide to prevent racking.
The answer can be obtained by refering to fig.1 of the mounting instructions. Since the slides are mounted to the sides of the cabinet, you need to measure the inside cabinet width, substact it from the drawer width, divide by two this will give you the side clearance. You then measure the thickness of the slide side mount that gets screwed to the cabinet sides in the gap between the drawer sides and the cabinet and you will then know if there is an interference or a clearance. https://www.accuride.com/media/amasty/amfile/attach/773214413e47bedc66909b884af3c86a.pdf
Yeah, I did that, and it looks like there's slack, but that doesn't mean that slack is "usable". I've never done a project with undermounted slides, and the literature doesn't actually say "gap account for 2/16 slop", so I just don't know that going even slightly over the widest recommended thickness of wood wouldn't cause binding.
The track is mounted inside the drawer sides, unless I misunderstood something, how will the extra sides thickness affect the slide position and it’s functioning ?
Seriously, in making furniture 1/32" does not matter. Really.
Lol, I mean, there's a voice inside me that says that, but then I think of projects I've done with side mounted soft close slides where 1/32 really DOES matter and I'm like... if I don't fix this now, and I assemble and glue these f-ing drawers, and this goes sideways, after having to have all that wood milled to 5/8... :)
No way all of those cut parts come out of a planer perfect. With the assumption that you have some just-in-case extra material on hand, make up a drawer and try it. (Cut the parts to the new correct length.) If you wind up needing a little room underneath you can always cut or rout in a rabbet to fit the slides.
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