Problem With Cabinet Build

[John Hays]

Hey all, I'm not much of a furniture builder, so I'll just put this out there for those of you who are.

I'm working on some shop cabinets using a ShopNotes design (see below) and one of the cabinets I built has quite a bit of a twist to it, meaning that the top-right-rear-corner and bottom-left-front-corner do not line up vertically with the rest of the cabinet. The top corner pushes in and the bottom corner pushes out.

As far as I can tell, none of the wood itself is warped and all the pieces are the correct dimensions. Does anyone have an idea of what might be going on here and how to fix it?

Here's the design in question:

253804

Thanks

[Brent VanFossen]

Is it twisted before glue-up or after?

[Lee Schierer]

I would suspect that your panels are not cut square. Check the diagonal measurements on each panel. They should all be the same. If the shelves are already glued up lay them on the top of your TS. Do they rock when you push on diagonal corners?

The secret to cabinet making is that all pieces have to be cut square. The runners along the sides of your panels have to be exactly the same length if they vary even a thirty second of an inch from one to the next you will have problems when you assemble it. For identical pieces I like to use a stop block on my miter gauge and cut all the pieces of a given length without making any adjustments.

[John Hays]

Brent: The twist happens after assembly.

Lee: I cut everything on my crosscut sled (used a stop block where I could) and did my best to make sure that all parts were as accurate as possible. But as we all know, no matter careful you are there's always something that gets out of whack along the way. I'll take it apart and check for rocking and what not.

The funny thing is, this is one of 9 cabinets that I've built in this style over the past month and none of the others have any alignment problems, so I'm kind of confused as to why this particular cabinet decided to act up.

Thanks for the suggestions and I'll let you know what I find.

[Bill ThompsonNM]

Could be one of your holes off a little bit also If slanted or vertically off it might twist as you tighten the bolts

[Jim Matthews]

Let's define some terms here;

when you say the top right corner and bottom left corner do you mean the top most part of the front or the back?
The bottom left corner is on the lowest shelf in the front?

By vertical misalignment, I take it you mean up and down, toward the ceiling and the floor?

What you're describing is compounding of errors caused by machine misalignments.
Do you have a block plane to make minor adjustments?

Even erector sets include a little "slop" to get things together "on the square".

[Phil Erup]

Oversize the holes for the carriage bolts a bit. Assemble the table but don't fully tighten the nuts. Set the table where you want it and wiggle it into a solid footing. Tighten the nuts with some weight on the shelves to hold the fit to the floor.

[John Hays]

Well, I might have found the problem today. I disassembled the cabinet and noticed that every one of the posts had a slight twist to them (some more than others), but the shelves were still fine.

When I purchased the 2x4s, a few of them were a little moist (as most big-box-store wood is), but I've never had much of a problem with them before. Even after sitting in my shop for a about a week, they were still a bit damp when I cut them. So, my guess is they twisted as they dried out.

I just cut 4 new posts, which seem to be adequately dry, so we'll see if those work any better.

Bill & Phil: I'll try those suggestions if the new posts don't pan out, thanks. :)

Jim: I thought the words I put in bold were pretty clear, but just in case... top-right-rear-corner refers to the back and bottom-left-front-corner refers to the front. And yes, you are correct with your understanding of what I meant by "vertical". Sorry for any confusion. As a side note, the guys at ShopNotes came up with a pretty solid design for these cabinets, which I discovered allows for plenty of "slop" and they still remain pretty square when built.

Thanks again for everyone's help, I'll report back with an update as soon as I can.

[Jim Matthews]

Well, I might have found the problem today. I disassembled the cabinet and noticed that every one of the posts had a slight twist to them (some more than others), but the shelves were still fine.

When I purchased the 2x4s, a few of them were a little moist (as most big-box-store wood is), but I've never had much of a problem with them before. Even after sitting in my shop for a about a week, they were still a bit damp when I cut them. So, my guess is they twisted as they dried out.

That makes a good deal of sense.

I'm thinking you might be able to correct for varying degrees of twist in each leg, fitting them one by one.
Do you have assembly squares? You could make a few from plywood. Cut a hole in each corner for a clamp to fit, and use them to assemble each leg.

I didn't realize you were using Borg lumber.
That stuff is still drying when it hits the rack...

[John Hays]

Jim: The way the legs are cut and how the whole system goes together, it's just easier to cut 4 new legs and call it good. LOL And yeah, borg lumber is pretty much all wet, bowed and twisted crap. Even their MDF is horrible, but I can't afford the gas it would take me each time I needed materials from the nearest lumber yard. As it is, I'm looking at $1,500+ to complete this project... which is about $1,000 too much IMHO.

Having said that, I have good news... the new legs I cut seem to have fixed the problem, so crisis averted! :)