Hoping for tips in squaring up a cabinet

[sailor55330]

Hi,

I'm in the process of building a stand with drawers for a 10" bandsaw. I'm using Tom Clark's book and method. I built a first carcass and it came out very out of square and I checked all my tools and both the miter saw and the cutoff sled for my table saw were off. I recalibrated the tools and started again. I verified using 3 squares and checked every piece multiple times. The parts were all 100% square and of equal size (sides, faceframes, other parts as necessary). When I went to put it together, I still ended up about 1/32-1/16" on a 22x16 cabinet. I'm not sure where I'm going wrong. Does anyone have any tips or suggestions to help with square assembly? I think I can live with this one as it's only a shop cabinet/tool stand, but I'd really like to get better.

Thank you in advance to anyone who offers advice.

[cabinetman]

I don't know what construction (joinery) methods you used. If the sides are the same and square, and the bottom is square, and whatever you used to connect the tops of the ends were the same length (also relative to the bottom), then the cabinet should come out at least as a parallelogram. Using a back, and a faceframe (optional), and a squaring technique (described below), should bring the carcass to square.

During assembly, if the bottom left corner to the top right corner measurement is equal to the top left corner to the bottom right corner, it should be a square assembly.

.

[leehljp]

A Japanese friend taught me the value of a smooth, level work table for assembly. He had one with a steel top 1 meter by 1 1/2 meter and smoothed (machined) to a tolerance of .001 across in all directions. Of course I can't afford that kind of table but he did impress on me that even a "relatively" smooth and relatively level 2x4 table top can influence warp in building "square" objects.

Not saying that is your problem but he made a believer out of me on that.

[sailor55330]

Thank you for the responses.

Cabinetman, I do understand your post and my pieces were as you described, yet I was still off just over 1/32 when I measured diagonally, so I'm not sure what happened.

Leehp--good advice. I assembled on the cast iron saw top with a piece of tempered hardboard as a protective cover. It's not perfect, but it's the best I have.

I guess I'll keep playing.

[chopnhack]

Measuring diagonals with a tape measure is often a hard way to get repeatable numbers, and if you are just off slightly with how you are hooking the tape you could easily be off by a 32nd.

What method are you using to determine you are off by a hair?

[toolguy1000]

one of the "tools" i find valuable in cabinetry is a very accurate crosscut sled. how accurate is yours? have you checked it with a square that has been verified with the "2 line flip" test. FWIW, and this may not be your problem, i pulled together a CC sled and then used this technique to build a really accurate CC sled. the difference was night and day.

https://www.ridgidforum.com/forum/t13945/

niki was an excellent woodworker and a terribly creative and sharing individual. try this for a sled. if you follow his instructions carefully, you get something like this that's a joy to use:

[LCHIEN]

having square cuts e.g. perfect 90 degree cuts helps a lot.
USing assembly squares helps a lot too,
http://www.rockler.com/product.cfm?p...mbly%20squares




I made my own - see post 11 here: http://www.bt3central.com/showthread...sembly+squares

Miter clamps like these can be used to set corners and T-intersections dead square while gluing and fastening.
http://www.rockler.com/product.cfm?p...=miter%20clamp


A good set of engineers squares like this helps, too to verify that your clamped assy is square. also good for checking dill press bit verticality, jointer fence, miter fence and TS blade at 90 degrees.

[All Thumbs]

Join the two sides, top, and bottom using whatever method you're using (pocket screws, dados with glue, biscuits, whatever). Assemble the cabinet so the front is facing the top of your bench. The back (which isn't installed yet) should be UP.

Once those first four pieces are joined, check for square by measuring the diagonals w/ a tape.

If an adjustment is necessary, squeeze the diagonal which is too long, and use clamps and blocks of wood to lock the four sides into square on the bench.

Once you have it secured in a squared-up position, install a back with glue and some staples or brads. Once the back is secured, the cabinet will keep square.

[toolguy1000]

....Once the back is secured, the cabinet will keep square.....

provided the back piece is, itself, square.

[JimD]

I agree with All Thumbs. I usually just accept the amount out of square you describe. All the commercial cabinets I've checked were out this much and all my houses have been out of square at least this much. But if I want it square, I arrange my clamping so that I can measure diagonally before the glue is set and use a clamp across the long diagonal to square it.

The back does not have to be perfectly square but I try to use the factory edges on two sides of the back. As long as you have enough clearance around the back (mine typically go in a rabbet) you can use the back to square the cabinet. Once you pull the cabinet square, if the back won't fit you can also trim a little so you can still install it. Glue and staples is my typical installation method and the clamp on the diagonal comes off after the glue is set.

Jim

[cabinetman]

An out of square of 1/32"-1/16" is nominal, and could be attributed to many things. What is the case is most likely a parallelogram situation, which forcing the cabinet to square can be done physically, and hopefully it will stay that way. All due care can be employed as to having all the carcass parts square, and sized to provide square. I will say that there is no comparison to machining dadoes and rabbets so the parts will fit like a puzzle. Even butt joints can do this by aligning all the edges before fastening.

Fortunately, with euro hinges and their extensive ability to be adjusted, that little bit of out of square will not be visible. It's not enough to affect drawer movement.

Using pocket screws can likely allow enough misalignment more than any other method. Once a cabinet is together, and if all was done to produce a square carcass, it can easily be nudged out of square by merely lifting one corner. This will be evident if a series of drawers have been installed or multiple doors, you'll see the doors not line up, etc.

If due care has been taken up to the time you are installing, shimming and leveling will prompt the case to its best condition of alignment. This is the final time to check for square, and viewing many fitted parts (like door and drawer front edges) will provide the visual aspect to make things right (or close enough).

.

[Shep]

1/32 = Square in my my shop.

[sailor55330]

Thank you all for the tips and advice. I did try the 2-cut flip method and everything seems dead on (can't catch a fingernail either way).

I think I'm going to give the assembly squares a shot, but since I dont' have a planer, I will probably have to buy and hope for accuracy.

Again,

Thank you

[leehljp]

I will say that there is no comparison to machining dadoes and rabbets so the parts will fit like a puzzle. Even butt joints can do this by aligning all the edges before fastening.

.

You know, this is something I was taught a long time ago, but because living in Japan for so long and knowing that I would have to disassemble most large items I made for shipment back home (space wise), I haven't used it and forgot about that. I need to incorporate that into my plans for book cases, desks and other things when possible from now on.

Thanks for the reminder.

[Brian G]

Some things I've learned, and mostly opinions:

Equalize clamp pressure. Sometimes that "one more turn for good measure" would have best been left in the muscles, and results in an out of square alignment.

Balance your clamps. If you have all of the clamp heads on the same side, it can pull things out of square because of the weight imbalance.

Glue is slippery. What is square in the dry fit ends up slipping out of square in the glue up.

Bad glue or uneven application can muck up a glue up. If one half of the joint is glue deprived, it may not hold up square.

We sometimes worry too much about squareness. If you can't look with the eye and notice it's out of square, and it doesn't rock, and it's not going tip over, does it really matter (within reason)?

Wood moves. I made a table that is square in the winter, but not square in the summer. It could have been the other way around, and there isn't a whole lot I can do about it. I can't tell when it's out of square without using a square, it doesn't rock, and it's not going to tip over. I'm fine with that.