Measurements

[Herman Family]

Is there some sort of standard for how inaccurate woodworking measurements can be?

I have been working on a fairly large and complex project and discovered that my depth gauge was 0.02" to 0.03" off, the square disagrees ever so slightly with the tape measure. This doesn't sound like much, but some of my cuts have to be very close to spec and I'm using two different machines (and measurements) to make the cuts.

Everything has been fine up until now because I haven't had to measure the same thing with two instruments. I had always used only one tape measure and regarded its measure as "truth". On this project I broke out the B&S electronic caliper, and a few other measurement tools. I'd put them away and stop all the trouble, but I have to make sure that some pretty tight clearances are met properly without a trial assembly.

Michael

[Edwin Pawlowski]

Depends on the cuts. if you are making a box that is 24 x 48 and the ruler is off (and you use the same one every time) you could end up with a box that is 23 1/2 x 47 1/2 and it will look and work just fine. If you have two pieces of wood 3" apart and have to fit a filler between, you better be pretty damned accurate.

Best to minimize the measuring tools and check one against the other to be sore they repeat. If all are off the same amount they will all work together. Squares are a different story. Heck, you could end up cutting a

54 degree angle when you really need a 36 degree. Then you end up with a 7 1/2 sided box. Ed [e-mail]

[John Flatley]

Ed,

You just HAD to get that 36/54 degree zinger in, didn't you!

:-)

Jack

[Michael Baglio]

Ah, the old 7-1/2 sided box... Otherwise known as "the 108-by-540".

Michael "Who needs metric?" Baglio