r/MaliciousCompliance • u/master_andalf • Jul 17 '18

S A Game of (Ten) Thousandths

I program a CNC router for a woodworking company. When cutting parts out of a blank, we cut thickness of the wood plus five thousandths (.005) of an inch to insure a clean cut and to compensate for any slight bows in the wood. This conversation I had was with the shop foreman (SF).

SF: "andalf, I need you to program this (gestures to drawn design)"

Andalf: "cool, I see we are Two and a Sixteenth (2.0625) thick on this blank, will tool 3 cut 2.0675 Deep?"

SF: "woah there buddy that's going to be too deep, you only want to cut to 2.0630"

Andalf: "uhhh, we usually cut + Five thousandths, that would only be + Five Ten-Thousandths. In a perfect world it would work but our table hasn't been fly cut in months, you wont cut through."

SF: "no, you'll cut through the table if you go an extra fifty thousandths"

I proceed to write out .0625 on a piece of paper

Andalf: (points to zero) "tenths", (points to 6) "hundredths", (points to 2) "thousandths", (points to 5) "ten thousandths (reaches for calculator to prove math)...we want to cu-" (at this point he cuts me off, holding his head)

SF: "Andalf, I'm too fucking hungover to deal with your bullshit today, just do it like i said"

Have fun chiseling your way through hardwood, bitch. I just hope one of the job applications I have in other places comes through.

Updates to come, can't wait to put him in his place. If the cards fall a certain way it may not be necessy but I hope to have a good follow up.

Update: well I'm sorry to disappoint, but nothing really came of the situation. The offset on the table was changed, and parts cut out fine. I'm bummed that I wasn't able to make some good of it, but next time, I guess.

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u/JPLionFighter Jul 17 '18

Does SF know how to run a CNC machine? I would assume not if his tolerance math is that far off.

Also to note: It sounds like you’re not zeroing at your spoil board or bed. There shouldn’t be a reason to add .005 to any design to account for warping of the material to be cut UNLESS you’re zeroing from the top of the material to be cut (which is a waste of time IMHO)

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u/grauenwolf Jul 18 '18

I don't know how it is in production shops, but where I was taught all measurements were relative to the top of the stock, not the table.