If you use Blum drawer slides, you recognize the number.
A few years ago, the school had their rummage sale and I purchased a case of Blum drawer slides. Two bucks for the box of ten sets or twenty cents per drawer. I still needed to buy the drawer clips but still... And finally I'll get rid of those drawer boxes that were assembled wrong.
Today I'm using the drawer slides to put drawers in the work bench. I dig out the class notes and build the opening 1-15/16" larger than the inside width of the drawer box. I install the slides in the bench and they don't fit the drawer box at all. Not even close. I go back over all the measurements. Everything is as intended.
I compare the drawer box sitting on top of the slides with some other cabinets. The drawer box and slide just doesn't look right. Then it hits me! The Blum slides are designed for 3/4" drawer box material and my drawer boxes are 1/32" less than 1/2". Aw Bat POOP!
I've kept a running S.O.P. of measurements, details, and clearances for fabrication conditions as I run into them. Every time I use a piece of hardware and it requires certain spacing or allowances, I write it down.
I find that trying to remember details can get me in a jam. Also, along the same lines, from every project, I save all the paperwork, drawings and lists. In the event I found some quick method, or procedure that made magic, I can go back and see the details that let me work out the problem instead of figuring it out all over again.
For planning opening sizes, I usually work from the dimensions that are pertinent. If there is a fitted supplement to go in a drawer, I'll note the size. Then any spacing for it's width. Then the drawer side thickness, and/or joinery to be used that will determine the overall width of the drawer. Once I have that, I figure the spacing needed for the opening, if side mount slides are used.
Of course, when using the same slides over and over, some of those dimensions become embedded. For example: For one type of full extension side mounts, I know they require 1 1/16" clearance. So my box will be 1 1/16" smaller than the opening. Once I start on the drawers and do a cut list, that figure plays a part in the rest.
>I've kept a running S.O.P. of measurements, details, and
>clearances for fabrication conditions as I run into them.
>Every time I use a piece of hardware and it requires certain
>spacing or allowances, I write it down.
Aw come on Paul! I'm doing this all bass ackwards! I built the drawer boxes wrong, so years later I'm putting a face frame into a HD garden bench that is my work bench to fit the slides that I bought at a rummage sale. No planning, just build the thing to fit the parts on hand.
Sort of like the Johnny Cash song about bringing enough car parts out of the assembly plant in his lunch box to build a car.