Woodworking Math

[Brian Kent]

I am beginning to get the hang of some woodworking math. If anyone could add to my math knowledge, I would appreciate it.


4/4 = 3/4

6/4 = 1-1/4

1 Thou = The thickness of bragging rights for a smoothing plane

7’ 11-3/4” = the length of a board that needs to be 8’

2x4 = 1.5x3.5

1/64” = accuracy goal

1/8” = daily wood movement of board fitted to 1/64” accuracy

[Larry Fox]

Here goes for me. However, I need to go to some higher math and throw in a few variables.

0 = the number of pencils or tape measures within reach at any given time.
X - 1 = the number of thing Y you have when you absolutely need X
X + 1/8 = the length of what you are trying to clamp if your clamps are X inches long
2X = the volume of the contents of my dust collection bin (whose volume is supposed to be X) before I realize it is full, backed up into the filter housing and need to empty it.
10X = the amount of time it takes me to actually do something when I extimate it will take X (same formula applies to the cost)

[Doug Palmer]

I've cut this board 3 times and still too short!

[Bobby O'Neal]

I've cut this board 3 times and still too short!

Well put. Sometimes when something fits just a little too loose, I make another pass or two through the planer.

[Brian Kent]

That's some good algebra, Larry!

[Ron Kellison]

As a breed, we woodworkers tend to devote enormous mental energy towards working to minute tolerances that have little relevance to the material we regularly turn into sawdust, chips and occasionally something worth keeping. I've become fond of less precise terms such as "skosh", "smidgen" and "hair", the latter having several derivatives usually related to colour. According to Wikipedia, human hair can vary in diameter from 17 to 180 µm (0.00067 to 0.0071 inches) which should be an adequate alternative measurement standard since our material moves more than that on a daily basis. Perhaps I have too much time on my hands...

[Larry Heflin]

I've experienced every one of those math examples. It's funny reading about it here. I don't recall laughing at the time I was looking at that math in the shop.

[Ken Fitzgerald]

I've experienced every one of those math examples. It's funny reading about it here. I don't recall laughing at the time I was looking at that math in the shop.

Was that before or after you threw something across the room?

[Keith Westfall]

Well put. Sometimes when something fits just a little too loose, I make another pass or two through the planer.

Bobby, that is hilarious!!

[Curt Putnam]

Loved it. Thank you.

Now, for the older among us who can remember the early days of computing.

2 + 2 = 5 for very large values of 2 and very small values of 5.

[Brian Kent]

Power tools multiply.

Hand Planes and Routers multiply exponentially.

[Rich Engelhardt]

Festool Wants /Harbor Freight paycheck = me....

[Paul Wunder]

Thanks, fellas. I needed a laugh this morning.

[Tom Cornish]

.5 of a sawblade's width of intended cut = 1.5 sawblade's width of actual cut

[Jeff Monson]

21 3/4" measurement for needed cut = 20 3/4" of actual cut......This is especially useful on highly figured wood, or on the last piece of any given wood you have at the time. The final dimension of the project is then reduced by 1".