what is a 4/4 board

[Okrafarmer]

So I'm guessing that it is one of those things where the meaning and purpose behind it has changed somewhat over time. I guess in the old days they cut a lot of lumber thinking in terms of quarters of an inch-- quite possibly the old time circle mills couldn't adjust any finer than that? So it was a matter of how many quarters of an inch did you want-- how many pulls on the lever to set the log over, or something like that? And the terminology continued on beyond when it could have been abandoned because it was entrenched both at the sawmill and at the manufacturers, maybe.
.............

Okra
Don't think you have it quite right there.    ;)
Maybe just a WAG?
But ok if you want to believe it.  ;D

Well, that's why I used so many question marks and words like "I guess" and "maybe."

[Ron Wenrich]

As long as you're doing WAGs.  My grandfather was a carpenter.  He came up around the turn of the last century.  Educational standards back then were maybe an 8th grade education.  He was a cabinet maker and a carpenter.  I asked him one time why he became a carpenter, and he told me he understood fractions.  Apparently, a lot of guys couldn't handle fractions, so they went in to other types of work.

It could be that the cabinet makers are the ones who talked in quarters, and the mills simply accommodated the market. 

[Bibbyman]

When I was a young man I ran a hay crew putting square bales in a barn for an old man.  We visited a bit while we worked.  He told that when they built a new barn in neighborhood,  he got to work in the shade marking out rafters and such because he was the only one that could read, understand and use a carpenter's square.

I worked for 33 years in the Engineering Department.  One time I had to go down to the factory floor and find out how come a part was always coming out wrong.  The dimension was something like 4.375 was always off.  I talked to the guy making the part.  He had no concept of decimal units (maybe fractions either). He pulled the tape out of his tape measure and said, "I only know the big marks.".   

They actually had all new hires go through an in-house remedial math class including reading measuring devices.  This wasn't the old days..  They were still doing this training when I left in 2005.  Many of these people had a high school education.

We still do a lot of business with people that can't understand board feet.  You explain and they don't even try to understand.  "Just tell me if I want to build a wall 8' tall and 100' long how much it's going to cost."

[Okrafarmer]

We still do a lot of business with people that can't understand board feet.  You explain and they don't even try to understand.  "Just tell me if I want to build a wall 8' tall and 100' long how much it's going to cost."

Maybe a little bit more for them than for most folks. At least that would be the temptation for me.

[beenthere]

Ron
Had a personal friend who did a lot of sawing and he said he always worked in twelfths of inches when sawing logs on circular saws. Said it was easy (once learned) and included a number of shortcuts. I think it is also used in grading hardwood lumber to calculate surface measure and cuttings. But am not exactly sure how.  This guy was behind the publication of Lunstrum's on Circular Saws that is so often referred to and read.

Now with digital displays and computer control, the use of fractions is likely less.

[Ron Wenrich]

They do use a lot of 12ths in the grading of lumber.  You take the length in feet and the width in inches, and you come up with a number called cutting units.  You need a certain number of cutting units in certain grades. 

For FAS, you would need 10/12 of the board in clear cuttings.  For a board with 4 bf, that would be 40 cutting units.  You are allowed an extra cut, but you have to get 11/12 of the board, and that 4 bf board would need 44 cutting units.  They also limit the number of cuts you need by each grade, and they have a minimum allowable size.  But, you can get a general idea how the 12ths come into play. 

Each grade has a different amount of cutting units.  FAS 10/12, 1 Com 8/12, and 2 Com is 6/12, 

As for computers, our setworks display in fractions.  No need to worry about decimals, as the chip coverts that over for you.  Mine goes down to the closest 32nd.  I can adjust my sets by any amount I want.  Same goes for target size.  Decimals would drive me nuts. 

[DR Buck]

Now if “Joe Smoo” comes in with a log,  I’ll talk to him about how thick he wants his 1” lumber. 

I usually have that same discussion once a week.  ;)   After I find out how thick he wants his 1" lumber I ask him how thick he wants his finished dried and planed board to be.   Then we decide how thick his 1" board  should be.  :D

I uses Wood-Mizer Accuset II  and 1" is 1" all the way down.  Accuset is preset for the kerf and does the calculations.

[Bibbyman]

 Accuset is preset for the kerf and does the calculations.

The kerf setting on the Accuset can be adjusted to account for different band thicknesses and set.  We have ours set at .100 and it works pretty well for any band we use.  

I'm told that some Accuset users still have it set at .000 and either don't count the kerf or make up for it in the "drop" settings.

There is some logic behind their choice.  For example, we have our "drops" set at 1-1/8" with a .100 kerf setting.  Thus, when the head drops for the next cut it drops 1.225 total and then displays in fractions of 1/32 of an inch.  It always display some odd fraction. 

On the other hand,  if you set the kerf to .000 and then set the drops to 1-1/4",  the head will drop 1.250 and thus the fractions will be in 1/4" increments and the numbers will added up easy.  The resulting board will only be .025 thicker.  Close enough for horseshoes and hand grenades.

[Magicman]

I had to input my kerf setting in my Simple SetWorks.  That way, using my cheat sheet to determine my starting point, my "dog board" is always the same as the others.  Of course, my sheet is designed for lumber that I normally saw.  Throw in some oddball thickness, and I'm back to  square one.   ;D

That Accuset must be one sweet baby.  I hope that my SetWorks doesn't break and I have to fine out.   :-\

[paul case]

are you fellas with accuset and simple setworks doing the math anyway?
i find that the more i cut the same thing the easier it gets but i still have a oops once in a while. pc

[Magicman]

When I'm sawing it's all second nature anyway.  I seldom have to check the sheet.  Anyway, there are a few figures that I have to fudge.  I've found that since I did the sheet, they are a bit off on a couple of dimensions.  I'll just adjust the figures when I do a new sheet.

When sawing dimensional framing lumber, I don't have to look at anything.  I can mix 2X4's and 2X6's and still hit the mark.  Of course, that is my "bread and butter".   ;)

[Meadows Miller]

Gday

An Inch is 25.4 mm so we have been sawing scant here since the 60s that adds up to nearly 1/2 an inch short on a 300 or 12 inch board Mate  ;) :D :D :D 

I saw in either inch or metric scales i have found inch easier to calculate even though the numbers you are pressing on the setworks are metric  ;) :D :D :D things like pallet and garden sleeper timber are good as you can work in inch  ;) and when i was looking into doing pallet timber by sawing cants and then passing them through a band resaw i could cut the cants spot on inch sizing  ;D   and with the thin kerf of the band still be within the  tolerance even when cutting things like deck boards but the company's  i was going to be dealing with didnt mind getting billed for 25mm boards that where resawn to 24mm thick as long as they where accurate  ;) ;D 8) 

Another thing to consider is that most larger circular saws run a 1/4 inch kerf with allowances so the 1/4 inch rule  might have had something to do with sizing on manual carriages  ;) if yo had say a 3 sided cant on the carriage 12' thick  14 to 15 inches wide and you where starting your finish run you would have your start point at 13' and 1/4 if you wanted to do 5 passes to get 6x 12x2' boards with each pass  with a 2" dog board  ;) I have used that trick  when canting out and resawing on most mills ;)

Ultimately at the end of the day it is the costomer who dictates the sizing practice used  ;)

Regards Chris

[weisyboy]

by to looks of things one hand dosnt know what the others doing.

i have been cutting feedstock 4x1 and 6x1, tehy all want it cut 106mm x 27mm - 156mm x 27mm, i worked out by cutting this size (and i only get paid for 25mm boards) im losing 5% recovery.

im guna tel tehm either its cut to 25mm or i get paid the extra.

[sigidi]

by to looks of things one hand dosnt know what the others doing.

i have been cutting feedstock 4x1 and 6x1, tehy all want it cut 106mm x 27mm - 156mm x 27mm, i worked out by cutting this size (and i only get paid for 25mm boards) im losing 5% recovery.

im guna tel tehm either its cut to 25mm or i get paid the extra.

In this case, I reckon it is better to go to them first and find out what they expect before I cut it so I get paid for what I cut - just simple really ;)