Worked off day shift Sunday, so I have about three days to get after my whack of SYP. When I first stacked my logs up, I scaled everything according to the Doyle Scale/little end and all that. I marked everything so when I started cutting I could compare. So using my new handy Woodmizer scale card:
(https://forestryforum.com/gallery/albums/userpics/34007/IMG_20150127_053930_187.jpg)
I scaled the boards that came off the mill yesterday and nearly every log yielded almost double in lumber than what I had scaled. Is this common to yield more lumber than log scale? I remember a post by drobertson some time back about overage. Is this the situation he was talking about?
That being said I managed to cut 312bf yesterday. Not a real blistering pace, i realize but the learning curve is straightening a little. Going to prestage a bunch of logs today on bunks so I can roll them on instead of stopping and loading after every log. Happy sawing all!
Yes, a good sawyer will exceed the log scale in board yield. If I remember right, Doyle uses a formula that basically figures a square in the small end of a log to calculate the board footage. Does not account for any boards from the four sides outside the square. This is why the over-run is greatest on small logs as even one board from the side represents a significant proportion of the total lumber. As the logs get larger, this proportion drops, and so does the over-run.
I have averaged about 1.3 to 1.4 actual scale versus log scale with Doyle.
Quote from: WDH on January 27, 2015, 07:39:10 AM
I have averaged about 1.3 to 1.4 actual scale versus log scale with Doyle.
As WHD said it runs about 1/3 overcut. I scaled / checked hundreds of thousands of BDFT of logs / lumber all on Doyle scale. If you stay in straight logs between 10" and 20" it will run up to 50%. I was taught that the Doyle scale was designed that way so the sawmill could "come out" on millions of bdft of logs including some crooks some defects. You are looking at a small select whack of logs, which makes your "overcut" look a lot better than it would if you had 10 loggers dropping 3 truck loads each a day on your yard.
When a customer asks me to scale his logs, I use the International 1/4" scale, then add 20% and it comes out pretty close.
Keep in mind that the 3 log scales were made for the circle mills years ago, which remove quite a lot more wood in the sawdust
UT,
I'm finding the same thing to be true with the overage I get out of my logs. Part of my problem making production is trying to save every 1X4 I can out of the side lumber and it is quickly becoming obvious some aren't going to be worth it.
I have been cutting around 200-500 bf at a time, usually 3-4 hours. I find most of my time is used setting up, moving boards, shifting the cant, etc. Obviously I'd be able to cut more with a good helper but I'm cutting by myself. I am learning the tricks required. Such as staging the log closer to the head so I don't have as far to walk each time, cutting several boards at a time before removing them from the mill for the same reason, not lifting the head as high so it gets back on the next cut faster, etc. These old timers here do these things and many more without even thinking about it. Us new guys have to think about every step and make a lot more steps than the older wood warriors.
Keep up the good work and have fun. Be careful of the gremilns.
The Doyle scale "punishes" the small log sellers. As the logs get larger the Doyle and Int'l scales yields get closer to each other.
My suggestion to you would be scale the same logs using both the Doyle and the Int'l scales and then compare those numbers with what you actually sawed.
For the purchase and sale of logs in all the New England states it is highly recommended that the Int'l scale be used.
Some buyers have the saying or adage, buy on Doyle and sell on boardfootage, especially when small logs are involved.
I've gotten overages of very little (long tapers or door stops hurt yield) to up to 37% overage using the Int'l scale.
Gerald
I only scale logs for curiosity because I bill by the bf sawed. I find that the smaller the log the greater oversaw and I probably average about one third over.
I don't often compare scale to actual output, but I would say I'm around 120% of Int. 1/4", but I edge really hard, as I don't have a lot of use for waney lumber.
If anyone has in-depth interest in the background of different log scale rules, then this .pdf might be interesting reading.
Compares many, and describes their history and calculations be it formula rule or whatever.
A Collection of Log Rules
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr01.pdf
...if I remember, aren't the scales (Doyle, Int'l) based on 1/4" circular saw blade kerf, whereas most band saw blades have 1/8" kerf? So roughly, for every 4 boards of 1" thickness, you "lose" 1 board to sawdust on a circular saw, whereas you only "lose" 1 board to sawdust for every 8 boards sawn using a band saw. The way I look at it, every 16" cant I cut yields 14 boards, whereas a circular saw/Doyle,Int' scale) yields 10 boards. Depending on board width and length, that's a pretty big difference and ends up being about 1/3 more, as has been discussed. Am I close? All the best, Rob.
Quote from: 78NHTFY on January 27, 2015, 10:43:49 AM
...if I remember, aren't the scales (Doyle, Int'l) based on 1/4" circular saw blade kerf, whereas most band saw blades have 1/8" kerf? So roughly, for every 4 boards of 1" thickness, you "lose" 1 board to sawdust on a circular saw, whereas you only "lose" 1 board to sawdust for every 8 boards sawn using a band saw. The way I look at it, every 16" cant I cut yields 14 boards, whereas a circular saw/Doyle,Int' scale) yields 10 boards. Depending on board width and length, that's a pretty big difference and ends up being about 1/3 more, as has been discussed. Am I close? All the best, Rob.
Very close, and the reason I consistently talk about the virtues of a Sash Gang. It stretches band saw blades in a frames and allows multiple 1/8 cuts in one pass. This allows for the reclamation of 1 to 2 boards per log.
Buy logs by scale. Custom saw by bdft sawed. That is unless you are running a charity. Over the long haul the scale will keep you profitable. You will hit nail, logs that are rotten, lumber that twist or splits for reason unknown to man, and all other sorts of misfortunes. When you are counting lumber from logs you have to count lumber sold to determine actual yield. It only counts if you get money for it.
Thanks to everyone for the responses. I cut two logs today that scaled 75 bf Doyle and yielded 148 bf of lumber. Very pleased. I had a slow day because I started the day by throwing together a log deck. I was by myself today so rigging and such took alot of time but overall a productive day.
(https://forestryforum.com/gallery/albums/userpics/34007/IMG_20150127_101541_898.jpg)
You did good. smiley_thumbsup
I sawed some nice, older growth, shortleaf pine yesterday. The tree was 22" in diameter. Here is a pic of the 2nd 8' log.
(https://forestryforum.com/gallery/albums/userpics/14370/IMG_0890.JPG)
Quartersawed the first three 8' logs. Total yield from the 3 logs was 312 BF. Doyle scaled 216, and International scaled 271. The over-run on Doyle was 1.4 and the over-run on International was 1.15. Got 7 boards that were 15" and wider.
(https://forestryforum.com/gallery/albums/userpics/14370/IMG_0891.JPG)
(https://forestryforum.com/gallery/albums/userpics/14370/IMG_0892.JPG)
It's heavy too. Building or selling?
Selling. Will kiln dry. Farm tables are very popular with the Ladies right now, and this wood will be exceptional for that use. Hard to find quartersawn, older growth (tight rings), kiln dried, pine that will plane out to a full 1" thick. But, you will be able to find it at Hamsley Hardwood :D.
I'm building Magic. Bought my mill strictly to build my own house. Can't tell you how excited I am that I am going to get a little more yield out of my whack.
WDH, You made some nice lumber. That log sure is nice and straight. I have several large logs with offset pith. I wonder how that will effect my yield. Do you generally get more scrap out of severely offset pith logs? I am suspending milling for a few days till I get my lumber shed built. I have to edge a few boards today and dig some post holes. Happy milling!
Oh No, Hamsley Hardwood is selling Softwood. :D
Quote from: Magicman on January 28, 2015, 08:35:13 AM
Oh No, Hamsley Hardwood is selling Softwood. :D
You just had to say it! 8) 8) 8)
Well, I did smile when I did it. :D
Just wanted you to know that I have a soft side, too.
Ah ha, you slipped out of that one. smiley_thumbsup
When your soft you can be slippery. :D :D :D
Quote from: WDH on January 28, 2015, 09:11:33 AM
Just wanted you to know that I have a soft side, too.
What chu talkn bout Willies? ;D
I figured I'd ask here rather than start a new thread.
The sawmill I buy from has me scale the logs as per below.
Measure both ends inside the bark on largest and smallest measurement and then average. This is done in centimeters.
The calculator they use takes the two end measurements and calculates cubic meters based on log length.
Is anyone familiar with this method? I know nothing about it.
I could copy and paste the formula they have in the excel spreadsheet but I'm not sure if is proprietary or not.
Sounds like this is just computing your log as a cylinder with one diameter (from the average of the large and small ends) and the length.
Here is one for you...
(https://forestryforum.com/gallery/albums/userpics/39553/Log_Scale~0.jpg)
The only time I look at the big end , Is to look for rot. ;D