Sequence of sawing

[appleseedtree]

Hello Forum. I'm a pro arborist but a rookie sawyer. I've bought an old LT40 non hydraulic and so far just completed one project sawing 5 small locust logs. My current project is on the mill, an 18' x 36" pine log. I've been around it once to trim it up and I've  taken a few 1" boards off of it.   One of the most perplexing things to me is knowing when to saw another board off the top and when to roll the log. It's currently a 25 x 26" cant with rounded corners. I'm looking to get as many 2 x 12s as it will yield. I thought I'd make a couple of 12" wide cants and then make the boards. The top and bottom boards would have lots of wane but I guess I could trim that off. Question is, can I set the two 12" wide cants side by side and saw both of them at the same time or is it better to saw them one at a time?  Not sure if the guides would even allow a 24" cut.
Advice appreciated

[ncsawyer]

In my experience, when sawing your log down to the desired cant size, you want to end up with a cant that has equal amounts of sap wood on either side of the pith.  The sap wood is stronger than the heart wood, and boards tend to warp "toward" the sap wood or away from the pith, if that makes sense.

So on a 12 inch cant, you would want to mill flitches off of the top of the log until you get down to about 6 inches from the pith, then flip over and mill flitches off of the log until you get down to the 12 inch cant, resulting in a 12 inch cant with about 6 inches of sap wood on both sides of the pith.  This gives you the most stable cant, assuming the pith is centered in the log, and your lumber should stay good and straight.

You mentioned sawing two 12 inch cants from your large log.  This will probably result in splitting the pith or at least yield "lop sided" cants with significantly more sap wood on one side of the pith than the other. In this situation you will probably observe the cants "curling away" from each other as you split your 24 inch cant into two 12 inch cants.  If this happens, all of your 2x12's will have a bow in them.

The best approach, in my opinion, is to cut 2 inch fliches off the sides of the log until you have one 12 inch cant with the pith centered.  Resaw flitches into 2x12s and mill 2x12s from the cant. You will will end up with about the same yield as two 12 inch cants, but much higher quality lumber.

[Magicman]

Absolutely and very well described ncsawyer.   

I always determine my target cant before I make the first face opening.  It's kinda like looking at a road map before you leave home because it's good to know where you are going before you leave. 

I will also echo the statement about "never splitting the pith".  It should be centered within the targeted cant.   

[WV Sawmiller]

   Well described by NC and MM. Yes you can often cut multiple cants at the same time when cutting the same thickness lumber but that is usually when cutting something like 2X4s or 2X6s or such.

    You will still get plenty of 2X12s off the side lumber before getting your 12" cant. The total yield will not be significantly different but cutting 2-12" cants and splitting the pith would sure give you lower quality results which you don't want.

   Good luck and welcome to the FF.

[appleseedtree]

Wow. Thanks for that. I was really unsure until I read your posts and I'll definitely heed the advice. I figure after sawing a few dozen thousand bf I'll know more!  At this point trying to avoid the big mistakes and get some usable lumber in the process.  And I have to say, between  calling the dealer for tech advice, speaking to friends, and researching the internet including you tube, I always end up at Forestry Forum for the best advice!
Thanks to all the contributors and sponsors!

[terrifictimbersllc]

Agree about taking a 12" cant across the center and sawing that into 12" wide boards.   

Just a slightly different way of saying things in case it is helpful.

Another way to think about your question of how to saw is to produce boards with the figure balanced in the width.  When you look at the grain pattern it is balanced from the center out to each side, the grain pattern is not cut down the middle.

But you'll have a lot of wide boards above and below it so what to do if you want 12" not 24" out of them.  Best performance for the 12" is to take a 12: out of the center of them and leave 6" on either side.  You'll need to decide how bad you want all 12's or fewer better performing ones.

I usually clean up the log like you say(often then putting on a fresh blade) and then cut deep for example 6" x 24 off of either face to leave the 12" cant.  Then come back to the 6x24's and cut a 12 out of the center and then cut this into 2x12s. This limits the wide sawing to 2 wide cuts in clean wood with a fresh blade in what will be the edges of the main 12" cant. 

Cutting wide with no waves is demanding on sharpness of blade. This goes to your question of whether to cut two wide cants side by side. I would never do this with 2 12" cants even if I had two of them on the mill.   Myself I only do this if the two cants are narrow say 6"+ 6", not too tall,  and don't need individual treatment because of having a bit of bow or something else, for example.  Cutting 12's one at a time rather than 24's you can go faster and expect flat cuts with less care.

[Magicman]

Since I do not sell/market lumber my setup is always geared toward the customer's cut list.  I have learned to not be concerned with whether I could have maybe squeezed another board out of the log.  I am better off setting my cant targets based on the cut list.   

[moodnacreek]

All good advice. Trying to keep the heart centered even when it's not there is the thing. On soft, straight or short ,fat pines you may be able to cheat and go faster as you will see.

[samandothers]

Your questions have been covered.  I just wanted to say welcome!

[Magicman]

Centering the pith can be quite elusive when sawing off center logs so you have to remember which center is important.  This illustration is what is regularly encountered when sawing SYP. 


  
This is a badly off centered log so I turned it so that it was centered horizontally.  The red chalk is for reference for the pictures.  I was illustrating how I determined my target cant.


 
Here I have made my opening face cut and taken two slabs to reach my target.  The slabs will be edged to the cut list.


 
Turned 90° and sawed down to the red line on the right which is my cant target.


 
Again turned 90° and slabs removed to reach my cant target which is then sawed into three 3 5/8" cants.  Notice that the pith is centered within the center cant.  This was not by accident.


 
Turned the final 90° and the "saw through" begins.  Notice what happened to that original off centered pith.   ;D

[pineywoods]

What's not so obvious but very important in Magic's demonstration is yield. I count 21 cuts through the log, for which he gets 36 dimension boards plus 6 slabs which will yield another 8 or 9 boards in as many cuts. approximately 45 pieces in 30 cuts.
Explains why MM has cut over a million board feet and turns out more lumber in a day's sawing than I can in 3 days.

[firefighter ontheside]

Welcome Appleseed.  I've been a member a few years, but have only had my mill for a few months.  I have not cut a thing on it yet.  Still getting it set up.
I have several great big yellow pine logs ready to be cut and am happy you asked this question.

Thanks Magicman for the great pictures.  I'm planning to mainly take 6x6's out of my logs, but I will follow your planning and cut process.  I've saved the series of pictures.

[appleseedtree]

Magic, so it looks like you've only rolled the log 3 times  and you leave the slabs in place while you saw the next one until you're ready to roll again. That's great to see, as I thought I'd get a reward for the most rolls to get the fewest boards out!  It appears that you are focused on most board feet for the least amount of effort.
Is that actually red chalk or a lumber crayon? 

[Magicman]

Yes three turns but the slabs were left on each time for picture illustrations.  Lumber crayon.

[Sixacresand]

I have been bit many times by milling a cant down to a desired width, only to have an ugly waves in the cant or bent boards  My policy is to mill cants down to approx 1 inch oversize, mill my boards, then edge, trim off any defects a few boards at a time.  It takes a lot more time and wastes material, but I like straight, uniform lumber.  Customer do not like to hear "turn the hump side up"..

[terrifictimbersllc]

 I'm guessing Magicman having sawn so many SYP logs like that, knows that this one is  clean and will give it a flat cut the way he is doing it. For example, in the next of the last photo above. I would do the same with a sharp blade on if I knew that that whole side was clean but that's not usually the case for me, I will turn it before I make all those wide cuts and take off the top so that when I make the wide cuts I am cutting into clean wood only. And with a sharp blade.

[Darrel]

Welcome to the forum appleseedtree!  I've learn a whole lot from the folk who have already responded. I've also learned quite a bit the hard way when I didn't follow their advice.  For example, here is why you don't want to split the pith. 

 

[Georgia088]

So, MM, you have (3) 3-5/8 cants.  So before you made the two cuts to give you 3-5/8s how large was the cant? 10-7/8s?  I know 3 times 3-5/8ths is 10-7/8ths, but do you allow for the saw blade? for instance an 1/8th per cut? So it would actually need to be 11-1/8?  I'm just curious as to how you figure that.  It never seems to come out exact for me.  It seems wherever I allow for the saw blade it needs to be on the other side lol. 
Thanks!

[appleseedtree]

Hey Darrel, I love those photos of the long boards. Looks like great boat lumber. Now I really get it. Don't split the pith! And regarding kerf, 1/8" seems to be a generous plenty to my inexperienced eye, I'd like to hear what others figure. And by the way, I've sawed a fair amount on someone else's old Mobile Dimension circle mill and I would figure 3/8" kerf to be on the safe side. You'd lose one board to sawdust for every 3 boards sawed!

[LeeB]

An 1/8" for kerf is pretty close but really depends on your blade thickness, set and a few other factors. I use an 1/8" and it works fine for me.

[dean herring]

MM how do you determine your exact cant target size?

[Magicman]

Sorry guys but I got a bit behind while spending a week with Jeff at the Cabin:  LINK

To answer the "starting point" question to reach the target and have all of the cants the same size, this is where Accuset 2 would be very handy.  Since I don't have it, I practiced many times to determine my "starting point" and have these points on my cheat sheet.  The actual numbers would be of little value to anyone else but yes Georgia088, you are on the right track.  Use your figures, try it, and then adjust accordingly.  When you find the "magic" point, write it down.  As LeeB pointed out, my old Setworks allows me to input the blade kerf and mine is not exactly 1/8" but is a decimal.

[Darrel]

So this is what I like about the forestry forum. I didn't even have to ask, in fact I didn't even know that I needed to ask.  But now I know that I should have. I have no setworks other than the rule on my mill and my brain and I know that my cants are a little bit off. I will play with it and figure it out. I'll have to write it down and probably draw a picture of where to stop the head between the lines on the rule. But I can do it.

[Magicman]

In your situation I would think that you could measure up from the bottom of the log to determine your targets.

[Darrel]

That's what I do Magicman, but when I get to the last one it would always be a little bit off because I was figuring 1/8" kerf (adding up the thickness of all cants + 1/8 for each). Then when you said that it's a "decimal" something clicked in my little brain and now I know what I need to do. It will probably involve me making my own magnetic scale to put on my mill for when I'm making 3 cants for cutting into 2x4's. But first I have to figure exactly what will work.

[LeeB]

And when you get it all figured out you have to make sure you stop exactly on the right spot. Not always easy to do even with a set works. They aren't 100% accurate and my eyes don't help me any as I get older.

[Darrel]

When I first got my mill, I had a hard time getting it to stop exactly where I wanted it. I have learned that if I drop the head a bit low then bump it back up that I'm just as accurate as any setworks. And thankfully at my age I am blessed by being able to read without my glasses. I do need them for distance vision but not close up. My problem is getting my brain to figure out where I need to stop. If I'm trying to make 3 cants 3 5/8" each, I always find that my last one is a bit different then the others. It's like a 1/16 inch thicker. If I'm cutting 3" batons and 5 cants, it gets worse.  I know it's only a 1/16" but it bothers my OCD.  So if I can fix it I will.

[Ga Mtn Man]

Darrel-  I can't understand why the error on your last cant would be so large (1/16") or why it would be worse when cutting more cants.  Assuming your actual kerf is 0.090, which would be typical for an 0.045 blade, and you are using the mill scale which allows 0.125" for the kerf, each cant, except for the bottom one, should be 0.125 - 0.090 = 0.035 strong, which is a little more than 1/32".  The error at the bottom should be the same regardless of how many drops you are making.  I've never had a customer who minded the extra thickness and if you start a little high on your first cut you can make the bottom one come out a little thick also.       

For five 3" cants:

Blade Hght   Board Thickness

15-1/2
                      3-1/32
12-3/8
                      3-1/32
9-1/4
                      3-1/32
6-1/8
                      3-1/32
3
                      3
0

 

[Darrel]

I don't understand either, but I will figure it out just as soon as winter comes back or the mud dries up. It's still January and the mud should be frozen but it is 6" deep and quite sloppy in my customer's/neighbor's field where my mill is. His logs are staged and ready to saw but it is way too muddy. So anyway, as soon as I can get there I'll figure it out. I've never had anybody complain about it but it does bother me. Chances are if I figure out what I'm doing wrong, I'll either fix it or maybe even choose to live with it but not knowing is a puzzle that I feel the compulsion to figure out.

Thanks for your reply. What you say sounds correct, I'm sure I'm the problem more than my mill. Probably just making some mistake in my figuring.

[dean herring]

Thanks MM
Last log came out MUCH better

[Magicman]

I was sawing some 2 3/8" stuff today that put a serious wrinkle in my cheat sheet.  Had to make a few "practice runs" to find my starting height. :-\

[ncsawyer]

Yes those "weird" sizes can be a little aggravating. 

[PAmizerman]

Boy reading this thread brings back old memories of my old lt30 manual. Now I'm spoiled with accuset 2
Just punch in the numbers and letter rip.

[Crossroads]

I'm not sure if this question should be in this thread or a new one, but have decided to just add to the conversation. Anyway, I have a job coming up milling some fir. Most of it is in the 10-12" range and the customer wants me to try to squeeze 2-4x6 or 2-4x8' out of each one. Since I can't do that without splitting the pith, should I tell the guy that I can only get one quality 4x with the heart centered? In which case he would end up with a bunch of side wood that he's made it clear he has no interest in.

[Magicman]

I will have a very similar (actually exact) situation tomorrow with a few logs.  I will get one heart centered 4X6 and discard the rest of the log...no side lumber.  I can bust through the logs without being concerned with waste or edging flitches/boards. 

It's gets down to communication with the customer.  I refuse to saw something that I know full well will be unusable after I am finished and gone.

[Don P]

That's sort of like taking the ribs and throwing out the tenderloin. Not that I don't appreciate the dilemma, been sawing through the bycatch from the timberframers for way too long on this job trying to clean the plate. I think I just mixed 3 metaphors  ;D

[Crossroads]

I was afraid that's what you were going to say, thank you for the conformation. I'll follow your lead and advise him to go with one quality over 2 questionables.

[Crossroads]

That's sort of like taking the ribs and throwing out the tenderloin. Not that I don't appreciate the dilemma, been sawing through the bycatch from the timberframers for way too long on this job trying to clean the plate. I think I just mixed 3 metaphors  ;D

Mmmm, tenderloins ;)

[Magicman]

The smaller logs had already been pulled as culls.  If I can bust through them and recover a 4X6 then all is good.  It will be quick and easy with 4 passes for ~$10.

[Crossroads]

Hopefully I can talk him into making 1x out of the sides, even if he sells them.

[Magicman]

In my instance here he does not want anything less than 12" so I won't saw any. 

[appleseedtree]

Thought I'd reopen this thread a year later to ask a similar question. I've got four 12' perfectly round, straight, about 26" D mostly tight grained SYP logs from a blow over and a standing tree that I want to make house siding out of. I've got the Wood Mizer lap siding attachment that came with the old mill but I've never used it. So tell me if I'm right about this. I believe I should use the heartwood only, and I'll only get one 8" cant from each log. Is it practical to get a couple of very small cants off the sides and make siding from those as well? Do I saw down until I hit knots then flip and discard the knotty center?   I'm matching siding that's already on the building and planning to put the new boards up "greenish" so I'll saw slightly oversized.