Log centering techniques

[Jcald327]

So I've been milling for about 2 weeks now on my new lucas.  Now that I'm actually filling orders for customers and got some mobile saw work set up, I've got a few question about setup.
 I know the goal is to center the pith in plane with the blade, and line up pith cracking/ that dead cracky band in the middle of the log so it comes out in 1 or 2 boards to minimize waste.

 That being said, with logs that have a slight taper or a significant change in diameter one end to the other, how you go about setting it up.  My take on it now is to center the pith in plane, and start on the small end, lined up with (in most cases) the start of the heartwood, and send the carriage down the track.  This results in a 1-2 inch thickness in 1 end, and 3-5 on the other, this is now waste.  I can rotate the log at this point if I'd like, allowing a more stable base, or just keep cutting.  This seems self explanatory to me, but the next question is what to do on the sides.  Do you center and trim the same taper off either side, or can you offset one end left or right to allow that edge to have far less waste, basically putting that edge parallel to saw travel?

I guess that's the question, do you take the small end diameter, and turn the whole log into a cylinder/square with those dimensions?
Next question is, in drying, how much being slightly out of line matters, say crossing the grain up and down (in the thickness of board plane) vs crossing growth rings in the left to right (width of board plane)?  Is one worse than the other?  Is one a sacred no no? Etc.

I'm thinking about grabbing some 4x4 x .25 steel square tubing for bunks and throwing an automotive scissor jacks on a say 12x12 quarter inch plate on each end (4 in total) to facilitate log leveling and getting things in plane after moving the mill from site to site.  Am I over complicating stuff here? (I've been known to do so lol)

[WV Sawmiller]

   I have a different kind of mill but the principle you describe with the jack sounds the same as me using my hydraulic toe boards where I lift the small end to the point, hopefully, the center of the pith is parallel to my rails/bed on my mill and I am sawing parallel to the centered pith. 

[timbour]

With a Lucas before making your initial cut you can move the blade to a horizontal position, center it over the log and just lower your rails until you are about 1" above at both ends of the log. Obviously, you might have to either push or pull slightly "up hill or down hill". As relates to the side I would use a tape and measure from the heart to the side rails and then move one end of the log in or out until both ends are the same.  I hope I understood your question and hopefully this helps.

[longtime lurker]

You don't.

Pith centered is the worst possible way to saw a log except when you want boxed heart beams.

In softwoods pith centered patterns lead to an increase in slope of grain, which is a serious strength limiting factor.

In hardwoods pith centered patterns result in lower overall grade of product. Your best boards come from under the bark.

Saw to taper... you get better quality timber and more of it.

[barbender]

Longtime, I've often wondered how one would grade saw with a swing mill? I think I understand how you would set up for an opening face, but how would you deal with taper on the other 3 faces without rotating the log?

[Jcald327]

Wow now I'm lost in the sauce  lol.  Why does sawing with the taper yeild a better graded board?  Not discounting your knowledge at all, just curious and always open to learning.   

With regards to the remaining 3 sides I suppose it doesnt really matter, you just end up with a lot of wedge shaped boards that will be shorter than original log once trimmed to legnth with you desired thickness.  

Wish I would have seen this earlier as I spent the day cutting without my normal offloader, push the mill back and forth measuring from carriage down to pith and jacking up the log, using shims to try to maintain a mostly parallel and level cut travel.  
Looking forward to the responses here

[trimguy]

I'm wondering also, I only cutting framing lumber, for now. I would have cut finish lumber the same way, always some thing to learn.( I'm new to this, so I know there is plenty I don't know .)

[scsmith42]

My 2 cents....

Good info from Longtime Lurker.  I'll add though that pith centered is the best way for quarter and rift sawing, in addition to beams.

If the logs are very low taper, pith centered is also ok for flat sawn grade milling.  However significant taper logs destined to be milled into flat sawn grade lumber should be milled full taper to yield the best grade.

Swing blades excel at milling quarter, rift, and beams.  They are fine for milling general purpose lumber for structures, etc.  Grade milling can be done with them but time spent log handling makes them a poor second to a band mill (unless your log is only clear on one face).

[YellowHammer]

Yep, identify the two best faces, saw them parrallel to the bark to get the absolute best and flattest boards, and then saw the other sides getting lower grade wood.

Or I just put the two best faces to the bed of the mill and saw the low grade off the top and when I rotate the cant I am automatically parrallel to those two sides.  

[trimguy]

So do throw the pith away or just saw the pith into numerous boards ?

[scsmith42]

So do throw the pith away or just saw the pith into numerous boards ?

Keep it in the middle board as you're milling, and then rip it out - leaving a pair of quartersawn boards. Or you can leave it in and rip it out after drying.

[Kwill]

Maybe im doing it all wrong. I saw mostly all cedar. I cut from the small end to big end. With cedar there can be quite a bit of taper. So what I do is raise the small end to match the big end. Basically level the log and make a cut. Then I turn the log a 1/4 and do the same thing. Then the other 2 sides I just saw. Is this wrong?

[Old Greenhorn]

Kwill, it maybe wrong, but that's how I do it too. Sometimes I do the first side (adjusted) and the 3rd side (flat), then the 4th side (adjusted) and the 2nd side (flat). but it is the same thing, just a different order. It works for me. I don't like long tapered slabs and I lose too much wood. I am cheap frugal thrifty when it comes to output for my own work. :D

[Brad_bb]

It depends what you are sawing (I didn't read you saying if you were sawing pine or hardwoods?), and what you want to get out of it.

I saw mostly beams(all hardwood) and once in a while quarter saw, so I level the pith in both directions.  I level it for the opening cut or cuts, then rotate the log 180° and open the opposite side.  If there is taper at the bottom, I take what boards I can get, and the first one or two will be cathedral grain.  It looks different than regular flat sawn and can be neat.  As has been said, Cathedral grain, that is sawing the taper parallel to the pith will give the first couple boards that the grain has slope.  Again, it depends what you want and what it's being used for.  It will not be grade sawn.  For maximum board strength you want no slope in the grain-continuous fibers.  What I notice is that even with taper, after the first 4ft long board, then a longer 6 or 8 footer, the slope will become more parallel.  Sometimes by the third board.

But again, I'm not sawing for grade, but for beams. So jacket boards are a by product for me, a good by product.  Once I have two opposing flat sides parallel to the pith, then I rotate 90 degrees and level the pith again, repeating the process.  Magic Man and a few others on here got me to start doing it this way and once used to it, I saw that this rotation method worked best for me.  I also try to have the small end at the start of the cut.  

I have no experience with the Lucas.  I run an LT15go woodmizer bandmill.

[Jcald327]

I understand the concept of both pith centered and taper cut techniques, still trying to figure out how best to apply it to a swingblade.  I really try to avoid rolling the log once I start as regardless of how carefully i try to make sure my bunks/mill rails are coplaner, I still end up with some tapered boards after a flip, and it takes me 2-3 adjustments to end with a perfectly sized slab.  
I think I like the idea of ignoring the 'center slab' end results, and instead just milling to bark taper will leave me more higher grade lumber, and a tapered wedge of cracked pith junk to add to the burn pile, and the last couple boards will just end up being trimmed to legnth based on where they fall below full thickness.

[Andries]

Pith centered is the worst possible way to saw a log except when you want boxed heart beams.

In softwoods pith centered patterns lead to an increase in slope of grain, which is a serious strength limiting factor.

In hardwoods pith centered patterns result in lower overall grade of product. Your best boards come from under the bark.

Saw to taper... you get better quality timber and more of it.

@Kwill and @ Old Greenhorn - your answer was posted via 'lurker', from down under; a super concentrated four sentence piece of experience and wisdom. . .  and echoed by yellowhammer.
Half baked advice just doesn't come from those two gents.
There is an absolute ton of value in that answer.
If you want boxed heart cedar beams, carry on. You aren't wrong.
If you want the maximum number of high quality boards and lumber, saw to the taper.
You'll get "better quality timber and more of it."
Any method that you use to mill will result in flitches or waste that you can't really use.
Sawing to the taper makes those waste pieces from the least valuable parts of the log.

** sorry, just recalled that rotating the log is not a normal part of milling with a swing blade or slabber **

[Kwill]

I guess I'm a idiot as I dont understand what you mean by sawing to the taper.my guess is you saying to set the log on the mill bunks and mill it. No raising the tow board and leveling the log?

[YellowHammer]

Arguably, two of the most valuable and aggravating logs I mill are walnut and veneer grade cherry.  Both have the highest grade wood coming from the sidewood heartwood, which is the heartwood immediately below the sapwood.  Both species are almost always highly stressed, and both have a pith that is totally unusable and rather large with respect to log size.  Also, as the cuts get deeper into the log, the grade always goes down as pin knots and other defects start appearing.  Also, of course, on both walnut and cherry, the pith is to be avoided because it is full of cracks and other defects, it is a boundary where no high grade board can be had.  To make matters worse, both cherry and walnut are graded on the percent sapwood on each face, be it low grade 70/50 (70 percent heartwood on one face, 50 percent on the other) or higher grade 90/80 or even better, 100/90, which is what we produce, which is all heartwood in one face, just a little sapwood allowed on the other.  So in order to do that, it's important to try to align the cut faces so that the heartwood shows in a long ribbon all along the board, as opposed to an unbalanced, tapered section.  So the only way to achieve the perfect stripe is to saw parrallel to the sapwood and heartwood which would be parrallel bark sawing.  In addition, if the sapwood were to be edged off to achieve a perfect heartwood face, then the straighter and less tapered the profile, the easier to edge with a minimum of waste.  The best way I can describe it is that's its like skinning the log in strips, or like peeling a carrot.  

As I mentioned, as the cuts get deeper, the grade of the lumber goes down.  It's vitally importamt to make gold in the first few cuts, and that where the big difference between the patterns arise.  Parrallel bark sawing targets the outer and most valuable boards in grade logs because grade always decreases the deeper the cuts are made into the cant, whereas with pith centered, the focus is moved toward the pith, and the sidewood is removed to maximize the pith alignment, not to make high grade lumber.

[Jcald327]

Yellowhammer, I had no idea you were out in newmarket, I grew up in the Huntsville,madison, harvest area, need to swing by next time I make a run home.

So given how the lucas mill cuts, I vastly prefer quartersawing smaller logs by taking off the sapwood down to a 6-10 wide inch strip centered on top, cutting a small wedge from the 1030 clock position corner, and quartersaw down to just about the pith, beit 6 inch or 4 inch tall boards, 5/4 or 9/4 thickness.  This 6 inch vertical cut, and 1-2 inch horizontal cut allows me to make it a single down and back cut versus a double pass horizontal cut, and single vertical (I hope this makes sense, the lucas does better making 2 cuts when cutting horizontally above say 5 inches).  I then make those double pass cuts splitting the middle of the log into 3 boards wide, normally some 4 inch wide 5/4 boards with the middle of these 2 layers being discarded pith boards. Then I normally continue flat sawing down maintaining 2 boards (of varying width per layer) keeping all but the tiniest corner in heartwood only.

I would say in the last day of cutting (ok 2 days but honestly only about 3 hours of working time) I've managed to get 260bf of cherry in what I would almost guarantee to go 90/100 in terms of heartwood content, on logs whose heartwood diameter should have only netted me about 150 per the doyle scale.  Granted I would say roughly 45-50bf are pith low grade boards, but at the 1.20 the wholesaler wants to buy at, I'm a little upset he wants no sapwood at all lol.  

[logboy]

Most of the guys here run bandsaws and are correctly explaining how they do it. Unfortunately for you its done backwards (one of a couple possible ways) on a swingblade. I don't have time right now but I'll try and pop back and explain how you do it on a Lucas. In the meantime, stop aligning your mill to the pith (unless youre sawing timbers), youre just throwing away your high grade jacket wood.

[Jcald327]

Logboy, much appreciated, waiting patiently for your guidance.  I think I understand what everyone's getting at.  This saves me the hardest part of the work anyway, getting the log up onto shims and measuring down to the pith back and forth vs just setting the end frame to the taper, which can be done in under a minute.  

Part of my initial problem is I have about a 12 inch downhill slope from 1 end to the other where my saw lives most of the time, so when I bottom out the end frame i still have 8 or so inches of lumber on left above my bunks (these have since been moved, shimmed, and added to leaving a 1.5 inch flitch on the bottom if I cut all the way through).  I was trying to set my swing mill up like a bandmill, where if I rolled my lock I would end up with a perfect slab, which after some "research" (read a few logs) I've determined this rarely results in a perfect slab, and decreases my projection rate by nearly half because I'm always messing with it.

[Magicman]

@Kwill your sawing sequence description in Reply #11 is exactly as I would saw ERC.  You are not sawing "grade" as described for Walnut and Cherry and it also allows you to capture a few short boards from the butt section of the log or they are waste.

Nothing of value is wasted per YellowHammer's sawing sequence.  The pith wedge is his waste whereas with your ERC sequence, the short butt boards are waste.

[longtime lurker]

So.... I cut everything to taper except boxed heart beams. Doesn't matter what the mill is - swing mill, the conventional circle, or the band.... all the technology does is change my cut sequence to get the desired result. But OP asked about the Lucas, and it really doesnt matter because its about where just a few cuts go and as I said.... any mill.

With a Lucas I start with my pith/run of the log centered left/right, and adjust my end frames so my opening cut goes in parellel to the taper... so maybe a couple inches height difference between the ends. (or toe board up the small end with a bandmill, or advance my small end headblock with the carriage mill) I'm usually looking for a cut that goes in maybe ½" under the sapwood both ends.

(If your log has a flared butt ignore that and go with the run of your taper not the big butt swell ok)

We're backsawing this one ...Take a board off etc etc. down through 1/3 or a little less of your log.... basicly just watch your small end and you want to pull up when you would be turning your blade for vertical cutting the sides on the small end. From here it depends if you saw smart or live saw.

LIVE SAWING
* (you need to know the two magic numbers for a Lucas mill to do this. 14... as in page 14 of the operators manual. The rails must stay parallel so this requires level ground (85% of badly sawn boards off a Lucas are because people can't read page 14 in the handbook.)
The other magic number is 6615. 6615mm is the end of rail to end of rail diagonal measurement on the 6m rails. If you start moving your frame a lot to account for taper you need to allow for diagonal movement too. Out of square on the diagonals accounts for most of the other 15% of badly sawn boards by a Lucas.) You dont need to be exact on that one but "close enough" saves a lot of carriage roller and gearbox wear.

Drop the high end frame down 1/2 the difference between the two... so if you started with one end 3" lower than the other to account for taper drop the high one 1½" or so. Take out a wedge shaped board. In high value timbers or if I've got a lot of taper I might actually wind the low end up an inch, drop the high end an inch, and take a wedge then a board.... but the idea is to get back to heart centred vertically ok?
Then kick one end frame sideways until your blade lines up with the near side taper of the log.
Saw across to the middle.
Kick the end frame back the other way so your blade is now lined up with the outside taper
Take a wedge out that encompasses your pith.
Saw across to the bark.
Kick the end frame back until your saw is in the "neutral" heart centered axis.
Drop the high end down the last bit so it's now running parrell to the bed which is also the taper of the bottom of the log
Saw him out.

Yah it sounds complex but it's actually pretty quick. But nasty, because I hate live sawing because you spend half your day shim cutting to account for log spring and the last board is always thin in the middle and thats just wasteful!

SMART SAWING.
Roll the log until your cut face is down. Align heart centered left/right again
Your taper will still be in line with the saw so just take a bark pass off and go at it until your small end is just slightly higher than your target board height..... if you're chasing say 6" x you want not less than 6½" of meat on the small end.
Kick your flitch sideways so the bark aligns with the saw, and go at him until you hit pith.


 Now... ya see that hack mark up the side there compared with the smooth top face.... thats because some idiot hit the rails this morning and the rails are parallel but not diagonally square.... that 6615 number I mentioned back up the page... so it's leading to one side (and flogging the carriage rollers doing it and the gearbox is carrying that extra strain as well) No matter because these are going DAR but.... icky. Anyway that flitch is about 2" thick under the target board this end and about 1" the other. I'll pull another inch board off him later.

Go at him until you hit pith
Kick the flitch back the other way until your saw axis is parallel to the outside bark.
Take a wedge out that encompasses your pith.


 

Take a board maybe.... but heres what you need to do.
As soon as your mill can hit the outside of the log start cutting back from the sap towards the middle, putting your vertical cuts in. You're doing this because (a) get rid of the sap you drop the sapwood tension and your flitch doesnt pull and (b) the more weight in the flitch the steadier it sits there and (c) the grade of board gets lower in the middle so cut wide first and if you get a thin one its the low grade near the pith one.


 
Once you've come back to the middle turn your saw horizontally and saw them out.

I can do that in my sleep.... in practice it's really basic. And yanno.... I saw for profit not lumber, so an extra 5 minutes to get a better grade of board across my whole log is worth it to me

[longtime lurker]

Now if you want to quarter saw (again Lucas)

Start parallel to top taper of log as per above. Open him to a nice width.
Quarter cut as per usual, but parellel to taper not to pith. That gives you the same width board as you were going to get anyway ( board width is determined between top face and the small end.... and no worries about wandering heart because except for the small end you're away from it. And you get nice bookmatched boards too, which sells easy. They'll spring a little or a lot depending.

Roll it over and come in from the other side, just like above. They won't spring so bad this time because sapwood is gone from opposing sides. Cut him down to where it makes sense.

Thennnnnnnnnnnnnnn... split the pith.  that drops all the spring out.
Saw your sprung wings out. This way you're getting straight boards, not sawing and watching them turn into bananas behind the saw


 

That's how you get 20' long gunbarrel straight quartercut boards straight off the saw, they just lie there flat and straight and walk out the door for a pretty penny 



And then there's radial backsawing in a log with an internal and external taper... and holding 30%+ recovery. Just keep turning and dogging and following that taper... s'why I love hydraulics - you cold never do that fast enough without turners and dogs.



 

[Jcald327]

Oh my lurker, I've officially got homework, this is going to take me a good minute to understand completely but extremely thorough and incredibly appreciated.  This is fantastic info... seriously.  THANK YOU! This should have come with a teaser, and a click here to buy the full instructions like all those get rich fast schemes on the internet, only 29.99 for all my (insert random scheme) secrets.

[longtime lurker]

Oh my lurker, I've officially got homework, this is going to take me a good minute to understand completely but extremely thorough and incredibly appreciated.  This is fantastic info... seriously.  THANK YOU! This should have come with a teaser, and a click here to buy the full instructions like all those get rich fast schemes on the internet, only 29.99 for all my (insert random scheme) secrets.

ahhhhhh thanks. Just the result of too many years hacking logs apart for a living, and the last ten of them with my own name on the door.

When I got time I'll draw some illustrations.... If you can see it as relationship of saw axis to log axis it all makes a lot more sense. 

What I'm really doing is sawing the log parallel to the bark from four different points. If you look at the middle picture with the wedge sawn in it...thats your horizontal two of them right? The top and bottom of the log are the same thing, just orientated vertically.

[Dakota]

Very good description by longtime lurker.  I'm lucky because the ponderosa pine I saw is straight with little taper. If you are cutting a log like this, here's an illustration of how I saw most of my logs.



 

[Dakota]

I should have added that it's not the sequence of cut, but the pattern.

[Old Greenhorn]

Well, everything I know about milling a log I learned here. This particular subject was never expressed in a way I would catch onto before, so now I too am re-thinking. I have to confess most of it makes sense, but I am a little stuck on the basic geometry. So I made a little sketch to help me think through it.



 

The first example shows how I do it now. I believe the second example shows what Lurker is talking about, is this correct? Basically you are 'leveling the taper' instead of the pith, correct?
 Or is it some derivation of the 3rd example?
 If it is the second example, then I understand and am keeping up. Basically your waste is in the pith, not the slabs. I have never sawn for grade, just trying to get the maximum yield in framing stuff from a log. Now I have to re-learn this all over again. But it's a good lesson, glad this came up. I am occasionally getting logs that yield some nice wood I would love to saw those for the best grade I can get and make some nicer 'stuff'. Man, the learning never stops. I am going to have to take my next log and try this out.

[longtime lurker]

Your second illustration is right on the money. My waste goes out as pith, and my shorts are all close to pith pallet grade material.

[Old Greenhorn]

OK, sorry I am a bit slow, I just wanted to make sure I had the fundamental concept correct before going further. (Maybe someone else will read this thread and be as slow as I, so this should make it clear for folks like me.)
 So you still need to adjust the toeboard (or whatever you use) but you are leveling the top of the log, not the pith. That is simple.
 Now my question is, as you approach center (and the grade goes down) you also get to a point where your cut will cross the pith and enter the far side of the log. Obviously you stop and flip at this point, but you should eventually wind up with a wedge in the center, what do you do with that or is it just a big waste chunk?

[Kwill]

So you level the log and your first cut is right down the pith?

[Kwill]

@Kwill your sawing sequence description in Reply #11 is exactly as I would saw ERC.  You are not sawing "grade" as described for Walnut and Cherry and it also allows you to capture a few short boards from the butt section of the log or they are waste.

Nothing of value is wasted per YellowHammer's sawing sequence.  The pith wedge is his waste whereas with your ERC sequence, the short butt boards are waste.

Thank you 

[Old Greenhorn]

So you level the log and your first cut is right down the pith?

I couldn't do that. I have no way to handle log halves. All by hand and hook here.

[dgdrls]

I have "experimented" with both techniques of pith centered and parallel to bark with nowhere near the expertise @longtime lurker has described and performed.
My last round of white cedar (more taper) parallel to the bark yielded better boards.
I did saw boxed heart beams for a friend holding the pith centered.

good photo of sawing parallel to bark with waste in the pith.


 

Lots to learn still :P :P

D

[YellowHammer]

Very good description by longtime lurker.  I'm lucky because the ponderosa pine I saw is straight with little taper. If you are cutting a log like this, here's an illustration of how I saw most of my logs.

This is a picture I made several years ago, its the way I still mill these type of high grade logs.  It will result in the least amount of sapwood, cup and bow in boards, especially, cherry and walnut.  I do this with a bandmill, so I'm not sure if the pattern can be done with a Lucas.
Notice that I rotate around and keep taking the high grade boards, going deeper and deeper into the cant knowing that as I do, the grade will fall off, and I stop when I get to the pith.  Its is useless and is discarded. 
The key on the illustration is that it is an end view and only in 2D.  Referring to Old Greenhorns useful illustration, it can be seen how it would look in 3D when sawing parallel to the bark.  
When sawing logs like this, I keep my options open, and at some point, I may switch over to other patterns on different faces, as grade changes, defects arise, etc.  Hydraulic toeboards makes this easy, and I do what I have to do to get the widest, cleanest, highest grade boards possible from the best faces, while I try to use the pith as my buffer if I need to make adjustments which generate tapered cuts.  The pith is my dedicated sacrificial waste area, so thats where I try to make the change of patterns show up.  Its hard to explain, but easy to do, sometimes.
   
  
 

[WDH]

Notice in YH's pic that the rings are balanced in each board.

[trimguy]

Ok old greenhorn I'm here ( the one that's as slow as you ) :D. Thank you everyone for the continuous explanation and pictures . I also think that I got it. All the logs I have now are SYP for framing material. But next time I get to go to the mill I might take one and try this .It will help it me remember it better. Thanks.

[Larry]

Saw parallel to the bark?  No problem.



Every log is unique along with different markets. "Sapwood no defect in steamed walnut", no wonder somebody is investigating a steamer.

Most logs, half taper will work out but that seems close to leveling the pith.

[Nebraska]

Thread added to bookmarks  can't digest it all now.  Better notes here than I got in some sections of my paid for schooling.

[kelLOGg]

How much taper must there be to reap significant yield over leveling the pith? Specifically, for a 16' log how much difference in diameters should there be in the big and little end?

I ask because I just sawed a 10' SYP with 17" and 14" diameters by leveling the pith and got 2 waste boards which were only good for stickers. I thought about taper sawing but I have never done that. 

[curved-wood]

In the book : ''Small log sawmills'' they made studies on yield VS taper. Interesting to see the yield chart and when it is better to cut full taper or split taper depending on the length and the taper of the log. EX: say you have 1.25''of taper for a 10 feet log, the chart tells you that for a 6'' or 8'' diameter you have a better yield split taper (pit center ); diam 10'' to14'' full taper; diam16'' split taper; diam 18'' full taper.    After reading that book I did understand that in no way I could calculate fast enough to beat those computerized mill. We are just talking about yield and not grade. But the few off center boards didn't influence the price of the whole run because they are allowed a certain percentage of lower grade. That is probably where those crocked 1x3 forenz come from.  

[Sixacresand]

@Larry  Cut oval cookies out that hump.  Crafts people love them.  

[longtime lurker]

The taper vs yield thing is a factor for sure.
As is log grade.

For me - my insistence on taper cutting is based on two things. Firstly, when I get good logs - or logs in a species that will garner a premium - I want to maximise my $ return value from them, rather than maximise my yield. In short I want to grade saw and maximise the useable length of high grade lumber.

But the bulk of my business is hardwood framing and I saw about 500MBF of average quality logs for that a year. Pipe and/or heart defect is very common in eucalypt species.  It's not that I want to.... I like nice logs as much as everyone else... but if I only ran on solid centred logs I wouldn't cut much at all. The allowable pipe guideline on logs off state land is.... well I get logs you could send a kid up with a torch to look about inside and that's a compulsory sawlog so far as the state is concerned.

Pith centered sawing requires that there be some wood near the pith, and that that wood is sound.  Yeah I wish.

[Jcald327]

Thread added to bookmarks  can't digest it all now.  Better notes here than I got in some sections of my paid for schooling.

I'm in the same boat, tons to digest.  I'm always leery of starting new threads as I know most things have been covered, sawmilling nor trees haven't changed much in the last 100 or so years (or more lol), but always seems to lead to really good ah haaas.  
I cut to taper yesterday, and while the nice big wide slabs in the middle were as straight and uniform as could be, the wood was not.  The customer was happy with them, but honestly the slab above and below to middle slabs (was cutting 2 near identical logs at once), had amazing uniform ray flecks and such, which I will attribute to being cut to taper (which resulted in a 2.25 inch by half inch tapered 'pith slab').
I think, someone correct me if I'm wrong, cutting to the taper will also result in more evenly sized slabs because the start higher on the bell side (read big side) of the log.

[longtime lurker]

Thread added to bookmarks  can't digest it all now.  Better notes here than I got in some sections of my paid for schooling.

I'm in the same boat, tons to digest.  I'm always leery of starting new threads as I know most things have been covered, sawmilling nor trees haven't changed much in the last 100 or so years (or more lol), but always seems to lead to really good ah haaas.  
I cut to taper yesterday, and while the nice big wide slabs in the middle were as straight and uniform as could be, the wood was not.  The customer was happy with them, but honestly the slab above and below to middle slabs (was cutting 2 near identical logs at once), had amazing uniform ray flecks and such, which I will attribute to being cut to taper (which resulted in a 2.25 inch by half inch tapered 'pith slab').
I think, someone correct me if I'm wrong, cutting to the taper will also result in more evenly sized slabs because the start higher on the bell side (read big side) of the log.

One of the things I do is make a dollar judgement about the "pith slab". Some of them I throw out, some of them I'll lift the thin end frame, and drop the thick end frame and chase a short inch or 1½" thick with a tapered end if it makes sense to do so. And sometimes I'll take that short out off the top of the centre cant..... depends on where the pith is and how much meat I have to play with.

It's one of the advantages of working off a level deck like I do... there's no sag in the middle as with live sawing, particularly when you roll the log to even up your tension. As you say there is nothing new in trees or sawmilling and that includes how best to deal with log tension.... roll the *danged log just like a boat builder named Noah must have. Livesawing has a place - deep in the woods when you're taking the mill to the log. As soon as you're working fixed it's a poor choice.... yeah I waste a couple minutes rolling the log but I save that in not having to face cut all the time and I get a better result: nothing piths me off more than looking at boards that are thin in the middle because of spring and/or sag

Even width is tree dependant but  - yeah - rule of thumb is they will be more uniform. Personally I find that uniform width slabs are easier to sell.

[Jcald327]

Yup, that was my suggestion, lop it off where it drops under a inch and a quarter, and you've got a small highly 'figured' (lots of knots and pockets for resin) section and a bigger one that has enough strength to support itself.

[doc henderson]

here is what I made to help me measure when I deem it needed.  a 2 foot large mark and number rule, and 2x4 cut to fit inside my drive chains.  it happens that that the flat stock it is sitting on, to the top of the bunks is 1.5 inches.  it allow me to measure from a bunk top if close enough, or from the 2x4 if between bunks.  the rigid ERC rule is nice, cuase I can lean it against the log end, and go back to my controls and hit the measurement I want.  although it may change the other end as well if the log end is cantilevered over a bunk.



 



 

[dogbo2013]

Arguably, two of the most valuable and aggravating logs I mill are walnut and veneer grade cherry.  Both have the highest grade wood coming from the sidewood heartwood, which is the heartwood immediately below the sapwood.  Both species are almost always highly stressed, and both have a pith that is totally unusable and rather large with respect to log size.  Also, as the cuts get deeper into the log, the grade always goes down as pin knots and other defects start appearing.  Also, of course, on both walnut and cherry, the pith is to be avoided because it is full of cracks and other defects, it is a boundary where no high grade board can be had.  To make matters worse, both cherry and walnut are graded on the percent sapwood on each face, be it low grade 70/50 (70 percent heartwood on one face, 50 percent on the other) or higher grade 90/80 or even better, 100/90, which is what we produce, which is all heartwood in one face, just a little sapwood allowed on the other.  So in order to do that, it's important to try to align the cut faces so that the heartwood shows in a long ribbon all along the board, as opposed to an unbalanced, tapered section.  So the only way to achieve the perfect stripe is to saw parrallel to the sapwood and heartwood which would be parrallel bark sawing.  In addition, if the sapwood were to be edged off to achieve a perfect heartwood face, then the straighter and less tapered the profile, the easier to edge with a minimum of waste.  The best way I can describe it is that's its like skinning the log in strips, or like peeling a carrot.  

As I mentioned, as the cuts get deeper, the grade of the lumber goes down.  It's vitally importamt to make gold in the first few cuts, and that where the big difference between the patterns arise.  Parrallel bark sawing targets the outer and most valuable boards in grade logs because grade always decreases the deeper the cuts are made into the cant, whereas with pith centered, the focus is moved toward the pith, and the sidewood is removed to maximize the pith alignment, not to make high grade lumber.

Yellowhammer, 
 
  This is a great post. I cut a lot of cherry and I always try to center the pith. I always end up with a lot of wasted outer beautiful wood. I think I understand the initial cut of sawing parallel to the bark, but I am still trying wrap my mind around the remaining cuts. Is there any way you cut make a video or drawing that would show this technique?

[YellowHammer]

I'll make a video, but the best analogy I have is peeling a carrot with a carrot peeler.  It doesn't matter how tapered the carrot is, the carrot peeler will only make a cut or peel parallel to the side or face of the carrot being peeled.  So that is parallel carrot peeling, which is the same as parallel bark sawing.  As the carrot is rotated, the peels keep coming off parallel to the surface being peeled, and when done, the remaining part of the carrot is still tapered, but the peels are all parallel to the surface.  

In real life, most times cherry and walnut has some good and bad faces, and so in those cases, to make the technique more practical, I'll parallel bark saw the two best faces, so I don't have to always fiddle with my toe boards in every rotation.  It also helps to be aware of any knots and put them in the non parallel bark sawn boards so they can be edged off later, without losing the value of the better pieces.  It's hard to explain, but pretty easy to do.  

It's all about getting the best, most parallel sapwood and heartwood boards from the best faces, to get the widest, highest grade boards.

[dogbo2013]

Got it. Thank you for the explanation. That makes good sense. Cant wait to try this!

[YellowHammer]

This is the kind of cherry I get from parallel bark sawing.  These were put on the sales rack yesterday.  Notice how the grain is generally centered and parallel to the face of the boards.  This keeps them flat and more well behaved and gives them a nice, uniform look.  Also, you might notice how there is no sapwood on these boards, which is a benefit from parallel bark sawing, the sapwood borders are even on both sides and ends so edging is easy and not too wasteful.  Looking closely at the board on the left, you can see a very parallel sawn face, basically tracking one growth ring, but on the right was a log with lots of sweep, and you can see that I had to play games with it, basically milling it with the sweep to the side so the stress in the log cause the board to curve, not bow.  It also has a very distinctive look, but results in a very flat board.  

The reality of it, I'll saw any log, any way, to get the flattest, prettiest, widest boards.  I'm not a purist, but more of a free styler.  However, there is a reason behind every cut I take, unless I hit a backstop. :D

 

[longtime lurker]

I'll make a video, but the best analogy I have is peeling a carrot with a carrot peeler.  It doesn't matter how tapered the carrot is, the carrot peeler will only make a cut or peel parallel to the side or face of the carrot being peeled.  So that is parallel carrot peeling, which is the same as parallel bark sawing.  As the carrot is rotated, the peels keep coming off parallel to the surface being peeled, and when done, the remaining part of the carrot is still tapered, but the peels are all parallel to the surface.  

In real life, most times cherry and walnut has some good and bad faces, and so in those cases, to make the technique more practical, I'll parallel bark saw the two best faces, so I don't have to always fiddle with my toe boards in every rotation.  It also helps to be aware of any knots and put them in the non parallel bark sawn boards so they can be edged off later, without losing the value of the better pieces.  It's hard to explain, but pretty easy to do.  

It's all about getting the best, most parallel sapwood and heartwood boards from the best faces, to get the widest, highest grade boards.

That carrot analogy is about the best explanation of taper sawing ever Robert. Really well put.

[Magicman]

Always be very aware of the orientation of the pith check when sawing both Cherry and Walnut and yes, they both always have one, some just more distinct than others. 




Not paying attention to it when opening faces will ruin both your lumber and your day. 

[WV Sawmiller]

Lynn/Robert,

 My biggest challenge comes when I look at a log like you just showed with a distinct heart check telling me "Saw parallel to me so the split is not in every board" and serious conflicting sweep that says saw opposite the normal crack so the board curve face in instead of to the side. Any thoughts and wisdom to share there?

[Magicman]

Every log is an individual unto itself, and every rule has an exception.  :  (Chapter 3, paragraph 7, in Sawmilling 101.)  :P

[YellowHammer]

This is a typical high grade, big money cherry log, big and sweet and well marked. It looks like it has an unworkable heart check but not really. It's really 2 logs in one and needs to be sawn with two patterns, as if it was two logs. If you look closely, you can see a distinct boundary of money heartwood and junk heartwood.  The actual core pith check is an even smaller inner circle between the innermost red lines only and can be seen to have a little shake at the center of the log.   I circled low grade/high grade heartwood boundary in the photo and can be seen in MM picture.  The wood inside the circle isn't all pith, there is some amount of good wood in there. You can clearly see a distinct boundary where the log is badly checked and appears to run to the outside heartwood but in actuality the major check, originating at the much smaller pith ring at the center of the log, stops at the hand drawn circle.  So there are several distinct boundaries in this log and they are the sapwood/high grade heartwood/low grade heartwood/pith.  However, the check that originates deep in the pith looks like it's running out of the low grade heartwood circle but that part of the check outside the circle is really a drying check that is being forced open by the stress of the pith check. There are other drying checks in a radial pattern in the heartwood outside the circle I drew. So the outside of the circle is a different sawing pattern than inside the circle. To reduce bow and induce curve or slip I would saw perpendicular to the check as indicated by the lines and get the good wood, and big boards. They won't have much of a drying crack in the end once the stress is removed and if they do, I would pack saw the ends off later because I cut the log with some trim left on. These big wide boards would be the best on the log. So only after I got all the cuts perpendicular to the check but not crossing the boundary circle would I then rotate the cant and get narrower and bowed boards parallel to the pith check but still outside the circular boundary.  These will all be excellent quality, high grade and probably clear boards but less so as I get closer to the circle.  However, these narrower ones will have a tendency to bow because they are sawn parallel to the major check.

Once the cant is about the size of the circle, I consider it another log and how I saw it depends on how big it is. If it's only about 6 inches or so wide I'd just saw parallel to the pith, until I get to the pith, and whatever get the boards I could, knowing any of these will be lower quality with some pin knots, bow, and some possible pith checks.  However, this wood inside the circle would be bonus wood, because I've already got the high grade filleted off.

As I said earlier, this is a money log and I'd buy it in an instant.  I don't know if this makes sense but look for the outer log and then the inner log and attack them differently. Also look for the distinctive boundary between pith a check and drying check, even if it looks like it's all the same.  Also look for areas of shake and heartwood discontinuities and saw it up accordingly.
  

[Magicman]

Robert's example above is very accurate but in my instance, an exception.  I am not in the lumber selling market.  I custom saw to the customer's specification, and in this instance he wanted the most and widest boards possible.  Here is a link: Log Setup in Sawmills and Milling  showing me sawing that log.  Also scroll down to Reply#11 and see another 31" Cherry log that I sawed the next day.

The cut list is what is important.  If it is yours you may saw it one way but if it is the customer's cut list, you saw it his way.

[Florida boy]

Ok we have gone over how and when to saw grade vs center . But how do you guys decide when to live edge slab or saw "straight through"? 
 Ive got a few walnut that are 18'long with bit of taper. Im thinking of sawing in half to maximize yeild but i could always just slab the whole log . Diameters start at 22" and go to about 16

Does anyone pull a live edge pith slab from center then cut the top and bottom halves for grade ? 

[doc henderson]

I would cut in half at least.  depends on if it takes a bend, or and abrupt diameter change.  also mostly, what are you or someone you might market to going to use it for.  Most wood workers do not want an 18 foot board.  although if I were building a huge bar and wanted a long dark strip...  what you describe would be fine.  It would be better if you already had each piece you plan to mill, sold or placed in a project.  I mill much of it 7/8th inch and can plane down to 3/4.  If you mill puts deep marks in the saw cut, you might go a full 1 inch to be able to plane down.  What you plan to do with the wood will help you decide how to mill it.

[YellowHammer]

Does anyone pull a live edge pith slab from center then cut the top and bottom halves for grade ?

I generally take my live edge slabs using the same sawing pattern, as the highest quality live edge are taken from the same places as the where the highest quality 4/4 is.  Notice in my drawing that those first cuts go bark to bark.  So I would cut the bark to bark lines in the drawing to 2 3/8" for live edge slabs, and go all the way down to where the pith just starts and shows on only one face of the last live edge board toward the center.  

Then rotate 180 and take live edge slabs down to were the pith crack is just showing in one face of the last live edge piece.  These are the widest possible live edge from the log without a two face pith crack.  

I almost never cut through the direct pith for a live edge slab as it will crack anyway when it dries and also will develop a lot of cup.  

Once I have cut down to the visible pith in both sides of the cant, I rotate 90 and take edged 8/4 or 4/4 from the remaining cant. So I normally get live edge and edged boards from the same log, and remain with the pithy center cant.

Sometimes I will go edge to edge and through saw the entire log, but rarely on cherry or walnut.

[redbeard]

@Florida boy the 22" walnut log your mentioning sounds like you may want too go for live edge slabs.
Here's a idea we do alot with logs that size, we go for glue up packages.
2-1/2" thick slabs will be the yield,
Keep the center slab with pith centered in the 2-1/2" and that will give you the best 90° cambium layer live edge and the other two 2-1/2" slabs are on each side of the pith.
This gives you some nice options for a nice 40"-42" wide glue up table top

 

[Florida boy]

Thanks guys seems like there plenty of ways to skin the cat and each one has a place . 
  Well i cut a walnut last weekend not the bigger one though.
 
It was 17'7" not sure  on the diamater now. I cut it in half lengthwise
Each piece had a little sweep to it so i orented those so that the curve would become crook instead of bow. Made some nice 5/4 10.5" wide stock. 
The pith oli left in a 3.5x3.5 maybe it can be cut down for table legs we will see how it dries

[Walnut Beast]

This is a typical high grade, big money cherry log, big and sweet and well marked. It looks like it has an unworkable heart check but not really. It's really 2 logs in one and needs to be sawn with two patterns, as if it was two logs. If you look closely, you can see a distinct boundary of money heartwood and junk heartwood.  The actual core pith check is an even smaller inner circle between the innermost red lines only and can be seen to have a little shake at the center of the log.   I circled low grade/high grade heartwood boundary in the photo and can be seen in MM picture.  The wood inside the circle isn't all pith, there is some amount of good wood in there. You can clearly see a distinct boundary where the log is badly checked and appears to run to the outside heartwood but in actuality the major check, originating at the much smaller pith ring at the center of the log, stops at the hand drawn circle.  So there are several distinct boundaries in this log and they are the sapwood/high grade heartwood/low grade heartwood/pith.  However, the check that originates deep in the pith looks like it's running out of the low grade heartwood circle but that part of the check outside the circle is really a drying check that is being forced open by the stress of the pith check. There are other drying checks in a radial pattern in the heartwood outside the circle I drew. So the outside of the circle is a different sawing pattern than inside the circle. To reduce bow and induce curve or slip I would saw perpendicular to the check as indicated by the lines and get the good wood, and big boards. They won't have much of a drying crack in the end once the stress is removed and if they do, I would pack saw the ends off later because I cut the log with some trim left on. These big wide boards would be the best on the log. So only after I got all the cuts perpendicular to the check but not crossing the boundary circle would I then rotate the cant and get narrower and bowed boards parallel to the pith check but still outside the circular boundary.  These will all be excellent quality, high grade and probably clear boards but less so as I get closer to the circle.  However, these narrower ones will have a tendency to bow because they are sawn parallel to the major check.

Once the cant is about the size of the circle, I consider it another log and how I saw it depends on how big it is. If it's only about 6 inches or so wide I'd just saw parallel to the pith, until I get to the pith, and whatever get the boards I could, knowing any of these will be lower quality with some pin knots, bow, and some possible pith checks.  However, this wood inside the circle would be bonus wood, because I've already got the high grade filleted off.

As I said earlier, this is a money log and I'd buy it in an instant.  I don't know if this makes sense but look for the outer log and then the inner log and attack them differently. Also look for the distinctive boundary between pith a check and drying check, even if it looks like it's all the same.  Also look for areas of shake and heartwood discontinuities and saw it up accordingly.
 

Some really good older reads by some really good people. Thanks to all you guys that take the time to post thorough examples 

[arky217]

I mill SYP for construction lumber only, such as 2x's and boards for floors, roofs, and board & batten.
I have always milled parallel to the pith and try to enclose the pith within one board, then
cut the pith out of that board to make 2 narrow boards.

Though I understand the concept of milling parallel to the bark,
in my instance, it doesn't seem too practical because my trees nearly always have a huge bell
at the stump end that extends usually about 4 feet up the log.

So, with that being the case, should I continue milling with the pith centered,
or should I level the portion of the log beyond the bell, cut the bell off first, then
cut parallel to the remaining bark ?

[btulloh]

For construction lumber I level the pith like you're doing.  I cut parallel to the bark for grade sawing furniture lumber, mainly in hardwood.  

[Lasershark]

  I have a different kind of mill but the principle you describe with the jack sounds the same as me using my hydraulic toe boards where I lift the small end to the point, hopefully, the center of the pith is parallel to my rails/bed on my mill and I am sawing parallel to the centered pith.

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

[Old Greenhorn]

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

Put my name on that list too! Maybe a beeper would also be helpful on certain days.

[YellowHammer]

As I was looking again at the picture of the money cherry log, it just jumps out that I would mill it as two distinct logs, because of the clearly visible shake.  For such a log, the alignment is really to the inside boundary of the shake, or parallel to the inner shake, as any board sawn that crosses the shake boundary on its board face will be ruined.  So it takes some Kentucky Windage to try to get that alignment.

That log is a great example, because if I was just doing a conventional through sawing technique, many of the boards would cross the shake boundary, in a couple places, and be trash by the time they came out of the kiln.    

[Stephen1]

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

Put my name on that list too! Maybe a beeper would also be helpful on certain days.

Put my name on the list. I have found I tell myself outloud that the toe boards are up and need to be lowered. :D

[trimguy]

☝️ And that doesn't always help !

[Bruno of NH]

Them dang toe boards  :D
I'm with ya folks 

[Walnut Beast]

As I was looking again at the picture of the money cherry log, it just jumps out that I would mill it as two distinct logs, because of the clearly visible shake.  For such a log, the alignment is really to the inside boundary of the shake, or parallel to the inner shake, as any board sawn that crosses the shake boundary on its board face will be ruined.  So it takes some Kentucky Windage to try to get that alignment.

That log is a great example, because if I was just doing a conventional through sawing technique, many of the boards would cross the shake boundary, in a couple places, and be trash by the time they came out of the kiln.    

Would it only be the bottom boards or would the top ones be affected? 

[YellowHammer]

The 12 o'clock position of the log as it sits has a clear double shake boundary, and it goes down to the 3 and 9 o clock position.  There is an indication of shake at the 6 o'clock position, but it hasn't started to de laminate yet, but I suspect it will.

Generally, most people will mill this log by rotating it 90° so that the major check is now horizontal and parallel to the mill deck, but this would put shake in almost every single wide board, especially on the shaken side.  There would be few usable to the shake boundary, but others would be dead boards off the mill.