How to center a log on a mill

[2StateTrigger]

So, I'm BRAND new to sawyering and am struggling with learning how to properly center logs on my mill.

Is there a quick and easy method of properly centering a log along it's length so as to reduce the number of cuts and the amount of time required to create a basic square post/beam out of the log?

Sorry to bore you guys with such a basic question but I'm learning that I'm wasting a ton of time by making multiple passes which is kinda upsetting me to no end....

Jeff

[WV Sawmiller]

2ST,

   What kind of mill are you talking or thinking about using? My mill has hydraulic toe boards or rollers at the front and back and I just toggle to raise the front or back. You can be precise and measure from the center of the log on both end or as most of us do most of the time just eyeball it. I will often raise the front or back to level the log then run my head the full length to see if my blade is approximately the same height from the log the entire length and adjust slightly to correct if not. When correct I'll take off the slab and maybe a flitch or two then I will often rotate 90 degrees and do the second side then lower the toe board for the next 2 sides. This is critical and I suspect most of will admit forgetting this step and cutting long embarrassing wedges.

    If you are using a manual mill without the hydraulic toebords I gather you have to jack up the low end and put a shim board or two in there till you square off the first and maybe second sides.

   Hope that answers your question.

[2StateTrigger]

WV Sawmiller,

Thx for the input...

I have a TimberKing2000 full hydraulic with the roller toeboards you've described.

Here's what I try to do....

Load log, rotate to what I believe is best position taking into account curves in the log...then I either raise the front toeboard (if the log tapers from large near blade to small) or do the opposite if the log is loaded small to large....once that's done I'll try to make my first pass so that there's an entire length of level FLAT area that's at least 3-5" in width so that when I rotate the log 90* (or 180* which I sometimes do) there's enough flat space in order to create my squared beam/post.....I hope you're able to follow my description here.....

Should I be measuring the small end diameter (say it's 10") then take 4" off (in an estimate) in efforts of coming out with a 6" post?

What's your suggestion?

[DDW_OR]

i also have a tk-2000. i made a T-square out of some scrap wood.
the top of the T is as wide as the saw bed ( round rods that the carriage roles on )
the T is used up-side-down.
the leg of the T is about 24 to 36 inches.
i use a spring clamp to mark the large end of the log, then move the T to the other end and use the toe board to raise the log to match.
cut, then rotate 90*, cut, then rotate 90*, then LOWER toe boards.

if i am doing 2x4, i now cut the "4", then rotate and cut the "2"

i try to cut my scrap slabs as 3/4 or 1.5 thick,
or 1 inch to be re-cut and used for stickers

when you are done the log should be in three groups
true lumber
usable scrap
junk and bark.

wish there was an easy way to make the sawdust into stove pellets.

FYI here is a link to some useful mods
https://forestryforum.com/board/index.php/topic,7789.msg1397352/topicseen.html#msg1397352

[Ga Mtn Man]

I have found that having the small end of the log at the front of the mill and the large end sitting on or close to a bunk speeds the process up considerably.  If your goal is to center the pith:  make one trip to the large end to find the center height (with a tape), raise the blade to that height and move it close to the small end, using the toe-rollers raise the small end until the center is at blade height.  If your goal is to level the log on the actual centers (ignoring the pith location) then:  measure the diameter of both ends (using a tape or the blade height), add the numbers together and divide by 2... the result gives you the height of the top of the small end.  Oftentimes just eye-balling for level is good enough.  There are plenty of other valid ways to do this but this is how I like to do it.      

[Sixacresand]

GMM, You should invent some kind of flashing red light (maybe a shock collar) for us amateurs to remind the us that the toe rollers are up.  :D

[WV Sawmiller]

2ST,

   I'm not real sure I am following your question. Are you trying to cut thick beams? If I wanted a 6x8 out of a 12" diameter log I make my first cut as described before. My first cut I would try to open a face at least 4 to 6 inches between the narrowest part of the bark such that I could trim a 1X4 or 1X6 based on my minimum size needed. If I wanted a 6X8 I'd cut another flitch or two to make sure the wide side of the log (my logs tend to be oval rather than actually round) had at least an 8" face then rotate 180 degrees lower the toe board and check the thickness and preset my setworks so it would land on the desired (8") mark and cut  flitches till I hit my mark, rotate 90 degrees, raise the little end to level the log, repeat opening that face and removing a flitch or two, rotate the final time, lower the toe board set my setworks and remove a slab then flitches till I hit my 6" mark then my beam would be finished and all I'd need to do would be edge my flitches.

    If the taper is long enough and I can salvage a short board or two I open the faces in 1" slices and trim out what I can salvage. If I don't want the side lumber I'd just slab everything deep and make 4 cuts.

   If cutting 4/4 or 8/4 I do the same only instead of cutting to a beam thickness I cut  the first 2 cuts to leave the cant at the width of the board(s) I want, rotate, square the 3rd side, rotate final time and start on my mark and saw boards to the bed. If cutting something like  2x4s after slabbing my 2nd cut I will cut several 4" cants as the log allows then rotate and slab, then start cut in 2" slices yielding multiple 2X4s at each pass.

    Hope that answers your question.

[D6c]

If you're just wanting to center the pith, I made a gauge that hangs on the mill frame...different saw but something similar could be made.  Do like was suggested and put the big end near a bed rail, set the gauge to the center of the big end, and then move it to the small end and adjust the toe board so the center matches the gauge.



 

[Magicman]

For normal sawing, the pith is seldom centered within the log, so orienting the log properly and centering the log is a necessity.


 
Notice that the pith is an equal distance from the top to the bottom of the log butt when the log is turned properly for the first face opening.  Now center the "log" on the top end and disregard the pith.

With off centered piths, I have seen the pith on one side of the log on one end and on the opposite side on the other end.  If you center the pith on both ends, you would have no log left.

[2StateTrigger]

i also have a tk-2000. i made a T-square out of some scrap wood.
the top of the T is as wide as the saw bed ( round rods that the carriage roles on )
the T is used up-side-down.
the leg of the T is about 24 to 36 inches.
i use a spring clamp to mark the large end of the log, then move the T to the other end and use the toe board to raise the log to match.
cut, then rotate 90*, cut, then rotate 90*, then LOWER toe boards.

if i am doing 2x4, i now cut the "4", then rotate and cut the "2"

i try to cut my scrap slabs as 3/4 or 1.5 thick,
or 1 inch to be re-cut and used for stickers

when you are done the log should be in three groups
true lumber
usable scrap
junk and bark.

wish there was an easy way to make the sawdust into stove pellets.

FYI here is a link to some useful mods
https://forestryforum.com/board/index.php/topic,7789.msg1397352/topicseen.html#msg1397352

DDW_OR, might you have several pics you could post of your T-Square?

Much appreciated.

[Brucer]

I have found that having the small end of the log at the front of the mill and the large end sitting on or close to a bunk speeds the process up considerably...
...  If your goal is to level the log on the actual centers (ignoring the pith location) then:  measure the diameter of both ends (using a tape or the blade height), add the numbers together and divide by 2... the result gives you the height of the top of the small end.

Be careful with the term "front end", as not everybody uses the same definition. Wood-Mizer calls the hitch end of the mill (which is where the operator stands) the front. That's the definition I use and I also like to have the small end of the log at the front (closest to the operator's station).

The reason for keeping the large end near a bunk (or bed rail) is so the big end doesn't move down a lot as you raise the small end.

Here's a variation you can try so you don't have to worry about the big end being close to a bunk. Raise the sawhead above the top of the log and move it so it is directly over the last bunk the log is sitting on. Lower the head until the blade just touches the top of the log -- use that number in place of the large diameter and do the calculation that Ga Mtn Man gives in his post. When you do it that way, it doesn't matter how much the big end moves when you level the log.

One things to watch for. Be sure the log is resting on the last bunk when you take the height measurement -- if the log can rock up or down, your height reading will change as you level the log. I always try to have any sweep going from side to side when I level the log this way.

[GAB]

GMM, You should invent some kind of flashing red light (maybe a shock collar) for us amateurs to remind the us that the toe rollers are up.  :D

I'm not an electrical guru, but in my mind the answer to your comment would be two lights on the control panel attached to switches that are activated by the toe rollers.  If the light is on then the roller is not all the way down.
I also have made some long wedges.
Gerald

[kelLOGg]

Here's my T-square. I glued a section of measuring tape to the T-square to match the reading of the cutting height scale.



 

[WV Sawmiller]

GAB,

   The mill makers should be reading your suggestion and if it makes them some money they should send you some of it. While they are at it they could design a warning or stop if the blade height is equal to or less than the side or clamp height. I think Kbeitz actually built something like that on his mill or it sounds like something he would have done.

   The bad thing is all these extra safeguards add to cost and maintenance. I know if they make the gas cans any safer I will never get gas out of one.

[Kbeitz]

The first time my blade skimmed off one of my dogs that was to high
I made this little arm. Now if I get to close to a dog it just stops my
head from moving. My drive wheels will just spins on the track. It has
worked really well. I'm very happy with it.



 

[DDW_OR]

DDW_OR, might you have several pics you could post of your T-Square?

Much appreciated.

large end

  
small end before toe board is raised

 

[kelLOGg]

If the pith is off center and you center the log on its geometric center what quality of lumber do you get? Seems to me that you would sometimes be sawing across the pith which is a no-no for straight lumber. So far, the only time I have centered a log end is if it contains the beginning of a crotch which is sorta like having 2 piths on that end.
Bob

[Magicman]

If every log with off centered piths were discarded/rejected, there would not be very much lumber sawed.

When the pith is badly off center such as Reply #8, you take what the log gives you.  It will still make satisfactory framing lumber which is what I am sawing.