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Another Lesson Learned

Started by Billbob, February 03, 2014, 06:09:20 PM

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Billbob

My brother in-law and I were milling this afternoon.  Bandsaw was working great.  Lumber coming out to true dimension until we got the the last log of the day.  A 12' pine log.  We got it into a 9" cant, measured the ends and found a 5/8" difference between the two ends.  Checked level on the log bunks and the rails.  All OK.  Tried trimming the cant.  Same thing happened.  We fiddled and farted.  Couldn't figure out what was wrong.  We squared the cant again, immediately turned it 180 degrees.  The cant lay flat on all the log bunks.  I stood there and watched one end bow up a good 1/4"!  Then I realized that the problem was the log.  When I cut the tree it had a branch as big as your thigh.  This huge knot was at one end of the saw log.  As we trimmed the log the stress the tree had been under because of the limb was being released causing the cant to bow!
Woodland Hm126 sawmill, LS 72hp tractor with FEL, homemade log winch, 8ft pulp trailer, Husqvarna 50, Husqvarna 353, homemade wood splitter, 12ft dump trailer, Polaris Sportsman 500 with ATV dump trailer

jmouton

             had the same thing happen to me  with  an oak log a while back  , couldt figure it out for a while, but then like you i noticed one end was bowed up a quarter or so  , took me a while , measured the bunks and thought for a while ,,finally  got it


                                                                                                           jim
lt-40 wide ,,bobcat,sterling tandem flatbed log truck,10 ton trailer, stihl 075,041,029,066,and a 2017 f-350,oh and an edger

thecfarm

Wait until there is a silver of wood on a bunk.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

drobertson

I feel your pain,  it gets better, and worse, logs are like cats, a mind of their own,       david
only have a few chain saws I'm not suppose to use, but will at times, one dog Dolly, pretty good dog, just not sure what for yet,  working on getting the gardening back in order, and kinda thinking on maybe a small bbq bizz,  thinking about it,

Magicman

Yes, that tree grew supporting the unbalanced weight of that limb.  The stored up potential energy in the log was released as you took boards off.

When this happens with me, I always point it out to the customer so that they can watch and understand that it is not me or the sawmill.  Very Important.   ;)
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

bandmiller2

BB, that's the nature of some logs, if you don't need the wood right away set that cant aside let it dry some and work out some of the demons then recut at a later date. Most claim you can keep turning the cant to relieve tension, I just seem to get a bunch of bowed boards. Frank C.
A man armed with common sense is packing a big piece

Billbob

The tree was a white pine.  The bottom 8' produced a lot of beautiful 10" boards that are mostly clear of knots but the middle of the next 12' section had some old damage on the outside about a foot long and 6" wide.  The kind of damage a porcupine will do when it's having lunch.  The wood in this log had a heavy red tinge to it.  So maybe the tree was starting to die out though you wouldn't know it from looking at the tree as all the branches were good with lush needles.

I cut this tree specifically for a good friend of mine.  He's going to use the lumber to make a toy box with dove tail corners for his 2 year old grandson.  I sawed the boards 1 1/4" thick and will plane them down to 1".  I think my friend will be happy with the results.
Woodland Hm126 sawmill, LS 72hp tractor with FEL, homemade log winch, 8ft pulp trailer, Husqvarna 50, Husqvarna 353, homemade wood splitter, 12ft dump trailer, Polaris Sportsman 500 with ATV dump trailer

customsawyer

My Uncle was watching me saw last week and I was showing him how the log would move as I sawed. He just stood there shaking his head and kept saying he would have never believed it if he hadn't seen it. When I am cutting the long timbers I have seen the far end of the log bow up more than 6" off the mill.
Two LT70s, Nyle L200 kiln, 4 head Pinheiro planer, 30" double surface Cantek planer, Lucas dedicated slabber, Slabmizer, and enough rolling stock and chainsaws to keep it all running.
www.thecustomsawyer.com

Billbob

That's what happened here also.  My brother in-law was sawing a 1" board off the cant.  By the time he got to the half way point the far end of the board had bowed 3" off the cant.
Woodland Hm126 sawmill, LS 72hp tractor with FEL, homemade log winch, 8ft pulp trailer, Husqvarna 50, Husqvarna 353, homemade wood splitter, 12ft dump trailer, Polaris Sportsman 500 with ATV dump trailer

WDH

You know that you have trouble when you are sawing a board and the back end of the board slaps you in the back  :D.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

NMFP

Ahhhhh the lessons of Compression and Tension wood.  Thats actually what my next lecture is about and how to minimize stresses when sawing logs.

Hope my students pay attention!

Cedarman

One thing we do to eliminate the thick and thin lumber from bowing logs is to have a person lift the far end of the bowed cant until the saw end touches the bed.  Saw down the log until the saw reaches the center.  The cant may need to be lowered as the saw goes along keeping the bottom of the log on the bed.  After halfway, the offbearer goes to the sawed end, lifts the cant the necessary amount and the sawyer continues to the end of the cant.  We do this for especially long wood.  It is a little slow, but the quality of the wood is much improved.
Once the cant is down to about 3" or so, heavy weights can be placed at the ends, holding the cant down to the bed.  We use  unsawed cants.  Again, a little time consuming, but saving  $1.50 lumber makes it pay.
I am in the pink when sawing cedar.

Billbob

We tried that.  Didn't work.  My brother in-law is a skinny fella! :laugh:
Woodland Hm126 sawmill, LS 72hp tractor with FEL, homemade log winch, 8ft pulp trailer, Husqvarna 50, Husqvarna 353, homemade wood splitter, 12ft dump trailer, Polaris Sportsman 500 with ATV dump trailer

WDH

My back hurts just thinking about it. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Billbob

Did much better today.  We milled up a few large 12' spruce.  Everything went good.  No warping, yawing or bowing.  Just a bunch of groans, moans and creeks from the two old guys working the mill.
Woodland Hm126 sawmill, LS 72hp tractor with FEL, homemade log winch, 8ft pulp trailer, Husqvarna 50, Husqvarna 353, homemade wood splitter, 12ft dump trailer, Polaris Sportsman 500 with ATV dump trailer

GDinMaine

Last Summer I squared up a cant and as I was sawing the first board it started curving SIDEWAYS  smiley_furious3 smiley_furious3 smiley_furious3.  By the time I was five feet into the eight foot cut the board curved about 2-3" to one side but otherwise was laying mostly flat on the cant.  I stopped and showed the log's owner what was happening. Several more boards from that log did the same thing. I just shook my head and didn't know what to do.
It's the going that counts not the distance!

WM LT-40HD-D42

WDH

I you split a log in the pith, and then saw both halves where the pith is on one side of every board, the boards usually will side bend like a "c". 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Magicman

Quote from: GDinMaine on February 04, 2014, 09:39:41 PM
Last Summer I squared up a cant and as I was sawing the first board it started curving SIDEWAYS
Setting the log up so that your final face opening and saw through is from either the hump or horn side will eliminate or at least minimize this.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

dboyt

If the log is bowing sideways, it might help to rotate it 90°.  Bowing up or down is a lot easier to deal with.

At least tension in the log is a good reason for taper in the cant.  A while back, I left the toe roller up, and didn't realize it until I sawed into it!  Ouch!
Norwood MX34 Pro portable sawmill, 8N Ford, Lewis Winch

LittleJohn

One of the first summers sawing with my dad, as hobbyists, we had a log that was more saddle than white pine.  The 8' log had about a 12" bow in it; needless to say a lot of whittling and fiddling to get boards off of it.

How about about this DUMB mistake; same mill different summer, milling spruce with witched taper, so of course had to use the manual leveling screw adjustment (on LT40) to support little end of log.  Stop me now if you have done this, cut log til flat on one side, then flip over till you get a few boards and forget to drop leveling - I wanted a huge door stop out of the middle of the log anyway  :-[

GDinMaine

Quote from: WDH on February 05, 2014, 07:28:43 AM
I you split a log in the pith, and then saw both halves where the pith is on one side of every board, the boards usually will side bend like a "c".

It was not split, but that's good to know.

Quote from: Magicman on February 05, 2014, 07:34:34 AM
Quote from: GDinMaine on February 04, 2014, 09:39:41 PM
Last Summer I squared up a cant and as I was sawing the first board it started curving SIDEWAYS
Setting the log up so that your final face opening and saw through is from either the hump or horn side will eliminate or at least minimize this.

Interesting you mention that.  I got into the habit of sawing the "horns" off first and then do the rest.  But if I follow your method I would have to lay the log "on it's side" to finish with the hump or horn. Will try that next time.
It's the going that counts not the distance!

WM LT-40HD-D42

Sixacresand

Quote from: customsawyer on February 04, 2014, 06:13:38 AM
My Uncle was watching me saw last week and I was showing him how the log would move as I sawed. He just stood there shaking his head and kept saying he would have never believed it if he hadn't seen it. When I am cutting the long timbers I have seen the far end of the log bow up more than 6" off the mill.
The time I watched you saw a long log down in Hazelhurzt, it rose up off the bed.  I thought you were doing tricks with the mill.   I was impressed.  ;D
"Sometimes you can make more hay with less equipment if you just use your head."  Tom, Forestry Forum.  Tenth year with a LT40 Woodmizer,

Magicman

Quote from: GDinMaine on February 05, 2014, 12:34:34 PM
Interesting you mention that.  I got into the habit of sawing the "horns" off first and then do the rest.  But if I follow your method I would have to lay the log "on it's side" to finish with the hump or horn. Will try that next time.
You are very correct if you turn 90° for each face opening.  I always lay the log with the horns toward the loader for the first face opening.  The horns come off with the second face opening.  That then positions the log for the hump side to come off last. 

If the first face is opened with the horns facing the side supports they often will extend past the side supports and interfere with the blade guide, etc. as the first face is opened.

This method produces lumber that might bow, but not crook.  Proper stickering will take care of the bow.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Cedarman

If you saw a little too high with the horns up, it is easy to correct.  Very seldom will you saw too deep, usually too light.

Even with a good cedar log you can get a little sidebend as you saw the cant.  Amazing watching the board move sideways as the saw goes forward.  Edging 1/2" off each edge will normally take care of the problem.  Rather deal with that than thick and thin boards.
Some logs are like boxes of crackerjacks, you never know what kind of surprize you will get.
I am in the pink when sawing cedar.

Peter Drouin

I do it the way Magicman does, if you cut trees try to cut straight logs. Crooked logs make crooked lumber every time :D ;D
A&P saw Mill LLC.
45' of Wood Mizer, cutting since 1987.
License NH softwood grader.

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