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Measure with a micrometer, mark with a crayon, cut it with an axe

Started by pine, May 12, 2015, 11:44:29 AM

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pine


Here goes.  My mill has been (or more precisely me and my mill have been) having an issue with rising in the cut.  Not the start of the cut but about 5-6 inches into the cut.  Everything seems normal (flat) then about 5-6 inches in, the blade rises rather quickly and then descends so that after about three more inches has descended back to the plane of the cut and proceeds normally.

I have checked alignment issues. 
I have tried to put more deflection on the guide rollers than the 1/8 inch that TK recommends in the manual, many on here say that 1/4 inch is better.
I increased the blade tension per TK's new numbers from 1200 psi on the gauge to 1300-1500psi on the gauge.
I have varied the cut entry speed from extremely slow to faster (up to the point that I will not enter faster).
I have changed the timing of speed increase after the cut entry from never (staying at a very slow crawl the entire cut) to distances well beyond the point of the rise.
I have tried various new blades straight out of the box.

None of these things has alleviated the issue of the rise at 5-6 inches (it does not happen every time but the majority of the time) .

Someone asked me what the set was on the blades I was using.  By the way this is happening on Douglas fir mostly.

I recently acquired a Cook's Hand Held Set Checker as I had no way to validly evaluate the set of the blades. What a nice piece of equipment that is.

Every so often I am reminded of that sentence in the title of the post.
Measure with a micrometer, mark with a crayon, cut it with an axe. 
The question I have: Is this one of the times that it applies?

With my new set checker I pulled a new, never before used blade out of the box and looked at it. 
The set to the outside of the band varied between never less than 0.018 and occasionally 0.020 maximum for the entire blade but averaged between 0.018 and 0.019 mostly.  Seemed quite consistent.
The set to the inside of the band varied mostly between 0.020 and 0.022 maximum (there were two teeth that were 0.018) with the average being between 0.021 and 0.022.  In general pretty consistent but very consistently set inward more that outward by about 0.003 set.
I also looked at the rakers and found them to be consistently not really straight but varied +/-0.003 of straight.  It seems to me that since they are traveling in the kerf that the +/- 0.003 set on the rakers is just a noise factor that has no impact.  (but what is the real answer as I do not know)

The main question that I have follows:  Is the differential in outboard set from inboard set enough that it could cause what I am seeing or is that also noise as far as the difference in the set of the new never used blades.  I also pulled one of my "used/dull blades" and checked it as well and it was nearly identical in set to the brand new one so not much set knocked out in my use at this point.

Obviously the set checker is very accurate (measure with a micrometer) and can read a very small deviation in set.  Is 0.003 average difference in set significant and basically are my new blades the cause because of asymmetric set anomalies or is the variance unimportant in the big scheme of it all? (mark with a crayon and cut with an axe)

PC-Urban-Sawyer

Can't answer your question but just wanted to say your title reminded me of the unofficial Navy definition of "Close Enough for Government Work".

When you measure it with a calibrated micrometer and
carefully mark it exactly with a fine piece of chalk and
have a qualified welder cut it with a well tuned blowtorch...
the end result is close enough for government work (if you do all the paperwork to document the process properly...)

Good luck!

Herb

drobertson

sounds to me if the mill is in fact level and aligned, then it is the blades, coupled with that particular batch of timber,  I've had SYP do funny stuff with the flatness of the cut, never sawn DF so blades would be on my radar,  I will say the set seems a bit on the shallow side, but, really I don't know that much, each log has it's own way of humbling me at times,
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,

Den-Den

The set you are finding seems low to me, I suspect it is at least part of the problem.  Since your problem is blade rise, I suggest that you SLIGHTLY tilt the blade down until the problem either goes away or becomes both rise and dive.
You may think that you can or may think you can't; either way, you are right.

AlaskaLes

Pine,
I just recently did a permanent mount for my mill.  Set up now on 10ea. 20' steel pilings and it is VERY solid and running within about 1/2 of a 1/8" laser level dot over the entire length of the 25' bed.  That having been said, I was doing everything to level the blade to the bunks per standard manuals. The solution for me was to add about 1/2 a degree of down angle at the tooth edge/front of the blade at a time; cut another pass and do it again.  Now it's at about 2 degrees of total down angle from flat.
The blade cuts straight at a very fast speed without any slowdown at entry and it only does the climb-drop now when the blade is getting dull.  Change the blade and back to straight cuts with absolutely no climb-dive cuts.  Now if it starts the wave, I know the blade is getting dull.
This was not in any manual, just something I was trying as an attempt to correct the same problem that you're having, worked like a charm.
We cut White Birch and White Spruce primarily.
Good Luck
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hackberry jake

I agree that tilting the blade downward a couple degrees should help, also make sure the band is running centered on your band wheels.
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EZ Boardwalk Jr. With 20hp Honda, 25' of track, and homemade setworks. 32x18 sawshed. 24x40 insulated shop. 30hp kubota with fel. 1978 Massey ferguson 230.

sandsawmill14

pine  i have the same problem mainly when sawing syp. before you change ANYTHING  next time you see the "hump" at the end of turn log around and saw from other end. i have had logs do it from both ends but not normally. I have had this problem with both mills ( hudson and timberking b20) for the last 10 yrs. If you are running new blades from more than 1 box it is not the blades  you might get 1 bad box but not 2. I would bet its pressure in the log but i dont know. but i do know i never change anything because of it.  its just comes and goes as it wants. remember "it'll plane out"  :D :D :D

          If you were sawing hardwoods it would be all together different.
  what kinda mill are you running?
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

Delawhere Jack

Quote from: sandsawmill14 on May 12, 2015, 05:59:57 PM
pine  i have the same problem mainly when sawing syp. before you change ANYTHING  next time you see the "hump" at the end of turn log around and saw from other end. ....

Yep. What SSM14 said. Does this happen all the time, or just occasionally? When it happens, are you milling the butt log from the stump end?

I get this often when the log was cut very low to the ground and has a lot of root flare. Mostly an issue in harder hardwoods, but it happens in other woods sometimes. It's due to the tension in the wood near the stump. Magicman confirmed this in a thread about a year ago. And if he says so, I believe it. Cutting from the upper end of the log will minimize, but not eliminate the issue.

Ocklawahaboy

I believe the term is compression wood.  The wood is denser and the grain pattern is wonky [scientific term].  Happens at the butt.  Magic man posted good pics once.  That's the first thing I thought of.

Ox

AlaskaLes has a very good suggestion.  I would follow what he has done to try to fix your problem.
The other suggestions are worth a look as well.
I also think your blades don't have enough set.  How about increasing the set to .025 for starters?  Pretty sure the set you described is more for hardwoods.
K.I.S.S. - Keep It Simple Stupid
Use it up, wear it out, make it do or do without
1989 GMC 3500 4x4 diesel dump and plow truck, 1964 Oliver 1600 Industrial with Parsons loader and backhoe, 1986 Zetor 5211, Cat's Claw sharpener, single tooth setter, homemade Linn Lumber 1900 style mill, old tools

coastlogger

Not nearly enough set IMO. Try 30 thou. Im betting itll cut straight every time.
clgr

4x4American

I've had good luck running .018"-.022" set.  Cooks recommended me to run .015" set in frozen wood and .018" or so in the warmer months.  Haven't had any problems.  Cook's and WM make a guide roller adjustment tool that will accurately help you set the angle on your guides.  I don't know of a better way to test the flatness of your guides.  A level is not accurate enough.  I had similar problems, after I got the tool and adjusted the guides proper, my problems went away. 
Boy, back in my day..

Brucer

For Douglas-Fir I use 10° blades set at 0.025. A difference of 0.003 from side to side is a bit more than I like -- I try for 0.001 when I set.

I've had a few cases similar to what you describe. A few times it has been an obvious misalignment problem. Most of the time it was due to poor sharpening or bad setting.

For many years I had my blades set. The first guy was excellent, but after he retired I started to have problems. Things went OK at first with the new guy (he'd ran a mill for years and did his own sharpening). After a while he got too busy sharpening so he automated; things started to go downhill after that. I had several instances of the blade climbing and dropping again at the start of the cut, and every time it was because of poor sharpening or bad setting. I think the problem was that he wasn't paying close enough attention to the automatic setter.

Not a single problem since I started setting and sharpening my own blades.

If you have the same problem with different blades in the same log, it's an easy check to see it the log orientation makes a difference.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

Bluejay27

I had an issue with the blade diving on my mill and aligned the whole thing twice as well as checking blade set. I ended up bumping it up all the way to 0.035" and it didn't really affect the problem. I had checked drive belt tension and it was proper, but I finally took a good look yesterday and realized the belt was worn enough that it road on the edge of the pulley, not the grooves. I replaced it and today I cut faster than I realized was possible. The motor sounded happy, finally being able to transfer power without basically a torque-limiter for a belt.

So it might not be causing your problem, but if you've checked belt tension, be sure to also check belt condition. My belt didn't look too bad except for shiny spots up in the root of the vee, but that's all it takes to slow down in a cut and start diving.
'98 Wood-Mizer LT40HDD42 Super, '08 LT40HDG28, '15 LT70HDD55-RW, '93 Clark GPX25 Forklift, '99 Ford F550

sandsawmill14

what is the total kerf you guys have with the wider sets. I run the factory set and have never checked or set a blade. I changed to wm blades three weeks ago so I could try their resharp service but havent got my first box back to try them yet. I set up autoship so I get 10 new blades every friday. 10 a week usually will do me but if I run out I sharpen a few with the catclaw sharpener to get by till they get here.
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

4x4American

good point, bj27, make sure your bandwheel belts are good.  If the band is touching metal at all they're done.  If your bandwheel belts are shot, usually your tracking will be off. 


Another thing to test: tension the blade to operating tension, throttle up and spin the band for a couple two-three-five or ten seconds.  Shut down the mill, throw away the key, then turn a bandwheel backwards five revolutions.  If the blade tracking doesn't stay the same then you prolly have bad belts.
Boy, back in my day..

barbender

I had the same issue as Bluejay27. My triple v drive belt had worn enough that it was touching the bottom of the grooves, so even with proper tension the belt was slipping. It's not the squeelin', screamin', alternator belt slipping kind of thing either. You don't really hear the belt slipping, I would just notice the mill seemed to cut really hard in wide cuts, and I would get a wave no matter how slow I went. Also, the engine didn't sound like it was loaded like it should have been. Something to check, anyhow ;)
Too many irons in the fire

ladylake



Pine  .
    I think your running a TK 1600, did you put a little piece of plastic above the movable guide arm to keep it from rising up when cutting and keeping the down pressure at 1/4".   Otherwise less hook angle will not raise in the cut as bad as 10°.  Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

Ox

How about trying a 4* blade?  I know it solves a lot of problems with troublesome logs.
I ground a 10* blade down to 4* for some really old and seasoned black locust.  Slower cut but straight and smooth.  .020 set on the teeth.
How do you guys get the little circle for the degree symbol when typing?
K.I.S.S. - Keep It Simple Stupid
Use it up, wear it out, make it do or do without
1989 GMC 3500 4x4 diesel dump and plow truck, 1964 Oliver 1600 Industrial with Parsons loader and backhoe, 1986 Zetor 5211, Cat's Claw sharpener, single tooth setter, homemade Linn Lumber 1900 style mill, old tools

redprospector

You don't have enough set for one thing. Doug Fir sawdust expands a lot when released, the wider the cut, the more set you need. I'd start out at about a 25 thou. set and you may wind up at 30. Depends on your logs.
It's always a good idea to stay on top of your belts, both drive and wheel.
I think it may be a combination of too little set, and maybe a slipping drive belt.
1996 Timber King B-20 with 14' extension, Morgan Mini Scragg Mill, Fastline Band Scragg Mill (project), 1973 JD 440-b skidder, 2008 Bobcat T-320 with buckets, grapple, auger, Tushogg mulching head, etc., 2006 Fecon FTX-90L with Bull Hog 74SS head, 1994 Vermeer 1250 BC Chipper. A bunch of chainsaws.

pine

One responder answered the one question I asked by saying that 0.003 was too much differential between inboard and outboard set which is what I thought but no one else commented on it. (Thank you @Brucer)
No one commented on the raker/straight tooth variance away from vertical so that must be an ok variance? 
I thought the set was a little low as the sawdust has been quite powdery so based on the responses I will up the set and make it symmetrical (or at least try to do better than the manufacturer's new blades were)

The set was what the blades came from the manufacturer with and I have not changed them.  I was concentrating on milling and was going to wait on blade sharpening/setting until I knew any issues that came up were not from my setting/sharpening skills.  Thus I was just going through the blades that came with the mill (lots of them) and putting them off to the side for future setting/sharpening.  Maybe I need to start setting/sharpening earlier than planned to remove the variable of the new blades that cause the problem. (and here I was trying not to inject my setting/sharpening skills as a variable.)  I have read where so many folks post not to learn both milling and blade sharpening/setting at the same time.
The Cooks setter/sharpener is being put to work rather than waiting any longer.

@ladylake I have a 2200 and am not familiar with the piece of plastic?

The band belts are wearing but still ok and the tracking is perfect, after I adjusted it.  Was not that good when I received the mill (another story)

Cooks advises tilting the blade, TK does not but I will give it a try as well.

The one thing I want to do is change one variable at a time, other wise I will never know what actually resolved the issue.

beenthere

pine
If you have done much reading of posts on the Forum, I'd think the conclusion would be that the blade must be tip-top shape first... the rest of the saw machine comes second.

The equipment cannot, IMO, make up for a blade that needs sharpening and setting. Just no way.

Seems like you are on the right track now. :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

pine

Quote from: beenthere on May 13, 2015, 03:40:49 PM
pine
If you have done much reading of posts on the Forum, I'd think the conclusion would be that the blade must be tip-top shape first... the rest of the saw machine comes second.

The equipment cannot, IMO, make up for a blade that needs sharpening and setting. Just no way.

Seems like you are on the right track now. :)

Beenthere
There has been no reason to believe that the blades were not in "tip-top shape first" up until the time that I had ruled out all the items that were detailed in the OP.  They were brand new.   Yes there can always be a bad blade or two, but all of them.  :-\ The manufacturer of the blades is a very reputable company and until I purchased the manual hand held set checker from Cook's I would not have known of the small variance in set which has only been commented on by Brucer.  No one else has commented on it.  There have been nearly equal comments about whether the set was enough or not from different responders so even that seems quite varied in opinion.

There have been many very helpful postings and I thank those folks for doing so and hope others chime in with helpful hints as well.

drobertson

if the lumber is still wavy, or, has a hump, and the blades are good, then the alignment somewhere has to be out.  A head scratcher but one that can be figured out, 
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,

sandsawmill14

pine i dont know about the +/- .003 on the set but i dont see any way it can matter other than tooth marks on the lumber. but i do know most  tolerances on the mill are more than .003. unless its for a special use the tolerance for bearings are .0015. Im not saying yall are wrong about liking more or less set or holding to .001 tolerance but this will NOT solve  his problem. the set is how you like it once you get out side of factory specs. everyone saws a little different. for an example ladylake and i both run timberking b 20s and he said using a 1/4 inch down pressure would help where i run absolutely 0 down pressure, i can saw faster and flatter than with the down pressure( ladylake I tried it again after we discussed this a few months ago) i dont know why but thats how it is.
pine when i am sawing syp from butt end i will get that bump in the first 3-8" and saw rest of the log perfectly flat. some days it will happen on 1/3 of logs some days it will only happen 2 or 3 logs. sawing from the top end it doesnt happen as much but still happens. I rarely see it in hardwood where in a early post someone said hardwood was worse.  but anyway i hope you figure it out soon :)
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

Andre

Quote from: Ox on May 13, 2015, 12:25:50 PM
How do you guys get the little circle for the degree symbol when typing?


You can get any character your computer can display by using the "Alt Key Codes"
http://symbolcodes.tlt.psu.edu/accents/codealt.html
Note that when using the forums editor some of the key combinations will be interpreted as Hot Keys and cause no end of trouble.  In that case you can type the Alt Key Code into notepad or some other simple text editor and copy and paste into the forums editor.

But also the forums editor does have some special characters as icons, the one for the deg symbol is just above the happy new year guy.

See ya
  Andre' B.

Ox

Andre - thanks for that info.  I got a PM from another member saying the same thing.  I never really realized all the gizmos up there... ::) :D
pine - I've found that when setting a blade there always seems to be several teeth that will push over farther than the rest, almost like they're a bit softer somewhere.  Which means the set will be up to .005 and sometimes .007 or so more on those few teeth.  Usually around .003 to .005 if I remember right.  It matters not except for tooth marks in the cut.  If you wanted to spend longer on setting the blade to the point of perfection I suppose you could take some pliers, bend it back and then readjust the setter for that one specific tooth and get it spot on.  Then you'd have to readjust the setter BACK to where you want it for the majority of the teeth.  Too much time for no improvement in cutting IMHO.
Every blade sets just a little different.  I've never been able to leave the setter at the same adjustment for any blade yet that I can remember.  I'm sure it's been brought back to the same adjustments for two different blades at one time or nother but not two in a row.
K.I.S.S. - Keep It Simple Stupid
Use it up, wear it out, make it do or do without
1989 GMC 3500 4x4 diesel dump and plow truck, 1964 Oliver 1600 Industrial with Parsons loader and backhoe, 1986 Zetor 5211, Cat's Claw sharpener, single tooth setter, homemade Linn Lumber 1900 style mill, old tools

4x4American

Quote from: Ox on May 13, 2015, 09:48:00 PM
pine - I've found that when setting a blade there always seems to be several teeth that will push over farther than the rest, almost like they're a bit softer somewhere.


I have found the same thing.  It pithes me off  :-X
Boy, back in my day..

pine

Quote from: sandsawmill14 on May 13, 2015, 08:46:32 PM
pine when i am sawing syp from butt end i will get that bump in the first 3-8" and saw rest of the log perfectly flat. some days it will happen on 1/3 of logs some days it will only happen 2 or 3 logs. sawing from the top end it doesnt happen as much but still happens. I rarely see it in hardwood where in a early post someone said hardwood was worse.  but anyway i hope you figure it out soon :)

Sandsawmill
Thank you very much for the comments.  I will pay real close attention to it and see if it happens more from the butt end or not.  Can't say I remember right now but could have been that. For several reasons I was doing a lot of butt end sawing a the time.
Really appreciate it your suggestions.

Ox
Thanks for the comments.


sandsawmill14

i think you will like the cooks sharpener once you get it figured out. IMO they are well built simple machines. :)
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

Ox

K.I.S.S. - Keep It Simple Stupid
Use it up, wear it out, make it do or do without
1989 GMC 3500 4x4 diesel dump and plow truck, 1964 Oliver 1600 Industrial with Parsons loader and backhoe, 1986 Zetor 5211, Cat's Claw sharpener, single tooth setter, homemade Linn Lumber 1900 style mill, old tools

4x4American

Boy, back in my day..

bkaimwood

.003" differentiation on hook set should make nooooo difference...just an opinion...interesting thing I never thought about...with no means of side tracking this thread...I use the same blades all the time...they cut everything great...but when I cut large white pine, I get heavy kerf marks...always attributed it to weak blade tension...but never bothered to look into it...it only happens when I slab white pine for tops, 24" or so...never persued it because the "clientele" seem to like its more rustic appearance. I call cooks, tell them mill specs, and tell them that I saw the ugliest, hardest garbage out there, and they deliver?? I'm not blade smart...I could learn much from this thread...
bk

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