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Sawing frozen oak

Started by sprucebunny, November 13, 2007, 05:08:58 PM

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bandmiller2

Joan, have you milled unfrozen oak without a problem?? Some light mills have problems with some blades in oak.Call Timberwolf on long Island ask for Art,tell him your problems,I bet he will send you some blades that work fine.
A man armed with common sense is packing a big piece

sprucebunny

Bandmiller2, yes. I recently cut about 400 BF of 1/2 thick and 4/4. Had some problems with the first log  but a couple days later every thing went fine. Never did try cutting the difficult one again. I suspected it was partly frozen. It looks like a featherboard  after what I did to it :D

Maybe I'll try a couple of the 9 degree. I find it hard to believe that one degree difference in hook could make a big difference ???
MS193, MS192 and an 026  Weeding and Thinning. Gilbert Champion sawmill

LOGDOG

Sprucebunny,
   
   Have you checked the alignment on your blade guide rollers recently with the alignment tool? I've got a feeling somethings not quite right. Might not be the blade.

LOGDOG

ladylake

Quote from: Tom on November 14, 2007, 09:39:28 AM
Hook angle is a relative measurement based on 0° being  vertical.  The more the tooth leans into the direction of travel, the higher the hook angle and the more aggressive the blade.  If the face is leaned to the rear, away from the direction of travel, you get a negative hook but the angle is still measured from vertical.

To change the meanings of hook and to change the relativity of the point of the tooth to the direction of travel is to redesign the science.  What you are doing is calling left, right; up, down; backwards, forwards and relying on head pressure to define feed speed when it's actually the tooth's configuration that defines it.
If someone cares to redefine the relativity, fine, but, you have to re-educate the whole rest of the world.

The more positive hook a tooth has, the more material it tries to take. until it begins to chatter.  It will either stop the blade or jump out of the wood.  The less angle, the more the point scrapes rather than digs and the less wood is removed per inch of travel. 


If you think that less hook drives the blade into the wood deeper, turn the blade around and you should cut faster than any man has ever cut before.


  Tom   I'm with you on this one, sure is confusing when people say less hook makes it bite more in hard wood or any wood. Common sense says more hook, more bite, more self feed. Seems like if you ran 0 hook the machine would have to push the blade in the wood. A good example would be a radial arm saw with a 15* hook verses a 0* hook.   Why does less hook work better in frozen or hard wood?  Still confused    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

footer

Quote from: ladylake on November 26, 2007, 03:54:08 PM
Quote from: Tom on November 14, 2007, 09:39:28 AM
Hook angle is a relative measurement based on 0° being  vertical.  The more the tooth leans into the direction of travel, the higher the hook angle and the more aggressive the blade.  If the face is leaned to the rear, away from the direction of travel, you get a negative hook but the angle is still measured from vertical.

To change the meanings of hook and to change the relativity of the point of the tooth to the direction of travel is to redesign the science.  What you are doing is calling left, right; up, down; backwards, forwards and relying on head pressure to define feed speed when it's actually the tooth's configuration that defines it.
If someone cares to redefine the relativity, fine, but, you have to re-educate the whole rest of the world.

The more positive hook a tooth has, the more material it tries to take. until it begins to chatter.  It will either stop the blade or jump out of the wood.  The less angle, the more the point scrapes rather than digs and the less wood is removed per inch of travel. 


If you think that less hook drives the blade into the wood deeper, turn the blade around and you should cut faster than any man has ever cut before.


  Tom   I'm with you on this one, sure is confusing when people say less hook makes it bite more in hard wood or any wood. Common sense says more hook, more bite, more self feed. Seems like if you ran 0 hook the machine would have to push the blade in the wood. A good example would be a radial arm saw with a 15* hook verses a 0* hook.   Why does less hook work better in frozen or hard wood?  Still confused    Steve 


I could be wrong, but I thought it has to do with the higher hook angle would dull faster in harder wood, kind of like  a square chissel chain will dull faster in some wood than the rounded corner ones.

Tom

Because the more you lean the tooth into the cut (direction of travel), the more wood it tries to remove and the more horses you need to do it.  If the wood is hard enough, the tooth will not penatrate deep enough, will quit cutting and will jump out of the wood.  It's what is called "chatter".   Either the tooth will jump out of the wood, or it will inbed itself so deeply that it brakes the engine and the engine stalls.

When the tooth is allowed to stand up straight, it is just scraping the surface of the wood and not digging in.  The curls are smaller, the blade is under less stress and there is no chattering.  A negative hook would allow the tooth to "skate" over the surface and, for the love of mike, I don't know how it would cut, but it does.  I think you see negative hook in things like steel cutting but I'm really not familiar with it.

It's kinda the same thing as digging your heels in to keep a roped horse from towing you off.  If you lay your feet flat on the ground, you will just skate along.

footer

Quote from: Tom on November 26, 2007, 09:04:12 PM
Because the more you lean the tooth into the cut (direction of travel), the more wood it tries to remove and the more horses you need to do it.  If the wood is hard enough, the tooth will not penatrate deep enough, will quit cutting and will jump out of the wood.  It's what is called "chatter".   Either the tooth will jump out of the wood, or it will inbed itself so deeply that it brakes the engine and the engine stalls.

When the tooth is allowed to stand up straight, it is just scraping the surface of the wood and not digging in.  The curls are smaller, the blade is under less stress and there is no chattering.  A negative hook would allow the tooth to "skate" over the surface and, for the love of mike, I don't know how it would cut, but it does.  I think you see negative hook in things like steel cutting but I'm really not familiar with it.

It's kinda the same thing as digging your heels in to keep a roped horse from towing you off.  If you lay your feet flat on the ground, you will just skate along.

You also see negative hook in melamine table saw blades and sliding compound miter saw and radial arm saw blades. You would think that they wouldn't cut at all, but they do.

kootenay sawyer

Hello,  Very new to your forum but been cutting wood for over 30 years. As far as frozen goes, ya freezin in and freezin out is something we all deal with in fall and spring in British Columbia but there is some things you can do to make it work. #1 fill your blade lube with windsheild washer anti-freeze and use lots of it to make your blade stay soaked. You want to try to aviod the spill from freezing back on to the cant or board before your blade passed through the cut. Go to as narrow a band as you can try to reduce the time that the blade is travelling over the freshly sawn spill. Adjust your feed speed accordingly, understand and know that there will be some logs that just cannot be cut while they are half frozen, at times we just set them aside when we run into them and let them freeze up good and saw them then. Anyhow wish you luck and keep on sawing!!!

customsawyer

I don't know this to be fact or any such thing as that but the blades with negative hook angle tendes to remind me of first watching my grandfather and then later doing it myself but have you ever used a piece of broken glass to shape a ax handle it will shave it off a bit at a time.
In the studies I have done with the blade angles and stuff there are some that teach that the more hook angle the faster the sawdust will go to the bottom of your gullet and in the harder woods the sawdust will start to spill over the gullet and past the blade which will affect your cutting as well.
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

ladylake

My  theory is that more hook is causing it to self more in harder wood, more to hook onto causing the blade to take off to which ever side has a little more set.  Just a theory.   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

SwampDonkey

Ok, here is a brush saw tooth



The top tooth is fresh out of the packaging sleeve and has a pre-sharpened and set tooth. The angle we use to sharpen the tooth is 20 °. The direction of the blade motion is to the right. Notice the negative (to the left of 90°) set of the tooth. The very tip of that blade it where the cutting takes place.


Now notice the bottom tooth. It has hit a field stone or iron and that hatched area has been taken off. The cutting edge is rounded over. It will take about twice the effort and gas to cover the same area of thinning that the well sharpened blade above does. Follow that damaged sliver down to the left and learn why. You now have a blade that is hitting the high spot which isn't sharp, so you might as well have a hub cap attacked to the saw. You do get some cutting, but you have to force the saw into the wood, which causes more friction and your saw looses power to spin the blade. ;D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

ladylake

I don't think we're talking about dull blades as you can put on a fresh one with to much hook and it wont saw straight. 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

SwampDonkey

ladylake, you are probably right. I was just looking for something to say. ;)
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

logwalker

Try throwing the gage on the blade and check that the guides are absolutely level. If it still wants to dive increase the tension and adjust the guides to a slightly upward angle. I have often wished I could just turn a dial on the guides to get thru problem logs. Anyone ever see that on a bandsaw? Joe
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Brucer

'Bout this time last year I got to try sawing some very green, very frozen white oak with my 10 degree "softwood" blades. The blade was all over the place.

We rolled the logs into the shop (they weren't very big -- came all the way from Ontario in the back of a van) and let them thaw out for a couple of days. Sawed like a dream after that.

I have problems with my blade diving when I cut Douglas-Fir with frozen sapwood. Not a problem when the blade is fully in the sapwood, not a problem when it's entirely in the heart wood. Guaranteed to dive if it hits both in the same cut.

Hey, kootenay sawyer, watcha doin' stealing my business name  ;D ;D?
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

SwampDonkey

Hey Brucer, family members bringing you logs from the east now?  ;D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

sprucebunny

Since the mill sawed fine one day and not the next, I'm guessing the problem was a combination of things that you all mentioned, but not the blade guides.

The logs have been on the ground since last spring and some of the bark is coming off so I think the outsides may be dryer. The problems always occur on the second cut- the one after the bark is off- so there could be dryer and wetter wood.
Also I think wild grain and wood tension is a factor.

If it had been my log, I would have cut it through the middle to see if it cut funny there but the customer doesn't want his oak in funny shapes  ;)

If I get caught up cutting firewood, I'll try an oak log I found in my yard.
MS193, MS192 and an 026  Weeding and Thinning. Gilbert Champion sawmill

Brucer

Quote from: SwampDonkey on November 30, 2007, 07:30:10 AM
Hey Brucer, family members bringing you logs from the east now?  ;D

Naw, family knows they're supposed to bring maple syrup ;D.

Got a lot of transplanted Ontarians and Quebecois in these parts. Something to do with the skiing.

Rossland = Red Moutain = Nance Greene & Karen Lee Gartner.
Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

jackpine

Another thing I re-learned yesterday about sawing half frozen oak. When you can not get a good cut, try changing bands. Some bands which will cut un-frozen wood just fine will not cut half frozen wood at all without waves. I believe the problem is inconsistent set in the teeth either because it was not set properly or the band hit a stone or something in the bark that affected only a few teeth. As soon as I changed bands the problem went away and I was able to saw until that band was extremely dull. I do not believe sharpness is as much of an issue as set,imho.

Bill

SwampDonkey

Brucer, seems to me job would be first priority wouldn't it? I've skied before and it didn't pay too good.  ::)  :D

I'm not educated enough in the sports arena so them names don't mean a thing to this country boy.  ;D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

getoverit

talking about negative aqngle blades and how they cut, next time you need to cut some sheet metal (barn roofing or siding), try putting a plywood blade in your skillsaw backwards

you will be amazed at how good it cuts through the tin.  It makes no sense that it will cut at all, but somehow it does.
I'm a lumberjack and I'm ok, I work all night and sleep all day

Furby

Just be careful doing that as carbides can come off and go flying.

WH_Conley

DON'T USE CARBIDE.

Don't ask me how I know this.

I was the one that always got to cut the metal, maybe because I was deaf, deef, whatever, nobody likes the scream, use hearing protection.
Bill

getoverit

plywood blades dont have carbides...
I'm a lumberjack and I'm ok, I work all night and sleep all day

Furby


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