Ok, whats up. I just cant seem get my 3/8" (stihl 20") chain to cut decent. I have a northern tool sharpener, the one that swept the forum here a couple of years ago. My chain looks like it is sharpened decent. But when I go to cut with it, it keeps curving to my left hand side the further down I cut. To the point where the chain and bar wont cut through the piece of wood because the bar will wedge itself into the log being its not strait. Is it because I didnt get the chain sharpened evenly? Or maybe my bar needs attention, or the rakers may need filing? I dont have any trouble sharpening the 1/4" chain on my smaller saw, but I haven't quite been able to get my larger chains to work decent.
Chain sharpening
- Thread starter reaperman
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blackdogon57
Addicted to ArboristSite
Try a caliper ( I just use adjustable wrench) on both sides of the cutters. They need to be the same width on each side or you will cut crooked and bar will get hot.
jburlingham
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it could be a variety of things. Most likely cutters arnt the same left to right, I believe I have read that some of the grinders don't tilt enough to get exactly the same both way, and it could be grinding longer on one then the other.
I would check to see if they are the same length all the way around and then check all the angles. after that put the bar edge on a piece of glass or verified straight edge to see if the bar has worn unevenly. Also check all the rakers.
I would check to see if they are the same length all the way around and then check all the angles. after that put the bar edge on a piece of glass or verified straight edge to see if the bar has worn unevenly. Also check all the rakers.
Butch(OH)
Addicted to ArboristSite
The cutters do not have to be the same on each side for the saw to cut straight. Except in extreem cases of poor sharpening skills it's the bar. Go buy a new chain and watch it cut crooked too, then take a look at the problem, the bar. It is either worn down further on one side than the other or the groove is worn out or both. Any saw shop worthy of the name can grind the rails true and close the groove up as long as the groove isnt too far gone. You can grind the rails yourself on a disk or belt sander and the rest set to 90.
blackdogon57
Addicted to ArboristSite
From Oregon website:
Several things can make a chain cut crooked, or pull to one side. The following are the causes and the remedies:
Uneven top plates can cause a chain to cut crooked. It's important to keep all top plates equal length.
Dull cutters damaged by rocks can cause a chain to cut crooked. It's important to remove all damage from cutters prior to cutting. Cutting with a dull chain can accelerate wear to the bar and chain.
Different depth gauge settings from left to right. Keep all depth gauge settings equal from left to right.
Different top-plate angles from left to right. If you sharpen your chain at a 25° setting on your left hand, your right hand cutters should match.
A worn guide bar. A badly worn bar cannot be repaired. If your system is cutting crooked and you have narrowed it down to the bar, more than likely the rails, or the inside of the bar, are damaged beyond repair.
Several things can make a chain cut crooked, or pull to one side. The following are the causes and the remedies:
Uneven top plates can cause a chain to cut crooked. It's important to keep all top plates equal length.
Dull cutters damaged by rocks can cause a chain to cut crooked. It's important to remove all damage from cutters prior to cutting. Cutting with a dull chain can accelerate wear to the bar and chain.
Different depth gauge settings from left to right. Keep all depth gauge settings equal from left to right.
Different top-plate angles from left to right. If you sharpen your chain at a 25° setting on your left hand, your right hand cutters should match.
A worn guide bar. A badly worn bar cannot be repaired. If your system is cutting crooked and you have narrowed it down to the bar, more than likely the rails, or the inside of the bar, are damaged beyond repair.
Suz
ArboristSite Guru
Cutting a curve that bad almost sounds like you didn't sharpen both sides of the chain but only one.
Sorry, but I had to throw that one in on the conversation.
I used to have that trouble when I first started filing chains. Because it seemed to me to be easier to sharpen one set of teeth than the other side, one set were sharper than the other and my chains would cut crooked.
Sorry, but I had to throw that one in on the conversation.
I used to have that trouble when I first started filing chains. Because it seemed to me to be easier to sharpen one set of teeth than the other side, one set were sharper than the other and my chains would cut crooked.
Cutting corners
I would wager my sawdust collection that it is the guidebar. Best surface I have found to check them is one of those free samples of granite that can be obtained from a local kitchen dealer, a nice long piece, like from a backsplash works best. It fancies up your work area too!
I would wager my sawdust collection that it is the guidebar. Best surface I have found to check them is one of those free samples of granite that can be obtained from a local kitchen dealer, a nice long piece, like from a backsplash works best. It fancies up your work area too!
Easy way to tell if bar problem or uneven teeth, just reverse bar.
If it still curves *left* suspect chain/teeth
Seems a lot of people find it easier to sharpen the teeth that face in one particular direction on the saw
This half gets better sharpen, and/or shorter teeth........curve balls
If it still curves *left* suspect chain/teeth
Seems a lot of people find it easier to sharpen the teeth that face in one particular direction on the saw
This half gets better sharpen, and/or shorter teeth........curve balls
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timothykamp
ArboristSite Member
Last Friday I too had the same problem of a saw cutting hard to the left. Anything over 5" thick I couldnt get through because the cut was so curved. I switched chains and problem immediately went away. Had the chain resharpened by an old timer who knows how to do it well and it cuts straight again.
Tim
Tim
blackdogon57
Addicted to ArboristSite
Good advice - rep for you !
KsWoodsMan
Addicted to ArboristSite
It sounds to me like half the chain is 'dull' or the drags arent even from side to side. If it is sharp it should "self feed" into the log without pressure from the operator.
Sharpening the chain involves more than just getting the top plate sharp. The sides sever the chips loose from the sides of the cut. The point pulls the toplate in to the depth the rakers or drags allow.
If the drags are set uneven, one side will bite harder than the other when it goes into the wood/log.
When the chain twists it rides one side of the bar harder than the other and causes uneven wear to the rails and inside the groove.
Keeping the tooth length as well as the depth setting on the drags even on both sides minimizes uneven wear and crooked cutting.
If the chain has been like this long enough the heels on the chain can have uneven wear as well as the bar rails. Swapping on a new chain or bar may correct the problem or it may just correct half of it. Optimizing your sharpening techinique , having it done by a reputable charpening service or just getting an extra loop would probaly square things up for you.
Sharpening the chain involves more than just getting the top plate sharp. The sides sever the chips loose from the sides of the cut. The point pulls the toplate in to the depth the rakers or drags allow.
If the drags are set uneven, one side will bite harder than the other when it goes into the wood/log.
When the chain twists it rides one side of the bar harder than the other and causes uneven wear to the rails and inside the groove.
Keeping the tooth length as well as the depth setting on the drags even on both sides minimizes uneven wear and crooked cutting.
If the chain has been like this long enough the heels on the chain can have uneven wear as well as the bar rails. Swapping on a new chain or bar may correct the problem or it may just correct half of it. Optimizing your sharpening techinique , having it done by a reputable charpening service or just getting an extra loop would probaly square things up for you.
kzack
ArboristSite Lurker
reaperman,
I had this same problem a while back. When I felt my chain teeth after I manually sharpened them, they felt sharp. I checked the bar and indeed one edge was worn down because I used the saw so much while cutting crooked. I thought that was the problem so I ground the edges of the bar to be even, put the chain back on. The problem persisted.
Check your chain teeth with a magnifying glass. This is what I did and one side was indeed dull. I had it professionally sharpened and it was fine. I check my teeth with a magnifying glass when sharpening now.
Keith
I had this same problem a while back. When I felt my chain teeth after I manually sharpened them, they felt sharp. I checked the bar and indeed one edge was worn down because I used the saw so much while cutting crooked. I thought that was the problem so I ground the edges of the bar to be even, put the chain back on. The problem persisted.
Check your chain teeth with a magnifying glass. This is what I did and one side was indeed dull. I had it professionally sharpened and it was fine. I check my teeth with a magnifying glass when sharpening now.
Keith
danrclem
Addicted to ArboristSite
I just got a NT grinder and if it doesn't tilt both ways grind the casting protrusion on the bottom flat. It looks like a filling hole from the mold and they just cut it instead of grinding it off.
My grinding wheel loaded up very quickly and started making a burr on the top cutter on the left side. I haven't used my chains since I did this but I bet this would cause a saw to cut crooked. Check and see if yours is doing the same thing. Cleaning the wheel or preferably buying a new quality wheel may help this problem.
My grinding wheel loaded up very quickly and started making a burr on the top cutter on the left side. I haven't used my chains since I did this but I bet this would cause a saw to cut crooked. Check and see if yours is doing the same thing. Cleaning the wheel or preferably buying a new quality wheel may help this problem.
Thanks for the responses guys. I'll have to do a bit more of trial and error. It seems like the chain is easier to sharpen on the side where you can see the grinding wheel actually come into contact with the chain pitch. When sharpening the opposite side, the rear of the cutter blocks the chain pitch making impossible to see the grinding wheel come into contact with the cutter. And there seems to be enough slop in the grinder where its almost necessary to see the wheel come into contact with the chain. I'm sure my bar has also seen its better day. I have used that bar for more than a dozen years without any maintenance. The chain, after sharpening, seemed to cut strait for a few cuts of ash, but when I took on some wet red oak, the oak was victorious.
blackdiesel
ArboristSite Operative
your problem is the grinder. learn to do it by hand, an electric sharpener cant even come close to a correctly hand sharpend chain
slofr8
ArboristSite Operative
Even if the teeth on one side are slightly longer then the other, if the angles and depth gage is consistent it would still cut O.K.
The bar will develop a burr on the bottom that has to be ground or filed off. It'll catch on the wood as you cut. Also, if the bar has seen a lot of use the groove can widen out enough to let the chain flop around. they sell chains with slightly wider riders for this. Its likely a sharpining issue but all these things play into it.
Dan.
Kong
ArboristSite Member
This is not true, in fact it is very close to the opposite of the truth. To say an electric sharpener can't even come close to hand sharpening is almost like saying the best machine shops use guys with files rather than modern machinery but beyond that the statement is just plain wrong for a more important reason. Your hand wobbles and a properly adjusted grinder, even a cheap one, does not. That is answer alone should be enough but it goes farther than that. A grinder will duplicate the angle and the depth of any cut time after time giving a consistant and sharp edge, a file will give a different cut with every single stroke giving a wavy and inherently dull edge. A file also produces a concave surface - similar to a hollow grind on a knife edge - and while inherently a keener edge than one ground flat it is also a thiner one that dulls more quickly. This of course is just the opposite of the flat plane cut by a grinder. As you may recall from grade-school geometry a straight line results from the intersection of two plane surfaces. In our case those two surfaces creat a sharp cutting edge at the intersecton of the flat steel of the cutter and the flat side of the grinder's wheel. Sharpen one with a file and you have the flat steel of the cutter and the wavy curve from the hand held file, and that will give you something but it won't be as sharp a cutting edge as the wheel gave you.
Of course the arguement could go on and on but in the end the simple fact that in the last 300 years we have not tried to make precision machinery by having guys with files and hack saws work on blocks of raw metal tells you all one needs to know about the marvels of modern technology.
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If he can sharpen his smaller chain fine, I'm sure the grinder is okay. Sounds like the bar to me. Just eyeball the bar, if you can see any bend, it will cut circles. If the bar won't stand on edge on your table, the rails are uneven.
Back to the filing issue. I also have a NT grinder. Very nice grinder for $100. Oregon wheel from Baileys is also nice. Anyways, the chains coming out of the grinder are not as sharp as I can do with a file. However, I can take a chain that's cut barb wire and have it cutting very good in a matter of minutes.
I will admit that when I hand file I slowly get the teeth uneven. After about 10 hand sharpenings, the chain will probably get a ride on the NT.
Back to the filing issue. I also have a NT grinder. Very nice grinder for $100. Oregon wheel from Baileys is also nice. Anyways, the chains coming out of the grinder are not as sharp as I can do with a file. However, I can take a chain that's cut barb wire and have it cutting very good in a matter of minutes.
I will admit that when I hand file I slowly get the teeth uneven. After about 10 hand sharpenings, the chain will probably get a ride on the NT.
jasult
ArboristSite Operative
we do so much cutting in our excavating business that we just cary a file in pockets and file as needed. I too can hand sharpen with darn good results and much faster on site. I have the jigs too but that is used when I have time to sit and be takin my time which is RARE
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