#1 mistake-not taking all the damage off the tooth. Then, all of the above.
What's the most common MISTAKE newbies make while sharpening a chainsaw chain?
- Thread starter samuelanali
- Start date
Help Support Arborist Forum:
GerbrandR
ArboristSite Lurker
I know I only have a few posts here, I am a lurker.
Is it just me or are the topics of the TS in line with the famous Hipastore topics?
Is it just me or are the topics of the TS in line with the famous Hipastore topics?
KostasVolos
ArboristSite Operative
Regarding file backward stroke :
"Cutting" of files is done not by removing material from the blank but rather displacing material .
(...)Forming teeth: The teeth are formed by a rapidly reciprocating chisel that strikes successive blows on the file. The hardened chisel cuts into the soft blank displacing and raising the steel into the desired tooth structure.
(...)
Imagine now how each file "tooth"actually looks like: A "tilted" triangle .At one side it's almost perpendicular to the file body ,while on the opposite side it has a slope.
During forward motion of the file ,the (almost) perpendicular
(to the body of file ) side of each tooth is facing towards the material to be removed ,while the very edge is well supported from the sloped backside of each tooth.In reverse motion the sloped face of each tooth contacts /faces the material to be removed ,while the perpendicular backside does not provide adequate support to the very edge of the tooth .Put enough pressure on a backward stroke and the very edges of the teeth most likely will chip ,thus dulling the file.
(...)
Keep the file cutting
One of the quickest ways to ruin a good file is to apply too much pressure, or too little, on the forward stroke. Different materials of course require different touches; however, in general, just enough pressure should be applied to keep the file cutting. If allowed to slide over the harder metals the teeth of the file rapidly become dull, and if they are overloaded by too much pressure, they are likely to chip or clog.
On the reverse stroke, it is best to lift the file clear of the workpiece, except on very soft metals. Even then pressure should be very light, never more than the weight of the file itself.(...)
https://images-na.ssl-images-amazon.com/images/I/81h0ZOhlOXL.pdf
PS : If the video mentioned is the following :
Then I have to note that the experiment has plenty of flaws to begin with .
"Cutting" of files is done not by removing material from the blank but rather displacing material .
(...)Forming teeth: The teeth are formed by a rapidly reciprocating chisel that strikes successive blows on the file. The hardened chisel cuts into the soft blank displacing and raising the steel into the desired tooth structure.
(...)
Imagine now how each file "tooth"actually looks like: A "tilted" triangle .At one side it's almost perpendicular to the file body ,while on the opposite side it has a slope.
During forward motion of the file ,the (almost) perpendicular
(to the body of file ) side of each tooth is facing towards the material to be removed ,while the very edge is well supported from the sloped backside of each tooth.In reverse motion the sloped face of each tooth contacts /faces the material to be removed ,while the perpendicular backside does not provide adequate support to the very edge of the tooth .Put enough pressure on a backward stroke and the very edges of the teeth most likely will chip ,thus dulling the file.
(...)
Keep the file cutting
One of the quickest ways to ruin a good file is to apply too much pressure, or too little, on the forward stroke. Different materials of course require different touches; however, in general, just enough pressure should be applied to keep the file cutting. If allowed to slide over the harder metals the teeth of the file rapidly become dull, and if they are overloaded by too much pressure, they are likely to chip or clog.
On the reverse stroke, it is best to lift the file clear of the workpiece, except on very soft metals. Even then pressure should be very light, never more than the weight of the file itself.(...)
https://images-na.ssl-images-amazon.com/images/I/81h0ZOhlOXL.pdf
PS : If the video mentioned is the following :
Then I have to note that the experiment has plenty of flaws to begin with .
After the teeth are formed the file then goes to heat treatment. Thus hardening the file. To say stroking back on the file is bad for it, especially in regards to sharpening a chain, I don't buy for a second, and never seen proof of it. I could conceded if it wad a very corse file and some darn hard material, but it's not the case when sharpening a chain.
Bullsh¡t. That's only true if the file is softer than the tooth...in which case, it wouldn't work on the forward stroke, either.
Yeah, bearing down on the file on the backstroke probably isn't a great idea, but just rubbing/dragging it backwards won't hurt a thing.
KostasVolos
ArboristSite Operative
You can easily imagine the whole "edge support" thing ,just by looking the image of the file teeth on my post.
Heat treatment ( usually to a hardness above 65-70 HRC ) is the major reason that file teeth CHIP .File heat treatment makes
it's teeth unable to even slightly bend ( elastic or plastic deformation ) and actually they are extremely prone to chipping.
You also seem to neglect that chain cutters are also heat treated and Chromium plated .They are softer than a file ,but still able to dull it .( A lot of machinists use files that are 20, 30 or even more years old and are still functional .Sharpening a single chain is enough to wear out a chainsaw file .Cutters are hard enough . )
Let alone to chip it's teeth when pressure is applied during a backstroke .My previous job was a lathe machinist for more than 20 years .FWIW ,you can believe whatever you like .
After all it's your files you treat this way ,not mine.
As for the proof you 're asking for ,it's relatively easy to obtain .
Just take two brand new files of the same brand and type and use one with only forward strokes when filling and the other like a hand saw :back and forth .See with your own eyes which file
of the two will service you longer and more efficiently.
Or you can search for info from all the major file manufacturers .
If you find any of them stating that it's ok to use a file like a hand saw,I will put a piercing through my @@ .
Furthermore ,one does not need to have an exceptionally high iq to realize that with a forward stroke of the file you sharpen a chain cutter ,while with a following back stroke of the file you are dulling it again.Cutters are supposed to be sharpened one way only .
From the inside side of the cutter to the outside side .
Right ?
KostasVolos
ArboristSite Operative
Edit: Read for second time your post .I agree .
Rubbing or dragging lightly backwards won't hurt a thing ,indeed.
Nope. The video I was referring to was specifically aimed at round files when used to sharpen chainsaws. It specifically addressed the "backstroke dulling the file" issue.
Where did I say anything about putting pressure on the back stroke? I'm sure as heck not taking it out of the cutter to vitue signal I care about the file. Since we're comparing qualification I co-oped into a heavy duty diesel machine shop straight out of highs school where else frequently took on one off projects for rare engines up to customers pulling engines. We were all trained in basic machine work including manual mill and lathe work. I'm no expert machinest, and don't claim to be but I've never once seen or experienced a file wearing out from the back stroke being in contact with the base metal. Can't tell.tou how many times I've told the old machines to prove it and watched the same demonstrations to their file not lasting any longer then the same file I used.
KostasVolos
ArboristSite Operative
Applying pressure on a backward stroke of a file except dulling the file ,it dulls the cutters too.
Actually ,with a forward stroke the file teeth function as a chisel ,removing material ,
while with a backward stroke the file teeth are displacing material ,
functioning rather like a plow .
Thus dulling the chain cutter also.
KostasVolos
ArboristSite Operative
Now you got me confused .
Most probably I have misunderstood .
Dragging lightly the file backwards is no big deal ,indeed.
Is that what you meant ?
That would be a common opinion, which had never been demonstrated, to my knowledge. "Functioning like a plow" doesn't exactly make any sense to me, either. Are you suggesting that the cutter is so soft it acquires furrow? Having spent a good deal of time studying cutting edges of microtome knives under a microscope, I can assure you that every metal cutting edge has furrows in it. Brand new razor blades look like a giant bandsaw blade if you look real close, and they make those edges by plowing tiny, tiny furrows into the metal. Sorry, but I think your "plowing" analogy is invalid.
BTW: The electron microscopes avoid that jagged cutting edge problem by using fractured glass cutters for really tiny work, and diamond knives for the finest quality of cut.
There are folks here that believe the chain should only be sharpened by stroking away from the cutting edge, and others will tell you that you are just making burrs and not sharpening if you don't stroke into the cutting edge. Myself, I think either way works fine, although the file chatters more stroking into the tooth from the tip of the bar, and less so stroking forward from the rear of the bar. It's a matter of preference. Kindly notice that all the filing jigs allow stroking in either direction.
I do know this: very few saw sharpeners reverse the direction of the wheel for grinding. So when grinding, you will always be hitting one side of the chain in a different direction the other side. Argueing that dragging backwards with the file will be dulling the chain is pretty much a mistaken notion, unless you are buying into the theory that dragging backwards also is removing metal from the cutter.
If the file isn't removing metal going backwards, then it won't be dulling the cutter. If you admit that the file is removing metal from the cutter while being dragged backwards, then that is a strong argument for sawing away on the cutter in the style you have so fervently opposed.
Hoo boy you weren't kidding... it's quite controversial!
All I know is that I work for a large aerospace company with large machining operations and one of the managers told me the first thing he learned was only cutting in one direction with a file, haha.
I have no proof either way, but I thought it more to do with keeping the right cutter profile than saving the file.
That's a very valid point. "Aerospace" mentality isn't exactly what you find with a bunch of woodcutters, however. Some of us don't like buying file$, and we realize we'll be sharpening that perfectly honed saw again, just as soon as we run into a hidden nail in some tree that used to be a tree house.
I hope you realize that was my point also.
Yes, we're in agreement.
KostasVolos
ArboristSite Operative
Ok ,lets make it simpler .
File teeth edges are not perpendicular to the file body.
They do not face directly up ,like mountain peaks.
Teeth edges are tilted towards the tip of the file ( has to be a reason for being made this way,right ? )
IF they were like mountain peaks ,
a file would function the same no matter the direction of the stroke.
Grinding wheels are grinding the same ,no matter if the wheel turns CW or CCW ,since they do not have teeth ,but randomly placed grit.
So far ,so good.
Since the teeth edges are tilted ,they do not function the same if the stroke is forward vs if the stroke is backwards.
During the forward motion of the file ,the teeth "bite" in the material and act as a chisel ,REMOVING material.
Now,during a backward motion of the file ( with pressure applied ),
the teeth "skate" on the material and act as a plow ,DISPLACING material .They do not form the same furrows you state ,like razor blades /microtome knives have,( which actually are perpendicular to the blade's edge ,made by the tiny abrasive particles of a sharpening wheel /band/stone** ) but the displaced material looks like galling burrs on a microscope .
**
Who knows? It might be that actual galling is taking place with the removed material still on the file being "cold welded" to the surface of the cutter's edge .
If you have access to a SEM ,then it would be easy for you to confirm .
(...)Traditional honing rods do not have sharp protrusions, and the metal swarf found on the surface is observed as flattened or smeared patches of metal. This type of metal removal (or transfer) is generally termed adhesive wear. Adhesive wear occurs at points of very high pressure that occur when the contact area is very small.(...)
https://scienceofsharp.com/2018/08/22/what-does-steeling-do-part-1/Like when filling chips are trapped between a file's teeth ,while the file slides/skates backwards on a surface.Friction between the tiny surface area of the chips and the cutter edge ( both being of same steel alloy ) can cause a type of adhesion wear ,known as galling .
https://en.m.wikipedia.org/wiki/Galling
As for sharpening chain cutters ,
I'm not aware of a single person sharpening the cutters from their outer side to the inner.Neither of
a chainsaw / chain /file brand that states that is ok or possible to sharpen this way .Neither have seen it done this way.It would be really awkward ,since there's not a direct visible contact with the top plate edge or the inside of the cutter.
In every chainsaw sharpening guide or vid ,the only way I 've seen as the right way is stroking the file forward from the inner side of the cutter towards its outer side.Stihl,Husqvarna,Oregon,
Carlton,Pferd,Vallorbe,etc all state :" From inner side towards the outer side" .
I must have missed something here ...Maybe it's a well kept secret to file the other way around .
PS: I've contacted both Vallorbe and Pferd and asked them to give me a scientific explanation as to why a file dulls on a backward stroke.Let us see what the specialists have to say.
I agree very much on these general aspects. If the raker is not at least close you might want to make a mess in the wind. The raker is a piece of the puzzle that can not be overlooked. I was one who did not always pat attention to the rakers which is a huge mistake. So many people who sharpen do not understand that they need to point the file down just slightly so that the corner of the tooth is a little more blunt and lifting slightly to make the top edge of the cutter very sharp. Thanks
How many days until spring, again?
beaverbandit
New Member
Biggest thing I've seen from rookies is inconsistency. I worked on a fire line crew with a guy who had clearly never handled a chainsaw. Within probably a week his saw was cutting crooked as can be. He had long teeth and short ones. His angles ranged from probably 25 up to almost 40. We had to grind his chains every other week.
Similar threads
